Sample records for radiation heat fluxes

  1. Design and calibration of a novel transient radiative heat flux meter for a spacecraft thermal test

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sheng, Chunchen; Hu, Peng, E-mail: hupeng@ustc.edu.cn; Cheng, Xiaofang

    2016-06-15

    Radiative heat flux measurement is significantly important for a spacecraft thermal test. To satisfy the requirements of both high accuracy and fast response, a novel transient radiative heat flux meter was developed. Its thermal receiver consists of a central thermal receiver and two thermal guarded annular plates, which ensure the temperature distribution of the central thermal receiver to be uniform enough for reasonably applying lumped heat capacity method in a transient radiative heat flux measurement. This novel transient radiative heat flux meter design can also take accurate measurements regardless of spacecraft surface temperature and incident radiation spectrum. The measurement principlemore » was elaborated and the coefficients were calibrated. Experimental results from testing a blackbody furnace and an Xenon lamp show that this novel transient radiative heat flux meter can be used to measure transient radiative heat flux up to 1400 W/m{sup 2} with high accuracy and the response time of less than 10 s.« less

  2. Comparison of measured and modeled radiation, heat and water vapor fluxes: FIFE pilot study

    NASA Technical Reports Server (NTRS)

    Blad, Blaine L.; Hubbard, Kenneth G.; Verma, Shashi B.; Starks, Patrick; Norman, John M.; Walter-Shea, Elizabeth

    1987-01-01

    The feasibility of using radio frequency receivers to collect data from automated weather stations to model fluxes of latent heat, sensible heat, and radiation using routine weather data collected by automated weather stations was tested and the estimated fluxes were compared with fluxes measured over wheat. The model Cupid was used to model the fluxes. Two or more automated weather stations, interrogated by radio frequency and other means, were utilized to examine some of the climatic variability of the First ISLSCP (International Satellite Land-Surface Climatology Project) Field Experiment (FIFE) site, to measure and model reflected and emitted radiation streams from various locations at the site and to compare modeled latent and sensible heat fluxes with measured values. Some bidirectional reflected and emitted radiation data were collected from 23 locations throughout the FIFE site. Analysis of these data along with analysis of the measured sensible and latent heat fluxes is just beginning.

  3. An Investigation of the Compatibility of Radiation and Convection Heat Flux Measurements

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.

    1996-01-01

    A method for determining time-resolved absorbed surface heat flux and surface temperature in radiation and convection environments is described. The method is useful for verification of aerodynamic, heat transfer and durability models. A practical heat flux gage fabrication procedure and a simple one-dimensional inverse heat conduction model and calculation procedure are incorporated in this method. The model provides an estimate of the temperature and heat flux gradient in the direction of heat transfer through the gage. This paper discusses several successful time-resolved tests of this method in hostile convective heating and cooling environments.

  4. Effect of radiator position and mass flux on the dryer room heat transfer rate

    NASA Astrophysics Data System (ADS)

    Mirmanto, M.; Sulistyowati, E. D.; Okariawan, I. D. K.

    A room radiator as usually used in cold countries, is actually able to be used as a heat source to dry goods, especially in the rainy season where the sun seldom shines due to much rain and cloud. Experiments to investigate effects of radiator position and mass flux on heat transfer rate were performed. This study is to determine the best position of the radiator and the optimum mass flux. The radiator used was a finned radiator made of copper pipes and aluminum fins with an overall dimension of 220 mm × 50 mm × 310 mm. The prototype room was constructed using plywood and wood frame with an overall size of 1000 mm × 1000 mm × 1000 mm. The working fluid was heated water flowing inside the radiator and air circulating naturally inside the prototype room. The nominal mass fluxes employed were 800, 900 and 1000 kg/m2 s. The water was kept at 80 °C at the radiator entrance, while the initial air temperature inside the prototype room was 30 °C. Three positions of the radiator were examined. The results show that the effect of the mass flux on the forced and free convection heat transfer rate is insignificant but the radiator position strongly affects the heat transfer rate for both forced and free convection.

  5. Thermotronics: Towards Nanocircuits to Manage Radiative Heat Flux

    NASA Astrophysics Data System (ADS)

    Ben-Abdallah, Philippe; Biehs, Svend-Age

    2017-02-01

    The control of electric currents in solids is at the origin of the modern electronics revolution that has driven our daily life since the second half of 20th century. Surprisingly, to date, there is no thermal analogue for a control of heat flux. Here, we summarise the very last developments carried out in this direction to control heat exchanges by radiation both in near and far-field in complex architecture networks.

  6. Comparison of measured and modeled radiation, heat and water vapor fluxes: FIFE pilot study

    NASA Technical Reports Server (NTRS)

    Blad, Blaine L.; Verma, Shashi B.; Hubbard, Kenneth G.; Starks, Patrick; Hays, Cynthia; Norman, John M.; Waltershea, Elizabeth

    1988-01-01

    The primary objectives of the 1985 study were to test the feasibility of using radio frequency receivers to collect data from automated weather stations and to evaluate the use of the data collected by the automated weather stations for modeling the fluxes of latent heat, sensible heat, and radiation over wheat. The model Cupid was used to calculate these fluxes which were compared with fluxes of these entities measured using micrometeorological techniques. The primary objectives of the 1986 study were to measure and model reflected and emitted radiation streams at a few locations within the First International Satellite Land-Surface Climatology Project Field Experiment (FIFE) site and to compare modeled and measured latent heat and sensible heat fluxes from the prairie vegetation.

  7. Systems with a constant heat flux with applications to radiative heat transport across nanoscale gaps and layers

    NASA Astrophysics Data System (ADS)

    Budaev, Bair V.; Bogy, David B.

    2018-06-01

    We extend the statistical analysis of equilibrium systems to systems with a constant heat flux. This extension leads to natural generalizations of Maxwell-Boltzmann's and Planck's equilibrium energy distributions to energy distributions of systems with a net heat flux. This development provides a long needed foundation for addressing problems of nanoscale heat transport by a systematic method based on a few fundamental principles. As an example, we consider the computation of the radiative heat flux between narrowly spaced half-spaces maintained at different temperatures.

  8. Validation experiments to determine radiation partitioning of heat flux to an object in a fully turbulent fire.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ricks, Allen; Blanchat, Thomas K.; Jernigan, Dann A.

    2006-06-01

    It is necessary to improve understanding and develop validation data of the heat flux incident to an object located within the fire plume for the validation of SIERRA/ FUEGO/SYRINX fire and SIERRA/CALORE. One key aspect of the validation data sets is the determination of the relative contribution of the radiative and convective heat fluxes. To meet this objective, a cylindrical calorimeter with sufficient instrumentation to measure total and radiative heat flux had been designed and fabricated. This calorimeter will be tested both in the controlled radiative environment of the Penlight facility and in a fire environment in the FLAME/Radiant Heatmore » (FRH) facility. Validation experiments are specifically designed for direct comparison with the computational predictions. Making meaningful comparisons between the computational and experimental results requires careful characterization and control of the experimental features or parameters used as inputs into the computational model. Validation experiments must be designed to capture the essential physical phenomena, including all relevant initial and boundary conditions. A significant question of interest to modeling heat flux incident to an object in or near a fire is the contribution of the radiation and convection modes of heat transfer. The series of experiments documented in this test plan is designed to provide data on the radiation partitioning, defined as the fraction of the total heat flux that is due to radiation.« less

  9. Heat flux microsensor measurements

    NASA Technical Reports Server (NTRS)

    Terrell, J. P.; Hager, J. M.; Onishi, S.; Diller, T. E.

    1992-01-01

    A thin-film heat flux sensor has been fabricated on a stainless steel substrate. The thermocouple elements of the heat flux sensor were nickel and nichrome, and the temperature resistance sensor was platinum. The completed heat flux microsensor was calibrated at the AEDC radiation facility. The gage output was linear with heat flux with no apparent temperature effect on sensitivity. The gage was used for heat flux measurements at the NASA Langley Vitiated Air Test Facility. Vitiated air was expanded to Mach 3.0 and hydrogen fuel was injected. Measurements were made on the wall of a diverging duct downstream of the injector during all stages of the hydrogen combustion tests. Because the wall and the gage were not actively cooled, the wall temperature reached over 1000 C (1900 F) during the most severe test.

  10. Spectral estimates of net radiation and soil heat flux

    USGS Publications Warehouse

    Daughtry, C.S.T.; Kustas, William P.; Moran, M.S.; Pinter, P. J.; Jackson, R. D.; Brown, P.W.; Nichols, W.D.; Gay, L.W.

    1990-01-01

    Conventional methods of measuring surface energy balance are point measurements and represent only a small area. Remote sensing offers a potential means of measuring outgoing fluxes over large areas at the spatial resolution of the sensor. The objective of this study was to estimate net radiation (Rn) and soil heat flux (G) using remotely sensed multispectral data acquired from an aircraft over large agricultural fields. Ground-based instruments measured Rn and G at nine locations along the flight lines. Incoming fluxes were also measured by ground-based instruments. Outgoing fluxes were estimated using remotely sensed data. Remote Rn, estimated as the algebraic sum of incoming and outgoing fluxes, slightly underestimated Rn measured by the ground-based net radiometers. The mean absolute errors for remote Rn minus measured Rn were less than 7%. Remote G, estimated as a function of a spectral vegetation index and remote Rn, slightly overestimated measured G; however, the mean absolute error for remote G was 13%. Some of the differences between measured and remote values of Rn and G are associated with differences in instrument designs and measurement techniques. The root mean square error for available energy (Rn - G) was 12%. Thus, methods using both ground-based and remotely sensed data can provide reliable estimates of the available energy which can be partitioned into sensible and latent heat under nonadvective conditions. ?? 1990.

  11. Circular heat and momentum flux radiated by magneto-optical nanoparticles

    NASA Astrophysics Data System (ADS)

    Ott, A.; Ben-Abdallah, P.; Biehs, S.-A.

    2018-05-01

    In the present article we investigate the heat and momentum fluxes radiated by a hot magneto-optical nanoparticle in its surroundings under the action of an external magnetic field. We show that the flux lines circulate in a confined region at a nanometric distance from the particle around the axis of the magnetic field in a vortexlike configuration. Moreover we prove that the spatial orientation of these vortices (clockwise or counterclockwise) is associated with the contribution of optical resonances with topological charges m =+1 or m =-1 to the thermal emission. This work paves the way for a geometric description of heat and momentum transport in lattices of magneto-optical particles. Moreover it could have important applications in the field of energy storage as well as in thermal management at nanoscale.

  12. Fundamentals of heat measurement. [heat flux transducers

    NASA Technical Reports Server (NTRS)

    Gerashchenko, O. A.

    1979-01-01

    Various methods and devices for obtaining experimental data on heat flux density over wide ranges of temperature and pressure are examined. Laboratory tests and device fabrication details are supplemented by theoretical analyses of heat-conduction and thermoelectric effects, providing design guidelines and information relevant to further research and development. A theory defining the measure of correspondence between transducer signal and the measured heat flux is established for individual (isolated) heat flux transducers subject to space and time-dependent loading. An analysis of the properties of stacked (series-connected) transducers of various types (sandwich-type, plane, and spiral) is used to derive a similarity theory providing general governing relationships. The transducers examined are used in 36 types of derivative devices involving direct heat loss measurements, heat conduction studies, radiation pyrometry, calorimetry in medicine and industry and nuclear reactor dosimetry.

  13. Nonlinear radiative heat flux and heat source/sink on entropy generation minimization rate

    NASA Astrophysics Data System (ADS)

    Hayat, T.; Khan, M. Waleed Ahmed; Khan, M. Ijaz; Alsaedi, A.

    2018-06-01

    Entropy generation minimization in nonlinear radiative mixed convective flow towards a variable thicked surface is addressed. Entropy generation for momentum and temperature is carried out. The source for this flow analysis is stretching velocity of sheet. Transformations are used to reduce system of partial differential equations into ordinary ones. Total entropy generation rate is determined. Series solutions for the zeroth and mth order deformation systems are computed. Domain of convergence for obtained solutions is identified. Velocity, temperature and concentration fields are plotted and interpreted. Entropy equation is studied through nonlinear mixed convection and radiative heat flux. Velocity and temperature gradients are discussed through graphs. Meaningful results are concluded in the final remarks.

  14. Nonlinear radiated MHD flow of nanoliquids due to a rotating disk with irregular heat source and heat flux condition

    NASA Astrophysics Data System (ADS)

    Mahanthesh, B.; Gireesha, B. J.; Shehzad, S. A.; Rauf, A.; Kumar, P. B. Sampath

    2018-05-01

    This research is made to visualize the nonlinear radiated flow of hydromagnetic nano-fluid induced due to rotation of the disk. The considered nano-fluid is a mixture of water and Ti6Al4V or AA7072 nano-particles. The various shapes of nanoparticles like lamina, column, sphere, tetrahedron and hexahedron are chosen in the analysis. The irregular heat source and nonlinear radiative terms are accounted in the law of energy. We used the heat flux condition instead of constant surface temperature condition. Heat flux condition is more relativistic and according to physical nature of the problem. The problem is made dimensionless with the help of suitable similarity constraints. The Runge-Kutta-Fehlberg scheme is adopted to find the numerical solutions of governing nonlinear ordinary differential systems. The solutions are plotted by considering the various values of emerging physical constraints. The effects of various shapes of nanoparticles are drawn and discussed.

  15. Effect of Cattaneo-Christov heat flux on buoyancy MHD nanofluid flow and heat transfer over a stretching sheet in the presence of Joule heating and thermal radiation impacts

    NASA Astrophysics Data System (ADS)

    Dogonchi, A. S.; Ganji, D. D.

    2018-06-01

    In this study, buoyancy MHD nanofluid flow and heat transfer over a stretching sheet in the presence of Joule heating and thermal radiation impacts, are studied. Cattaneo-Christov heat flux model instead of conventional Fourier's law of heat conduction is applied to investigate the heat transfer characteristics. A similarity transformation is used to transmute the governing momentum and energy equations into non-linear ordinary differential equations with the appropriate boundary conditions. The obtained non-linear ordinary differential equations are solved numerically. The impacts of diverse active parameters such as the magnetic parameter, the radiation parameter, the buoyancy parameter, the heat source parameter, the volume fraction of nanofluid and the thermal relaxation parameter are examined on the velocity and temperature profiles. In addition, the value of the Nusselt number is calculated and presented through figures. The results demonstrate that the temperature profile is lower in the case of Cattaneo-Christov heat flux model as compared to Fourier's law. Moreover, the Nusselt number raises with the raising volume fraction of nanofluid and it abates with the ascending the radiation parameter.

  16. Heat flux microsensor measurements and calibrations

    NASA Technical Reports Server (NTRS)

    Terrell, James P.; Hager, Jon M.; Onishi, Shinzo; Diller, Thomas E.

    1992-01-01

    A new thin-film heat flux gage has been fabricated specifically for severe high temperature operation using platinum and platinum-10 percent rhodium for the thermocouple elements. Radiation calibrations of this gage were performed at the AEDC facility over the available heat flux range (approx. 1.0 - 1,000 W/cu cm). The gage output was linear with heat flux with a slight increase in sensitivity with increasing surface temperature. Survivability of gages was demonstrated in quench tests from 500 C into liquid nitrogen. Successful operation of gages to surface temperatures of 750 C has been achieved. No additional cooling of the gages is required because the gages are always at the same temperature as the substrate material. A video of oxyacetylene flame tests with real-time heat flux and temperature output is available.

  17. Pyrolytic graphite gauge for measuring heat flux

    NASA Technical Reports Server (NTRS)

    Bunker, Robert C. (Inventor); Ewing, Mark E. (Inventor); Shipley, John L. (Inventor)

    2002-01-01

    A gauge for measuring heat flux, especially heat flux encountered in a high temperature environment, is provided. The gauge includes at least one thermocouple and an anisotropic pyrolytic graphite body that covers at least part of, and optionally encases the thermocouple. Heat flux is incident on the anisotropic pyrolytic graphite body by arranging the gauge so that the gauge surface on which convective and radiative fluxes are incident is perpendicular to the basal planes of the pyrolytic graphite. The conductivity of the pyrolytic graphite permits energy, transferred into the pyrolytic graphite body in the form of heat flux on the incident (or facing) surface, to be quickly distributed through the entire pyrolytic graphite body, resulting in small substantially instantaneous temperature gradients. Temperature changes to the body can thereby be measured by the thermocouple, and reduced to quantify the heat flux incident to the body.

  18. Impact of heat source/sink on radiative heat transfer to Maxwell nanofluid subject to revised mass flux condition

    NASA Astrophysics Data System (ADS)

    Khan, M.; Irfan, M.; Khan, W. A.

    2018-06-01

    Nanofluids retain noteworthy structure that have absorbed attentions of numerous investigators because of their exploration in nanotechnology and nanoscience. In this scrutiny a mathematical computation of 2D flows of Maxwell nanoliquid influenced by a stretched cylinder has been established. The heat transfer structure is conceded out in the manifestation of thermal radiation and heat source/sink. Moreover, the nanoparticles mass flux condition is engaged in this exploration. This newly endorsed tactic is more realistic where the conjecture is made that the nanoparticle flux is zero and nanoparticle fraction regulates itself on the restrictions consequently. By utilizing apposite conversion the governing PDEs are transformed into ODEs and then tackled analytically via HAM. The attained outcomes are plotted and deliberated in aspect for somatic parameters. It is remarked that with an intensification in the Deborah number β diminish the liquid temperature while it boosts for radiation parameter Rd . Furthermore, the concentration of Maxwell liquid has conflicting impact for Brownian motion Nb and thermophoresis parameters Nt .

  19. Reversible and irreversible heat transfer by radiation

    NASA Astrophysics Data System (ADS)

    del Río, Fernando; de la Selva, Sara María Teresa

    2015-05-01

    The theme of heat transfer by radiation is absent from most textbooks on thermodynamics, and its treatment in the applied literature presents some basic discrepancies concerning the validity of the Clausius relation between the quantity of heat exchanged, δ Q, and the accompanying entropy change, dS. We review the reversible and irreversible heat transfers by radiation to clarify the validity of the Clausius relation, and we show that in both cases, the Clausius relation is obeyed, as it should be. We also deal with radiation diluted by the presence of matter, introducing a dilution coefficient, ϕ, and an irreversibility factor, χ (φ ). This treatment requires the use of the correct relation between energy and heat fluxes, the spectral fluxes of energy and entropy, and Planck’s equation for the entropy of monochromatic radiation. For the irreversible case of diluted radiation, we recover the ratio between the fluxes of heat and entropy that agree with Clausius’ inequality, including an irreversibility factor, (4/3)χ (φ ). An improved modification for the explicit function χ (φ ) is given. As an illustration, the fluxes of energy and entropy from the Sun to the Earth are obtained. We also calculate the fluxes re-emitted by the Earth, taking into account the greenhouse effect. We find the value of 1.258 W{{m}-2}{{K}-1} for the re-emitted entropy flux after the radiation has been thermalized, which is much larger than the incident flux, in agreement with other authors.

  20. Fabrication of Thin Film Heat Flux Sensors

    NASA Technical Reports Server (NTRS)

    Will, Herbert A.

    1992-01-01

    Prototype thin film heat flux sensors have been constructed and tested. The sensors can be applied to propulsion system materials and components. The sensors can provide steady state and fast transient heat flux information. Fabrication of the sensor does not require any matching of the mounting surface. Heat flux is proportional to the temperature difference across the upper and lower surfaces of an insulation material. The sensor consists of an array of thermocouples on the upper and lower surfaces of a thin insulating layer. The thermocouples for the sensor are connected in a thermopile arrangement. A 100 thermocouple pair heat flux sensor has been fabricated on silicon wafers. The sensor produced an output voltage of 200-400 microvolts when exposed to a hot air heat gun. A 20 element thermocouple pair heat flux sensor has been fabricated on aluminum oxide sheet. Thermocouples are Pt-Pt/Rh with silicon dioxide as the insulating material. This sensor produced an output of 28 microvolts when exposed to the radiation of a furnace operating at 1000 C. Work is also underway to put this type of heat flux sensor on metal surfaces.

  1. An Analysis of Inter-annual Variability and Uncertainty of Continental Surface Heat Fluxes

    NASA Astrophysics Data System (ADS)

    Huang, S. Y.; Deng, Y.; Wang, J.

    2016-12-01

    The inter-annual variability and the corresponding uncertainty of land surface heat fluxes during the first decade of the 21st century are re-evaluated at continental scale based on the heat fluxes estimated by the maximum entropy production (MEP) model. The MEP model predicted heat fluxes are constrained by surface radiation fluxes, automatically satisfy surface energy balance, and are independent of temperature/moisture gradient, wind speed, and roughness lengths. The surface radiation fluxes and temperature data from Clouds and the Earth's Radiant Energy System and the surface specific humidity data from Modern-Era Retrospective analysis for Research and Applications were used to reproduce the global surface heat fluxes with land-cover data from the NASA Energy and Water cycle Study (NEWS). Our analysis shows that the annual means of continental latent heat fluxes have increasing trends associated with increasing trends in surface net radiative fluxes. The sensible heat fluxes also have increasing trends over most continents except for South America. Ground heat fluxes have little trends. The continental-scale analysis of the MEP fluxes are compared with other existing global surface fluxes data products and the implications of the results for inter-annual to decadal variability of regional surface energy budget are discussed.

  2. MHD effects and heat transfer for the UCM fluid along with Joule heating and thermal radiation using Cattaneo-Christov heat flux model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shah, S., E-mail: sajidshah313@yahoo.com; Hussain, S.; Sagheer, M.

    2016-08-15

    Present study examines the numerical analysis of MHD flow of Maxwell fluid with thermal radiation and Joule heating by considering the recently developed Cattaneo-Christov heat flux model which explains the time relaxation characteristics for the heat flux. The objective is to analyze the governing parameters such as viscoelastic fluid parameter, Magnetic parameter, Eckert and Prandtl number’s impact on the velocity and temperature profiles through graphs and tables. Suitable similarity transformations have been used to reduce the formulated PDEs into a system of coupled non-linear ODEs. Shooting technique has been invoked for finding the numerical solutions of the dimensionless velocity andmore » temperature profiles. Additionally, the MATLAB built-in routine bvp4c has also been used to verify and strengthen the results obtained by shooting method. From some special cases of the present work, a comparison with the previously published results has been presented.« less

  3. Radiative flux opens new window on climate research

    NASA Technical Reports Server (NTRS)

    Pinker, R. T.; Laszlo, I.; Whitlock, C. H.; Charlock, T. P.

    1995-01-01

    For several decades, global satellite observations have been made of the rate at which electromagnetic energy (radiative flux) is emerging from the top of the atmosphere of our planet in the spectral range of about 0.2-50.0 microns. At the same time, models have been developed to infer the radiative flux at the surface from the values observed by the satellites at the upper boundary. The balance of incoming and outgoing radiative flux (radiation budget) at both boundaries, determines the net gain or loss of the radiative energy within an atmospheric column. Climate researchers can use the radiative flux as a tool to validate climate models, separate the radiative impact of clouds from surface and atmosphere contributions, and to understand the global hydrological cycle. When applied to physical processes occurring at the surface, information on the radiative flux has the potential to substantially advance our understanding of the transport of heat, moisture, and momentum across the surface/atmosphere interface. Geophysicists of many disciplines stand to benefit from efforts to improve the use of this latter untapped resource. Oceanographers can improve the representation of the selective absorption of radiation in the oceans; biologists and ecologists can improve their models for carbon dioxide exchange and biological heating in oceans; agronomists can model more realistically biomass and crop yields; and environmentalists can obtain better assessment of natural resources of radiation.

  4. Self similar flow behind an exponential shock wave in a self-gravitating, rotating, axisymmetric dusty gas with heat conduction and radiation heat flux

    NASA Astrophysics Data System (ADS)

    Bajargaan, Ruchi; Patel, Arvind

    2018-04-01

    One-dimensional unsteady adiabatic flow behind an exponential shock wave propagating in a self-gravitating, rotating, axisymmetric dusty gas with heat conduction and radiation heat flux, which has exponentially varying azimuthal and axial fluid velocities, is investigated. The shock wave is driven out by a piston moving with time according to an exponential law. The dusty gas is taken to be a mixture of a non-ideal gas and small solid particles. The density of the ambient medium is assumed to be constant. The equilibrium flow conditions are maintained and energy is varying exponentially, which is continuously supplied by the piston. The heat conduction is expressed in the terms of Fourier's law, and the radiation is assumed of diffusion type for an optically thick grey gas model. The thermal conductivity and the absorption coefficient are assumed to vary with temperature and density according to a power law. The effects of the variation of heat transfer parameters, gravitation parameter and dusty gas parameters on the shock strength, the distance between the piston and the shock front, and on the flow variables are studied out in detail. It is interesting to note that the similarity solution exists under the constant initial angular velocity, and the shock strength is independent from the self gravitation, heat conduction and radiation heat flux.

  5. Miniature Convection Cooled Plug-type Heat Flux Gauges

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.

    1994-01-01

    Tests and analysis of a new miniature plug-type heat flux gauge configuration are described. This gauge can simultaneously measure heat flux on two opposed active surfaces when heat flux levels are equal to or greater than about 0.2 MW/m(sup 2). The performance of this dual active surface gauge was investigated over a wide transient and steady heat flux and temperature range. The tests were performed by radiatively heating the front surface with an argon arc lamp while the back surface was convection cooled with air. Accuracy is about +20 percent. The gauge is responsive to fast heat flux transients and is designed to withstand the high temperature (1300 K), high pressure (15 MPa), erosive and corrosive environments in modern engines. This gauge can be used to measure heat flux on the surfaces of internally cooled apparatus such as turbine blades and combustors used in jet propulsion systems and on the surfaces of hypersonic vehicles. Heat flux measurement accuracy is not compromised when design considerations call for various size gauges to be fabricated into alloys of various shapes and properties. Significant gauge temperature reductions (120 K), which can lead to potential gauge durability improvement, were obtained when the gauges were air-cooled by forced convection.

  6. Comparing convective heat fluxes derived from thermodynamics to a radiative-convective model and GCMs

    NASA Astrophysics Data System (ADS)

    Dhara, Chirag; Renner, Maik; Kleidon, Axel

    2015-04-01

    The convective transport of heat and moisture plays a key role in the climate system, but the transport is typically parameterized in models. Here, we aim at the simplest possible physical representation and treat convective heat fluxes as the result of a heat engine. We combine the well-known Carnot limit of this heat engine with the energy balances of the surface-atmosphere system that describe how the temperature difference is affected by convective heat transport, yielding a maximum power limit of convection. This results in a simple analytic expression for convective strength that depends primarily on surface solar absorption. We compare this expression with an idealized grey atmosphere radiative-convective (RC) model as well as Global Circulation Model (GCM) simulations at the grid scale. We find that our simple expression as well as the RC model can explain much of the geographic variation of the GCM output, resulting in strong linear correlations among the three approaches. The RC model, however, shows a lower bias than our simple expression. We identify the use of the prescribed convective adjustment in RC-like models as the reason for the lower bias. The strength of our model lies in its ability to capture the geographic variation of convective strength with a parameter-free expression. On the other hand, the comparison with the RC model indicates a method for improving the formulation of radiative transfer in our simple approach. We also find that the latent heat fluxes compare very well among the approaches, as well as their sensitivity to surface warming. What our comparison suggests is that the strength of convection and their sensitivity in the climatic mean can be estimated relatively robustly by rather simple approaches.

  7. Divertor heat flux mitigation in the National Spherical Torus Experimenta)

    NASA Astrophysics Data System (ADS)

    Soukhanovskii, V. A.; Maingi, R.; Gates, D. A.; Menard, J. E.; Paul, S. F.; Raman, R.; Roquemore, A. L.; Bell, M. G.; Bell, R. E.; Boedo, J. A.; Bush, C. E.; Kaita, R.; Kugel, H. W.; Leblanc, B. P.; Mueller, D.; NSTX Team

    2009-02-01

    Steady-state handling of divertor heat flux is a critical issue for both ITER and spherical torus-based devices with compact high power density divertors. Significant reduction of heat flux to the divertor plate has been achieved simultaneously with favorable core and pedestal confinement and stability properties in a highly shaped lower single null configuration in the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 2000] using high magnetic flux expansion at the divertor strike point and the radiative divertor technique. A partial detachment of the outer strike point was achieved with divertor deuterium injection leading to peak flux reduction from 4-6MWm-2to0.5-2MWm-2 in small-ELM 0.8-1.0MA, 4-6MW neutral beam injection-heated H-mode discharges. A self-consistent picture of the outer strike point partial detachment was evident from divertor heat flux profiles and recombination, particle flux and neutral pressure measurements. Analytic scrape-off layer parallel transport models were used for interpretation of NSTX detachment experiments. The modeling showed that the observed peak heat flux reduction and detachment are possible with high radiated power and momentum loss fractions, achievable with divertor gas injection, and nearly impossible to achieve with main electron density, divertor neutral density or recombination increases alone.

  8. Capabilities of VOS-based fluxes for estimating ocean heat budget and its variability

    NASA Astrophysics Data System (ADS)

    Gulev, S.; Belyaev, K.

    2016-12-01

    We consider here the perspective of using VOS observations by merchant ships available form the ICOADS data for estimating ocean surface heat budget at different time scale. To this purpose we compute surface turbulent heat fluxes as well as short- and long-wave radiative fluxes from the ICOADS reports for the last several decades in the North Atlantic mid latitudes. Turbulent fluxes were derived using COARE-3 algorithm and for computation of radiative fluxes new algorithms accounting for cloud types were used. Sampling uncertainties in the VOS-based fluxes were estimated by sub-sampling of the recomputed reanalysis (ERA-Interim) fluxes according to the VOS sampling scheme. For the turbulent heat fluxes we suggest an approach to minimize sampling uncertainties. The approach is based on the integration of the turbulent heat fluxes in the coordinates of steering parameters (vertical surface temperature and humidity gradients on one hand and wind speed on the other) for which theoretical probability distributions are known. For short-wave radiative fluxes sampling uncertainties were minimized by "rotating local observation time around the clock" and using probability density functions for the cloud cover occurrence distributions. Analysis was performed for the North Atlantic latitudinal band from 25 N to 60 N, for which also estimates of the meridional heat transport are available from the ocean cross-sections. Over the last 35 years turbulent fluxes within the region analysed increase by about 6 W/m2 with the major growth during the 1990s and early 2000s. Decreasing incoming short wave radiation during the same time (about 1 W/m2) implies upward change of the ocean surface heat loss by about 7-8 W/m2. We discuss different sources of uncertainties of computations as well as potential of the application of the analysis concept to longer time series going back to 1920s.

  9. Fluctuations of radiative heat exchange between two bodies

    NASA Astrophysics Data System (ADS)

    Biehs, S.-A.; Ben-Abdallah, P.

    2018-05-01

    We present a theory to describe the fluctuations of nonequilibrium radiative heat transfer between two bodies both in the far- and near-field regimes. As predicted by the blackbody theory, in the far field, we show that the variance of radiative heat flux is of the same order of magnitude as its mean value. However, in the near-field regime, we demonstrate that the presence of surface polaritons makes this variance more than one order of magnitude larger than the mean flux. We further show that the correlation time of heat flux in this regime is comparable to the relaxation time of heat carriers in each medium. This theory could open the way to an experimental investigation of heat exchanges far from the thermal equilibrium condition.

  10. Numerical Analysis of a Radiant Heat Flux Calibration System

    NASA Technical Reports Server (NTRS)

    Jiang, Shanjuan; Horn, Thomas J.; Dhir, V. K.

    1998-01-01

    A radiant heat flux gage calibration system exists in the Flight Loads Laboratory at NASA's Dryden Flight Research Center. This calibration system must be well understood if the heat flux gages calibrated in it are to provide useful data during radiant heating ground tests or flight tests of high speed aerospace vehicles. A part of the calibration system characterization process is to develop a numerical model of the flat plate heater element and heat flux gage, which will help identify errors due to convection, heater element erosion, and other factors. A 2-dimensional mathematical model of the gage-plate system has been developed to simulate the combined problem involving convection, radiation and mass loss by chemical reaction. A fourth order finite difference scheme is used to solve the steady state governing equations and determine the temperature distribution in the gage and plate, incident heat flux on the gage face, and flat plate erosion. Initial gage heat flux predictions from the model are found to be within 17% of experimental results.

  11. Towards Improved Estimates of Ocean Heat Flux

    NASA Astrophysics Data System (ADS)

    Bentamy, Abderrahim; Hollman, Rainer; Kent, Elisabeth; Haines, Keith

    2014-05-01

    Recommendations and priorities for ocean heat flux research are for instance outlined in recent CLIVAR and WCRP reports, eg. Yu et al (2013). Among these is the need for improving the accuracy, the consistency, and the spatial and temporal resolution of air-sea fluxes over global as well as at region scales. To meet the main air-sea flux requirements, this study is aimed at obtaining and analyzing all the heat flux components (latent, sensible and radiative) at the ocean surface over global oceans using multiple satellite sensor observations in combination with in-situ measurements and numerical model analyses. The fluxes will be generated daily and monthly for the 20-year (1992-2011) period, between 80N and 80S and at 0.25deg resolution. Simultaneous estimates of all surface heat flux terms have not yet been calculated at such large scale and long time period. Such an effort requires a wide range of expertise and data sources that only recently are becoming available. Needed are methods for integrating many data sources to calculate energy fluxes (short-wave, long wave, sensible and latent heat) across the air-sea interface. We have access to all the relevant, recently available satellite data to perform such computations. Yu, L., K. Haines, M. Bourassa, M. Cronin, S. Gulev, S. Josey, S. Kato, A. Kumar, T. Lee, D. Roemmich: Towards achieving global closure of ocean heat and freshwater budgets: Recommendations for advancing research in air-sea fluxes through collaborative activities. INTERNATIONAL CLIVAR PROJECT OFFICE, 2013: International CLIVAR Publication Series No 189. http://www.clivar.org/sites/default/files/ICPO189_WHOI_fluxes_workshop.pdf

  12. The Influence of Ablation on Radiative Heating for Earth Entry

    NASA Technical Reports Server (NTRS)

    Johnston, Christopher O.; Gnoffo, Peter A.; Sutton, Kenneth

    2008-01-01

    Using the coupled ablation and radiation capability recently included in the LAURA flowfield solver, this paper investigates the influence of ablation on the shock-layer radiative heating for Earth entry. The extension of the HARA radiation model, which provides the radiation predictions in LAURA, to treat a gas consisting of the elements C, H, O, and N is discussed. It is shown that the absorption coefficient of air is increased with the introduction of the C and H elements. A simplified shock layer model is studied to show the impact of temperature, as well as the abundance of C and H, on the net absorption or emission from an ablation contaminated boundary layer. It is found that the ablation species reduce the radiative flux in the vacuum ultraviolet, through increased absorption, for all temperatures. However, in the infrared region of the spectrum, the ablation species increase the radiative flux, through strong emission, for temperatures above 3,000 K. Thus, depending on the temperature and abundance of ablation species, the contaminated boundary layer may either provide a net increase or decrease in the radiative flux reaching the wall. To assess the validity of the coupled ablation and radiation LAURA analysis, a previously analyzed Mars-return case (15.24 km/s), which contains significant ablation and radiation coupling, is studied. Exceptional agreement with previous viscous shock-layer results is obtained. A 40% decrease in the radiative flux is predicted for ablation rates equal to 20% of the free-stream mass flux. The Apollo 4 peak-heating case (10.24 km/s) is also studied. For ablation rates up to 3.4% of the free-stream mass flux, the radiative heating is reduced by up to 19%, while the convective heating is reduced by up to 87%. Good agreement with the Apollo 4 radiometer data is obtained by considering absorption in the radiometer cavity. For both the Mars return and the Apollo 4 cases, coupled radiation alone is found to reduce the radiative

  13. Latent Heat in Soil Heat Flux Measurements

    USDA-ARS?s Scientific Manuscript database

    The surface energy balance includes a term for soil heat flux. Soil heat flux is difficult to measure because it includes conduction and convection heat transfer processes. Accurate representation of soil heat flux is an important consideration in many modeling and measurement applications. Yet, the...

  14. Tests of a robust eddy correlation system for sensible heat flux

    NASA Astrophysics Data System (ADS)

    Blanford, J. H.; Gay, L. W.

    1992-03-01

    Sensible heat flux estimates from a simple, one-propeller eddy correlation system (OPEC) were compared with those from a sonic anemometer eddy correlation system (SEC). In accordance with similarity theory, the performance of the OPEC system improved with increasing height of the sensor above the surface. Flux totals from the two systems at sites with adequate fetch were in excellent agreement after frequency response corrections were applied. The propeller system appears suitable for long periods of unattended measurement. The sensible heat flux measurements can be combined with net radiation and soil heat flux measurements to estimate latent heat as a residual in the surface energy balance.

  15. Wind stress and heat fluxes over a Brazilian Coastal Upwelling

    NASA Astrophysics Data System (ADS)

    Dourado, Marcelo; Candella, Rogério

    2017-04-01

    Coastal upwelling zones have been intensively studied in the last decades especially due to their importance to the biological cycle. The coastal upwelling system of the Cabo Frio region (east coast of the Rio de Janeiro state, Brazil) keeps the surface water cold during most part of the year, what induces a stable atmospheric boundary layer associated to northeast winds. The main goal of this study is to investigate the wind stress and heat fluxes exchanges between the ocean and the atmosphere in that area. For this purpose, a set of hourly data meteorological and oceanographic data collected by a Wavescan metocean buoy anchored at 23o59S; 42oW, were used, as well as solar radiation and relative humidity from a terrestrial meteorological station from the Instituto Nacional de Meteorologia (InMet). COARE 3.0 algorithm was used to calculate the latent and sensible heat fluxes. In this discussion, positive values represent fluxes towards the ocean. The average net heat flux over our study period is 88 W m-2. The reduction of the net heat flux is due to the increase of the ocean latent heat loss, although a reduction in incoming shortwave radiation and an increase in ocean long wave cooling also contributes. The latent heat is 20 times larger than the sensible heat flux, but the mean value of the latent heat flux, 62 W m-2, is half the typical value found in open ocean. The temporal variability of both sensible and latent heat fluxes reflects their dependence on wind speed and air-sea temperature differences. When upwelling events, here periods when diurnal SST is lower than 18oC, are compared with undisturbed (without upwelling) events, it can be noted the sensible heat fluxes are positives and 10 times greater in magnitude. This is related to an increment, during these upwelling events, of the air-sea temperature difference and an increasing of the wind speed. The cold waters of the upwelling increase the air-sea temperature gradient and, also, the horizontal land

  16. The effects of radiative heat loss on microgravity flame spread

    NASA Technical Reports Server (NTRS)

    Fakheri, Ahmad; Olson, Sandra L.

    1989-01-01

    The effect of radiative heat loss from the surface of a solid material burning in a zero gravity environment in an opposed flow is studied through the use of a numerical model. Radiative heat loss is found to decrease the flame spread rate, the boundary layer thickness, and pyrolysis lengths. Blowoff extinction is predicted to occur at slower opposesd flow velocities than would occur if the radiative loss is not present. The radiative heat fluxes are comparable to the conduction fluxes, indicating the significance of the surface energy loss.

  17. Atmospheric State, Cloud Microphysics and Radiative Flux

    DOE Data Explorer

    Mace, Gerald

    2008-01-15

    Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

  18. Causes of Potential Urban Heat Island Space Using Heat flux Budget Under Urban Canopy

    NASA Astrophysics Data System (ADS)

    Kwon, Y. J.; Lee, D. K.

    2017-12-01

    Raised concerns about possible contribution from urban heat island to global warming is about 30 percent. Therefore, mitigating urban heat island became one of major issues to solve among urban planners, urban designers, landscape architects, urban affair decision makers and etc. Urban heat island effect on a micro-scale is influenced by factors such as wind, water vapor and solar radiation. Urban heat island effect on a microscale is influenced by factors like wind, water vapor and solar radiation. These microscopic climates are also altered by factors affecting the heat content in space, like SVF and aspect ratio depending on the structural characteristics of various urban canyon components. Indicators of heat mitigation in urban design stage allows us to create a spatial structure considering the heat balance budget. The spatial characteristics affect thermal change by varying heat storage, emitting or absorbing the heat. The research defines characteristics of the space composed of the factors affecting the heat flux change as the potential urban heat island space. Potential urban heat island spaces are that having higher heat flux than periphery space. The study is to know the spatial characteristics that affects the subsequent temperature rise by the heat flux. As a research method, four types of potential heat island space regions were analyzed. I categorized the spatial types by comparing parameters' value of energy balance in day and night: 1) day severe areas, 2) day comfort areas, 3) night severe areas, 4) night comfort areas. I have looked at these four types of potential urban heat island areas from a microscopic perspective and investigated how various forms of heat influences on higher heat flux areas. This research was designed to investigate the heat indicators to be reflected in the design of urban canyon for heat mitigation. As a result, severe areas in daytime have high SVF rate, sensible heat is generated. Day comfort areas have shadow effect

  19. Automated Heat-Flux-Calibration Facility

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.; Weikle, Donald H.

    1989-01-01

    Computer control speeds operation of equipment and processing of measurements. New heat-flux-calibration facility developed at Lewis Research Center. Used for fast-transient heat-transfer testing, durability testing, and calibration of heat-flux gauges. Calibrations performed at constant or transient heat fluxes ranging from 1 to 6 MW/m2 and at temperatures ranging from 80 K to melting temperatures of most materials. Facility developed because there is need to build and calibrate very-small heat-flux gauges for Space Shuttle main engine (SSME).Includes lamp head attached to side of service module, an argon-gas-recirculation module, reflector, heat exchanger, and high-speed positioning system. This type of automated heat-flux calibration facility installed in industrial plants for onsite calibration of heat-flux gauges measuring fluxes of heat in advanced gas-turbine and rocket engines.

  20. Calibration of High Heat Flux Sensors at NIST

    PubMed Central

    Murthy, A. V.; Tsai, B. K.; Gibson, C. E.

    1997-01-01

    An ongoing program at the National Institute of Standards and Technology (NIST) is aimed at improving and standardizing heat-flux sensor calibration methods. The current calibration needs of U.S. science and industry exceed the current NIST capability of 40 kW/m2 irradiance. In achieving this goal, as well as meeting lower-level non-radiative heat flux calibration needs of science and industry, three different types of calibration facilities currently are under development at NIST: convection, conduction, and radiation. This paper describes the research activities associated with the NIST Radiation Calibration Facility. Two different techniques, transfer and absolute, are presented. The transfer calibration technique employs a transfer standard calibrated with reference to a radiometric standard for calibrating the sensors using a graphite tube blackbody. Plans for an absolute calibration facility include the use of a spherical blackbody and a cooled aperture and sensor-housing assembly to calibrate the sensors in a low convective environment. PMID:27805156

  1. Heat Flux Sensor

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A heat flux microsensor developed under a NASP Small Business Innovation Research (SBIR) has a wide range of potential commercial applications. Vatell Corporation originally designed microsensors for use in very high temperatures. The company then used the technology to develop heat flux sensors to measure the rate of heat energy flowing in and out of a surface as well as readings on the surface temperature. Additional major advantages include response to heat flux in less than 10 microseconds and the ability to withstand temperatures up to 1,200 degrees centigrade. Commercial applications are used in high speed aerodynamics, supersonic combustion, blade cooling, and mass flow measurements, etc.

  2. Latent heat sink in soil heat flux measurements

    USDA-ARS?s Scientific Manuscript database

    The surface energy balance includes a term for soil heat flux. Soil heat flux is difficult to measure because it includes conduction and convection heat transfer processes. Accurate representation of soil heat flux is an important consideration in many modeling and measurement applications. Yet, the...

  3. Fine fuel heating by radiant flux

    Treesearch

    David Frankman; Brent W. Webb; Bret W. Butler; Don J. Latham

    2010-01-01

    Experiments were conducted wherein wood shavings and Ponderosa pine needles in quiescent air were subjected to a steady radiation heat flux from a planar ceramic burner. The internal temperature of these particles was measured using fine diameter (0.076mm diameter) type K thermocouples. A narrow angle radiometer was used to determine the emissive power generated by the...

  4. Light-intensity modulator withstands high heat fluxes

    NASA Technical Reports Server (NTRS)

    Maples, H. G.; Strass, H. K.

    1966-01-01

    Mechanism modulates and controls the intensity of luminous radiation in light beams associated with high-intensity heat flux. This modulator incorporates two fluid-cooled, externally grooved, contracting metal cylinders which when rotated about their longitudinal axes present a circular aperture of varying size depending on the degree of rotation.

  5. Heat transfer in melt ponds with convection and radiative heating: observationally-inspired modelling

    NASA Astrophysics Data System (ADS)

    Wells, A.; Langton, T.; Rees Jones, D. W.; Moon, W.; Kim, J. H.; Wilkinson, J.

    2016-12-01

    Melt ponds have key impacts on the evolution of Arctic sea ice and summer ice melt. Small changes to the energy budget can have significant consequences, with a net heat-flux perturbation of only a few Watts per square metre sufficient to explain the thinning of sea ice over recent decades. Whilst parameterisations of melt-pond thermodynamics often assume that pond temperatures remain close to the freezing point, recent in-situ observations show more complex thermal structure with significant diurnal and synoptic variability. We here consider the energy budget of melt ponds and explore the role of internal convective heat transfer in determining the thermal structure within the pond in relatively calm conditions with low winds. We quantify the energy fluxes and temperature variability using two-dimensional direct numerical simulations of convective turbulence within a melt pond, driven by internal radiative heating and surface fluxes. Our results show that the convective flow dynamics are modulated by changes to the incoming radiative flux and sensible heat flux at the pond surface. The evolving pond surface temperature controls the outgoing longwave emissions from the pond. Hence the convective flow modifies the net energy balance of a melt pond, modulating the relative fractions of the incoming heat flux that is re-emitted to the atmosphere or transferred downward into the sea ice to drive melt.

  6. Magnetogasdynamic spherical shock wave in a non-ideal gas under gravitational field with conductive and radiative heat fluxes

    NASA Astrophysics Data System (ADS)

    Nath, G.; Vishwakarma, J. P.

    2016-11-01

    Similarity solutions are obtained for the flow behind a spherical shock wave in a non-ideal gas under gravitational field with conductive and radiative heat fluxes, in the presence of a spatially decreasing azimuthal magnetic field. The shock wave is driven by a piston moving with time according to power law. The radiation is considered to be of the diffusion type for an optically thick grey gas model and the heat conduction is expressed in terms of Fourier's law for heat conduction. Similarity solutions exist only when the surrounding medium is of constant density. The gas is assumed to have infinite electrical conductivity and to obey a simplified van der Waals equation of state. It is shown that an increase of the gravitational parameter or the Alfven-Mach number or the parameter of the non-idealness of the gas decreases the compressibility of the gas in the flow-field behind the shock, and hence there is a decrease in the shock strength. The pressure and density vanish at the inner surface (piston) and hence a vacuum is formed at the center of symmetry. The shock waves in conducting non-ideal gas under gravitational field with conductive and radiative heat fluxes can be important for description of shocks in supernova explosions, in the study of a flare produced shock in the solar wind, central part of star burst galaxies, nuclear explosion etc. The solutions obtained can be used to interpret measurements carried out by space craft in the solar wind and in neighborhood of the Earth's magnetosphere.

  7. Tropical Cloud Properties and Radiative Heating Profiles

    DOE Data Explorer

    Mather, James

    2008-01-15

    We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.

  8. Baseline high heat flux and plasma facing materials for fusion

    NASA Astrophysics Data System (ADS)

    Ueda, Y.; Schmid, K.; Balden, M.; Coenen, J. W.; Loewenhoff, Th.; Ito, A.; Hasegawa, A.; Hardie, C.; Porton, M.; Gilbert, M.

    2017-09-01

    In fusion reactors, surfaces of plasma facing components (PFCs) are exposed to high heat and particle flux. Tungsten and Copper alloys are primary candidates for plasma facing materials (PFMs) and coolant tube materials, respectively, mainly due to high thermal conductivity and, in the case of tungsten, its high melting point. In this paper, recent understandings and future issues on responses of tungsten and Cu alloys to fusion environments (high particle flux (including T and He), high heat flux, and high neutron doses) are reviewed. This review paper includes; Tritium retention in tungsten (K. Schmid and M. Balden), Impact of stationary and transient heat loads on tungsten (J.W. Coenen and Th. Loewenhoff), Helium effects on surface morphology of tungsten (Y. Ueda and A. Ito), Neutron radiation effects in tungsten (A. Hasegawa), and Copper and copper alloys development for high heat flux components (C. Hardie, M. Porton, and M. Gilbert).

  9. Heat transfer experiments with a central receiver tube subjected to unsteady and non-uniform heat flux

    NASA Astrophysics Data System (ADS)

    Fernández-Torrijos, María; Marugán-Cruz, Carolina; Sobrino, Celia; Santana, Domingo

    2017-06-01

    In this work, a molten salt test loop to study the heat transfer process in external molten salt receivers is described. The experimental installation is formed by a cylindrical molten salt tank, a pump, a flow meter, and an induction heater to generate the heat flux, which is applied in a small rectangular region of the tube surface. In central tower plants, the external receiver pipe is considered to be under unilateral concentrated solar radiation, because only one side of the pipe receives high heat flux. The main advantage of using an induction heater is the control of heating in different areas of the tube. In order to measure the effects of a non-homogenous and unsteady heat flux on the wall temperature distribution a series of experiments have been carried out. 4 K-type thermocouples have been welded at different axial and azimuthal positions of the pipe to obtain the wall temperature distribution. Different temperature measurements have been made varying the heat flux and water velocity to study their effects on the heat transfer process.

  10. Apparatus for measuring high-flux heat transfer in radiatively heated compact exchangers

    NASA Technical Reports Server (NTRS)

    Olson, Douglas A.

    1989-01-01

    An apparatus is described which can deliver uniform heat flux densities of up to 80 W/sq cm over an area 7.8 cm x 15.2 cm for use in measuring the heat transfer and pressure drop in thin (6 mm or less), compact heat exchangers. Helium gas at flow rates of 0 to 40 kg/h and pressures to 6.9 MPa (1000 psi) is the working fluid. The instrumentation used in the apparatus and the methods for analyzing the data is described. The apparatus will be used initially to test the performance of prototype cooling jackets for the engine struts of the National Aerospace Plane (NASP).

  11. Offline GCSS Intercomparison of Cloud-Radiation Interaction and Surface Fluxes

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Johnson, D.; Krueger, S.; Zulauf, M.; Donner, L.; Seman, C.; Petch, J.; Gregory, J.

    2004-01-01

    Simulations of deep tropical clouds by both cloud-resolving models (CRMs) and single-column models (SCMs) in the GEWEX Cloud System Study (GCSS) Working Group 4 (WG4; Precipitating Convective Cloud Systems), Case 2 (19-27 December 1992, TOGA-COARE IFA) have produced large differences in the mean heating and moistening rates (-1 to -5 K and -2 to 2 grams per kilogram respectively). Since the large-scale advective temperature and moisture "forcing" are prescribed for this case, a closer examination of two of the remaining external types of "forcing", namely radiative heating and air/sea hear and moisture transfer, are warranted. This paper examines the current radiation and surface flux of parameterizations used in the cloud models participating in the GCSS WG4, be executing the models "offline" for one time step (12 s) for a prescribed atmospheric state, then examining the surface and radiation fluxes from each model. The dynamic, thermodynamic, and microphysical fluids are provided by the GCE-derived model output for Case 2 during a period of very active deep convection (westerly wind burst). The surface and radiation fluxes produced from the models are then divided into prescribed convective, stratiform, and clear regions in order to examine the role that clouds play in the flux parameterizations. The results suggest that the differences between the models are attributed more to the surface flux parameterizations than the radiation schemes.

  12. Features of Afterbody Radiative Heating for Earth Entry

    NASA Technical Reports Server (NTRS)

    Johnston, Christopher O.; Brandis, Aaron

    2014-01-01

    Radiative heating is identified as a major contributor to afterbody heating for Earth entry capsules at velocities above 10 km/s. Because of rate-limited electron-ion recombination processes, a large fraction of the electronically-excited N and O atoms produced in the high temperature/pressure forebody remain as they expand into the afterbody region, which results in significant afterbody radiation. Large radiative heating sensitivities to electron-impact ionization rates and escape factors are identified. Ablation products from a forebody ablator are shown to increase the afterbody radiation by as much as 40%. The tangent-slab radiation transport approach is shown to over-predict the radiative flux by as much as 40% in the afterbody, therefore making the more computationally expensive ray-tracing approach necessary for accurate radiative flux predictions. For the Stardust entry, the afterbody radiation is predicted to be nearly twice as large as the convective heating during the peak heating phase of the trajectory. Comparisons between simulations and the Stardust Echelle observation measurements, which are shown to be dominated by afterbody emission, indicate agreement within 20% for various N and O lines. Similarly, calorimeter measurements from the Fire II experiment are identified as a source of validation data for afterbody radiation. For the afterbody calorimeter measurement closest to the forebody, which experiences the largest afterbody radiative heating component, the convective heating alone is shown to under-predict the measurement, even for the fullycatalytic assumption. Agreement with the measurements is improved with the addition of afterbody radiation. These comparisons with Stardust and Fire II measurements provide validation that the significant afterbody radiation values proposed in this work are legitimate.

  13. Remote Heat Flux Using a Self Calibration Multiwavelength Pyrometer and a Transparent Material

    NASA Technical Reports Server (NTRS)

    Ng, Daniel

    1998-01-01

    A self calibrating multiwavelength pyrometer was used to conduct remote heat flux measurements using a transparent sapphire disk by determining the sapphire disk's front and back surface temperatures. Front surface temperature (Tfs) was obtained from detection of surface emitted radiation at long wavelengths (k = 6 gm). Back surface temperature (Tbs) was obtained from short wavelength (1 to 5 gm) radiation transmitted through the sapphire disk. The thermal conductivity of the sapphire disk and the heat transfer coefficients h, and h2 of its surfaces are determined experimentally. An analysis of the heat flux measurement is presented.

  14. Fabrication of thin film heat flux sensors

    NASA Technical Reports Server (NTRS)

    Will, Herbert

    1991-01-01

    Thin-film heat-flux sensors have been constructed in the form of arrays of thermocouples on upper and lower surfaces of an insulating layer, so that flux values are proportional to the temperature difference across the upper and lower surface of the insulation material. The sensor thermocouples are connected in thermopile arrangement, and the structure is patterned with photolithographic techniques. Both chromel-alumel and Pt-Pt/Rh thermocouples have been devised; the later produced 28 microvolts when exposed to the radiation of a 1000 C furnace.

  15. Comparison of the Radiative Two-Flux and Diffusion Approximations

    NASA Technical Reports Server (NTRS)

    Spuckler, Charles M.

    2006-01-01

    Approximate solutions are sometimes used to determine the heat transfer and temperatures in a semitransparent material in which conduction and thermal radiation are acting. A comparison of the Milne-Eddington two-flux approximation and the diffusion approximation for combined conduction and radiation heat transfer in a ceramic material was preformed to determine the accuracy of the diffusion solution. A plane gray semitransparent layer without a substrate and a non-gray semitransparent plane layer on an opaque substrate were considered. For the plane gray layer the material is semitransparent for all wavelengths and the scattering and absorption coefficients do not vary with wavelength. For the non-gray plane layer the material is semitransparent with constant absorption and scattering coefficients up to a specified wavelength. At higher wavelengths the non-gray plane layer is assumed to be opaque. The layers are heated on one side and cooled on the other by diffuse radiation and convection. The scattering and absorption coefficients were varied. The error in the diffusion approximation compared to the Milne-Eddington two flux approximation was obtained as a function of scattering coefficient and absorption coefficient. The percent difference in interface temperatures and heat flux through the layer obtained using the Milne-Eddington two-flux and diffusion approximations are presented as a function of scattering coefficient and absorption coefficient. The largest errors occur for high scattering and low absorption except for the back surface temperature of the plane gray layer where the error is also larger at low scattering and low absorption. It is shown that the accuracy of the diffusion approximation can be improved for some scattering and absorption conditions if a reflectance obtained from a Kubelka-Munk type two flux theory is used instead of a reflection obtained from the Fresnel equation. The Kubelka-Munk reflectance accounts for surface reflection and

  16. Divertor Heat Flux Reduction and Detachment in the National Spherical Torus eXperiment.

    NASA Astrophysics Data System (ADS)

    Soukhanovskii, Vsevolod

    2007-11-01

    Steady-state handling of the heat flux is a critical divertor issue for both the International Thermonuclear Experimental Reactor and spherical torus (ST) devices. Because of an inherently compact divertor, it was thought that ST-based devices might not be able to fully utilize radiative and dissipative divertor techniques based on induced power and momentum loss. However, initial experiments conducted in the National Spherical Torus Experiment in an open geometry horizontal carbon plate divertor using 0.8 MA 2-6 MW NBI-heated lower single null H-mode plasmas at the lower end of elongations κ=1.8-2.4 and triangularities δ=0.45-0.75 demonstrated that high divertor peak heat fluxes, up to 6-10 MW/ m^2, could be reduced by 50-75% using a high-recycling radiative divertor regime with D2 injection. Furthermore, similar reduction was obtained with a partially detached divertor (PDD) at high D2 injection rates, however, it was accompanied by an X-point MARFE that quickly led to confinement degradation. Another approach takes advantage of the ST relation between strong shaping and high performance, and utilizes the poloidal magnetic flux expansion in the divertor region. Up to 60 % reduction in divertor peak heat flux was achieved at similar levels of scrape-off layer power by varying plasma shaping and thereby increasing the outer strike point (OSP) poloidal flux expansion from 4-6 to 18-22. In recent experiments conducted in highly-shaped 1.0-1.2 MA 6 MW NBI heated H-mode plasmas with divertor D2 injection at rates up to 10^22 s-1, a PDD regime with OSP peak heat flux 0.5-1.5 MW/m^2 was obtained without noticeable confinement degradation. Calculations based on a two point scrape-off layer model with parameterized power and momentum losses show that the short parallel connection length at the OSP sets the upper limit on the radiative exhaust channel, and both the impurity radiation and large momentum sink achievable only at high divertor neutral pressures are required

  17. Characteristics of the Surface Turbulent Flux and the Components of Radiation Balance over the Grasslands in the Southeastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Li, H.; Xiao, Z.; Wei, J.

    2016-12-01

    Characteristics of the Surface Turbulent Flux and the Components of Radiation Balance over the Grasslands in the Southeastern Tibetan PlateauHongyi Li 1, Ziniu Xiao 2 and Junhong Wei31 China Meteorological Administration Training Centre, Beijing, China2 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China 3Theory of Atmospheric Dynamics and Climate, Institute for Atmospheric and Environmental Sciences, Goethe University of Frankfurt, Campus Riedberg, GermanyAbstract:Based on the field observation data over the grasslands in the southeastern Tibetan Plateau and the observational datasets in Nyingchi weather station for the period from May 20 to July 9, 2013, the variation characteristics of the basic meteorological elements in Nyingchi weather station, the surface turbulent fluxes and the components of radiation balance over the grasslands, as well as their relationships, are analyzed in this paper. The results show that in Nyingchi weather station, the daily variations of relative humidity and average total cloud cover are consistent with that of precipitation, but that those of daily average air temperature, daily average ground temperature, daily average wind speed and daily sunshine duration have an opposite change to that of precipitation. During the observation period, latent heat exchange is greater than sensible heat exchange, and latent heat flux is significantly higher when there is rainfall, but sensible heat flux and soil heat flux are lower. The daily variation of the total solar radiation (DR) is synchronous with that of sensible heat flux, and the daily variations of reflective solar radiation (UR), long wave radiation by earth (ULR), net radiation (Rn) and surface albedo are consistent with DR, but that of the long wave radiation by atmosphere (DLR) has an opposite change. The diurnal variations of sensible heat flux, latent

  18. New low-cost high heat flux source

    NASA Astrophysics Data System (ADS)

    Cheng, Dah Yu

    1993-11-01

    Intense heat sources are needed to address new manufacturing techniques, such as, the Rapid Thermal Process for silicon wafer manufacturing. The current technology of high heat flux sources is the laser for its ability to do welding and cutting is well-known. The laser with its coherent radiation allows an image to be focused down to very small sizes to reach extremely high heat flux. But the laser also has problems: it is inefficient in its use because of its singular wave length and brings up OSHA safety related problems. Also heavy industrial manufacturing requires much higher total energy in addition to the high heat flux which makes the current laser system too slow to be economical. The system I am proposing starts with a parabolic curve. If the curve is rotated about the axis of the parabola, it generates the classical parabolic reflector as we know it. On the other hand, when the curve is rotated about the chord, a line passing through the focal point and perpendicular to the axis, generates a new surface called the Orthogonal Parabolic Surface. A new optical reflector geometry is presented which integrates a linear white light (continuum spectra) source through a coherent path to be focused to a very small area.

  19. Spectral tuning of near-field radiative heat transfer by graphene-covered metasurfaces

    NASA Astrophysics Data System (ADS)

    Zheng, Zhiheng; Wang, Ao; Xuan, Yimin

    2018-03-01

    When two gratings are respectively covered by a layer of graphene sheet, the near-field radiative heat transfer between two parallel gratings made of silica (SiO2) could be greatly improved. As the material properties of doped silicon (n-type doping concentration is 1020 cm-3, marked as Si-20) and SiO2 differ greatly, we theoretically investigate the near-field radiative heat transfer between two parallel graphene-covered gratings made of Si-20 to explore some different phenomena, especially for modulating the spectral properties. The radiative heat flux between two parallel bulks made of Si-20 can be enhanced by using gratings instead of bulks. When the two gratings are respectively covered by a layer of graphene sheet, the radiative heat flux between two gratings made of Si-20 can be further enhanced. By tuning graphene chemical potential μ and grating filling factor f, due to the interaction between surface plasmon polaritons (SPPs) of graphene sheets and grating structures, the spectral properties of the radiative heat flux between two parallel graphene-covered gratings can be effectively regulated. This work will develop and supplement the effects of materials on the near-field radiative heat transfer for this kind of system configuration, paving a way to modulate the spectral properties of near-field radiative heat transfer.

  20. High heat flux loop heat pipes

    NASA Astrophysics Data System (ADS)

    North, Mark T.; Sarraf, David B.; Rosenfeld, John H.; Maidanik, Yuri F.; Vershinin, Sergey

    1997-01-01

    Loop Heat Pipes (LHPs) can transport very large thermal power loads, over long distances, through flexible, small diameter tubes and against high gravitational heads. While recent LHPs have transported as much as 1500 W, the peak heat flux through a LHP's evaporator has been limited to about 0.07 MW/m2. This limitation is due to the arrangement of vapor passages next to the heat load which is one of the conditions necessary to ensure self priming of the device. This paper describes work aimed at raising this limit by threefold to tenfold. Two approaches were pursued. One optimized the vapor passage geometry for the high heat flux conditions. The geometry improved the heat flow into the wick and working fluid. This approach also employed a finer pored wick to support higher vapor flow losses. The second approach used a bidisperse wick material within the circumferential vapor passages. The bidisperse material increased the thermal conductivity and the evaporative surface area in the region of highest heat flux, while providing a flow path for the vapor. Proof-of-concept devices were fabricated and tested for each approach. Both devices operated as designed and both demonstrated operation at a heat flux of 0.70 MW/m2. This performance exceeded the known state of the art by a factor of more than six for both conventional heat pipes and for loop heat pipes using ammonia. In addition, the bidisperse-wick device demonstrated boiling heat transfer coefficients up to 100,000 W/m2.K, and the fine pored device demonstrated an orientation independence with its performance essentially unaffected by whether its evaporator was positioned above, below or level with the condenser.

  1. Two-Flux Method for Transient Radiative Transfer in a Semitransparent Layer

    NASA Technical Reports Server (NTRS)

    Siegel, Robert

    1996-01-01

    The two-flux method was used to obtain transient solutions for a plane layer including internal reflections and scattering. The layer was initially at uniform temperature, and was heated or cooled by external radiation and convection. The two-flux equations were examined as a means for evaluating the radiative flux gradient in the transient energy equation. Comparisons of transient temperature distributions using the two-flux method were made with results where the radiative flux gradient was evaluated from the exact radiative transfer equations. Good agreement was obtained for optical thicknesses from 0.5 to 5 and for refractive indices of 1 and 2. Illustrative results obtained with the two-flux method demonstrate the effect of isotropic scattering coupled with changing the refractive index. For small absorption with large scattering the maximum layer temperature is increased when the refractive index is increased. For larger absorption the effect is opposite, and the maximum temperature decreases with increased refractive index .

  2. Sensors for Metering Heat Flux Area Density and Metrological Equipment for the Heat Flux Density Measurement

    NASA Astrophysics Data System (ADS)

    Doronin, D. O.

    2018-04-01

    The demand in measuring and studies of heat conduction of various media is very urgent now. This article considers the problem of heat conduction monitoring and measurement in various media and materials in any industries and branches of science as well as metrological support of the heat flux measurement equipment. The main study objects are both the sensors manufactured and facilities onto which these sensors will be installed: different cladding structures of the buildings, awnings, rocket fairings, boiler units, internal combustion engines. The Company develops and manufactures different types of heat flux sensors: thermocouple, thin-film, heterogeneous gradient as well as metrological equipment for the gauging calibration of the heat flux density measurement. The calibration shall be performed using both referencing method in the unit and by fixed setting of the heat flux in the unit. To manufacture heterogeneous heat flux gradient sensors (HHFGS) the Company developed and designed a number of units: diffusion welding unit, HHFGS cutting unit. Rather good quality HHFGS prototypes were obtained. At this stage the factory tests on the equipment for the heat flux density measurement equipment are planned. A high-sensitivity heat flux sensor was produced, now it is tested at the Construction Physics Research Institute (Moscow). It became possible to create thin-film heat flux sensors with the sensitivity not worse than that of the sensors manufactured by Captec Company (France). The Company has sufficient premises to supply the market with a wide range of sensors, to master new sensor manufacture technologies which will enable their application range.

  3. Linearized Flux Evolution (LiFE): A technique for rapidly adapting fluxes from full-physics radiative transfer models

    NASA Astrophysics Data System (ADS)

    Robinson, Tyler D.; Crisp, David

    2018-05-01

    Solar and thermal radiation are critical aspects of planetary climate, with gradients in radiative energy fluxes driving heating and cooling. Climate models require that radiative transfer tools be versatile, computationally efficient, and accurate. Here, we describe a technique that uses an accurate full-physics radiative transfer model to generate a set of atmospheric radiative quantities which can be used to linearly adapt radiative flux profiles to changes in the atmospheric and surface state-the Linearized Flux Evolution (LiFE) approach. These radiative quantities describe how each model layer in a plane-parallel atmosphere reflects and transmits light, as well as how the layer generates diffuse radiation by thermal emission and by scattering light from the direct solar beam. By computing derivatives of these layer radiative properties with respect to dynamic elements of the atmospheric state, we can then efficiently adapt the flux profiles computed by the full-physics model to new atmospheric states. We validate the LiFE approach, and then apply this approach to Mars, Earth, and Venus, demonstrating the information contained in the layer radiative properties and their derivatives, as well as how the LiFE approach can be used to determine the thermal structure of radiative and radiative-convective equilibrium states in one-dimensional atmospheric models.

  4. The Effect of the Heat Flux on the Self-Ignition of Oriented Strand Board

    NASA Astrophysics Data System (ADS)

    Hirle, Siegfried; Balog, Karol

    2017-06-01

    This article deals with the initiation phase of flaming and smouldering burning of oriented strand board. The influence of heat flux on thermal degradation of OSB boards, time to ignition, heat release rate and mass loss rate using thermal analysis and vertical electrical radiation panel methods were studied. Significant information on the influence of the heat flux density and the thickness of the material on time to ignition was obtained.

  5. Spatial variability of shortwave radiative fluxes in the context of snowmelt

    NASA Astrophysics Data System (ADS)

    Pinker, Rachel T.; Ma, Yingtao; Hinkelman, Laura; Lundquist, Jessica

    2014-05-01

    Snow-covered mountain ranges are a major source of water supply for run-off and groundwater recharge. Snowmelt supplies as much as 75% of surface water in basins of the western United States. Factors that affect the rate of snow melt include incoming shortwave and longwave radiation, surface albedo, snow emissivity, snow surface temperature, sensible and latent heat fluxes, ground heat flux, and energy transferred to the snowpack from deposited snow or rain. The net radiation generally makes up about 80% of the energy balance and is dominated by the shortwave radiation. Complex terrain poses a great challenge for obtaining the needed information on radiative fluxes from satellites due to elevation issues, spatially-variable cloud cover, rapidly changing surface conditions during snow fall and snow melt, lack of high quality ground truth for evaluation of the satellite based estimates, as well as scale issues between the ground observations and the satellite footprint. In this study we utilize observations of high spatial resolution (5-km) as available from the Moderate Resolution Imaging Spectro-radiometer (MODIS) to derive surface shortwave radiative fluxes in complex terrain, with attention to the impact of slopes on the amount of radiation received. The methodology developed has been applied to several water years (January to July during 2003, 2004, 2005 and 2009) over the western part of the United States, and the available information was used to derive metrics on spatial and temporal variability in the shortwave fluxes. It is planned to apply the findings from this study for testing improvements in Snow Water Equivalent (SWE) estimates.

  6. Development of Advanced Thermal and Environmental Barrier Coatings Using a High-Heat-Flux Testing Approach

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    2003-01-01

    The development of low conductivity, robust thermal and environmental barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity and cyclic resistance at very high surface temperatures (up to 1700 C) under large thermal gradients. In this study, a laser high-heat-flux test approach is established for evaluating advanced low conductivity, high temperature capability thermal and environmental barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) program. The test approach emphasizes the real-time monitoring and assessment of the coating thermal conductivity, which initially rises under the steady-state high temperature thermal gradient test due to coating sintering, and later drops under the cyclic thermal gradient test due to coating cracking/delamination. The coating system is then evaluated based on damage accumulation and failure after the combined steady-state and cyclic thermal gradient tests. The lattice and radiation thermal conductivity of advanced ceramic coatings can also be evaluated using laser heat-flux techniques. The external radiation resistance of the coating is assessed based on the measured specimen temperature response under a laser- heated intense radiation-flux source. The coating internal radiation contribution is investigated based on the measured apparent coating conductivity increases with the coating surface test temperature under large thermal gradient test conditions. Since an increased radiation contribution is observed at these very high surface test temperatures, by varying the laser heat-flux and coating average test temperature, the complex relation between the lattice and radiation conductivity as a function of surface and interface test temperature may be derived.

  7. Advanced high temperature heat flux sensors

    NASA Technical Reports Server (NTRS)

    Atkinson, W.; Hobart, H. F.; Strange, R. R.

    1983-01-01

    To fully characterize advanced high temperature heat flux sensors, calibration and testing is required at full engine temperature. This required the development of unique high temperature heat flux test facilities. These facilities were developed, are in place, and are being used for advanced heat flux sensor development.

  8. Turbulent convection driven by internal radiative heating of melt ponds on sea ice

    NASA Astrophysics Data System (ADS)

    Wells, Andrew; Langton, Tom; Rees Jones, David; Moon, Woosok

    2016-11-01

    The melting of Arctic sea ice is strongly influenced by heat transfer through melt ponds which form on the ice surface. Melt ponds are internally heated by the absorption of incoming radiation and cooled by surface heat fluxes, resulting in vigorous buoyancy-driven convection in the pond interior. Motivated by this setting, we conduct two-dimensional direct-numerical simulations of the turbulent convective flow of a Boussinesq fluid between two horizontal boundaries, with internal heating predicted from a two-stream radiation model. A linearised thermal boundary condition describes heat exchange with the overlying atmosphere, whilst the lower boundary is isothermal. Vertically asymmetric convective flow modifies the upper surface temperature, and hence controls the partitioning of the incoming heat flux between emission at the upper and lower boundaries. We determine how the downward heat flux into the ice varies with a Rayleigh number based on the internal heating rate, the flux ratio of background surface cooling compared to internal heating, and a Biot number characterising the sensitivity of surface fluxes to surface temperature. Thus we elucidate the physical controls on heat transfer through Arctic melt ponds which determine the fate of sea ice in the summer.

  9. Solution of Radiation and Convection Heat-Transfer Problems

    NASA Technical Reports Server (NTRS)

    Oneill, R. F.

    1986-01-01

    Computer program P5399B developed to accommodate variety of fin-type heat conduction applications involving radiative or convective boundary conditions with additionally imposed local heat flux. Program also accommodates significant variety of one-dimensional heat-transfer problems not corresponding specifically to fin-type applications. Program easily accommodates all but few specialized one-dimensional heat-transfer analyses as well as many twodimensional analyses.

  10. Two-Flux Green's Function Analysis for Transient Spectral Radiation in a Composite

    NASA Technical Reports Server (NTRS)

    Siegel, Robert

    1996-01-01

    An analysis is developed for obtaining transient temperatures in a two-layer semitransparent composite with spectrally dependent properties. Each external boundary of the composite is subjected to radiation and convection. The two-flux radiative transfer equations are solved by deriving a Green's function. This yields the local radiative heat source needed to numerically solve the transient energy equation. An advantage of the two-flux method is that isotropic scattering is included without added complexity. The layer refractive indices are larger than one. This produces internal reflections at the boundaries and the internal interface; the reflections are assumed diffuse. Spectral results using the Green's function method are verified by comparing with numerical solutions using the exact radiative transfer equations. Transient temperature distributions are given to illustrate the effect of radiative heating on one side of a composite with external convective cooling. The protection of a material from incident radiation is illustrated by adding scattering to the layer adjacent to the radiative source.

  11. Measuring Fluxes Of Heat To A Plasma-Arc Anode

    NASA Technical Reports Server (NTRS)

    Sankovic, John M.; Menart, James A.; Pfender, Emil; Heberlein, Joachim

    1995-01-01

    Three probes constructed to provide measurements indicative of conductive, convective, and radiative transfer of heat from free-burning plasma arc to water-cooled copper anode used in generating arc. Each probe consists mainly of copper body with two thermocouples embedded at locations 4 mm apart along length. Thermocouples provide measure of rate of conduction of heat along probe and transfers of heat from plasma to sensing surface at tip of probe. Probes identical except sensing surface of one uncoated and other two coated with different materials to make them sensitive to different components of overall flux of heat.

  12. The Response of the Ocean Thermal Skin Layer to Air-Sea Surface Heat Fluxes

    NASA Astrophysics Data System (ADS)

    Wong, Elizabeth Wing-See

    There is much evidence that the ocean is heating as a result of an increase in concentrations of greenhouse gases (GHGs) in the atmosphere from human activities. GHGs absorb infrared radiation and re-emit infrared radiation back to the ocean's surface which is subsequently absorbed. However, the incoming infrared radiation is absorbed within the top micrometers of the ocean's surface which is where the thermal skin layer exists. Thus the incident infrared radiation does not directly heat the upper few meters of the ocean. We are therefore motivated to investigate the physical mechanism between the absorption of infrared radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that since heat lost through the air-sea interface is controlled by the thermal skin layer, which is directly influenced by the absorption and emission of infrared radiation, the heat flow through the thermal skin layer adjusts to maintain the surface heat loss, assuming the surface heat loss does not vary, and thus modulates the upper ocean heat content. This hypothesis is investigated through utilizing clouds to represent an increase in incoming longwave radiation and analyzing retrieved thermal skin layer vertical temperature profiles from a shipboard infrared spectrometer from two research cruises. The data are limited to night-time, no precipitation and low winds of less than 2 m/s to remove effects of solar radiation, wind-driven shear and possibilities of thermal skin layer disruption. The results show independence of the turbulent fluxes and emitted radiation on the incident radiative fluxes which rules out the immediate release of heat from the absorption of the cloud infrared irradiance back into the atmosphere through processes such as evaporation and increase infrared emission. Furthermore, independence was confirmed between the incoming and outgoing radiative flux which implies the heat sink for upward flowing heat at the air-sea interface is more

  13. Controlling Radiative Heat Transfer Across the Mold Flux Layer by the Scattering Effect of the Borosilicate Mold Flux System with Metallic Iron

    NASA Astrophysics Data System (ADS)

    Yoon, Dae-Woo; Cho, Jung-Wook; Kim, Seon-Hyo

    2017-08-01

    The present study proposes a countermeasure for regulating total heat flux through the mold flux layer by designed mold flux with additive metallic iron particles. The heat flux through the B2O3-CaO-SiO2-Na2O-CaF2-Fe system was investigated using the infrared emitter technique to evaluate total flux density across the mold flux film. Both scanning electron microscope (SEM) and X-ray diffraction analysis were employed in order to identify the morphological and compositional changes of the crystalline phase, according to increasing iron contents in the mold flux. It was confirmed that the crystalline layer of studied mold fluxes does not have a meaningful effect on the total heat flux density due to the similar structure and fraction of the crystalline phase. The extinction coefficient was measured for glassy mold fluxes using an ultraviolet/visible and a Fourier transformation-infrared ray spectrometer in the range of 0.5 to 5 μm. For analyzing the scattering behavior of iron particles on the extinction coefficient, the number density and diameter of particles were observed by an automated SEM (auto-SEM). With these data, Mie scattering theory is adopted to define the scattering behavior of dispersed iron droplets in glassy matrix. It was found that the theoretical scattering coefficient demonstrated about 1623 to 3295 m-1, which is in accordance with the experimental results. In doing so, this study successfully achieves the strong scattering behavior that would contribute greatly to the optimization of overall heat flux through the mold flux film during the casting process.

  14. Magnetogasdynamics shock waves in a rotational axisymmetric non-ideal gas with increasing energy and conductive and radiative heat-fluxes

    NASA Astrophysics Data System (ADS)

    Nath, Gorakh

    2016-07-01

    Self-similar solutions are obtained for one-dimensional adiabatic flow behind a magnetogasdynamics cylindrical shock wave propagating in a rotational axisymmetric non ideal gas with increasing energy and conductive and radiative heat fluxes in presence of an azimuthal magnetic field. The fluid velocities and the azimuthal magnetic field in the ambient medium are assume to be varying and obeying power laws. In order to find the similarity solutions the angular velocity of the ambient medium is taken to be decreasing as the distance from the axis increases. The heat conduction is expressed in terms of Fourier's law and the radiation is considered to be the diffusion type for an optically thick grey gas model. The thermal conductivity and the absorption coefficient are assumed to vary with temperature and density. The effects of the presence of radiation and conduction, the non-idealness of the gas and the magnetic field on the shock propagation and the flow behind the shock are investigated.

  15. Heat fluxes across the Antarctic Circumpolar Current

    NASA Astrophysics Data System (ADS)

    Ferrari, Ramiro; Provost, Christine; Hyang Park, Young; Sennéchael, Nathalie; Garric, Gilles; Bourdallé-Badie, Romain

    2014-05-01

    Determining the processes responsible for the Southern Ocean heat balance is fundamental to our understanding of the weather and climate systems. Therefore, in the last decades, various studies aimed at analyzing the major mechanisms of the oceanic poleward heat flux in this region. Previous works stipulated that the cross-stream heat flux due to the mesoscale transient eddies was responsible for the total meridional heat transport across the Antarctic Circumpolar Current (ACC). Several numerical modelling and current meters data studies have recently challenged this idea. These showed that the heat flux due to the mean flow in the southern part of the Antarctic Circumpolar Current could be larger than the eddy heat flux contribution by two orders of magnitude. Eddy heat flux and heat flux by the mean flow distributions of were examined in Drake Passage using in situ measurements collected during the DRAKE 2006-9 project (from January 2006 to March 2009), available observations from the historical DRAKE 79 experiment and high resolution model outputs (ORCA 12, MERCATOR). The Drake Passage estimations provided a limited view of heat transport in the Southern Ocean. The small spatial scales shown by the model derived heat flux by the mean flow indicate that circumpolar extrapolations from a single point observation are perilous. The importance of the heat flux due by the mean flow should be further investigated using other in situ observations and numerical model outputs. Similar situation has been observed, with important implication for heat flux due to the mean flow, in other topographically constricted regions with strong flow across prominent submarine ridges (choke points). We have estimated the heat flux due to the mean flow revisiting other ACC mooring sites where in situ time series are available, e.g. south of Australia (Tasmania) (Phillips and Rintoul, 2000), southeast of New Zealand (Campbell Plateau) (Bryden and Heath, 1985). Heat fluxes due to the mean

  16. Radiative Heating on the After-Body of Martian Entry Vehicles

    NASA Technical Reports Server (NTRS)

    Brandis, A. M.; Saunders, D. A.; Johnston, C. O.; Cruden, B. A.; White, T. R.

    2015-01-01

    This paper presents simulations of the radiative heat flux imparted on the after-body of vehicles entering the Martian atmosphere. The radiation is dominated by CO2 bands emitting in the mid-wave infrared spectral region. This mechanism has traditionally not been considered in the design of past Mars entry vehicles. However, with recent analysis showing that the CO2 radiation can be greater than convective heating in the wake, and with several upcoming and proposed missions to Mars potentially affected, an investigation of the impact of this radiation is warranted. The focus of this paper is to provide a better understanding of the impact to aerothermal heating predictions and to provide comparisons between NASA's two main radiation codes, NEQAIR and HARA. The tangent slab approximation is shown to be overly conservative, by as much as 58 percent, for most back- shell body point locations compared to using a full angular integration method. However, due to the complexity of the wake flow, it is also shown that tangent slab does not always represent an upper limit for radiative heating. Furthermore, analysis in this paper shows that it is not possible to provide a general knock-down factor from the tangent slab results to those obtained using the more rigorous full integration method. When the radiative heating is accounted for on the after-body, the unmargined total heat flux can be as high as 14 watts per square centimeter.

  17. Geometrical correction factors for heat flux meters

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.; Papell, S. S.

    1974-01-01

    General formulas are derived for determining gage averaging errors of strip-type heat flux meters used in the measurement of one-dimensional heat flux distributions. The local averaging error e(x) is defined as the difference between the measured value of the heat flux and the local value which occurs at the center of the gage. In terms of e(x), a correction procedure is presented which allows a better estimate for the true value of the local heat flux. For many practical problems, it is possible to use relatively large gages to obtain acceptable heat flux measurements.

  18. Multi Seasonal and Diurnal Characterization of Sensible Heat Flux in an Arid Land Environment

    NASA Astrophysics Data System (ADS)

    Al-Mashharawi, S.; Aragon, B.; McCabe, M.

    2017-12-01

    In sparsely vegetated arid and semi-arid regions, the available energy is transformed primarily into sensible heat, with little to no energy partitioned into latent heat. The characterization of bare soil arid environments are rather poorly understood in the context of both local, regional and global energy budgets. Using data from a long-term surface layer scintillometer and co-located meteorological installation, we examine the diurnal and seasonal patterns of sensible heat flux and the net radiation to soil heat flux ratio. We do this over a bare desert soil located adjacent to an irrigated agricultural field in the central region of Saudi Arabia. The results of this exploratory analysis can be used to inform upon remote sensing techniques for surface flux estimation, to derive and monitor soil heat flux dynamics, estimate the heat transfer resistance and the thermal roughness length over bare soils, and to better inform efforts that model the advective effects that complicate the accurate representation of agricultural energy budgets in the arid zone.

  19. Dynamic Modulation of Radiative Heat Transfer beyond the Blackbody Limit.

    PubMed

    Ito, Kota; Nishikawa, Kazutaka; Miura, Atsushi; Toshiyoshi, Hiroshi; Iizuka, Hideo

    2017-07-12

    Dynamic control of electromagnetic heat transfer without changing mechanical configuration opens possibilities in intelligent thermal management in nanoscale systems. We confirmed by experiment that the radiative heat transfer is dynamically modulated beyond the blackbody limit. The near-field electromagnetic heat exchange mediated by phonon-polariton is controlled by the metal-insulator transition of tungsten-doped vanadium dioxide. The functionalized heat flux is transferred over an area of 1.6 cm 2 across a 370 nm gap, which is maintained by the microfabricated spacers and applied pressure. The uniformity of the gap is validated by optical interferometry, and the measured heat transfer is well modeled as the sum of the radiative and the parasitic conductive components. The presented methodology to form a nanometric gap with functional heat flux paves the way to the smart thermal management in various scenes ranging from highly integrated systems to macroscopic apparatus.

  20. Dynamics of charged bulk viscous collapsing cylindrical source with heat flux

    NASA Astrophysics Data System (ADS)

    Shah, S. M.; Abbas, G.

    2017-04-01

    In this paper, we have explored the effects of dissipation on the dynamics of charged bulk viscous collapsing cylindrical source which allows the out-flow of heat flux in the form of radiations. The Misner-Sharp formalism has been implemented to drive the dynamical equation in terms of proper time and radial derivatives. We have investigated the effects of charge and bulk viscosity on the dynamics of collapsing cylinder. To determine the effects of radial heat flux, we have formulated the heat transport equations in the context of Müller-Israel-Stewart theory by assuming that thermodynamics viscous/heat coupling coefficients can be neglected within some approximations. In our discussion, we have introduced the viscosity by the standard (non-causal) thermodynamics approach. The dynamical equations have been coupled with the heat transport equation; the consequences of the resulting coupled heat equation have been analyzed in detail.

  1. [Characteristics of water and heat fluxes and its footprint climatology on farmland in low hilly region of red soil].

    PubMed

    Li, Yang; Jing, Yuan Shu; Qin, Ben Ben

    2017-01-01

    The analysis of the characteristics and footprint climatology of farmland water and heat fluxes has great significance to strengthen regional climate resource management and improve the hydrothermal resource utilization in the region of red soil. Based on quality controlled data from large aperture scintillometer and automatic meteorological station in hilly region of red soil, this paper analyzed in detail the characteristics of farmland water and heat fluxes at different temporal scales and the corresponding source area distribution of flux measurement in the non-rainy season and crop growth period in hilly region of red soil. The results showed that the diurnal variation of water and heat fluxes showed a unimodal trend, but compared with the sunny day, the diurnal variation curves fluctuated more complicatedly on cloudy day. In the whole, either ten-day periods or month scale, the water and heat fluxes were greater in August than in September, while the net radiation flux was more distributed to latent heat exchange. The proportion of net radiation to latent heat flux decreased in September compared to August, but the sensible heat flux was vice versa. With combined effects of weather conditions (particularly wind), stability, and surface condition, the source areas of flux measurement at different temporal scales showed different distribution characteristics. Combined with the underlying surface crops, the source areas at different temporal scales also had different contribution sources.

  2. Heat flux viscosity in collisional magnetized plasmas

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, C., E-mail: cliu@pppl.gov; Fox, W.; Bhattacharjee, A.

    2015-05-15

    Momentum transport in collisional magnetized plasmas due to gradients in the heat flux, a “heat flux viscosity,” is demonstrated. Even though no net particle flux is associated with a heat flux, in a plasma there can still be momentum transport owing to the velocity dependence of the Coulomb collision frequency, analogous to the thermal force. This heat-flux viscosity may play an important role in numerous plasma environments, in particular, in strongly driven high-energy-density plasma, where strong heat flux can dominate over ordinary plasma flows. The heat flux viscosity can influence the dynamics of the magnetic field in plasmas through themore » generalized Ohm's law and may therefore play an important role as a dissipation mechanism allowing magnetic field line reconnection. The heat flux viscosity is calculated directly using the finite-difference method of Epperlein and Haines [Phys. Fluids 29, 1029 (1986)], which is shown to be more accurate than Braginskii's method [S. I. Braginskii, Rev. Plasma Phys. 1, 205 (1965)], and confirmed with one-dimensional collisional particle-in-cell simulations. The resulting transport coefficients are tabulated for ease of application.« less

  3. Heat flux variations over sea ice observed at the coastal area of the Sejong Station, Antarctica

    NASA Astrophysics Data System (ADS)

    Park, Sang-Jong; Choi, Tae-Jin; Kim, Seong-Joong

    2013-08-01

    This study presents variations of sensible heat flux and latent heat flux over sea ice observed in 2011 from the 10-m flux tower located at the coast of the Sejong Station on King George Island, Antarctica. A period from July to September was selected as a sea ice period based on daily record of sea state and hourly photos looking at the Marian Cove in front of the Sejong Station. For the sea ice period, mean sensible heat flux is about -11 Wm-2, latent heat flux is about +2 W m-2, net radiation is -12 W m-2, and residual energy is -3 W m-2 with clear diurnal variations. Estimated mean values of surface exchange coefficients for momentum, heat and moisture are 5.15 × 10-3, 1.19 × 10-3, and 1.87 × 10-3, respectively. The observed exchange coefficients of heat shows clear diurnal variations while those of momentum and moisture do not show diurnal variation. The parameterized exchange coefficients of heat and moisture produces heat fluxes which compare well with the observed diurnal variations of heat fluxes.

  4. Tuning near field radiative heat flux through surface excitations with a metal insulator transition.

    PubMed

    van Zwol, P J; Ranno, L; Chevrier, J

    2012-06-08

    The control of heat flow is a formidable challenge due to lack of good thermal insulators. Promising new opportunities for heat flow control were recently theoretically discovered for radiative heat flow in near field, where large heat flow contrasts may be achieved by tuning electronic excitations on surfaces. Here we show experimentally that the phase transition of VO2 entails a change of surface polariton states that significantly affects radiative heat transfer in near field. In all cases the Derjaguin approximation correctly predicted radiative heat transfer in near field, but it underestimated the far field limit. Our results indicate that heat flow contrasts can be realized in near field that can be larger than those obtained in far field.

  5. High flux heat exchanger

    NASA Astrophysics Data System (ADS)

    Flynn, Edward M.; Mackowski, Michael J.

    1993-01-01

    This interim report documents the results of the first two phases of a four-phase program to develop a high flux heat exchanger for cooling future high performance aircraft electronics. Phase 1 defines future needs for high flux heat removal in advanced military electronics systems. The results are sorted by broad application categories: (1) commercial digital systems, (2) military data processors, (3) power processors, and (4) radar and optical systems. For applications expected to be fielded in five to ten years, the outlook is for steady state flux levels of 30-50 W/sq cm for digital processors and several hundred W/sq cm for power control applications. In Phase 1, a trade study was conducted on emerging cooling technologies which could remove a steady state chip heat flux of 100 W/sq cm while holding chip junction temperature to 90 C. Constraints imposed on heat exchanger design, in order to reflect operation in a fighter aircraft environment, included a practical lower limit on coolant supply temperature, the preference for a nontoxic, nonflammable, and nonfreezing coolant, the need to minimize weight and volume, and operation in an accelerating environment. The trade study recommended the Compact High Intensity Cooler (CHIC) for design, fabrication, and test in the final two phases of this program.

  6. Heat flux measurements on ceramics with thin film thermocouples

    NASA Technical Reports Server (NTRS)

    Holanda, Raymond; Anderson, Robert C.; Liebert, Curt H.

    1993-01-01

    Two methods were devised to measure heat flux through a thick ceramic using thin film thermocouples. The thermocouples were deposited on the front and back face of a flat ceramic substrate. The heat flux was applied to the front surface of the ceramic using an arc lamp Heat Flux Calibration Facility. Silicon nitride and mullite ceramics were used; two thicknesses of each material was tested, with ceramic temperatures to 1500 C. Heat flux ranged from 0.05-2.5 MW/m2(sup 2). One method for heat flux determination used an approximation technique to calculate instantaneous values of heat flux vs time; the other method used an extrapolation technique to determine the steady state heat flux from a record of transient data. Neither method measures heat flux in real time but the techniques may easily be adapted for quasi-real time measurement. In cases where a significant portion of the transient heat flux data is available, the calculated transient heat flux is seen to approach the extrapolated steady state heat flux value as expected.

  7. Effect of Index of Refraction on Radiation Characteristics in a Heated Absorbing, Emitting, and Scattering Layer

    NASA Technical Reports Server (NTRS)

    Siegel, R.; Spuckler, C. M.

    1992-01-01

    The effect of the index of refraction on the temperature distribution and radiative heat flux in semitransparent materials, such as some ceramics, is investigated analytically. In the case considered here, a plane layer of a ceramic material is subjected to external radiative heating incident on each of its surfaces; the material emits, absorbs, and isotropically scatters radiation. It is shown that, for radiative equilibrium in a gray layer with diffuse interfaces, the temperature distribution and radiative heat flux for any index of refraction can be obtained in a simple manner from the results for an index of refraction of unity.

  8. Modelling radiation fluxes in simple and complex environments: basics of the RayMan model.

    PubMed

    Matzarakis, Andreas; Rutz, Frank; Mayer, Helmut

    2010-03-01

    Short- and long-wave radiation flux densities absorbed by people have a significant influence on their energy balance. The heat effect of the absorbed radiation flux densities is parameterised by the mean radiant temperature. This paper presents the physical basis of the RayMan model, which simulates the short- and long-wave radiation flux densities from the three-dimensional surroundings in simple and complex environments. RayMan has the character of a freely available radiation and human-bioclimate model. The aim of the RayMan model is to calculate radiation flux densities, sunshine duration, shadow spaces and thermo-physiologically relevant assessment indices using only a limited number of meteorological and other input data. A comparison between measured and simulated values for global radiation and mean radiant temperature shows that the simulated data closely resemble measured data.

  9. Measurement of local high-level, transient surface heat flux

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.

    1988-01-01

    This study is part of a continuing investigation to develop methods for measuring local transient surface heat flux. A method is presented for simultaneous measurements of dual heat fluxes at a surface location by considering the heat flux as a separate function of heat stored and heat conducted within a heat flux gage. Surface heat flux information is obtained from transient temperature measurements taken at points within the gage. Heat flux was determined over a range of 4 to 22 MW/sq m. It was concluded that the method is feasible. Possible applications are for heat flux measurements on the turbine blade surfaces of space shuttle main engine turbopumps and on the component surfaces of rocket and advanced gas turbine engines and for testing sensors in heat flux gage calibrators.

  10. Laboratory experiments of heat and moisture fluxes through supraglacial debris

    NASA Astrophysics Data System (ADS)

    Nicholson, Lindsey; Mayer, Christoph; Wirbel, Anna

    2014-05-01

    Inspired by earlier work (Reznichenko et al., 2010), we have carried out experiments within a climate chamber to explore the best ways to measure the heat and moisture fluxes through supraglacial debris. Sample ice blocks were prepared with debris cover of varying lithology, grain size and thickness and were instrumented with a combination of Gemini TinyTag temperature/relative humidity sensors and Decagon soil moisture sensors in order to monitor the heat and moisture fluxes through the overlying debris material when the experiment is exposed to specified solar lamp radiation and laminar airflow within the temperature-controlled climate chamber. Experimental results can be used to determine the optimal set up for numerical models of heat and moisture flux through supraglacial debris and also indicate the performance limitations of such sensors that can be expected in field installations. Reznichenko, N., Davies, T., Shulmeister, J. and McSaveney, M. (2010) Effects of debris on ice-surface melting rates: an experimental study. Journal of Glaciology, Volume 56, Number 197, 384-394.

  11. Air-sea heat flux climatologies in the Mediterranean Sea: Surface energy balance and its consistency with ocean heat storage

    NASA Astrophysics Data System (ADS)

    Song, Xiangzhou; Yu, Lisan

    2017-05-01

    This study provides an analysis of the Mediterranean Sea surface energy budget using nine surface heat flux climatologies. The ensemble mean estimation shows that the net downward shortwave radiation (192 ± 19 W m-2) is balanced by latent heat flux (-98 ± 10 W m-2), followed by net longwave radiation (-78 ± 13 W m-2) and sensible heat flux (-13 ± 4 W m-2). The resulting net heat budget (Qnet) is 2 ± 12 W m-2 into the ocean, which appears to be warm biased. The annual-mean Qnet should be -5.6 ± 1.6 W m-2 when estimated from the observed net transport through the Strait of Gibraltar. To diagnose the uncertainty in nine Qnet climatologies, we constructed Qnet from the heat budget equation by using historic hydrological observations to determine the heat content changes and advective heat flux. We also used the Qnet from a data-assimilated global ocean state estimation as an additional reference. By comparing with the two reference Qnet estimates, we found that seven products (NCEP 1, NCEP 2, CFSR, ERA-Interim, MERRA, NOCSv2.0, and OAFlux+ISCCP) overestimate Qnet, with magnitude ranging from 6 to 27 W m-2, while two products underestimate Qnet by -6 W m-2 (JRA55) and -14 W m-2 (CORE.2). Together with the previous warm pool work of Song and Yu (2013), we show that CFSR, MERRA, NOCSv2.0, and OAFlux+ISCCP are warm-biased not only in the western Pacific warm pool but also in the Mediterranean Sea, while CORE.2 is cold-biased in both regions. The NCEP 1, 2, and ERA-Interim are cold-biased over the warm pool but warm-biased in the Mediterranean Sea.

  12. Recent trends (2003-2013) of land surface heat fluxes on the southern side of the central Himalayas, Nepal

    NASA Astrophysics Data System (ADS)

    Amatya, Pukar Man; Ma, Yaoming; Han, Cunbo; Wang, Binbin; Devkota, Lochan Prasad

    2015-12-01

    Novice efforts have been made in order to study the regional distribution of land surface heat fluxes on the southern side of the central Himalayas utilizing high-resolution remotely sensed products, but these have been on instantaneous scale. In this study the Surface Energy Balance System model is used to obtain annual averaged maps of the land surface heat fluxes for 11 years (2003-2013) and study their annual trends on the central Himalayan region. The maps were derived at 5 km resolution using monthly input products ranging from satellite derived to Global Land Data Assimilation System meteorological data. It was found that the net radiation flux is increasing as a result of decreasing precipitation (drier environment). The sensible heat flux did not change much except for the northwestern High Himalaya and High Mountains. In northwestern High Himalaya sensible heat flux is decreasing because of decrease in wind speed, ground-air temperature difference, and increase in winter precipitation, whereas in High Mountains it is increasing due to increase in ground-air temperature difference and high rate of deforestation. The latent heat flux has an overall increasing trend with increase more pronounced in the lower regions compared to high elevated regions. It has been reported that precipitation is decreasing with altitude in this region. Therefore, the increasing trend in latent heat flux can be attributed to increase in net radiation flux under persistent forest cover and irrigation land used for agriculture.

  13. Heat flux measurement in SSME turbine blade tester

    NASA Astrophysics Data System (ADS)

    Liebert, Curt H.

    1990-11-01

    Surface heat flux values were measured in the turbine blade thermal cycling tester located at NASA-Marshall. This is the first time heat flux has been measured in a space shuttle main engine turbopump environment. Plots of transient and quasi-steady state heat flux data over a range of about 0 to 15 MW/sq m are presented. Data were obtained with a miniature heat flux gage device developed at NASA-Lewis. The results from these tests are being incorporated into turbine design models. Also, these gages are being considered for airfoil surface heat flux measurement on turbine vanes mounted in SSME turbopump test bed engine nozzles at Marshall. Heat flux effects that might be observed on degraded vanes are discussed.

  14. Heat flux measurement in SSME turbine blade tester

    NASA Astrophysics Data System (ADS)

    Liebert, Curt H.

    Surface heat flux values were measured in the turbine blade thermal cycling tester located at NASA-Marshall. This is the first time heat flux has been measured in a space shuttle main engine turbopump environment. Plots of transient and quasi-steady state heat flux data over a range of about 0 to 15 MW/sq m are presented. Data were obtained with a miniature heat flux gage device developed at NASA-Lewis. The results from these tests are being incorporated into turbine design models. Also, these gages are being considered for airfoil surface heat flux measurement on turbine vanes mounted in SSME turbopump test bed engine nozzles at Marshall. Heat flux effects that might be observed on degraded vanes are discussed.

  15. Nonequilibrium Stagnation-Line Radiative Heating for Fire II

    NASA Technical Reports Server (NTRS)

    Johnston, Christopher O.; Hollis, Brian R.; Sutton, Kenneth

    2007-01-01

    This paper presents a detailed analysis of the shock-layer radiative heating to the Fire II vehicle using a new air radiation model and a viscous shock-layer flowfield model. This new air radiation model contains the most up-to-date properties for modeling the atomic-line, atomic photoionization, molecular band, and non-Boltzmann processes. The applied viscous shock-layer flowfield analysis contains the same thermophysical properties and nonequilibrium models as the LAURA Navier-Stokes code. Radiation-flowfield coupling, or radiation cooling, is accounted for in detail in this study. It is shown to reduce the radiative heating by about 30% for the peak radiative heating points, while reducing the convective heating only slightly. A detailed review of past Fire II radiative heating studies is presented. It is observed that the scatter in the radiation predicted by these past studies is mostly a result of the different flowfield chemistry models and the treatment of the electronic state populations. The present predictions provide, on average throughout the trajectory, a better comparison with Fire II flight data than any previous study. The magnitude of the vacuum ultraviolet (VUV) contribution to the radiative flux is estimated from the calorimeter measurements. This is achieved using the radiometer measurements and the predicted convective heating. The VUV radiation predicted by the present model agrees well with the VUV contribution inferred from the Fire II calorimeter measurement, although only when radiation-flowfield coupling is accounted for. This agreement provides evidence that the present model accurately models the VUV radiation, which is shown to contribute significantly to the Fire II radiative heating.

  16. Role of surface heat fluxes underneath cold pools

    DOE PAGES

    Gentine, Pierre; Garelli, Alix; Park, Seung -Bu; ...

    2016-01-05

    In this paper, the role of surface heat fluxes underneath cold pools is investigated using cloud–resolving simulations with either interactive or horizontally homogenous surface heat fluxes over an ocean and a simplified land surface. Over the ocean, there are limited changes in the distribution of the cold pool temperature, humidity, and gust front velocity, yet interactive heat fluxes induce more cold pools, which are smaller, and convection is then less organized. Correspondingly, the updraft mass flux and lateral entrainment are modified. Over the land surface, the heat fluxes underneath cold pools drastically impact the cold pool characteristics with more numerousmore » and smaller pools, which are warmer and more humid and accompanied by smaller gust front velocities. The interactive fluxes also modify the updraft mass flux and reduce convective organization. These results emphasize the importance of interactive surface fluxes instead of prescribed flux boundary conditions, as well as the formulation of surface heat fluxes, when studying convection.« less

  17. Role of surface heat fluxes underneath cold pools

    PubMed Central

    Garelli, Alix; Park, Seung‐Bu; Nie, Ji; Torri, Giuseppe; Kuang, Zhiming

    2016-01-01

    Abstract The role of surface heat fluxes underneath cold pools is investigated using cloud‐resolving simulations with either interactive or horizontally homogenous surface heat fluxes over an ocean and a simplified land surface. Over the ocean, there are limited changes in the distribution of the cold pool temperature, humidity, and gust front velocity, yet interactive heat fluxes induce more cold pools, which are smaller, and convection is then less organized. Correspondingly, the updraft mass flux and lateral entrainment are modified. Over the land surface, the heat fluxes underneath cold pools drastically impact the cold pool characteristics with more numerous and smaller pools, which are warmer and more humid and accompanied by smaller gust front velocities. The interactive fluxes also modify the updraft mass flux and reduce convective organization. These results emphasize the importance of interactive surface fluxes instead of prescribed flux boundary conditions, as well as the formulation of surface heat fluxes, when studying convection. PMID:27134320

  18. The Heat Flux through the Ice Shell on Europa, Constraints from Measurements in Terrestrial Conditions

    NASA Astrophysics Data System (ADS)

    Hruba, J.; Kletetschka, G.

    2017-12-01

    Heat transport across the ice shell of Europa controls the thermal evolution of its interior. Such process involves energy sources that drive ice resurfacing (1). More importantly, heat flux through the ice shell controls the thickness of the ice (2), that is poorly constrained between 1 km to 30+ km (3). Thin ice would allow ocean water to be affected by radiation from space. Thick ice would limit the heat ocean sources available to the rock-ocean interface at the ocean's bottom due to tidal dissipation and potential radioactive sources. The heat flux structures control the development of geometrical configurations on the Europa's surface like double ridges, ice diapirs, chaos regions because the rheology of ice is temperature dependent (4).Analysis of temperature record of growing ice cover over a pond and water below revealed the importance of solar radiation during the ice growth. If there is no snow cover, a sufficient amount of solar radiation can penetrate through the ice and heat the water below. Due to temperature gradient, there is a heat flux from the water to the ice (Qwi), which may reduce ice growth at the bottom. Details and variables that constrain the heat flux through the ice can be utilized to estimate the ice thickness. We show with this analog analysis provides the forth step towards measurement strategy on the surface of Europa. We identify three types of thermal profiles (5) and fourth with combination of all three mechanisms.References:(1) Barr, A. C., A. P. Showman, 2009, Heat transfer in Europa's icy shell, University of Arizona Press, p. 405-430.(2) Ruiz, J., J. A. Alvarez-Gómez, R. Tejero, and N. Sánchez, 2007, Heat flow and thickness of a convective ice shell on Europa for grain size-dependent rheologies: Icarus, v. 190, p. 145-154.(3) Billings, S. E., S. A. Kattenhorn, 2005, The great thickness debate: Ice shell thickness models for Europa and comparisons with estimates based on flexure at ridges: Icarus, v. 177, p. 397-412.(4) Quick

  19. Revisiting the global surface energy budgets with maximum-entropy-production model of surface heat fluxes

    NASA Astrophysics Data System (ADS)

    Huang, Shih-Yu; Deng, Yi; Wang, Jingfeng

    2017-09-01

    The maximum-entropy-production (MEP) model of surface heat fluxes, based on contemporary non-equilibrium thermodynamics, information theory, and atmospheric turbulence theory, is used to re-estimate the global surface heat fluxes. The MEP model predicted surface fluxes automatically balance the surface energy budgets at all time and space scales without the explicit use of near-surface temperature and moisture gradient, wind speed and surface roughness data. The new MEP-based global annual mean fluxes over the land surface, using input data of surface radiation, temperature data from National Aeronautics and Space Administration-Clouds and the Earth's Radiant Energy System (NASA CERES) supplemented by surface specific humidity data from the Modern-Era Retrospective Analysis for Research and Applications (MERRA), agree closely with previous estimates. The new estimate of ocean evaporation, not using the MERRA reanalysis data as model inputs, is lower than previous estimates, while the new estimate of ocean sensible heat flux is higher than previously reported. The MEP model also produces the first global map of ocean surface heat flux that is not available from existing global reanalysis products.

  20. Optical heat flux gauge

    DOEpatents

    Noel, Bruce W.; Borella, Henry M.; Cates, Michael R.; Turley, W. Dale; MaCarthur, Charles D.; Cala, Gregory C.

    1991-01-01

    A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

  1. Thin Film Heat Flux Sensors: Design and Methodology

    NASA Technical Reports Server (NTRS)

    Fralick, Gustave C.; Wrbanek, John D.

    2013-01-01

    Thin Film Heat Flux Sensors: Design and Methodology: (1) Heat flux is one of a number of parameters, together with pressure, temperature, flow, etc. of interest to engine designers and fluid dynamists, (2) The measurement of heat flux is of interest in directly determining the cooling requirements of hot section blades and vanes, and (3)In addition, if the surface and gas temperatures are known, the measurement of heat flux provides a value for the convective heat transfer coefficient that can be compared with the value provided by CFD codes.

  2. CHROMOSPHERIC HEATING BY ACOUSTIC WAVES COMPARED TO RADIATIVE COOLING

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sobotka, M.; Heinzel, P.; Švanda, M.

    Acoustic and magnetoacoustic waves are among the possible candidate mechanisms that heat the upper layers of the solar atmosphere. A weak chromospheric plage near the large solar pore NOAA 11005 was observed on 2008 October 15, in the Fe i 617.3 nm and Ca ii 853.2 nm lines of the Interferometric Bidimemsional Spectrometer attached to the Dunn Solar Telescope. In analyzing the Ca ii observations (with spatial and temporal resolutions of 0.″4 and 52 s) the energy deposited by acoustic waves is compared to that released by radiative losses. The deposited acoustic flux is estimated from the power spectra ofmore » Doppler oscillations measured in the Ca ii line core. The radiative losses are calculated using a grid of seven one-dimensional hydrostatic semi-empirical model atmospheres. The comparison shows that the spatial correlation of the maps of radiative losses and acoustic flux is 72%. In a quiet chromosphere, the contribution of acoustic energy flux to radiative losses is small, only about 15%. In active areas with a photospheric magnetic-field strength between 300 and 1300 G and an inclination of 20°–60°, the contribution increases from 23% (chromospheric network) to 54% (a plage). However, these values have to be considered as lower limits and it might be possible that the acoustic energy flux is the main contributor to the heating of bright chromospheric network and plages.« less

  3. Chromospheric Heating Driven by Cancellations of Internetwork Magnetic Flux

    NASA Astrophysics Data System (ADS)

    Gosic, M.; de la Cruz Rodriguez, J.; De Pontieu, B.; Bellot Rubio, L.; Esteban Pozuelo, S.; Ortiz-Carbonell, A. N.

    2017-12-01

    The heating of the solar chromosphere remains to be one of the most important questions in solar physics. It is believed that this phenomenon may significantly be supported by small-scale internetwork (IN) magnetic fields. Indeed, cancellations of IN magnetic flux can generate transient brightenings in the chromosphere and transition region. These bright structures might be the signature of energy release and plasma heating, probably driven by magnetic reconnection of IN field lines. Using high resolution, multiwavelength, coordinated observations recorded with the Interface Region Imaging Spectrograph (IRIS) and the Swedish 1-m Solar Telescope (SST), we analyzed cancellations of IN flux and their impact on the energetics and dynamics of the quiet Sun atmosphere. From their temporal and spatial evolution, we determine that these events can heat locally the upper atmospheric layers. However, employing multi-line inversions of the Mg II h & k lines, we show that cancellations, although occurring ubiquitously over IN regions, are not capable of sustaining the total radiative losses of the quiet Sun chromosphere.

  4. Backshell Radiative Heating on Human-Scale Mars Entry Vehicles

    NASA Technical Reports Server (NTRS)

    West,Thomas K., IV; Theisinger, John E.; Brune, Andrew J.; Johnston, Christopher O.

    2017-01-01

    This work quantifies the backshell radiative heating experienced by payloads on human- scale vehicles entering the Martian atmosphere. Three underlying configurations were studied: a generic sphere, a sphere-cone forebody with a cylindrical payload, and an ellipsled. Computational fluid dynamics simulations of the flow field and radiation were performed using the LAURA and HARA codes, respectively. Results of this work indicated the primary contributor to radiative heating is emission from the CO2 IR band system. Furthermore, the backshell radiation component of heating can persist lower than 2 km/s during entry and descent. For the sphere-cone configuration a peak heat flux of about 3.5 W/cm(exp. 2) was observed at the payload juncture during entry. At similar conditions, the ellipsled geometry experienced about 1.25 W/cm(exp. 2) on the backshell, but as much as 8 W/cm(exp. 2) on the base at very high angle of attack. Overall, this study sheds light on the potential magnitudes of backshell radiative heating that various configurations may experience. These results may serve as a starting point for thermal protection system design or configuration changes necessary to accommodate thermal radiation levels.

  5. Cloud Properties and Radiative Heating Rates for TWP

    DOE Data Explorer

    Comstock, Jennifer

    2013-11-07

    A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.

  6. Numerical and experimental analyses of the radiant heat flux produced by quartz heating systems

    NASA Technical Reports Server (NTRS)

    Turner, Travis L.; Ash, Robert L.

    1994-01-01

    A method is developed for predicting the radiant heat flux distribution produced by tungsten filament, tubular fused-quartz envelope heating systems with reflectors. The method is an application of Monte Carlo simulation, which takes the form of a random walk or ray tracing scheme. The method is applied to four systems of increasing complexity, including a single lamp without a reflector, a single lamp with a Hat reflector, a single lamp with a parabolic reflector, and up to six lamps in a six-lamp contoured-reflector heating unit. The application of the Monte Carlo method to the simulation of the thermal radiation generated by these systems is discussed. The procedures for numerical implementation are also presented. Experiments were conducted to study these quartz heating systems and to acquire measurements of the corresponding empirical heat flux distributions for correlation with analysis. The experiments were conducted such that several complicating factors could be isolated and studied sequentially. Comparisons of the experimental results with analysis are presented and discussed. Good agreement between the experimental and simulated results was obtained in all cases. This study shows that this method can be used to analyze very complicated quartz heating systems and can account for factors such as spectral properties, specular reflection from curved surfaces, source enhancement due to reflectors and/or adjacent sources, and interaction with a participating medium in a straightforward manner.

  7. Optical heat flux gauge

    DOEpatents

    Noel, Bruce W.; Borella, Henry M.; Cates, Michael R.; Turley, W. Dale; MacArthur, Charles D.; Cala, Gregory C.

    1991-01-01

    A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator wherein each thermographic layer comprises a plurality of respective thermographic phosphors. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

  8. A heat flux modulator from carbon nanotubes.

    PubMed

    Jiang, Shaohui; Zhang, Guang; Xia, Dan; Liu, Changhong; Fan, Shoushan

    2015-08-28

    For a heat flux modulator, the most difficult problem is that the main carriers named 'phonons' have little response to external fields. Of the existing studies on heat flux modulators, most were theoretical work and the materials systems for the theoretical calculations were artificial lattices. In this paper, we made a heat modulator with ultrathin buckypaper which was made of multi-layer carbon nanotube sheets overlapped together, and achieved an on/off ratio whose value was 1.41 using an pendent block in experiments without special optimizations. When the temperatures of the two sides were of appropriate values, we could even see a negative heat flux. Intuitively, the heat flux was tuned by the gap between the buckypaper and the pendent gate, and we observed that there was heat transferred to the pendent block. The structure of the modulator is similar to a CNT transistor with a contactless gate, hence this type of micromodulator will be easy to manufacture in the future.

  9. Tracking heat flux sensors for concentrating solar applications

    DOEpatents

    Andraka, Charles E; Diver, Jr., Richard B

    2013-06-11

    Innovative tracking heat flux sensors located at or near the solar collector's focus for centering the concentrated image on a receiver assembly. With flux sensors mounted near a receiver's aperture, the flux gradient near the focus of a dish or trough collector can be used to precisely position the focused solar flux on the receiver. The heat flux sensors comprise two closely-coupled thermocouple junctions with opposing electrical polarity that are separated by a thermal resistor. This arrangement creates an electrical signal proportional to heat flux intensity, and largely independent of temperature. The sensors are thermally grounded to allow a temperature difference to develop across the thermal resistor, and are cooled by a heat sink to maintain an acceptable operating temperature.

  10. Radiative Heating in MSL Entry: Comparison of Flight Heating Discrepancy to Ground Test and Predictive Models

    NASA Technical Reports Server (NTRS)

    Cruden, Brett A.; Brandis, Aaron M.; White, Todd R.; Mahzari, Milad; Bose, Deepak

    2014-01-01

    During the recent entry of the Mars Science Laboratory (MSL), the heat shield was equipped with thermocouple stacks to measure in-depth heating of the thermal protection system (TPS). When only convective heating was considered, the derived heat flux from gauges in the stagnation region was found to be underpredicted by as much as 17 W/sq cm, which is significant compared to the peak heating of 32 W/sq cm. In order to quantify the contribution of radiative heating phenomena to the discrepancy, ground tests and predictive simulations that replicated the MSL entry trajectory were performed. An analysis is carried through to assess the quality of the radiation model and the impact to stagnation line heating. The impact is shown to be significant, but does not fully explain the heating discrepancy.

  11. Global Intercomparison of 12 Land Surface Heat Flux Estimates

    NASA Technical Reports Server (NTRS)

    Jimenez, C.; Prigent, C.; Mueller, B.; Seneviratne, S. I.; McCabe, M. F.; Wood, E. F.; Rossow, W. B.; Balsamo, G.; Betts, A. K.; Dirmeyer, P. A.; hide

    2011-01-01

    A global intercomparison of 12 monthly mean land surface heat flux products for the period 1993-1995 is presented. The intercomparison includes some of the first emerging global satellite-based products (developed at Paris Observatory, Max Planck Institute for Biogeochemistry, University of California Berkeley, University of Maryland, and Princeton University) and examples of fluxes produced by reanalyses (ERA-Interim, MERRA, NCEP-DOE) and off-line land surface models (GSWP-2, GLDAS CLM/ Mosaic/Noah). An intercomparison of the global latent heat flux (Q(sub le)) annual means shows a spread of approx 20 W/sq m (all-product global average of approx 45 W/sq m). A similar spread is observed for the sensible (Q(sub h)) and net radiative (R(sub n)) fluxes. In general, the products correlate well with each other, helped by the large seasonal variability and common forcing data for some of the products. Expected spatial distributions related to the major climatic regimes and geographical features are reproduced by all products. Nevertheless, large Q(sub le)and Q(sub h) absolute differences are also observed. The fluxes were spatially averaged for 10 vegetation classes. The larger Q(sub le) differences were observed for the rain forest but, when normalized by mean fluxes, the differences were comparable to other classes. In general, the correlations between Q(sub le) and R(sub n) were higher for the satellite-based products compared with the reanalyses and off-line models. The fluxes were also averaged for 10 selected basins. The seasonality was generally well captured by all products, but large differences in the flux partitioning were observed for some products and basins.

  12. The potential influence of multiple scattering on longwave flux and heating rate simulations with clouds

    NASA Astrophysics Data System (ADS)

    Kuo, C. P.; Yang, P.; Huang, X.; Feldman, D.; Flanner, M.; Kuo, C.; Mlawer, E. J.

    2017-12-01

    Clouds, which cover approximately 67% of the globe, serve as one of the major modulators in adjusting radiative energy on the Earth. Since rigorous radiative transfer computations including multiple scattering are costly, only absorption is considered in the longwave spectral bands in the radiation sub-models of the general circulation models (GCMs). Quantification of the effect of ignoring longwave scattering for flux and heating rate simulations is performed by using the GCM version of the Longwave Rapid Radiative Transfer Model (RRTMG_LW) with an implementation with the 16-stream Discrete Ordinates Radiative Transfer (DISORT) Program for a Multi-Layered Plane-Parallel Medium in conjunction with the 2010 CCCM products that merge satellite observations from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), the CloudSat, the Clouds and the Earth's Radiant Energy System (CERES) and the Moderate Resolution Imaging Spectrometer (MODIS). One-year global simulations show that neglecting longwave scattering overestimates upward flux at the top of the atmosphere (TOA) and underestimates downward flux at the surface by approximately 2.63 and 1.15 W/m2, respectively. Furthermore, when longwave scattering is included in the simulations, the tropopause is cooled by approximately 0.018 K/day and the surface is heated by approximately 0.028 K/day. As a result, the radiative effects of ignoring longwave scattering and doubling CO2 are comparable in magnitude.

  13. A Semi-parametric Multivariate Gap-filling Model for Eddy Covariance Latent Heat Flux

    NASA Astrophysics Data System (ADS)

    Li, M.; Chen, Y.

    2010-12-01

    Quantitative descriptions of latent heat fluxes are important to study the water and energy exchanges between terrestrial ecosystems and the atmosphere. The eddy covariance approaches have been recognized as the most reliable technique for measuring surface fluxes over time scales ranging from hours to years. However, unfavorable micrometeorological conditions, instrument failures, and applicable measurement limitations may cause inevitable flux gaps in time series data. Development and application of suitable gap-filling techniques are crucial to estimate long term fluxes. In this study, a semi-parametric multivariate gap-filling model was developed to fill latent heat flux gaps for eddy covariance measurements. Our approach combines the advantages of a multivariate statistical analysis (principal component analysis, PCA) and a nonlinear interpolation technique (K-nearest-neighbors, KNN). The PCA method was first used to resolve the multicollinearity relationships among various hydrometeorological factors, such as radiation, soil moisture deficit, LAI, and wind speed. The KNN method was then applied as a nonlinear interpolation tool to estimate the flux gaps as the weighted sum latent heat fluxes with the K-nearest distances in the PCs’ domain. Two years, 2008 and 2009, of eddy covariance and hydrometeorological data from a subtropical mixed evergreen forest (the Lien-Hua-Chih Site) were collected to calibrate and validate the proposed approach with artificial gaps after standard QC/QA procedures. The optimal K values and weighting factors were determined by the maximum likelihood test. The results of gap-filled latent heat fluxes conclude that developed model successful preserving energy balances of daily, monthly, and yearly time scales. Annual amounts of evapotranspiration from this study forest were 747 mm and 708 mm for 2008 and 2009, respectively. Nocturnal evapotranspiration was estimated with filled gaps and results are comparable with other studies

  14. Structures for handling high heat fluxes

    NASA Astrophysics Data System (ADS)

    Watson, R. D.

    1990-12-01

    The divertor is reconized as one of the main performance limiting components for ITER. This paper reviews the critical issues for structures that are designed to withstand heat fluxes > 5 MW/m 2. High velocity, sub-cooled water with twisted tape inserts for enhanced heat transfer provides a critical heat flux limit of 40-60 MW/m 2. Uncertainties in physics and engineering heat flux peaking factors require that the design heat flux not exceed 10 MW/m 2 to maintain an adequate burnout safety margin. Armor tiles and heat sink materials must have a well matched thermal expansion coefficient to minimize stresses. The divertor lifetime from sputtering erosion is highly uncertain. The number of disruptions specified for ITER must be reduced to achieve a credible design. In-situ plasma spray repair with thick metallic coatings may reduce the problems of erosion. Runaway electrons in ITER have the potential to melt actively cooled components in a single event. A water leak is a serious accident because of steam reactions with hot carbon, beryllium, or tungsten that can mobilize large amounts of tritium and radioactive elements. If the plasma does not shutdown immediately, the divertor can melt in 1-10 s after a loss of coolant accident. Very high reliability of carbon tile braze joints will be required to achieve adequate safety and performance goals. Most of these critical issues will be addressed in the near future by operation of the Tore Supra pump limiters and the JET pumped divertor. An accurate understanding of the power flow out of edge of a DT burning plasma is essential to successful design of high heat flux components.

  15. Effect of a finite ionization rate on the radiative heating of outer planet atmospheric entry probes

    NASA Technical Reports Server (NTRS)

    Nelson, H. F.

    1981-01-01

    The influence of finite rate ionization in the inviscid gas just behind the stagnation shock wave on the radiation heating of probes entering the hydrogen helium atmospere of the major planets was investigated. At the present time, there is disagreement as to whether the radiative flux increases or decreases relative to its equilibrium value when finite rate ionization is considered. Leibowitz and Kuo content that the finite rate ionization in the hydrogen gas just behind the shock wave reduces the radiative flux to the probe, whereas Tiwari and Szema predict that it increases the radiative flux. The radiation modeling used in the calculations of both pairs of these investigators was reviewed. It is concluded that finite rate ionization in the inviscid region of the shock layer should reduce the cold wall radiative heating below the values predicted by equilibrium chemistry assumptions.

  16. Experiments of Transient Condensation Heat Transfer on the Heat Flux Senor

    NASA Astrophysics Data System (ADS)

    Wang, Xuwen; Liu, Qiusheng; Zhu, Zhiqiang; Chen, Xue

    2015-09-01

    The influence of transient heat transfer in different condensation condition was investigated experimentally in the present paper. Getting condensation heat and mass transfer regularity and characteristics in space can provide theoretical basis for thermodynamic device such as heat pipes, loop heat pipes and capillary pumped loops as well as other fluid management engineering designing. In order to study the condensation process in space, an experimental study has been carried out on the ground for space experiment. The results show that transit heat transfer coefficient of film condensation is related to the condensation film width, the flow condition near the two phase interface and the pressure of the vapor and non-condensable gas in chamber. On the ground, the condensation heat flux on vertical surface is higher than it on horizontal surface. The transit heat flux of film condensation is affected by the temperature of superheated vapor, the temperature of condensation surface and non-condensable gas pressure. Condensation heat flux with vapor forced convection is many times more than it with natural convection. All of heat flux for both vapor forced convection and natural convection condensation in limited chamber declines dramatically over time. The present experiment is preliminary work for our future space experiments of the condensation and heat transfer process onboard the Chinese Spacecraft "TZ-1" to be launched in 2016.

  17. Optical heat flux gauge

    DOEpatents

    Noel, Bruce W.; Borella, Henry M.; Cates, Michael R.; Turley, W. Dale; MacArthur, Charles D.; Cala, Gregory C.

    1991-01-01

    A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

  18. Experimental Performance of a Micromachined Heat Flux Sensor

    NASA Technical Reports Server (NTRS)

    Stefanescu, S.; DeAnna, R. G.; Mehregany, M.

    1998-01-01

    Steady-state and frequency response calibration of a microfabricated heat-flux sensor have been completed. This sensor is batch fabricated using standard, micromachining techniques, allowing both miniaturization and the ability to create arrays of sensors and their corresponding interconnects. Both high-frequency and spatial response is desired, so the sensors are both thin and of small cross-sectional area. Thin-film, temperature-sensitive resistors are used as the active gauge elements. Two sensor configurations are investigated: (1) a Wheatstone-bridge using four resistors; and (2) a simple, two-resistor design. In each design, one resistor (or pair) is covered by a thin layer (5000 A) thermal barrier; the other resistor (or pair) is covered by a thick (5 microns) thermal barrier. The active area of a single resistor is 360 microns by 360 microns; the total gauge area is 1.5 mm square. The resistors are made of 2000 A-thick metal; and the entire gauge is fabricated on a 25 microns-thick flexible, polyimide substrate. Heat flux through the surface changes the temperature of the resistors and produces a corresponding change in resistance. Sensors were calibrated using two radiation heat sources: (1) a furnace for steady-state, and (2) a light and chopper for frequency response.

  19. Influence of snow cover changes on surface radiation and heat balance based on the WRF model

    NASA Astrophysics Data System (ADS)

    Yu, Lingxue; Liu, Tingxiang; Bu, Kun; Yang, Jiuchun; Chang, Liping; Zhang, Shuwen

    2017-10-01

    The snow cover extent in mid-high latitude areas of the Northern Hemisphere has significantly declined corresponding to the global warming, especially since the 1970s. Snow-climate feedbacks play a critical role in regulating the global radiation balance and influencing surface heat flux exchange. However, the degree to which snow cover changes affect the radiation budget and energy balance on a regional scale and the difference between snow-climate and land use/cover change (LUCC)-climate feedbacks have been rarely studied. In this paper, we selected Heilongjiang Basin, where the snow cover has changed obviously, as our study area and used the WRF model to simulate the influences of snow cover changes on the surface radiation budget and heat balance. In the scenario simulation, the localized surface parameter data improved the accuracy by 10 % compared with the control group. The spatial and temporal analysis of the surface variables showed that the net surface radiation, sensible heat flux, Bowen ratio, temperature and percentage of snow cover were negatively correlated and that the ground heat flux and latent heat flux were positively correlated with the percentage of snow cover. The spatial analysis also showed that a significant relationship existed between the surface variables and land cover types, which was not obviously as that for snow cover changes. Finally, six typical study areas were selected to quantitatively analyse the influence of land cover types beneath the snow cover on heat absorption and transfer, which showed that when the land was snow covered, the conversion of forest to farmland can dramatically influence the net radiation and other surface variables, whereas the snow-free land showed significantly reduced influence. Furthermore, compared with typical land cover changes, e.g., the conversion of forest into farmland, the influence of snow cover changes on net radiation and sensible heat flux were 60 % higher than that of land cover changes

  20. Effects of Mixed Layer Shear on Vertical Heat Flux

    DTIC Science & Technology

    2016-12-01

    correlation of ice speed to heat flux (r = .312, p < .001). Relationships between ice speed and shear (r = .107, p < .001), ice speed and inverse ...Richardson number (r = .035, p = .256), inverse Richardson number and heat flux (r = .3, p < .001), heat content and heat flux (r = .084, p < .001) were...correlation of ice speed to heat flux (r = .312, p < .001). Relationships between ice speed and shear (r = .107, p < .001), ice speed and inverse Richardson

  1. Spatialization of instantaneous and daily average net radiation and soil heat flux in the territory of Itaparica, Northeast Brazil

    NASA Astrophysics Data System (ADS)

    Lopes, Helio L.; Silva, Bernardo B.; Teixeira, Antônio H. C.; Accioly, Luciano J. O.

    2012-09-01

    This work has as aim to quantify the energy changes between atmosphere and surface by modeling both net radiation and soil heat flux related to land use and cover. The methodology took into account modeling and mapping of physical and biophysical parameters using MODIS images and SEBAL algorithm in an area of native vegetation and irrigated crops. The results showed that there are variations in the values of the estimated parameters for different land cover types and mainly in caatinga cover. The dense caatinga presents mean values of soil heat flux (Go) of 124.9 Wm-2 while sparse caatinga with incidence of erosion, present average value of 132.6 Wm-2. For irrigated plots cultivated with banana, coconut, and papaya the mean Go values were 103.8, 98.6, 113.9 Wm-2, respectively. With regard to the instantaneous net radiation (Rn), dense caatinga presented mean value of 626.1 Wm-2, while sparse caatinga a mean value of 575.2 Wm-2. Irrigated areas cultivated with banana, coconut, and papaya presented Rn of 658.1, 647.4 and 617.9 W m-2 respectively. Applying daily mean net radiation (RnDAve) it was found that dense caatinga had a mean value of 417.1 W m-2, while sparse caatinga had a mean value of 379.9 W m-2. For the irrigated crops of banana, coconut and papaya the RnDAve values were 430.9, 431.3 and 411.6 W m-2, respectively. Sinusoidal model can be applied to determine the maximum and RnDAve considering the diverse classes of LULC; however, there is a need to compare the results with field data for validation of this model.

  2. Solar Flux Deposition And Heating Rates In Jupiter's Atmosphere

    NASA Astrophysics Data System (ADS)

    Perez-Hoyos, Santiago; Sánchez-Lavega, A.

    2009-09-01

    We discuss here the solar downward net flux in the 0.25 - 2.5 µm range in the atmosphere of Jupiter and the associated heating rates under a number of vertical cloud structure scenarios focusing in the effect of clouds and hazes. Our numerical model is based in the doubling-adding technique to solve the radiative transfer equation and it includes gas absorption by CH4, NH3 and H2, in addition to Rayleigh scattering by a mixture of H2 plus He. Four paradigmatic Jovian regions have been considered (hot-spots, belts, zones and Polar Regions). The hot-spots are the most transparent regions with downward net fluxes of 2.5±0.5 Wm-2 at the 6 bar level. The maximum solar heating is 0.04±0.01 K/day and occurs above 1 bar. Belts and zones characterization result in a maximum net downward flux of 0.5 Wm-2 at 2 bar and 0.015 Wm-2 at 6 bar. Heating is concentrated in the stratospheric and tropospheric hazes. Finally, Polar Regions are also explored and the results point to a considerable stratospheric heating of 0.04±0.02 K/day. In all, these calculations suggest that the role of the direct solar forcing in the Jovian atmospheric dynamics is limited to the upper 1 - 2 bar of the atmosphere except in the hot-spot areas. Acknowledgments: This work has been funded by Spanish MEC AYA2006-07735 with FEDER support and Grupos Gobierno Vasco IT-464-07.

  3. Parallel-plate submicron gap formed by micromachined low-density pillars for near-field radiative heat transfer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ito, Kota, E-mail: kotaito@mosk.tytlabs.co.jp; Research Center for Advanced Science and Technology; Miura, Atsushi

    Near-field radiative heat transfer has been a subject of great interest due to the applicability to thermal management and energy conversion. In this letter, a submicron gap between a pair of diced fused quartz substrates is formed by using micromachined low-density pillars to obtain both the parallelism and small parasitic heat conduction. The gap uniformity is validated by the optical interferometry at four corners of the substrates. The heat flux across the gap is measured in a steady-state and is no greater than twice of theoretically predicted radiative heat flux, which indicates that the parasitic heat conduction is suppressed tomore » the level of the radiative heat transfer or less. The heat conduction through the pillars is modeled, and it is found to be limited by the thermal contact resistance between the pillar top and the opposing substrate surface. The methodology to form and evaluate the gap promotes the near-field radiative heat transfer to various applications such as thermal rectification, thermal modulation, and thermophotovoltaics.« less

  4. Oxy-fuel combustion of coal and biomass, the effect on radiative and convective heat transfer and burnout

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smart, John P.; Patel, Rajeshriben; Riley, Gerry S.

    This paper focuses on results of co-firing coal and biomass under oxy-fuel combustion conditions on the RWEn 0.5 MWt Combustion Test Facility (CTF). Results are presented of radiative and convective heat transfer and burnout measurements. Two coals were fired: a South African coal and a Russian Coal under air and oxy-fuel firing conditions. The two coals were also co-fired with Shea Meal at a co-firing mass fraction of 20%. Shea Meal was also co-fired at a mass fraction of 40% and sawdust at 20% with the Russian Coal. An IFRF Aerodynamically Air Staged Burner (AASB) was used. The thermal inputmore » was maintained at 0.5 MWt for all conditions studied. The test matrix comprised of varying the Recycle Ratio (RR) between 65% and 75% and furnace exit O{sub 2} was maintained at 3%. Carbon-in-ash samples for burnout determination were also taken. Results show that the highest peak radiative heat flux and highest flame luminosity corresponded to the lowest recycle ratio. The effect of co-firing of biomass resulted in lower radiative heat fluxes for corresponding recycle ratios. Furthermore, the highest levels of radiative heat flux corresponded to the lowest convective heat flux. Results are compared to air firing and the air equivalent radiative and convective heat fluxes are fuel type dependent. Reasons for these differences are discussed in the main text. Burnout improves with biomass co-firing under both air and oxy-fuel firing conditions and burnout is also seen to improve under oxy-fuel firing conditions compared to air. (author)« less

  5. A novel approach to evaluate soil heat flux calculation: An analytical review of nine methods: Soil Heat Flux Calculation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gao, Zhongming; Russell, Eric S.; Missik, Justine E. C.

    We evaluated nine methods of soil heat flux calculation using field observations. All nine methods underestimated the soil heat flux by at least 19%. This large underestimation is mainly caused by uncertainties in soil thermal properties.

  6. Optical heat flux gauge

    DOEpatents

    Noel, B.W.; Borella, H.M.; Cates, M.R.; Turley, W.D.; MacArthur, C.D.; Cala, G.C.

    1991-04-09

    A heat flux gauge is disclosed comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable. 9 figures.

  7. Nonlinear fluid simulation of particle and heat fluxes during burst of ELMs on DIII-D with BOUT++ code [Fluid Simulation of Particle and Heat Fluxes during Burst of ELMs on DIID with BOUT++ code

    DOE PAGES

    Xia, T. Y.; Xu, X. Q.

    2015-09-01

    In order to study the distribution and evolution of the transient particle and heat fluxes during edge-localized mode (ELM) bursts, a BOUT++ six-field two-fluid model based on the Braginskii equations with non-ideal physics effects is used to simulate pedestal collapse in divertor geometry. We used the profiles from the DIII-D H-mode discharge #144382 with fast target heat flux measurements as the initial conditions for the simulations. Moreover, a flux-limited parallel thermal conduction is used with three values of the flux-limiting coefficientmore » $${{\\alpha}_{j}}$$ , free streaming model with $${{\\alpha}_{j}}=1$$ , sheath-limit with $${{\\alpha}_{j}}=0.05$$ , and one value in between. The studies show that a 20 times increase in $${{\\alpha}_{j}}$$ leads to ~6 times increase in the heat flux amplitude to both the inner and outer targets, and the widths of the fluxes are also expanded. The sheath-limit model of flux-limiting coefficient is found to be the most appropriate one, which shows ELM sizes close to the measurements. The evolution of the density profile during the burst of ELMs of DIII-D discharge #144382 is simulated, and the collapse in width and depth of $${{n}_{\\text{e}}}$$ are reproduced at different time steps. The growing process of the profiles for the heat flux at divertor targets during the burst of ELMs measured by IRTV (infrared television) is also reproduced by this model. The widths of heat fluxes towards targets are a little narrower, and the peak amplitudes are twice the measurements possibly due to the lack of a model of divertor radiation which can effectively reduce the heat fluxes. The magnetic flutter combined with parallel thermal conduction is found to be able to increase the total heat loss by around 33% since the magnetic flutter terms provide the additional conductive heat transport in the radial direction. Finally, the heat flux profile at both the inner and outer targets is obviously broadened by magnetic flutter. The

  8. The radiation budget of stratocumulus clouds measured by tethered balloon instrumentation: Variability of flux measurements

    NASA Technical Reports Server (NTRS)

    Duda, David P.; Stephens, Graeme L.; Cox, Stephen K.

    1990-01-01

    Measurements of longwave and shortwave radiation were made using an instrument package on the NASA tethered balloon during the FIRE Marine Stratocumulus experiment. Radiation data from two pairs of pyranometers were used to obtain vertical profiles of the near-infrared and total solar fluxes through the boundary layer, while a pair of pyrgeometers supplied measurements of the longwave fluxes in the cloud layer. The radiation observations were analyzed to determine heating rates and to measure the radiative energy budget inside the stratocumulus clouds during several tethered balloon flights. The radiation fields in the cloud layer were also simulated by a two-stream radiative transfer model, which used cloud optical properties derived from microphysical measurements and Mie scattering theory.

  9. High heat flux measurements and experimental calibrations/characterizations

    NASA Technical Reports Server (NTRS)

    Kidd, Carl T.

    1992-01-01

    Recent progress in techniques employed in the measurement of very high heat-transfer rates in reentry-type facilities at the Arnold Engineering Development Center (AEDC) is described. These advances include thermal analyses applied to transducer concepts used to make these measurements; improved heat-flux sensor fabrication methods, equipment, and procedures for determining the experimental time response of individual sensors; performance of absolute heat-flux calibrations at levels above 2,000 Btu/cu ft-sec (2.27 kW/cu cm); and innovative methods of performing in-situ run-to-run characterizations of heat-flux probes installed in the test facility. Graphical illustrations of the results of extensive thermal analyses of the null-point calorimeter and coaxial surface thermocouple concepts with application to measurements in aerothermal test environments are presented. Results of time response experiments and absolute calibrations of null-point calorimeters and coaxial thermocouples performed in the laboratory at intermediate to high heat-flux levels are shown. Typical AEDC high-enthalpy arc heater heat-flux data recently obtained with a Calspan-fabricated null-point probe model are included.

  10. Simplified model for determining local heat flux boundary conditions for slagging wall

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bingzhi Li; Anders Brink; Mikko Hupa

    2009-07-15

    In this work, two models for calculating heat transfer through a cooled vertical wall covered with a running slag layer are investigated. The first one relies on a discretization of the velocity equation, and the second one relies on an analytical solution. The aim is to find a model that can be used for calculating local heat flux boundary conditions in computational fluid dynamics (CFD) analysis of such processes. Two different cases where molten deposits exist are investigated: the black liquor recovery boiler and the coal gasifier. The results show that a model relying on discretization of the velocity equationmore » is more flexible in handling different temperature-viscosity relations. Nevertheless, a model relying on an analytical solution is the one fast enough for a potential use as a CFD submodel. Furthermore, the influence of simplifications to the heat balance in the model is investigated. It is found that simplification of the heat balance can be applied when the radiation heat flux is dominant in the balance. 9 refs., 7 figs., 10 tabs.« less

  11. Forced Convection Boiling and Critical Heat Flux of Ethanol in Electrically Heated Tube Tests

    NASA Technical Reports Server (NTRS)

    Meyer, Michael L.; Linne, Diane L.; Rousar, Donald C.

    1998-01-01

    Electrically heated tube tests were conducted to characterize the critical heat flux (transition from nucleate to film boiling) of subcritical ethanol flowing at conditions relevant to the design of a regeneratively cooled rocket engine thrust chamber. The coolant was SDA-3C alcohol (95% ethyl alcohol, 5% isopropyl alcohol by weight), and tests were conducted over the following ranges of conditions: pressure from 144 to 703 psia, flow velocities from 9.7 to 77 ft/s, coolant subcooling from 33 to 362 F, and critical heat fluxes up to 8.7 BTU/in(exp 2)/sec. For the data taken near 200 psia, critical heat flux was correlated as a function of the product of velocity and fluid subcooling to within +/- 20%. For data taken at higher pressures, an additional pressure term is needed to correlate the critical heat flux. It was also shown that at the higher test pressures and/or flow rates, exceeding the critical heat flux did not result in wall burnout. This result may significantly increase the engine heat flux design envelope for higher pressure conditions.

  12. Maximal near-field radiative heat transfer between two plates

    NASA Astrophysics Data System (ADS)

    Nefzaoui, Elyes; Ezzahri, Younès; Drévillon, Jérémie; Joulain, Karl

    2013-09-01

    Near-field radiative transfer is a promising way to significantly and simultaneously enhance both thermo-photovoltaic (TPV) devices power densities and efficiencies. A parametric study of Drude and Lorentz models performances in maximizing near-field radiative heat transfer between two semi-infinite planes separated by nanometric distances at room temperature is presented in this paper. Optimal parameters of these models that provide optical properties maximizing the radiative heat flux are reported and compared to real materials usually considered in similar studies, silicon carbide and heavily doped silicon in this case. Results are obtained by exact and approximate (in the extreme near-field regime and the electrostatic limit hypothesis) calculations. The two methods are compared in terms of accuracy and CPU resources consumption. Their differences are explained according to a mesoscopic description of nearfield radiative heat transfer. Finally, the frequently assumed hypothesis which states a maximal radiative heat transfer when the two semi-infinite planes are of identical materials is numerically confirmed. Its subsequent practical constraints are then discussed. Presented results enlighten relevant paths to follow in order to choose or design materials maximizing nano-TPV devices performances.

  13. Heat Flux Sensors for Infrared Thermography in Convective Heat Transfer

    PubMed Central

    Carlomagno, Giovanni Maria; de Luca, Luigi; Cardone, Gennaro; Astarita, Tommaso

    2014-01-01

    This paper reviews the most dependable heat flux sensors, which can be used with InfraRed (IR) thermography to measure convective heat transfer coefficient distributions, and some of their applications performed by the authors' research group at the University of Naples Federico II. After recalling the basic principles that make IR thermography work, the various heat flux sensors to be used with it are presented and discussed, describing their capability to investigate complex thermo-fluid-dynamic flows. Several applications to streams, which range from natural convection to hypersonic flows, are also described. PMID:25386758

  14. Evaluation of radiative fluxes over the north Indian Ocean

    NASA Astrophysics Data System (ADS)

    Ramesh Kumar, M. R.; Pinker, Rachel T.; Mathew, Simi; Venkatesan, R.; Chen, W.

    2018-05-01

    Radiative fluxes are a key component of the surface heat budget of the oceans. Yet, observations over oceanic region are sparse due to the complexity of radiation measurements; moreover, certain oceanic regions are substantially under-sampled, such as the north Indian Ocean. The National Institute of Ocean Technology, Chennai, India, under its Ocean Observation Program has deployed an Ocean Moored Network for the Northern Indian Ocean (OMNI) both in the Arabian Sea and the Bay of Bengal. These buoys are equipped with sensors to measure radiation and rainfall, in addition to other basic meteorological parameters. They are also equipped with sensors to measure sub-surface currents, temperature, and conductivity from the surface up to a depth of 500 m. Observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the National Aeronautics and Space Administration (NASA) AQUA and TERRA satellites have been used to infer surface radiation over the north Indian Ocean. In this study, we focus only on the shortwave (SW↓) fluxes. The evaluations of the MODIS-based SW↓ fluxes against the RAMA observing network have shown a very good agreement between them, and therefore, we use the MODIS-derived fluxes as a reference for the evaluation of the OMNI observations. In an early deployment of the OMNI buoys, the radiation sensors were placed at 2 m above the sea surface; subsequently, the height of the sensors was raised to 3 m. In this study, we show that there was a substantial improvement in the agreement between the buoy observations and the satellite estimates, once the sensors were raised to higher levels. The correlation coefficient increased from 0.87 to 0.93, and both the bias and standard deviations decreased substantially.

  15. Effect of Particle Size Distribution on Wall Heat Flux in Pulverized-Coal Furnaces and Boilers

    NASA Astrophysics Data System (ADS)

    Lu, Jun

    A mathematical model of combustion and heat transfer within a cylindrical enclosure firing pulverized coal has been developed and tested against two sets of measured data (one is 1993 WSU/DECO Pilot test data, the other one is the International Flame Research Foundation 1964 Test (Beer, 1964)) and one independent code FURN3D from the Argonne National Laboratory (Ahluwalia and IM, 1992). The model called PILC assumes that the system is a sequence of many well-stirred reactors. A char burnout model combining diffusion to the particle surface, pore diffusion, and surface reaction is employed for predicting the char reaction, heat release, and evolution of char. The ash formation model included relates the ash particle size distribution to the particle size distribution of pulverized coal. The optical constants of char and ash particles are calculated from dispersion relations derived from reflectivity, transmissivity and extinction measurements. The Mie theory is applied to determine the extinction and scattering coefficients. The radiation heat transfer is modeled using the virtual zone method, which leads to a set of simultaneous nonlinear algebraic equations for the temperature field within the furnace and on its walls. This enables the heat fluxes to be evaluated. In comparisons with the experimental data and one independent code, the model is successful in predicting gas temperature, wall temperature, and wall radiative flux. When the coal with greater fineness is burnt, the particle size of pulverized coal has a consistent influence on combustion performance: the temperature peak was higher and nearer to burner, the radiation flux to combustor wall increased, and also the absorption and scattering coefficients of the combustion products increased. The effect of coal particle size distribution on absorption and scattering coefficients and wall heat flux is significant. But there is only a small effect on gas temperature and fuel fraction burned; it is speculated

  16. Corrections of Heat Flux Measurements on Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Reinarts, Thomas R.; Matson, Monique L.; Walls, Laurie K.

    2002-01-01

    Knowledge of aerothermally induced convective heat transfer is important in the design of thermal protection systems for launch vehicles. Aerothermal models are typically calibrated via the data from circular, in-flight, flush-mounted surface heat flux gauges exposed to the thermal and velocity boundary layers of the external flow. Typically, copper or aluminum Schmidt- Boelter gauges, which take advantage of the one-dimensional Fourier's law of heat conduction, are used to measure the incident heat flux. This instrumentation, when surrounded by low-conductivity insulation, has a wall temperature significantly lower than the insulation. As a result of this substantial disturbance to the thermal boundary layer, the heat flux incident on the gauge tends to be considerably higher than it would have been on the insulation had the calorimeter not been there. In addition, radial conductive heat transfer from the hotter insulation can cause the calorimeter to indicate heat fluxes higher than actual. An overview of an effort to develop and calibrate gauge correction techniques for both of these effects will be presented.

  17. Measuring Subsurface Water Fluxes Using a Heat Pulse Sensor

    NASA Astrophysics Data System (ADS)

    Ochsner, T. E.; Wang, Q.; Horton, R.

    2001-12-01

    Subsurface water flux is an important parameter in studies of runoff, infiltration, groundwater recharge, and subsurface chemical transport. Heat pulse sensors have been proposed as promising tools for measuring subsurface water fluxes. Our heat pulse probe consists of three 4-cm stainless-steel needles embedded in a waterproof epoxy body. The needles contain resistance heaters and thermocouples. The probes are connected to an external datalogger and power supply and then installed in soil. To measure the water flux, a 15-s heat pulse is generated at the middle needle using the power supply and the resistance heater, and the temperature increases at the needles 6-mm upstream and downstream from the heater are recorded using the thermocouples and datalogger. To date, heat pulse methods have required cumbersome mathematical analysis to calculate soil water flux from this measured data. We present a new mathematical analysis showing that a simple relationship exists between water flux and the ratio of the temperature increase downstream from the line heat source to the temperature increase upstream from the line heat source. The simplicity of this relationship makes heat pulse sensors a more attractive option for measuring subsurface water fluxes.

  18. Radiative Flux Analysis

    DOE Data Explorer

    Long, Chuck [NOAA

    2008-05-14

    The Radiative Flux Analysis is a technique for using surface broadband radiation measurements for detecting periods of clear (i.e. cloudless) skies, and using the detected clear-sky data to fit functions which are then used to produce continuous clear-sky estimates. The clear-sky estimates and measurements are then used in various ways to infer cloud macrophysical properties.

  19. A new one-dimensional radiative equilibrium model for investigating atmospheric radiation entropy flux.

    PubMed

    Wu, Wei; Liu, Yangang

    2010-05-12

    A new one-dimensional radiative equilibrium model is built to analytically evaluate the vertical profile of the Earth's atmospheric radiation entropy flux under the assumption that atmospheric longwave radiation emission behaves as a greybody and shortwave radiation as a diluted blackbody. Results show that both the atmospheric shortwave and net longwave radiation entropy fluxes increase with altitude, and the latter is about one order in magnitude greater than the former. The vertical profile of the atmospheric net radiation entropy flux follows approximately that of the atmospheric net longwave radiation entropy flux. Sensitivity study further reveals that a 'darker' atmosphere with a larger overall atmospheric longwave optical depth exhibits a smaller net radiation entropy flux at all altitudes, suggesting an intrinsic connection between the atmospheric net radiation entropy flux and the overall atmospheric longwave optical depth. These results indicate that the overall strength of the atmospheric irreversible processes at all altitudes as determined by the corresponding atmospheric net entropy flux is closely related to the amount of greenhouse gases in the atmosphere.

  20. Applications of Radiative Heating for Space Exploration

    NASA Technical Reports Server (NTRS)

    Brandis, Aaron

    2017-01-01

    Vehicles entering planetary atmospheres at high speeds (6 - 12 kms) experience intense heating by flows with temperatures of the order 10 000K. The flow around the vehicle experiences significant dissociation and ionization and is characterized by thermal and chemical non-equilibrium near the shock front, relaxing toward equilibrium. Emission from the plasma is intense enough to impart a significant heat flux on the entering spacecraft, making it necessary to predict the magnitude of radiative heating. Shock tubes represent a unique method capable of characterizing these processes in a flight-similar environment. The Electric Arc Shock tube (EAST) facility is one of the only facilities in its class, able to produce hypersonic flows at speeds up to Mach 50. This talk will review the characterization of radiation measured in EAST with simulations by the codes DPLR and NEQAIR, and in particular, focus on the impact these analyses have on recent missions to explore the solar system.

  1. Diamond Microchannel Heat Sink Designs For High Heat Flux Thermal Control

    NASA Astrophysics Data System (ADS)

    Corbin, Michael V.; DeBenedictis, Matthew M.; James, David B.; LeBlanc, Stephen P.; Paradis, Leo R.

    2002-08-01

    Directed energy weapons, wide band gap semiconductor based radars, and other powerful systems present significant thermal control challenges to component designers. heat Flux levels approaching 2000 W/cm(2) are encountered at the base of laser diodes, and levels as high as 500 WI /cm(2) are expected in laser slabs and power amplifier tube collectors. These impressive heat flux levels frequently combine with strict operating temperature requirements to further compound the thermal control problem. Many investigators have suggested the use of diamond heat spreaders to reduce flux levels at or near to its source, and some have suggested that diamond microchannel heat sinks ultimately may play a significant role in the solution of these problems. Design engineers at Raytheon Company have investigated the application of all-diamond microchannel heat sinks to representative high heat flux problems and have found the approach promising. Diamond microchannel fabrication feasibility has been demonstrated; integration into packaging systems and the accompanying material compatibility issues have been addressed; and thermal and hydrodynamic performance predictions have been made for selected, possible applications. An example of a practical, all diamond microchannel heat sink has been fabricated, and another is in process and will be performance tested. The heat sink assembly is made entirely of optical quality, CVD diamond and is of sufficient strength to withstand the thermal and pressure-induced mechanical loads associated with manufacture and use in tactical weapons environment. The work presented describes the development program's accomplishments to date, and highlights many of the areas for future study.

  2. Quantitative method for measuring heat flux emitted from a cryogenic object

    DOEpatents

    Duncan, Robert V.

    1993-01-01

    The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infra-red sensing devices.

  3. Quantitative method for measuring heat flux emitted from a cryogenic object

    DOEpatents

    Duncan, R.V.

    1993-03-16

    The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

  4. Radiative Heat Transfer in Finite Cylindrical Enclosures with Nonhomogeneous Participating Media

    NASA Technical Reports Server (NTRS)

    Hsu, Pei-Feng; Ku, Jerry C.

    1994-01-01

    Results of a numerical solution for radiative heat transfer in homogeneous and nonhomogeneous participating media are presented. The geometry of interest is a finite axisymmetric cylindrical enclosure. The integral formulation for radiative transport is solved by the YIX method. A three-dimensional solution scheme is applied to two-dimensional axisymmetric geometry to simplify kernel calculations and to avoid difficulties associated with treating boundary conditions. As part of the effort to improve modeling capabilities for turbulent jet diffusion flames, predicted distributions for flame temperature and soot volume fraction are used to calculate radiative heat transfer from soot particles in such flames. It is shown that the nonhomogeneity of radiative property has very significant effects. The peak value of the divergence of radiative heat flux could be underestimated by 2 factor of 7 if a mean homogeneous radiative property is used. Since recent studies have shown that scattering by soot agglomerates is significant in flames, the effect of magnitude of scattering is also investigated and found to be nonnegligible.

  5. Tropical Gravity Wave Momentum Fluxes and Latent Heating Distributions

    NASA Technical Reports Server (NTRS)

    Geller, Marvin A.; Zhou, Tiehan; Love, Peter T.

    2015-01-01

    Recent satellite determinations of global distributions of absolute gravity wave (GW) momentum fluxes in the lower stratosphere show maxima over the summer subtropical continents and little evidence of GW momentum fluxes associated with the intertropical convergence zone (ITCZ). This seems to be at odds with parameterizations forGWmomentum fluxes, where the source is a function of latent heating rates, which are largest in the region of the ITCZ in terms of monthly averages. The authors have examined global distributions of atmospheric latent heating, cloud-top-pressure altitudes, and lower-stratosphere absolute GW momentum fluxes and have found that monthly averages of the lower-stratosphere GW momentum fluxes more closely resemble the monthly mean cloud-top altitudes rather than the monthly mean rates of latent heating. These regions of highest cloud-top altitudes occur when rates of latent heating are largest on the time scale of cloud growth. This, plus previously published studies, suggests that convective sources for stratospheric GW momentum fluxes, being a function of the rate of latent heating, will require either a climate model to correctly model this rate of latent heating or some ad hoc adjustments to account for shortcomings in a climate model's land-sea differences in convective latent heating.

  6. Relationships between outgoing longwave radiation and diabatic heating in reanalyses

    NASA Astrophysics Data System (ADS)

    Zhang, Kai; Randel, William J.; Fu, Rong

    2017-10-01

    This study investigates relationships between daily variability in National Oceanographic and Atmospheric Administration (NOAA) outgoing longwave radiation (OLR), as a proxy for deep convection, and the global diabatic heat budget derived from reanalysis data sets. Results are evaluated based on data from ECMWF Reanalysis (ERA-Interim), Japanese 55-year Reanalysis (JRA-55) and Modern-Era Retrospective Analysis for Research and Applications (MERRA2). The diabatic heating is separated into components linked to `physics' (mainly latent heat fluxes), plus longwave (LW) and shortwave (SW) radiative tendencies. Transient variability in deep convection is highly correlated with diabatic heating throughout the troposphere and stratosphere. Correlation patterns and composite analyses show that enhanced deep convection (lower OLR) is linked to amplified heating in the tropical troposphere and in the mid-latitude storm tracks, tied to latent heat release. Enhanced convection is also linked to radiative cooling in the lower stratosphere, due to weaker upwelling LW from lower altitudes. Enhanced transient deep convection increases LW and decreases SW radiation in the lower troposphere, with opposite effects in the mid to upper troposphere. The compensating effects in LW and SW radiation are largely linked to variations in cloud fraction and water content (vapor, liquid and ice). These radiative balances in reanalyses are in agreement with idealized calculations using a column radiative transfer model. The overall relationships between OLR and diabatic heating are robust among the different reanalyses, although there are differences in radiative tendencies in the tropics due to large differences of cloud water and ice content among the reanalyses. These calculations provide a simple statistical method to quantify variations in diabatic heating linked to transient deep convection in the climate system.

  7. Evaluation of bulk heat fluxes from atmospheric datasets

    NASA Astrophysics Data System (ADS)

    Farmer, Benton

    Heat fluxes at the air-sea interface are an important component of the Earth's heat budget. In addition, they are an integral factor in determining the sea surface temperature (SST) evolution of the oceans. Different representations of these fluxes are used in both the atmospheric and oceanic communities for the purpose of heat budget studies and, in particular, for forcing oceanic models. It is currently difficult to quantify the potential impact varying heat flux representations have on the ocean response. In this study, a diagnostic tool is presented that allows for a straightforward comparison of surface heat flux formulations and atmospheric data sets. Two variables, relaxation time (RT) and the apparent temperature (T*), are derived from the linearization of the bulk formulas. They are then calculated to compare three bulk formulae and five atmospheric datasets. Additionally, the linearization is expanded to the second order to compare the amount of residual flux present. It is found that the use of a bulk formula employing a constant heat transfer coefficient produces longer relaxation times and contains a greater amount of residual flux in the higher order terms of the linearization. Depending on the temperature difference, the residual flux remaining in the second order and above terms can reach as much as 40--50% of the total residual on a monthly time scale. This is certainly a non-negligible residual flux. In contrast, a bulk formula using a stability and wind dependent transfer coefficient retains much of the total flux in the first order term, as only a few percent remain in the residual flux. Most of the difference displayed among the bulk formulas stems from the sensitivity to wind speed and the choice of a constant or spatially varying transfer coefficient. Comparing the representation of RT and T* provides insight into the differences among various atmospheric datasets. In particular, the representations of the western boundary current, upwelling

  8. Giant Enhancement in Radiative Heat Transfer in Sub-30 nm Gaps of Plane Parallel Surfaces.

    PubMed

    Fiorino, Anthony; Thompson, Dakotah; Zhu, Linxiao; Song, Bai; Reddy, Pramod; Meyhofer, Edgar

    2018-06-13

    Radiative heat transfer rates that exceed the blackbody limit by several orders of magnitude are expected when the gap size between plane parallel surfaces is reduced to the nanoscale. To date, experiments have only realized enhancements of ∼100 fold as the smallest gap sizes in radiative heat transfer studies have been limited to ∼50 nm by device curvature and particle contamination. Here, we report a 1,200-fold enhancement with respect to the far-field value in the radiative heat flux between parallel planar silica surfaces separated by gaps as small as ∼25 nm. Achieving such small gap sizes and the resultant dramatic enhancement in near-field energy flux is critical to achieve a number of novel near-field based nanoscale energy conversion systems that have been theoretically predicted but remain experimentally unverified.

  9. Radiation fluxes at the FIFE site

    NASA Technical Reports Server (NTRS)

    Walter-Shea, Elizabeth A.; Blad, Blaine L.; Zara, Pedro; Vining, Roel; Hays, Cynthia J.; Mesarch, Mark A.

    1993-01-01

    The main objective of the International Satellite Land Surface Climatology Project (ISLSCP) has been stated as 'the development of techniques that may be applied to satellite observations of the radiation reflected and emitted from the Earth to yield quantitative information concerning land surface climatological conditions'. The major field study, FIFE (the First ISLSCP Field Experiment), was conducted in 1987-89 to accomplish this objective. Four intensive field campaigns (IFC's) were carried out in 1987 and one in 1989. Factors contributing to observed reflected radiation from the FIFE site must be understood before the radiation observed by satellites can be used to quantify surface processes. Our last report (Walter-Shea et al., 1992b) focused on slope effects on incoming and outgoing shortwave radiation and net radiation from data collected in 1989. We report here on the final analysis of the slope data as well as results from thermal radiation studies conducted during the FIFE experiment. The specific areas reported are the following: (1) analysis of slope effects on measured reflectance values and estimates of surface albedo; (2) using remotely-measured surface temperatures as a means of estimating sensible heat flux from the Konza Prairie; (3) extracting canopy temperatures from remotely-measured composite surface temperatures; (4) modeling the measured composite temperature of partially vegetated surfaces; and (5) estimating gap distribution in partially vegetated surfaces from reflectance measurements.

  10. A new heat flux model for the Antarctic Peninsula incorporating spatially variable upper crustal radiogenic heat production

    NASA Astrophysics Data System (ADS)

    Burton-Johnson, A.; Halpin, J. A.; Whittaker, J. M.; Graham, F. S.; Watson, S. J.

    2017-06-01

    A new method for modeling heat flux shows that the upper crust contributes up to 70% of the Antarctic Peninsula's subglacial heat flux and that heat flux values are more variable at smaller spatial resolutions than geophysical methods can resolve. Results indicate a higher heat flux on the east and south of the Peninsula (mean 81 mW m-2) where silicic rocks predominate, than on the west and north (mean 67 mW m-2) where volcanic arc and quartzose sediments are dominant. While the data supports the contribution of heat-producing element-enriched granitic rocks to high heat flux values, sedimentary rocks can be of comparative importance dependent on their provenance and petrography. Models of subglacial heat flux must utilize a heterogeneous upper crust with variable radioactive heat production if they are to accurately predict basal conditions of the ice sheet. Our new methodology and data set facilitate improved numerical model simulations of ice sheet dynamics.Plain Language SummaryAs the climate changes, the Antarctic ice sheet represents the single largest potential source of sea level rise. However, one key parameter controlling how the ice sheet flows remains poorly constrained: the effect of <span class="hlt">heat</span> derived from the Earth's geology on the base of the ice sheet (known as subglacial <span class="hlt">heat</span> <span class="hlt">flux</span>). Although this may not seem like a lot of <span class="hlt">heat</span>, under slow-flowing ice, this "<span class="hlt">heat</span> <span class="hlt">flux</span>" can control how well the ice sheet can flow over the rocks and even lead to melting of the ice at its base. Current models for Antarctica's <span class="hlt">heat</span> <span class="hlt">flux</span> use geophysics to determine how thin the crust is and consequently how easily <span class="hlt">heat</span> from the Earth's mantle can warm the surface. We show here that <span class="hlt">heat</span> produced by radioactive decay within the Earth's crust can have an even greater and much more variable contribution to the subglacial <span class="hlt">heat</span> <span class="hlt">flux</span> than estimated by these previous models. We present a new methodology allowing this crustal <span class="hlt">heat</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/963766','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/963766"><span>QUANTIFICATION OF <span class="hlt">HEAT</span> <span class="hlt">FLUX</span> FROM A REACTING THERMITE SPRAY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Eric Nixon; Michelle Pantoya</p> <p>2009-07-01</p> <p>Characterizing the combustion behaviors of energetic materials requires diagnostic tools that are often not readily or commercially available. For example, a jet of thermite spray provides a high temperature and pressure reaction that can also be highly corrosive and promote undesirable conditions for the survivability of any sensor. Developing a diagnostic to quantify <span class="hlt">heat</span> <span class="hlt">flux</span> from a thermite spray is the objective of this study. Quick response sensors such as thin film <span class="hlt">heat</span> <span class="hlt">flux</span> sensors can not survive the harsh conditions of the spray, but more rugged sensors lack the response time for the resolution desired. A sensor that willmore » allow for adequate response time while surviving the entire test duration was constructed. The sensor outputs interior temperatures of the probes at known locations and utilizes an inverse <span class="hlt">heat</span> conduction code to calculate <span class="hlt">heat</span> <span class="hlt">flux</span> values. The details of this device are discussed and illustrated. Temperature and <span class="hlt">heat</span> <span class="hlt">flux</span> measurements of various thermite spray conditions are reported. Results indicate that this newly developed energetic material <span class="hlt">heat</span> <span class="hlt">flux</span> sensor provides quantitative data with good repeatability.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018RScI...89f4901D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018RScI...89f4901D"><span>Development of a <span class="hlt">radiative</span> <span class="hlt">heating</span> facility for studying flow and <span class="hlt">heat</span> transfer in hydrocarbon-cooled structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dong, Da; Lu, Yang; Yuan, Yueming; Fan, Xuejun</p> <p>2018-06-01</p> <p>An experimental facility was designed to simulate the <span class="hlt">heat</span> exchange between the hot gas and the fuel-cooled wall in a scramjet combustor. Thermal <span class="hlt">radiation</span> from an electrically <span class="hlt">heated</span> graphite plate is employed to unilaterally <span class="hlt">heat</span> up a multi-channeled cooling plate. A maximum <span class="hlt">heat</span> <span class="hlt">flux</span> of over 0.8 MW/m2 was achieved for an effective <span class="hlt">heating</span> area up to 1000 mm × 40 mm. Precise control of the back pressure of a coolant (up to 5 MPa) in a unique way was also demonstrated. With this facility, studies of flow and <span class="hlt">heat</span> transfer in hydrocarbon-cooled structures can be performed under a well-controlled manner.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985tehs.nasa...51A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985tehs.nasa...51A"><span>Development of <span class="hlt">heat</span> <span class="hlt">flux</span> sensors for turbine airfoils</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Atkinson, William H.; Cyr, Marcia A.; Strange, Richard R.</p> <p>1985-10-01</p> <p>The objectives of this program are to develop <span class="hlt">heat</span> <span class="hlt">flux</span> sensors suitable for installation in hot section airfoils of advanced aircraft turbine engines and to experimentally verify the operation of these <span class="hlt">heat</span> <span class="hlt">flux</span> sensors in a cylinder in a cross flow experiment. Embedded thermocouple and Gardon gauge sensors were developed and fabricated into both blades and vanes. These were then calibrated using a quartz lamp bank <span class="hlt">heat</span> source and finally subjected to thermal cycle and thermal soak testing. These sensors were also fabricated into cylindrical test pieces and tested in a burner exhaust to verify <span class="hlt">heat</span> <span class="hlt">flux</span> measurements produced by these sensors. The results of the cylinder in cross flow tests are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880001761','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880001761"><span>Development of <span class="hlt">heat</span> <span class="hlt">flux</span> sensors for turbine airfoils</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Atkinson, William H.; Cyr, Marcia A.; Strange, Richard R.</p> <p>1985-01-01</p> <p>The objectives of this program are to develop <span class="hlt">heat</span> <span class="hlt">flux</span> sensors suitable for installation in hot section airfoils of advanced aircraft turbine engines and to experimentally verify the operation of these <span class="hlt">heat</span> <span class="hlt">flux</span> sensors in a cylinder in a cross flow experiment. Embedded thermocouple and Gardon gauge sensors were developed and fabricated into both blades and vanes. These were then calibrated using a quartz lamp bank <span class="hlt">heat</span> source and finally subjected to thermal cycle and thermal soak testing. These sensors were also fabricated into cylindrical test pieces and tested in a burner exhaust to verify <span class="hlt">heat</span> <span class="hlt">flux</span> measurements produced by these sensors. The results of the cylinder in cross flow tests are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994usee.work..203D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994usee.work..203D"><span>Measurement of a surface <span class="hlt">heat</span> <span class="hlt">flux</span> and temperature</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davis, R. M.; Antoine, G. J.; Diller, T. E.; Wicks, A. L.</p> <p>1994-04-01</p> <p>The <span class="hlt">Heat</span> <span class="hlt">Flux</span> Microsensor is a new sensor which was recently patented by Virginia Tech and is just starting to be marketed by Vatell Corp. The sensor is made using the thin-film microfabrication techniques directly on the material that is to be measured. It consists of several thin-film layers forming a differential thermopile across a thermal resistance layer. The measured <span class="hlt">heat</span> <span class="hlt">flux</span> q is proportional to the temperature difference across the resistance layer q= k(sub g)/delta(sub g) x (t(sub 1) - T(sub 2)), where k(sub g) is the thermal conductivity and delta (sub g) is the thickness of the thermal resistance layer. Because the gages are sputter coated directly onto the surface, their total thickness is less than 2 micrometers, which is two orders of magnitude thinner than previous gages. The resulting temperature difference across the thermal resistance layer (delta is less than 1 micrometer) is very small even at high <span class="hlt">heat</span> <span class="hlt">fluxes</span>. To generate a measurable signal many thermocouple pairs are put in series to form a differential thermopile. The combination of series thermocouple junctions and thin-film design creates a gage with very attractive characteristics. It is not only physically non-intrusive to the flow, but also causes minimal disruption of the surface temperature. Because it is so thin, the response time is less than 20 microsec. Consequently, the frequency response is flat from 0 to over 50 kHz. Moreover, the signal of the <span class="hlt">Heat</span> <span class="hlt">Flux</span> Microsensor is directly proportional to the <span class="hlt">heat</span> <span class="hlt">flux</span>. Therefore, it can easily be used in both steady and transient flows, and it measures both the steady and unsteady components of the surface <span class="hlt">heat</span> <span class="hlt">flux</span>. A version of the <span class="hlt">Heat</span> <span class="hlt">Flux</span> Microsensor has been developed to meet the harsh demands of combustion environments. These gages use platinum and platinum-10 percent rhodium as the thermoelectric materials. The thermal resistance layer is silicon monoxide and a protective coating of Al2O3 is deposited on top of the sensor. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940031900','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940031900"><span>Measurement of a surface <span class="hlt">heat</span> <span class="hlt">flux</span> and temperature</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davis, R. M.; Antoine, G. J.; Diller, T. E.; Wicks, A. L.</p> <p>1994-01-01</p> <p>The <span class="hlt">Heat</span> <span class="hlt">Flux</span> Microsensor is a new sensor which was recently patented by Virginia Tech and is just starting to be marketed by Vatell Corp. The sensor is made using the thin-film microfabrication techniques directly on the material that is to be measured. It consists of several thin-film layers forming a differential thermopile across a thermal resistance layer. The measured <span class="hlt">heat</span> <span class="hlt">flux</span> q is proportional to the temperature difference across the resistance layer q= k(sub g)/delta(sub g) x (t(sub 1) - T(sub 2)), where k(sub g) is the thermal conductivity and delta (sub g) is the thickness of the thermal resistance layer. Because the gages are sputter coated directly onto the surface, their total thickness is less than 2 micrometers, which is two orders of magnitude thinner than previous gages. The resulting temperature difference across the thermal resistance layer (delta is less than 1 micrometer) is very small even at high <span class="hlt">heat</span> <span class="hlt">fluxes</span>. To generate a measurable signal many thermocouple pairs are put in series to form a differential thermopile. The combination of series thermocouple junctions and thin-film design creates a gage with very attractive characteristics. It is not only physically non-intrusive to the flow, but also causes minimal disruption of the surface temperature. Because it is so thin, the response time is less than 20 microsec. Consequently, the frequency response is flat from 0 to over 50 kHz. Moreover, the signal of the <span class="hlt">Heat</span> <span class="hlt">Flux</span> Microsensor is directly proportional to the <span class="hlt">heat</span> <span class="hlt">flux</span>. Therefore, it can easily be used in both steady and transient flows, and it measures both the steady and unsteady components of the surface <span class="hlt">heat</span> <span class="hlt">flux</span>. A version of the <span class="hlt">Heat</span> <span class="hlt">Flux</span> Microsensor has been developed to meet the harsh demands of combustion environments. These gages use platinum and platinum-10 percent rhodium as the thermoelectric materials. The thermal resistance layer is silicon monoxide and a protective coating of Al2O3 is deposited on top of the sensor. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018A%26A...612A..28L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018A%26A...612A..28L"><span>Chromospheric <span class="hlt">heating</span> during <span class="hlt">flux</span> emergence in the solar atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leenaarts, Jorrit; de la Cruz Rodríguez, Jaime; Danilovic, Sanja; Scharmer, Göran; Carlsson, Mats</p> <p>2018-04-01</p> <p>Context. The <span class="hlt">radiative</span> losses in the solar chromosphere vary from 4 kW m-2 in the quiet Sun, to 20 kW m-2 in active regions. The mechanisms that transport non-thermal energy to and deposit it in the chromosphere are still not understood. Aim. We aim to investigate the atmospheric structure and <span class="hlt">heating</span> of the solar chromosphere in an emerging <span class="hlt">flux</span> region. Methods: We have used observations taken with the CHROMIS and CRISP instruments on the Swedish 1-m Solar Telescope in the Ca II K , Ca II 854.2 nm, Hα, and Fe I 630.1 nm and 630.2 nm lines. We analysed the various line profiles and in addition perform multi-line, multi-species, non-local thermodynamic equilibrium (non-LTE) inversions to estimate the spatial and temporal variation of the chromospheric structure. Results: We investigate which spectral features of Ca II K contribute to the frequency-integrated Ca II K brightness, which we use as a tracer of chromospheric <span class="hlt">radiative</span> losses. The majority of the <span class="hlt">radiative</span> losses are not associated with localised high-Ca II K-brightness events, but instead with a more gentle, spatially extended, and persistent <span class="hlt">heating</span>. The frequency-integrated Ca II K brightness correlates strongly with the total linear polarization in the Ca II 854.2 nm, while the Ca II K profile shapes indicate that the bulk of the <span class="hlt">radiative</span> losses occur in the lower chromosphere. Non-LTE inversions indicate a transition from <span class="hlt">heating</span> concentrated around photospheric magnetic elements below log τ500 = -3 to a more space-filling and time-persistent <span class="hlt">heating</span> above log τ500 = -4. The inferred gas temperature at log τ500 = -3.8 correlates strongly with the total linear polarization in the Ca II 854.2 nm line, suggesting that that the <span class="hlt">heating</span> rate correlates with the strength of the horizontal magnetic field in the low chromosphere. Movies attached to Figs. 1 and 4 are available at http://https://www.aanda.org/</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940024321','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940024321"><span><span class="hlt">Heat</span> <span class="hlt">flux</span> instrumentation for Hyflite thermal protection system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Diller, T. E.</p> <p>1994-01-01</p> <p>Using Thermal Protection Tile core samples supplied by NASA, the surface characteristics of the FRCI, TUFI, and RCG coatings were evaluated. Based on these results, appropriate methods of surface preparation were determined and tested for the required sputtering processes. Sample sensors were fabricated on the RCG coating and adhesion was acceptable. Based on these encouraging results, complete <span class="hlt">Heat</span> <span class="hlt">Flux</span> Microsensors were fabricated on the RCG coating. The issue of lead attachment was addressed with the annnealing and welding methods developed at NASA Lewis. Parallel gap welding appears to be the best method of lead attachment with prior <span class="hlt">heat</span> treatment of the sputtered pads. Sample <span class="hlt">Heat</span> <span class="hlt">Flux</span> Microsensors were submitted for testing in the NASA Ames arc jet facility. Details of the project are contained in two attached reports. One additional item of interest is contained in the attached AIAA paper, which gives details of the transient response of a <span class="hlt">Heat</span> <span class="hlt">Flux</span> Microsensors in a shock tube facility at Virginia Tech. The response of the <span class="hlt">heat</span> <span class="hlt">flux</span> sensor was measured to be faster than 10 micro-s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JARS...11d6012L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JARS...11d6012L"><span>Estimation of land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> based on visible infrared imaging radiometer suite data: case study in northern China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Xiaojun; Xin, Xiaozhou; Peng, Zhiqing; Zhang, Hailong; Li, Li; Shao, Shanshan; Liu, Qinhuo</p> <p>2017-10-01</p> <p>Evapotranspiration (ET) plays an important role in surface-atmosphere interactions and can be monitored using remote sensing data. The visible infrared imaging radiometer suite (VIIRS) sensor is a generation of optical satellite sensors that provide daily global coverage at 375- to 750-m spatial resolutions with 22 spectral channels (0.412 to 12.05 μm) and capable of monitoring ET from regional to global scales. However, few studies have focused on methods of acquiring ET from VIIRS images. The objective of this study is to introduce an algorithm that uses the VIIRS data and meteorological variables to estimate the energy budgets of land surfaces, including the net <span class="hlt">radiation</span>, soil <span class="hlt">heat</span> <span class="hlt">flux</span>, sensible <span class="hlt">heat</span> <span class="hlt">flux</span>, and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span>. A single-source model that based on surface energy balance equation is used to obtain surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> within the Zhangye oasis in China. The results were validated using observations collected during the HiWATER (Heihe Watershed Allied Telemetry Experimental Research) project. To facilitate comparison, we also use moderate resolution imaging spectrometer (MODIS) data to retrieve the regional surface <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The validation results show that it is feasible to estimate the turbulent <span class="hlt">heat</span> <span class="hlt">flux</span> based on the VIIRS sensor and that these data have certain advantages (i.e., the mean bias error of sensible <span class="hlt">heat</span> <span class="hlt">flux</span> is 15.23 W m-2) compared with MODIS data (i.e., the mean bias error of sensible <span class="hlt">heat</span> <span class="hlt">flux</span> is -29.36 W m-2). Error analysis indicates that, in our model, the accuracies of the estimated sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> rely on the errors in the retrieved surface temperatures and the canopy heights.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040086711','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040086711"><span>Thermal Conductivity of Advanced Ceramic Thermal Barrier Coatings Determined by a Steady-state Laser <span class="hlt">Heat-flux</span> Approach</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhu, Dong-Ming; Miller, Robert A.</p> <p>2004-01-01</p> <p>The development of low conductivity and high temperature capable thermal barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity under future high-performance and low-emission engine <span class="hlt">heat-flux</span> conditions. In this paper, a unique steady-state CO2 laser (wavelength 10.6 microns) <span class="hlt">heat-flux</span> approach is described for determining the thermal conductivity and conductivity deduced cyclic durability of ceramic thermal and environmental barrier coating systems at very high temperatures (up to 1700 C) under large thermal gradients. The thermal conductivity behavior of advanced thermal and environmental barrier coatings for metallic and Si-based ceramic matrix composite (CMC) component applications has also been investigated using the laser conductivity approach. The relationships between the lattice and <span class="hlt">radiation</span> conductivities as a function of <span class="hlt">heat</span> <span class="hlt">flux</span> and thermal gradient at high temperatures have been examined for the ceramic coating systems. The steady-state laser <span class="hlt">heat-flux</span> conductivity approach has been demonstrated as a viable means for the development and life prediction of advanced thermal barrier coatings for future turbine engine applications.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070035068','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070035068"><span>The Effect of Cumulus Cloud Field Anisotropy on Domain-Averaged Solar <span class="hlt">Fluxes</span> and Atmospheric <span class="hlt">Heating</span> Rates</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hinkelman, Laura M.; Evans, K. Franklin; Clothiaux, Eugene E.; Ackerman, Thomas P.; Stackhouse, Paul W., Jr.</p> <p>2006-01-01</p> <p>Cumulus clouds can become tilted or elongated in the presence of wind shear. Nevertheless, most studies of the interaction of cumulus clouds and <span class="hlt">radiation</span> have assumed these clouds to be isotropic. This paper describes an investigation of the effect of fair-weather cumulus cloud field anisotropy on domain-averaged solar <span class="hlt">fluxes</span> and atmospheric <span class="hlt">heating</span> rate profiles. A stochastic field generation algorithm was used to produce twenty three-dimensional liquid water content fields based on the statistical properties of cloud scenes from a large eddy simulation. Progressively greater degrees of x-z plane tilting and horizontal stretching were imposed on each of these scenes, so that an ensemble of scenes was produced for each level of distortion. The resulting scenes were used as input to a three-dimensional Monte Carlo <span class="hlt">radiative</span> transfer model. Domain-average transmission, reflection, and absorption of broadband solar <span class="hlt">radiation</span> were computed for each scene along with the average <span class="hlt">heating</span> rate profile. Both tilt and horizontal stretching were found to significantly affect calculated <span class="hlt">fluxes</span>, with the amount and sign of <span class="hlt">flux</span> differences depending strongly on sun position relative to cloud distortion geometry. The mechanisms by which anisotropy interacts with solar <span class="hlt">fluxes</span> were investigated by comparisons to independent pixel approximation and tilted independent pixel approximation computations for the same scenes. Cumulus anisotropy was found to most strongly impact solar <span class="hlt">radiative</span> transfer by changing the effective cloud fraction, i.e., the cloud fraction when the field is projected on a surface perpendicular to the direction of the incident solar beam.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhD...50n5101Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhD...50n5101Z"><span>Active control of near-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer between graphene-covered metamaterials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Qimei; Zhou, Ting; Wang, Tongbiao; Liu, Wenxing; Liu, Jiangtao; Yu, Tianbao; Liao, Qinghua; Liu, Nianhua</p> <p>2017-04-01</p> <p>In this study, the near-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer between graphene-covered metamaterials is investigated. The electric surface plasmons (SPs) supported by metamaterials can be coupled with the SPs supported by graphene. The near-field <span class="hlt">heat</span> transfer between the graphene-covered metamaterials is significantly larger than that between metamaterials because of the strong coupling in our studied frequency range. The relationship between <span class="hlt">heat</span> <span class="hlt">flux</span> and chemical potential is studied for different vacuum gaps. Given that the chemical potential of graphene can be tuned by the external electric field, <span class="hlt">heat</span> transfer can be actively controlled by modulating the chemical potential. The <span class="hlt">heat</span> <span class="hlt">flux</span> for certain vacuum gaps can reach a maximum value when the chemical potential is at a particular value. The results of this study are beneficial for actively controlling energy transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010039530&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2BFlux','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010039530&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2BFlux"><span>Coronal <span class="hlt">Heating</span> and the Magnetic <span class="hlt">Flux</span> Content of the Network</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.; Rose, M. Franklin (Technical Monitor)</p> <p>2001-01-01</p> <p>Previously, from analysis of SOHO coronal images in combination with Kitt Peak magnetograms, we found that the quiet corona is the sum of two components: the large-scale corona and the coronal network. The large-scale corona consists of all coronal-temperature (T approximately 10(exp 6) K) structures larger than supergranules (greater than approximately 30,000 kilometers). The coronal network (1) consists of all coronal-temperature structures smaller than supergranules, (2) is rooted in and loosely traces the photospheric magnetic network, (3) has its brightest features seated on polarity dividing lines (neutral lines) in the network magnetic <span class="hlt">flux</span>, and (4) produces only about 5% of the total coronal emission in quiet regions. The <span class="hlt">heating</span> of the coronal network is apparently magnetic in origin. Here, from analysis of EIT coronal images of quiet regions in combination with magnetograms of the same quiet regions from SOHO/MDI and from Kitt Peak, we examine the other 95% of the quiet corona and its relation to the underlying magnetic network. We find: (1) Dividing the large-scale corona into its bright and dim halves divides the area into bright "continents" and dark "oceans" having spans of 2-4 supergranules. (2) These patterns are also present in the photospheric magnetograms: the network is stronger under the bright half and weaker under the dim half. (3) The <span class="hlt">radiation</span> from the large-scale corona increases roughly as the cube root of the magnetic <span class="hlt">flux</span> content of the underlying magnetic network. In contrast, the coronal <span class="hlt">radiation</span> from an active region increases roughly linearly with the magnetic <span class="hlt">flux</span> content of the active region. We assume, as is widely held, that nearly all of the large-scale corona is magnetically rooted in the network. Our results suggest that either the coronal <span class="hlt">heating</span> in quiet regions has a large non-magnetic component, or, if the <span class="hlt">heating</span> is predominantly produced via the magnetic field, the mechanism is significantly different than in active</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5275074','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/5275074"><span>Remote high-temperature insulatorless <span class="hlt">heat-flux</span> gauge</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Noel, B.W.</p> <p>1993-12-28</p> <p>A remote optical <span class="hlt">heat-flux</span> gauge for use in extremely high temperature environments is described. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet or laser light. The luminescence emitted by the two phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the <span class="hlt">heat</span> <span class="hlt">flux</span> incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial <span class="hlt">heat-flux</span> measurements can be made by scanning the light across the surface of the gauge. 3 figures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869091','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869091"><span>Remote high-temperature insulatorless <span class="hlt">heat-flux</span> gauge</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Noel, Bruce W.</p> <p>1993-01-01</p> <p>A remote optical <span class="hlt">heat-flux</span> gauge for use in extremely high temperature environments is described. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet or laser light. The luminescence emitted by the two phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the <span class="hlt">heat</span> <span class="hlt">flux</span> incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial <span class="hlt">heat-flux</span> measurements can be made by scanning the light across the surface of the gauge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JQSRT.202..154N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JQSRT.202..154N"><span>Near-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer in scanning thermal microscopy computed with the boundary element method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nguyen, K. L.; Merchiers, O.; Chapuis, P.-O.</p> <p>2017-11-01</p> <p>We compute the near-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer between a hot AFM tip and a cold substrate. This contribution to the tip-sample <span class="hlt">heat</span> transfer in Scanning Thermal Microscopy is often overlooked, despite its leading role when the tip is out of contact. For dielectrics, we provide power levels exchanged as a function of the tip-sample distance in vacuum and spatial maps of the <span class="hlt">heat</span> <span class="hlt">flux</span> deposited into the sample which indicate the near-contact spatial resolution. The results are compared to analytical expressions of the Proximity <span class="hlt">Flux</span> Approximation. The numerical results are obtained by means of the Boundary Element Method (BEM) implemented in the SCUFF-EM software, and require first a thorough convergence analysis of the progressive implementation of this method to the thermal emission by a sphere, the <span class="hlt">radiative</span> transfer between two spheres, and the <span class="hlt">radiative</span> exchange between a sphere and a finite substrate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160010107','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160010107"><span>Advancements in Afterbody <span class="hlt">Radiative</span> <span class="hlt">Heating</span> Simulations for Earth Entry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnston, Christopher O.; Panesi, Marco; Brandis, Aaron M.</p> <p>2016-01-01</p> <p>Four advancements to the simulation of backshell <span class="hlt">radiative</span> <span class="hlt">heating</span> for Earth entry are presented. The first of these is the development of a flow field model that treats electronic levels of the dominant backshell <span class="hlt">radiator</span>, N, as individual species. This is shown to allow improvements in the modeling of electron-ion recombination and two-temperature modeling, which are shown to increase backshell <span class="hlt">radiative</span> <span class="hlt">heating</span> by 10 to 40%. By computing the electronic state populations of N within the flow field solver, instead of through the quasi-steady state approximation in the <span class="hlt">radiation</span> code, the coupling of <span class="hlt">radiative</span> transition rates to the species continuity equations for the levels of N, including the impact of non-local absorption, becomes feasible. Implementation of this additional level of coupling between the flow field and <span class="hlt">radiation</span> codes represents the second advancement presented in this work, which is shown to increase the backshell <span class="hlt">radiation</span> by another 10 to 50%. The impact of <span class="hlt">radiative</span> transition rates due to non-local absorption indicates the importance of accurate <span class="hlt">radiation</span> transport in the relatively complex flow geometry of the backshell. This motivates the third advancement, which is the development of a ray-tracing <span class="hlt">radiation</span> transport approach to compute the <span class="hlt">radiative</span> transition rates and divergence of the <span class="hlt">radiative</span> <span class="hlt">flux</span> at every point for coupling to the flow field, therefore allowing the accuracy of the commonly applied tangent-slab approximation to be assessed for <span class="hlt">radiative</span> source terms. For the sphere considered at lunar-return conditions, the tangent-slab approximation is shown to provide a sufficient level of accuracy for the <span class="hlt">radiative</span> source terms, even for backshell cases. This is in contrast to the agreement between the two approaches for computing the <span class="hlt">radiative</span> <span class="hlt">flux</span> to the surface, which differ by up to 40%. The final advancement presented is the development of a nonequilibrium model for NO <span class="hlt">radiation</span>, which provides significant backshell</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017HMT....53.2317C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017HMT....53.2317C"><span>Monte Carlo calculation model for <span class="hlt">heat</span> <span class="hlt">radiation</span> of inclined cylindrical flames and its application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Zhangyu; Ji, Jingwei; Huang, Yuankai; Wang, Zhiyi; Li, Qingjie</p> <p>2017-07-01</p> <p>Based on Monte Carlo method, a calculation model and its C++ calculating program for radiant <span class="hlt">heat</span> transfer from an inclined cylindrical flame are proposed. In this model, the total <span class="hlt">radiation</span> energy of the inclined cylindrical flame is distributed equally among a certain number of energy beams, which are emitted randomly from the flame surface. The incident <span class="hlt">heat</span> <span class="hlt">flux</span> on a surface is calculated by counting the number of energy beams which could reach the surface. The paper mainly studies the geometrical evaluation criterion for validity of energy beams emitted by inclined cylindrical flames and received by other surfaces. Compared to Mudan's formula results for a straight cylinder or a cylinder with 30° tilt angle, the calculated view factors range from 0.0043 to 0.2742 and the predicted view factors agree well with Mudan's results. The changing trend and values of incident <span class="hlt">heat</span> <span class="hlt">fluxes</span> computed by the model is consistent with experimental data measured by Rangwala et al. As a case study, incident <span class="hlt">heat</span> <span class="hlt">fluxes</span> on a gasoline tank, both the side and the top surface are calculated by the model. The <span class="hlt">heat</span> <span class="hlt">radiation</span> is from an inclined cylindrical flame generated by another 1000 m3 gasoline tank 4.6 m away from it. The cone angle of the flame to the adjacent oil tank is 45° and the polar angle is 0°. The top surface and the side surface of the tank are divided into 960 and 5760 grids during the calculation, respectively. The maximum incident <span class="hlt">heat</span> <span class="hlt">flux</span> on the side surface is 39.64 and 51.31 kW/m2 on the top surface. Distributions of the incident <span class="hlt">heat</span> <span class="hlt">flux</span> on the surface of the oil tank and on the ground around the fire tank are obtained, too.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87b3504B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87b3504B"><span>Feedback system for divertor impurity seeding based on real-time measurements of surface <span class="hlt">heat</span> <span class="hlt">flux</span> in the Alcator C-Mod tokamak</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brunner, D.; Burke, W.; Kuang, A. Q.; LaBombard, B.; Lipschultz, B.; Wolfe, S.</p> <p>2016-02-01</p> <p>Mitigation of the intense <span class="hlt">heat</span> <span class="hlt">flux</span> to the divertor is one of the outstanding problems in fusion energy. One technique that has shown promise is impurity seeding, i.e., the injection of low-Z gaseous impurities (typically N2 or Ne) to <span class="hlt">radiate</span> and dissipate the power before it arrives to the divertor target plate. To this end, the Alcator C-Mod team has created a first-of-its-kind feedback system to control the injection of seed gas based on real-time surface <span class="hlt">heat</span> <span class="hlt">flux</span> measurements. Surface thermocouples provide real-time measurements of the surface temperature response to the plasma <span class="hlt">heat</span> <span class="hlt">flux</span>. The surface temperature measurements are inputted into an analog computer that "solves" the 1-D <span class="hlt">heat</span> transport equation to deliver accurate, real-time signals of the surface <span class="hlt">heat</span> <span class="hlt">flux</span>. The surface <span class="hlt">heat</span> <span class="hlt">flux</span> signals are sent to the C-Mod digital plasma control system, which uses a proportional-integral-derivative (PID) algorithm to control the duty cycle demand to a pulse width modulated piezo valve, which in turn controls the injection of gas into the private <span class="hlt">flux</span> region of the C-Mod divertor. This paper presents the design and implementation of this new feedback system as well as initial results using it to control divertor <span class="hlt">heat</span> <span class="hlt">flux</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26931846','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26931846"><span>Feedback system for divertor impurity seeding based on real-time measurements of surface <span class="hlt">heat</span> <span class="hlt">flux</span> in the Alcator C-Mod tokamak.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brunner, D; Burke, W; Kuang, A Q; LaBombard, B; Lipschultz, B; Wolfe, S</p> <p>2016-02-01</p> <p>Mitigation of the intense <span class="hlt">heat</span> <span class="hlt">flux</span> to the divertor is one of the outstanding problems in fusion energy. One technique that has shown promise is impurity seeding, i.e., the injection of low-Z gaseous impurities (typically N2 or Ne) to <span class="hlt">radiate</span> and dissipate the power before it arrives to the divertor target plate. To this end, the Alcator C-Mod team has created a first-of-its-kind feedback system to control the injection of seed gas based on real-time surface <span class="hlt">heat</span> <span class="hlt">flux</span> measurements. Surface thermocouples provide real-time measurements of the surface temperature response to the plasma <span class="hlt">heat</span> <span class="hlt">flux</span>. The surface temperature measurements are inputted into an analog computer that "solves" the 1-D <span class="hlt">heat</span> transport equation to deliver accurate, real-time signals of the surface <span class="hlt">heat</span> <span class="hlt">flux</span>. The surface <span class="hlt">heat</span> <span class="hlt">flux</span> signals are sent to the C-Mod digital plasma control system, which uses a proportional-integral-derivative (PID) algorithm to control the duty cycle demand to a pulse width modulated piezo valve, which in turn controls the injection of gas into the private <span class="hlt">flux</span> region of the C-Mod divertor. This paper presents the design and implementation of this new feedback system as well as initial results using it to control divertor <span class="hlt">heat</span> <span class="hlt">flux</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B33N..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B33N..04K"><span>Energy exchanges in a Central Business District - Interpretation of Eddy Covariance and <span class="hlt">radiation</span> <span class="hlt">flux</span> measurements (London UK)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kotthaus, S.; Grimmond, S.</p> <p>2013-12-01</p> <p>Global urbanisation brings increasingly dense and complex urban structures. To manage cities sustainably and smartly, currently and into the future under changing climates, urban climate research needs to advance in areas such as Central Business Districts (CBD) where human interactions with the environment are particularly concentrated. Measurement and modelling approaches may be pushed to their limits in dense urban settings, but if urban climate research is to contribute to the challenges of real cities those limits have to be addressed. The climate of cities is strongly governed by surface-atmosphere exchanges of energy, moisture and momentum. Observations of the relevant <span class="hlt">fluxes</span> provide important information for improvement and evaluation of modelling approaches. Due to the CBD's heterogeneity, a very careful analysis of observations is required to understand the relevant processes. Current approaches used to interpret observations and set them in a wider context may need to be adapted for use in these more complex areas. Here, we present long-term observations of the <span class="hlt">radiation</span> balance components and turbulent <span class="hlt">fluxes</span> of latent <span class="hlt">heat</span>, sensible <span class="hlt">heat</span> and momentum in the city centre of London. This is one of the first measurement studies in a CBD covering multiple years with analysis at temporal scales from days to seasons. Data gathered at two sites in close vicinity, but with different measurement heights, are analysed to investigate the influence of source area characteristics on long-term <span class="hlt">radiation</span> and turbulent <span class="hlt">fluxes</span>. Challenges of source area modelling and the critical aspect of siting in such a complex environment are considered. Outgoing long- and short-wave <span class="hlt">radiation</span> are impacted by the anisotropic nature of the urban surface and the high reflectance materials increasingly being used as building materials. Results highlight the need to consider the source area of radiometers in terms of diffuse and direct irradiance. Sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> (QH) are positive</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...49..391C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...49..391C"><span>ENSO related SST anomalies and relation with surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> over south Pacific and Atlantic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chatterjee, S.; Nuncio, M.; Satheesan, K.</p> <p>2017-07-01</p> <p>The role of surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> in Southern Pacific and Atlantic Ocean SST anomalies associated with El Nino Southern Oscillation (ENSO) is studied using observation and ocean reanalysis products. A prominent dipole structure in SST anomaly is found with a positive (negative) anomaly center over south Pacific (65S-45S, 120W-70W) and negative (positive) one over south Atlantic (50S-30S, 30W-0E) during austral summer (DJF) of El Nino (LaNina). During late austral spring-early summer (OND) of El Nino (LaNina), anomalous northerly (southerly) meridional moisture transport and a positive (negative) sea level pressure anomaly induces a suppressed (enhanced) latent <span class="hlt">heat</span> <span class="hlt">flux</span> from the ocean surface over south Pacific. This in turn results in a shallower than normal mixed layer depth which further helps in development of the SST anomaly. Mixed layer thins further due to anomalous shortwave <span class="hlt">radiation</span> during summer and a well developed SST anomaly evolves. The south Atlantic pole exhibits exactly opposite characteristics at the same time. The contribution from the surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> to mixed layer temperature change is found to be dominant over the advective processes over both the basins. Net surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> anomaly is also found to be maximum during late austral spring-early summer period, with latent <span class="hlt">heat</span> <span class="hlt">flux</span> having a major contribution to it. The anomalous latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> between atmosphere and ocean surface play important role in the growth of observed summertime SST anomaly. Sea-surface height also shows similar out-of-phase signatures over the two basins and are well correlated with the ENSO related SST anomalies. It is also observed that the magnitude of ENSO related anomalies over the southern ocean are weaker in LaNina years than in El Nino years, suggesting an intensified tropics-high latitude tele-connection during warm phases of ENSO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950010662&hterms=shrubs&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dshrubs','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950010662&hterms=shrubs&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dshrubs"><span>On the use of <span class="hlt">radiative</span> surface temperature to estimate sensible <span class="hlt">heat</span> <span class="hlt">flux</span> over sparse shrubs in Nevada</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chehbouni, A.; Nichols, W. D.; Qi, J.; Njoku, E. G.; Kerr, Y. H.; Cabot, F.</p> <p>1994-01-01</p> <p>The accurate partitioning of available energy into sensible and latent <span class="hlt">heat</span> <span class="hlt">flux</span> is crucial to the understanding of surface atmosphere interactions. This issue is more complicated in arid and semi arid regions where the relative contribution to surface <span class="hlt">fluxes</span> from the soil and vegetation may vary significantly throughout the day and throughout the season. A three component model to estimate sensible <span class="hlt">heat</span> <span class="hlt">flux</span> over heterogeneous surfaces is presented. The surface was represented with two adjacent compartments. The first compartment is made up of two components, shrubs and shaded soil, the second of open 'illuminated' soil. Data collected at two different sites in Nevada (U.S.) during the Summers of 1991 and 1992 were used to evaluate model performance. The results show that the present model is sufficiently general to yield satisfactory results for both sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950037243&hterms=impact+art&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dimpact%2Bart','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950037243&hterms=impact+art&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dimpact%2Bart"><span>The impact of land-surface wetness heterogeneity on mesoscale <span class="hlt">heat</span> <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chen, Fei; Avissar, Roni</p> <p>1994-01-01</p> <p>Vertical <span class="hlt">heat</span> <span class="hlt">fluxes</span> associated with mesoscale circulations generated by land-surface wetness discontinuities are often stronger than turbulent <span class="hlt">fluxes</span>, especially in the upper part of the atmospheric planetary boundary layer. As a result, they contribute significantly to the subgrid-scale <span class="hlt">fluxes</span> in large-scale atmospheric models. Yet they are not considered in these models. To provide some insights into the possible parameterization of these <span class="hlt">fluxes</span> in large-scale models, a state-of-the-art mesoscale numerical model was used to investigate the relationships between mesoscale <span class="hlt">heat</span> <span class="hlt">fluxes</span> and atmospheric and land-surface characteristics that play a key role in the generation of mesoscale circulations. The distribution of land-surface wetness, the wavenumber and the wavelength of the land-surface discontinuities, and the large-scale wind speed have a significant impact on the mesoscale <span class="hlt">heat</span> <span class="hlt">fluxes</span>. Empirical functions were derived to characterize the relationships between mesoscale <span class="hlt">heat</span> <span class="hlt">fluxes</span> and the spatial distribution of land-surface wetness. The strongest mesoscale <span class="hlt">heat</span> <span class="hlt">fluxes</span> were obtained for a wavelength of forcing corresponding approximately to the local Rossby deformation radius. The mesoscale <span class="hlt">heat</span> <span class="hlt">fluxes</span> are weakened by large-scale background winds but remain significant even with moderate winds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JHyd..254..215Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JHyd..254..215Z"><span>Estimation of sensible and latent <span class="hlt">heat</span> <span class="hlt">flux</span> from natural sparse vegetation surfaces using surface renewal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zapata, N.; Martínez-Cob, A.</p> <p>2001-12-01</p> <p>This paper reports a study undertaken to evaluate the feasibility of the surface renewal method to accurately estimate long-term evaporation from the playa and margins of an endorreic salty lagoon (Gallocanta lagoon, Spain) under semiarid conditions. High-frequency temperature readings were taken for two time lags ( r) and three measurement heights ( z) in order to get surface renewal sensible <span class="hlt">heat</span> <span class="hlt">flux</span> ( HSR) values. These values were compared against eddy covariance sensible <span class="hlt">heat</span> <span class="hlt">flux</span> ( HEC) values for a calibration period (25-30 July 2000). Error analysis statistics (index of agreement, IA; root mean square error, RMSE; and systematic mean square error, MSEs) showed that the agreement between HSR and HEC improved as measurement height decreased and time lag increased. Calibration factors α were obtained for all analyzed cases. The best results were obtained for the z=0.9 m ( r=0.75 s) case for which α=1.0 was observed. In this case, uncertainty was about 10% in terms of relative error ( RE). Latent <span class="hlt">heat</span> <span class="hlt">flux</span> values were obtained by solving the energy balance equation for both the surface renewal ( LESR) and the eddy covariance ( LEEC) methods, using HSR and HEC, respectively, and measurements of net <span class="hlt">radiation</span> and soil <span class="hlt">heat</span> <span class="hlt">flux</span>. For the calibration period, error analysis statistics for LESR were quite similar to those for HSR, although errors were mostly at random. LESR uncertainty was less than 9%. Calibration factors were applied for a validation data subset (30 July-4 August 2000) for which meteorological conditions were somewhat different (higher temperatures and wind speed and lower solar and net <span class="hlt">radiation</span>). Error analysis statistics for both HSR and LESR were quite good for all cases showing the goodness of the calibration factors. Nevertheless, the results obtained for the z=0.9 m ( r=0.75 s) case were still the best ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720000147','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720000147"><span>Conical electromagnetic <span class="hlt">radiation</span> <span class="hlt">flux</span> concentrator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, E. R.</p> <p>1972-01-01</p> <p>Concentrator provides method of concentrating a beam of electromagnetic <span class="hlt">radiation</span> into a smaller beam, presenting a higher <span class="hlt">flux</span> density. Smaller beam may be made larger by sending <span class="hlt">radiation</span> through the device in the reverse direction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC24C..04C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC24C..04C"><span>Improving Global Net Surface <span class="hlt">Heat</span> <span class="hlt">Flux</span> with Ocean Reanalysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carton, J.; Chepurin, G. A.; Chen, L.; Grodsky, S.</p> <p>2017-12-01</p> <p>This project addresses the current level of uncertainty in surface <span class="hlt">heat</span> <span class="hlt">flux</span> estimates. Time mean surface <span class="hlt">heat</span> <span class="hlt">flux</span> estimates provided by atmospheric reanalyses differ by 10-30W/m2. They are generally unbalanced globally, and have been shown by ocean simulation studies to be incompatible with ocean temperature and velocity measurements. Here a method is presented 1) to identify the spatial and temporal structure of the underlying errors and 2) to reduce them by exploiting hydrographic observations and the analysis increments produced by an ocean reanalysis using sequential data assimilation. The method is applied to <span class="hlt">fluxes</span> computed from daily state variables obtained from three widely used reanalyses: MERRA2, ERA-Interim, and JRA-55, during an eight year period 2007-2014. For each of these seasonal <span class="hlt">heat</span> <span class="hlt">flux</span> errors/corrections are obtained. In a second set of experiments the <span class="hlt">heat</span> <span class="hlt">fluxes</span> are corrected and the ocean reanalysis experiments are repeated. This second round of experiments shows that the time mean error in the corrected <span class="hlt">fluxes</span> is reduced to within ±5W/m2 over the interior subtropical and midlatitude oceans, with the most significant changes occuring over the Southern Ocean. The global <span class="hlt">heat</span> <span class="hlt">flux</span> imbalance of each reanalysis is reduced to within a few W/m2 with this single correction. Encouragingly, the corrected forms of the three sets of <span class="hlt">fluxes</span> are also shown to converge. In the final discussion we present experiments beginning with a modified form of the ERA-Int reanalysis, produced by the DAKKAR program, in which state variables have been individually corrected based on independent measurements. Finally, we discuss the separation of <span class="hlt">flux</span> error from model error.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT........56V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT........56V"><span>Modeling of a <span class="hlt">heat</span> sink and high <span class="hlt">heat</span> <span class="hlt">flux</span> vapor chamber</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vadnjal, Aleksander</p> <p></p> <p>An increasing demand for a higher <span class="hlt">heat</span> <span class="hlt">flux</span> removal capability within a smaller volume for high power electronics led us to focus on a novel cold plate design. A high <span class="hlt">heat</span> <span class="hlt">flux</span> evaporator and micro channel <span class="hlt">heat</span> sink are the main components of a cold plate which is capable of removing couple of 100 W/cm2. In order to describe performance of such porous media device a proper modeling has to be addressed. A universal approach based on the volume average theory (VAT) to transport phenomena in porous media is shown. An approach on how to treat the closure for momentum and energy equations is addressed and a proper definition for friction factors and <span class="hlt">heat</span> transfer coefficients are discussed. A numerical scheme using a solution to Navier-Stokes equations over a representative elementary volume (REV) and the use of VAT is developed to show how to compute friction factors and <span class="hlt">heat</span> transfer coefficients. The calculation show good agreement with the experimental data. For the <span class="hlt">heat</span> transfer coefficient closure, a proper average for both fluid and solid is investigated. Different types of <span class="hlt">heating</span> are also investigated in order to determine how it influences the <span class="hlt">heat</span> transfer coefficient. A higher <span class="hlt">heat</span> <span class="hlt">fluxes</span> in small area condensers led us to the micro channels in contrast to the classical <span class="hlt">heat</span> fin design. A micro channel can have various shapes to enhance <span class="hlt">heat</span> transfer, but the shape that will lead to a higher <span class="hlt">heat</span> <span class="hlt">flux</span> removal with a moderate pumping power needs to be determined. The standard micro-channel terminology is usually used for channels with a simple cross section, e.g. square, round, triangle, etc., but here the micro channel cross section is going to be expanded to describe more complicated and interconnected micro scale channel cross sections. The micro channel geometries explored are pin fins (in-line and staggered) and sintered porous micro channels. The problem solved here is a conjugate problem involving two <span class="hlt">heat</span> transfer mechanisms; (1) porous media</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1131309-diagnostic-quantifying-heat-flux-from-thermite-spray','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1131309-diagnostic-quantifying-heat-flux-from-thermite-spray"><span>A diagnostic for quantifying <span class="hlt">heat</span> <span class="hlt">flux</span> from a thermite spray</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>E. P. Nixon; M. L. Pantoya; D. J. Prentice</p> <p>2010-02-01</p> <p>Characterizing the combustion behaviors of energetic materials requires diagnostic tools that are often not readily or commercially available. For example, a jet of thermite spray provides a high temperature and pressure reaction that can also be highly corrosive and promote undesirable conditions for the survivability of any sensor. Developing a diagnostic to quantify <span class="hlt">heat</span> <span class="hlt">flux</span> from a thermite spray is the objective of this study. Quick response sensors such as thin film <span class="hlt">heat</span> <span class="hlt">flux</span> sensors cannot survive the harsh conditions of the spray, but more rugged sensors lack the response time for the resolution desired. A sensor that will allowmore » for adequate response time while surviving the entire test duration was constructed. The sensor outputs interior temperatures of the probes at known locations and utilizes an inverse <span class="hlt">heat</span> conduction code to calculate <span class="hlt">heat</span> <span class="hlt">flux</span> values. The details of this device are discussed and illustrated. Temperature and <span class="hlt">heat</span> <span class="hlt">flux</span> measurements of various thermite sprays are reported. Results indicate that this newly designed <span class="hlt">heat</span> <span class="hlt">flux</span> sensor provides quantitative data with good repeatability suitable for characterizing energetic material combustion.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910015008','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910015008"><span>Calibrator tests of <span class="hlt">heat</span> <span class="hlt">flux</span> gauges mounted in SSME blades</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liebert, Curt H.</p> <p>1989-01-01</p> <p>Measurements of <span class="hlt">heat</span> <span class="hlt">flux</span> to space shuttle main engine (SSME) turbine blade surfaces are being made in the Lewis <span class="hlt">heat</span> <span class="hlt">flux</span> calibration facility. Surface <span class="hlt">heat</span> <span class="hlt">flux</span> information is obtained from transient temperature measurements taken at points within the gauge. A 100-kW Vortek arc lamp is used as a source of thermal radiant energy. Thermoplugs, with diameters of about 0.190 cm and lengths varying from about 0.190 to 0.320 cm, are being investigated. The thermoplug is surrounded on all surfaces except the active surface by a pocket of air located in the circular annulus and under the back cover. Since the thermoplug is insulated, it is assumed that <span class="hlt">heat</span> is conducted in a one-dimensional manner from the hot active surface to the cooler back side of the thermoplug. It is concluded that the miniature plug-type gauge concept is feasible for measurement of blade surface <span class="hlt">heat</span> <span class="hlt">flux</span>. It is suggested that it is important to measure <span class="hlt">heat</span> <span class="hlt">flux</span> near the hub on the suction surface and at the throat on SSME blades rotating in engines because stress and <span class="hlt">heat</span> transfer coefficients are high in this region.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhLA..380..452G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhLA..380..452G"><span>Understanding of <span class="hlt">flux</span>-limited behaviors of <span class="hlt">heat</span> transport in nonlinear regime</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, Yangyu; Jou, David; Wang, Moran</p> <p>2016-01-01</p> <p>The classical Fourier's law of <span class="hlt">heat</span> transport breaks down in highly nonequilibrium situations as in nanoscale <span class="hlt">heat</span> transport, where nonlinear effects become important. The present work is aimed at exploring the <span class="hlt">flux</span>-limited behaviors based on a categorization of existing nonlinear <span class="hlt">heat</span> transport models in terms of their theoretical foundations. Different saturation <span class="hlt">heat</span> <span class="hlt">fluxes</span> are obtained, whereas the same qualitative variation trend of <span class="hlt">heat</span> <span class="hlt">flux</span> versus exerted temperature gradient is got in diverse nonlinear models. The phonon hydrodynamic model is proposed to act as a standard to evaluate other <span class="hlt">heat</span> <span class="hlt">flux</span> limiters because of its more rigorous physical foundation. A deeper knowledge is thus achieved about the phenomenological generalized <span class="hlt">heat</span> transport models. The present work provides deeper understanding and accurate modeling of nonlocal and nonlinear <span class="hlt">heat</span> transport beyond the diffusive limit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940008316','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940008316"><span>Measuring surface <span class="hlt">fluxes</span> in CAPE</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kanemasu, E. T.; D-Shah, T.; Nie, Dalin</p> <p>1992-01-01</p> <p>Two stations (site 1612 and site 2008) were operated by the University of Georgia group from 6 July 1991 to 18 August 1991. The following data were collected continuously: surface energy <span class="hlt">fluxes</span> (i.e., net <span class="hlt">radiation</span>, soil <span class="hlt">heat</span> <span class="hlt">fluxes</span>, sensible <span class="hlt">heat</span> <span class="hlt">flux</span> and latent <span class="hlt">heat</span> <span class="hlt">flux</span>), air temperature, vapor pressure, soil temperature (at 1 cm depth), and precipitation. Canopy reflectance and light interception data were taken three times at each site between 6 July and 18 August. Soil moisture content was measured twice at each site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740006541','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740006541"><span><span class="hlt">Heat</span> pipe <span class="hlt">radiator</span>. [for spacecraft waste <span class="hlt">heat</span> rejection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Swerdling, B.; Alario, J.</p> <p>1973-01-01</p> <p>A 15,000 watt spacecraft waste <span class="hlt">heat</span> rejection system utilizing <span class="hlt">heat</span> pipe <span class="hlt">radiator</span> panels was investigated. Of the several concepts initially identified, a series system was selected for more in-depth analysis. As a demonstration of system feasibility, a nominal 500 watt <span class="hlt">radiator</span> panel was designed, built and tested. The panel, which is a module of the 15,000 watt system, consists of a variable conductance <span class="hlt">heat</span> pipe (VCHP) header, and six isothermalizer <span class="hlt">heat</span> pipes attached to a <span class="hlt">radiating</span> fin. The thermal load to the VCHP is supplied by a Freon-21 liquid loop via an integral <span class="hlt">heat</span> exchanger. Descriptions of the results of the system studies and details of the <span class="hlt">radiator</span> design are included along with the test results for both the <span class="hlt">heat</span> pipe components and the assembled <span class="hlt">radiator</span> panel. These results support the feasibility of using <span class="hlt">heat</span> pipes in a spacecraft waste <span class="hlt">heat</span> rejection system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.891a2223K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.891a2223K"><span>Study on coal char ignition by radiant <span class="hlt">heat</span> <span class="hlt">flux</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Korotkikh, A. G.; Slyusarskiy, K. V.</p> <p>2017-11-01</p> <p>The study on coal char ignition by CO2-continuous laser was carried out. The coal char samples of T-grade bituminous coal and 2B-grade lignite were studied via CO2-laser ignition setup. Ignition delay times were determined at ambient condition in <span class="hlt">heat</span> <span class="hlt">flux</span> density range 90-200 W/cm2. The average ignition delay time value for lignite samples were 2 times lower while this difference is larger in high <span class="hlt">heat</span> <span class="hlt">flux</span> region and lower in low <span class="hlt">heat</span> <span class="hlt">flux</span> region. The kinetic constants for overall oxidation reaction were determined using analytic solution of simplified one-dimensional <span class="hlt">heat</span> transfer equation with radiant <span class="hlt">heat</span> transfer boundary condition. The activation energy for lignite char was found to be less than it is for bituminous coal char by approximately 20 %.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/111419','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/111419"><span>A comparison of critical <span class="hlt">heat</span> <span class="hlt">flux</span> in tubes and bilaterally <span class="hlt">heated</span> annuli</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Doerffer, S.; Groeneveld, D.C.; Cheng, S.C.</p> <p>1995-09-01</p> <p>This paper examines the critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) behaviour for annular flow in bilaterally <span class="hlt">heated</span> annuli and compares it to that in tubes and unilaterally <span class="hlt">heated</span> annuli. It was found that the differences in CHF between bilaterally and unilaterally <span class="hlt">heated</span> annuli or tubes strongly depend on pressure and quality. the CHF in bilaterally <span class="hlt">heated</span> annuli can be predicted by tube CHF prediction methods for the simultaneous CHF occurrence at both surfaces, and the following flow conditions: pressure 7-10 MPa, mass <span class="hlt">flux</span> 0.5-4.0 Mg/m{sup 2}s and critical quality 0.23-0.9. The effect on CHF of the outer-to-inner surface <span class="hlt">heat</span> <span class="hlt">flux</span> ratio, wasmore » also examined. The prediction of CHF for bilaterally <span class="hlt">heated</span> annuli was based on the droplet-diffusion model proposed by Kirillov and Smogalev. While their model refers only to CHF occurrence at the inner surface, we extended it to cases where CHF occurs at the outer surface, and simultaneously at both surfaces, thus covering all cases of CHF occurrence in bilaterally <span class="hlt">heated</span> annuli. From the annuli CHF data of Becker and Letzter, we derived empirical functions required by the model. the proposed equations provide good accuracy for the CHF data used in this study. Moreover, the equations can predict conditions at which CHF occurs simultaneously at both surfaces. Also, this method can be used for cases with only one <span class="hlt">heated</span> surface.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhLA..381.3621L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhLA..381.3621L"><span>Size effects in non-linear <span class="hlt">heat</span> conduction with <span class="hlt">flux</span>-limited behaviors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Shu-Nan; Cao, Bing-Yang</p> <p>2017-11-01</p> <p>Size effects are discussed for several non-linear <span class="hlt">heat</span> conduction models with <span class="hlt">flux</span>-limited behaviors, including the phonon hydrodynamic, Lagrange multiplier, hierarchy moment, nonlinear phonon hydrodynamic, tempered diffusion, thermon gas and generalized nonlinear models. For the phonon hydrodynamic, Lagrange multiplier and tempered diffusion models, <span class="hlt">heat</span> <span class="hlt">flux</span> will not exist in problems with sufficiently small scale. The existence of <span class="hlt">heat</span> <span class="hlt">flux</span> needs the sizes of <span class="hlt">heat</span> conduction larger than their corresponding critical sizes, which are determined by the physical properties and boundary temperatures. The critical sizes can be regarded as the theoretical limits of the applicable ranges for these non-linear <span class="hlt">heat</span> conduction models with <span class="hlt">flux</span>-limited behaviors. For sufficiently small scale <span class="hlt">heat</span> conduction, the phonon hydrodynamic and Lagrange multiplier models can also predict the theoretical possibility of violating the second law and multiplicity. Comparisons are also made between these non-Fourier models and non-linear Fourier <span class="hlt">heat</span> conduction in the type of fast diffusion, which can also predict <span class="hlt">flux</span>-limited behaviors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013IJTP...52.3598A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013IJTP...52.3598A"><span>Gravitational Collapse with <span class="hlt">Heat</span> <span class="hlt">Flux</span> and Gravitational Waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahmad, Zahid; Ahmed, Qazi Zahoor; Awan, Abdul Sami</p> <p>2013-10-01</p> <p>In this paper, we investigated the cylindrical gravitational collapse with <span class="hlt">heat</span> <span class="hlt">flux</span> by considering the appropriate geometry of the interior and exterior spacetimes. For this purpose, we matched collapsing fluid to an exterior containing gravitational waves.The effects of <span class="hlt">heat</span> <span class="hlt">flux</span> on gravitational collapse are investigated and matched with the results obtained by Herrera and Santos (Class. Quantum Gravity 22:2407, 2005).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940011344','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940011344"><span>Explosive Boiling at Very Low <span class="hlt">Heat</span> <span class="hlt">Fluxes</span>: A Microgravity Phenomenon</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hasan, M. M.; Lin, C. S.; Knoll, R. H.; Bentz, M. D.</p> <p>1993-01-01</p> <p>The paper presents experimental observations of explosive boiling from a large (relative to bubble sizes) flat <span class="hlt">heating</span> surface at very low <span class="hlt">heat</span> <span class="hlt">fluxes</span> in microgravity. The explosive boiling is characterized as either a rapid growth of vapor mass over the entire <span class="hlt">heating</span> surface due to the flashing of superheated liquid or a violent boiling spread following the appearance of single bubbles on the <span class="hlt">heating</span> surface. Pool boiling data with saturated Freon 113 was obtained in the microgravity environment of the space shuttle. The unique features of the experimental results are the sustainability of high liquid superheat for long periods and the occurrence of explosive boiling at low <span class="hlt">heat</span> <span class="hlt">fluxes</span> (0.2 to 1.2 kW/sq m). For a <span class="hlt">heat</span> <span class="hlt">flux</span> of 1.0 kW/sq m a wall superheat of 17.9 degrees C was attained in ten minutes of <span class="hlt">heating</span>. This was followed by an explosive boiling accompanied with a pressure spike and a violent bulk liquid motion. However, at this <span class="hlt">heat</span> <span class="hlt">flux</span> the vapor blanketing the <span class="hlt">heating</span> surface could not be sustained. Stable nucleate boiling continued following the explosive boiling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhST..170a4007B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhST..170a4007B"><span>Comparison of <span class="hlt">heat</span> <span class="hlt">flux</span> measurement techniques during the DIII-D metal ring campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barton, J. L.; Nygren, R. E.; Unterberg, E. A.; Watkins, J. G.; Makowski, M. A.; Moser, A.; Rudakov, D. L.; Buchenauer, D.</p> <p>2017-12-01</p> <p>The <span class="hlt">heat</span> <span class="hlt">fluxes</span> expected in the ITER divertor raise concerns about the damage tolerances of tungsten, especially due to thermal transients caused by edge localized modes (ELMs) as well as frequent temperature cycling from high to low extremes. Therefore we are motivated to understand the <span class="hlt">heat</span> <span class="hlt">flux</span> conditions that can cause not only enhanced erosion but also bulk thermo-mechanical damage to a tungsten divertor. For the metal ring campaign in DIII-D, tungsten-coated TZM tile inserts were installed making two toroidal arrays of metal tile inserts in the lower divertor. This study examines the deposited <span class="hlt">heat</span> <span class="hlt">flux</span> on these rings with embedded thermocouples (TCs) sampling at 10 kHz and compares them to Langmuir probe (LP) and infrared thermography (IRTV) <span class="hlt">heat</span> <span class="hlt">flux</span> measurements. We see agreement of the TC, LP, and IRTV data within 20% of the <span class="hlt">heat</span> <span class="hlt">flux</span> averaged over the entire discharge, and that all three diagnostics suggest parallel <span class="hlt">heat</span> <span class="hlt">flux</span> at the OSP location increases linearly with input <span class="hlt">heating</span> power. The TC and LP <span class="hlt">heat</span> <span class="hlt">flux</span> time traces during the discharge trend together during large changes to the average <span class="hlt">heat</span> <span class="hlt">flux</span>. By subtracting the LP measured inter-ELM <span class="hlt">heat</span> <span class="hlt">flux</span> from TC data, using a rectangular ELM energy pulse shape, and taking the relative size and duration of each ELM from {{D}}α measurements, we extract the ELM <span class="hlt">heat</span> <span class="hlt">fluxes</span> from TC data. This over-estimates the IRTV measured ELM <span class="hlt">heat</span> <span class="hlt">fluxes</span> by a factor of 1.9, and could be due to the simplicity of the TC <span class="hlt">heat</span> <span class="hlt">flux</span> model and the assumed ELM energy pulse shape. ELM <span class="hlt">heat</span> <span class="hlt">fluxes</span> deposited on the inserts are used to model tungsten erosion in this campaign. These TC ELM <span class="hlt">heat</span> <span class="hlt">flux</span> estimates are used in addition to IRTV, especially in cases where the IRTV view to the metal ring is obstructed. We observe that some metal inserts were deformed due to exposed leading edges. The thermal conditions on these inserts are investigated with the thermal modeling code ABAQUS using our <span class="hlt">heat</span> <span class="hlt">flux</span> measurements when these edges</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850027078','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850027078"><span>Development of advanced high-temperature <span class="hlt">heat</span> <span class="hlt">flux</span> sensors. Phase 2: Verification testing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Atkinson, W. H.; Cyr, M. A.; Strange, R. R.</p> <p>1985-01-01</p> <p>A two-phase program is conducted to develop <span class="hlt">heat</span> <span class="hlt">flux</span> sensors capable of making <span class="hlt">heat</span> <span class="hlt">flux</span> measurements throughout the hot section of gas turbine engines. In Phase 1, three types of <span class="hlt">heat</span> <span class="hlt">flux</span> sensors are selected; embedded thermocouple, laminated, and Gardon gauge sensors. A demonstration of the ability of these sensors to operate in an actual engine environment is reported. A segmented liner of each of two combustors being used in the Broad Specification Fuels Combustor program is instrumented with the three types of <span class="hlt">heat</span> <span class="hlt">flux</span> sensors then tested in a high pressure combustor rig. Radiometer probes are also used to measure the radiant <span class="hlt">heat</span> loads to more fully characterize the combustor environment. Test results show the <span class="hlt">heat</span> <span class="hlt">flux</span> sensors to be in good agreement with radiometer probes and the predicted data trends. In general, <span class="hlt">heat</span> <span class="hlt">flux</span> sensors have strong potential for use in combustor development programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4646773','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4646773"><span>High geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> measured below the West Antarctic Ice Sheet</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fisher, Andrew T.; Mankoff, Kenneth D.; Tulaczyk, Slawek M.; Tyler, Scott W.; Foley, Neil</p> <p>2015-01-01</p> <p>The geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> is a critical thermal boundary condition that influences the melting, flow, and mass balance of ice sheets, but measurements of this parameter are difficult to make in ice-covered regions. We report the first direct measurement of geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> into the base of the West Antarctic Ice Sheet (WAIS), below Subglacial Lake Whillans, determined from the thermal gradient and the thermal conductivity of sediment under the lake. The <span class="hlt">heat</span> <span class="hlt">flux</span> at this site is 285 ± 80 mW/m2, significantly higher than the continental and regional averages estimated for this site using regional geophysical and glaciological models. Independent temperature measurements in the ice indicate an upward <span class="hlt">heat</span> <span class="hlt">flux</span> through the WAIS of 105 ± 13 mW/m2. The difference between these <span class="hlt">heat</span> <span class="hlt">flux</span> values could contribute to basal melting and/or be advected from Subglacial Lake Whillans by flowing water. The high geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> may help to explain why ice streams and subglacial lakes are so abundant and dynamic in this region. PMID:26601210</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26601210','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26601210"><span>High geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> measured below the West Antarctic Ice Sheet.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fisher, Andrew T; Mankoff, Kenneth D; Tulaczyk, Slawek M; Tyler, Scott W; Foley, Neil</p> <p>2015-07-01</p> <p>The geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> is a critical thermal boundary condition that influences the melting, flow, and mass balance of ice sheets, but measurements of this parameter are difficult to make in ice-covered regions. We report the first direct measurement of geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> into the base of the West Antarctic Ice Sheet (WAIS), below Subglacial Lake Whillans, determined from the thermal gradient and the thermal conductivity of sediment under the lake. The <span class="hlt">heat</span> <span class="hlt">flux</span> at this site is 285 ± 80 mW/m(2), significantly higher than the continental and regional averages estimated for this site using regional geophysical and glaciological models. Independent temperature measurements in the ice indicate an upward <span class="hlt">heat</span> <span class="hlt">flux</span> through the WAIS of 105 ± 13 mW/m(2). The difference between these <span class="hlt">heat</span> <span class="hlt">flux</span> values could contribute to basal melting and/or be advected from Subglacial Lake Whillans by flowing water. The high geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> may help to explain why ice streams and subglacial lakes are so abundant and dynamic in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960042871','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960042871"><span>Two-<span class="hlt">Flux</span> and Green's Function Method for Transient <span class="hlt">Radiative</span> Transfer in a Semi-Transparent Layer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siegel, Robert</p> <p>1995-01-01</p> <p>A method using a Green's function is developed for computing transient temperatures in a semitransparent layer by using the two-<span class="hlt">flux</span> method coupled with the transient energy equation. Each boundary of the layer is exposed to a hot or cold <span class="hlt">radiative</span> environment, and is <span class="hlt">heated</span> or cooled by convection. The layer refractive index is larger than one, and the effect of internal reflections is included with the boundaries assumed diffuse. The analysis accounts for internal emission, absorption, <span class="hlt">heat</span> conduction, and isotropic scattering. Spectrally dependent <span class="hlt">radiative</span> properties are included, and transient results are given to illustrate two-band spectral behavior with optically thin and thick bands. Transient results using the present Green's function method are verified for a gray layer by comparison with a finite difference solution of the exact <span class="hlt">radiative</span> transfer equations; excellent agreement is obtained. The present method requires only moderate computing times and incorporates isotropic scattering without additional complexity. Typical temperature distributions are given to illustrate application of the method by examining the effect of strong <span class="hlt">radiative</span> <span class="hlt">heating</span> on one side of a layer with convective cooling on the other side, and the interaction of strong convective <span class="hlt">heating</span> with <span class="hlt">radiative</span> cooling from the layer interior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914314B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914314B"><span>The forgotten component of sub-glacial <span class="hlt">heat</span> flow: Upper crustal <span class="hlt">heat</span> production and resultant total <span class="hlt">heat</span> <span class="hlt">flux</span> on the Antarctic Peninsula</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burton-Johnson, Alex; Halpin, Jacqueline; Whittaker, Joanne; Watson, Sally</p> <p>2017-04-01</p> <p>Seismic and magnetic geophysical methods have both been employed to produce estimates of <span class="hlt">heat</span> <span class="hlt">flux</span> beneath the Antarctic ice sheet. However, both methods use a homogeneous upper crustal model despite the variable concentration of <span class="hlt">heat</span> producing elements within its composite lithologies. Using geological and geochemical datasets from the Antarctic Peninsula we have developed a new methodology for incorporating upper crustal <span class="hlt">heat</span> production in <span class="hlt">heat</span> <span class="hlt">flux</span> models and have shown the greater variability this introduces in to estimates of crustal <span class="hlt">heat</span> <span class="hlt">flux</span>, with implications for glaciological modelling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=287479','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=287479"><span>The effect of <span class="hlt">heat</span> <span class="hlt">fluxes</span> on ammonia emission from swine waste lagoon based on neural network analyses</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Understanding factors that affect ammonia emissions from swine waste lagoons or any animal waste receptacles is a necessary first step in deploying potential remediation options. In this study, we examined the various meteorological factors (i.e., air temperatures, solar <span class="hlt">radiation</span>, and <span class="hlt">heat</span> <span class="hlt">fluxes</span>)...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS22B..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS22B..05M"><span>Atmospheric responses to sensible and latent <span class="hlt">heating</span> <span class="hlt">fluxes</span> over the Gulf Stream</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Minobe, S.; Ida, T.; Takatama, K.</p> <p>2016-12-01</p> <p>Air-sea interaction over mid-latitude oceanic fronts such as the Gulf Stream attracted large attention in the last decade. Observational analyses and modelling studies revealed that atmospheric responses over the Gulf Stream including surface wind convergence, enhanced precipitation and updraft penetrating to middle-to-upper troposphere roughly on the Gulf Stream current axis or on the warmer flank of sea-surface temperature (SST) front of the Gulf Stream . For these atmospheric responses, oceanic information should be transmitted to the atmosphere via turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span>, and thus the mechanisms for atmospheric responses can be understood better by examining latent and sensible air-sea <span class="hlt">heat</span> <span class="hlt">fluxes</span> more closely. Thus, the roles of the sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> are examined by conducting a series of numerical experiments using the IPRC Regional Atmospheric Model over the Gulf Stream by applying SST smoothing for latent and sensible <span class="hlt">heating</span> separately. The results indicate that the sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> affect the atmosphere differently. Sensible <span class="hlt">heat</span> <span class="hlt">flux</span> intensifies surface wind convergence to produce sea-level pressure (SLP) anomaly. Latent <span class="hlt">heat</span> <span class="hlt">flux</span> supplies moistures and maintains enhanced precipitation. The different <span class="hlt">heat</span> <span class="hlt">flux</span> components cause upward wind velocity at different levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29624394','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29624394"><span>Ultrahigh <span class="hlt">Flux</span> Thin Film Boiling <span class="hlt">Heat</span> Transfer Through Nanoporous Membranes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Qingyang; Chen, Renkun</p> <p>2018-05-09</p> <p>Phase change <span class="hlt">heat</span> transfer is fundamentally important for thermal energy conversion and management, such as in electronics with power density over 1 kW/cm 2 . The critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) of phase change <span class="hlt">heat</span> transfer, either evaporation or boiling, is limited by vapor <span class="hlt">flux</span> from the liquid-vapor interface, known as the upper limit of <span class="hlt">heat</span> <span class="hlt">flux</span>. This limit could in theory be greater than 1 kW/cm 2 on a planar surface, but its experimental realization has remained elusive. Here, we utilized nanoporous membranes to realize a new "thin film boiling" regime that resulted in an unprecedentedly high CHF of over 1.2 kW/cm 2 on a planar surface, which is within a factor of 4 of the theoretical limit, and can be increased to a higher value if mechanical strength of the membranes can be improved (demonstrated with 1.85 kW/cm 2 CHF in this work). The liquid supply is achieved through a simple nanoporous membrane that supports the liquid film where its thickness automatically decreases as <span class="hlt">heat</span> <span class="hlt">flux</span> increases. The thin film configuration reduces the conductive thermal resistance, leads to high frequency bubble departure, and provides separate liquid-vapor pathways, therefore significantly enhances the <span class="hlt">heat</span> transfer. Our work provides a new nanostructuring approach to achieve ultrahigh <span class="hlt">heat</span> <span class="hlt">flux</span> in phase change <span class="hlt">heat</span> transfer and will benefit both theoretical understanding and application in thermal management of high power devices of boiling <span class="hlt">heat</span> transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO54F3320B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO54F3320B"><span>Satellite-based Calibration of <span class="hlt">Heat</span> <span class="hlt">Flux</span> at the Ocean Surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barron, C. N.; Dastugue, J. M.; May, J. C.; Rowley, C. D.; Smith, S. R.; Spence, P. L.; Gremes-Cordero, S.</p> <p>2016-02-01</p> <p>Model forecasts of upper ocean <span class="hlt">heat</span> content and variability on diurnal to daily scales are highly dependent on estimates of <span class="hlt">heat</span> <span class="hlt">flux</span> through the air-sea interface. Satellite remote sensing is applied to not only inform the initial ocean state but also to mitigate errors in surface <span class="hlt">heat</span> <span class="hlt">flux</span> and model representations affecting the distribution of <span class="hlt">heat</span> in the upper ocean. Traditional assimilation of sea surface temperature (SST) observations re-centers ocean models at the start of each forecast cycle. Subsequent evolution depends on estimates of surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> and upper-ocean processes over the forecast period. The COFFEE project (Calibration of Ocean Forcing with satellite <span class="hlt">Flux</span> Estimates) endeavors to correct ocean forecast bias through a responsive error partition among surface <span class="hlt">heat</span> <span class="hlt">flux</span> and ocean dynamics sources. A suite of experiments in the southern California Current demonstrates a range of COFFEE capabilities, showing the impact on forecast error relative to a baseline three-dimensional variational (3DVAR) assimilation using Navy operational global or regional atmospheric forcing. COFFEE addresses satellite-calibration of surface <span class="hlt">fluxes</span> to estimate surface error covariances and links these to the ocean interior. Experiment cases combine different levels of <span class="hlt">flux</span> calibration with different assimilation alternatives. The cases may use the original <span class="hlt">fluxes</span>, apply full satellite corrections during the forecast period, or extend hindcast corrections into the forecast period. Assimilation is either baseline 3DVAR or standard strong-constraint 4DVAR, with work proceeding to add a 4DVAR expanded to include a weak constraint treatment of the surface <span class="hlt">flux</span> errors. Covariance of <span class="hlt">flux</span> errors is estimated from the recent time series of forecast and calibrated <span class="hlt">flux</span> terms. While the California Current examples are shown, the approach is equally applicable to other regions. These approaches within a 3DVAR application are anticipated to be useful for global and larger</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170002665&hterms=geomagnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dgeomagnetism','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170002665&hterms=geomagnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dgeomagnetism"><span>GEM-CEDAR Challenge: Poynting <span class="hlt">Flux</span> at DMSP and Modeled Joule <span class="hlt">Heat</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rastaetter, Lutz; Shim, Ja Soon; Kuznetsova, Maria M.; Kilcommons, Liam M.; Knipp, Delores J.; Codrescu, Mihail; Fuller-Rowell, Tim; Emery, Barbara; Weimer, Daniel R.; Cosgrove, Russell; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20170002665'); toggleEditAbsImage('author_20170002665_show'); toggleEditAbsImage('author_20170002665_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20170002665_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170002665_hide"></p> <p>2016-01-01</p> <p>Poynting <span class="hlt">flux</span> into the ionosphere measures the electromagnetic energy coming from the magnetosphere. This energy <span class="hlt">flux</span> can vary greatly between quiet times and geomagnetic active times. As part of the Geospace Environment Modeling-coupling energetics and dynamics of atmospheric regions modeling challenge, physics-based models of the 3-D ionosphere and ionospheric electrodynamics solvers of magnetosphere models that specify Joule <span class="hlt">heat</span> and empirical models specifying Poynting <span class="hlt">flux</span> were run for six geomagnetic storm events of varying intensity. We compared model results with Poynting <span class="hlt">flux</span> values along the DMSP-15 satellite track computed from ion drift meter and magnetic field observations. Although being a different quantity, Joule <span class="hlt">heat</span> can in practice be correlated to incoming Poynting <span class="hlt">flux</span> because the energy is dissipated primarily in high latitudes where Poynting <span class="hlt">flux</span> is being deposited. Within the physics-based model group, we find mixed results with some models overestimating Joule <span class="hlt">heat</span> and some models agreeing better with observed Poynting <span class="hlt">flux</span> rates as integrated over auroral passes. In contrast, empirical models tend to underestimate integrated Poynting <span class="hlt">flux</span> values. Modeled Joule <span class="hlt">heat</span> or Poynting <span class="hlt">flux</span> patterns often resemble the observed Poynting <span class="hlt">flux</span> patterns on a large scale, but amplitudes can differ by a factor of 2 or larger due to the highly localized nature of observed Poynting <span class="hlt">flux</span> deposition that is not captured by the models. In addition, the positioning of modeled patterns appear to be randomly shifted against the observed Poynting <span class="hlt">flux</span> energy input. This study is the first to compare Poynting <span class="hlt">flux</span> and Joule <span class="hlt">heat</span> in a large variety of models of the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AtmEn..40.3561S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AtmEn..40.3561S"><span>Land use planning and surface <span class="hlt">heat</span> island formation: A parcel-based <span class="hlt">radiation</span> <span class="hlt">flux</span> approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stone, Brian; Norman, John M.</p> <p></p> <p>This article presents a study of residential parcel design and surface <span class="hlt">heat</span> island formation in a major metropolitan region of the southeastern United States. Through the integration of high-resolution multispectral data (10 m) with property tax records for over 100,000 single-family residential parcels in the Atlanta, Georgia, metropolitan region, the influence of the size and material composition of residential land use on an indicator of surface <span class="hlt">heat</span> island formation is reported. In contrast to previous work on the urban <span class="hlt">heat</span> island, this study derives a parcel-based indicator of surface warming to permit the impact of land use planning regulations governing the density and design of development on the excess surface <span class="hlt">flux</span> of <span class="hlt">heat</span> energy to be measured. The results of this study suggest that the contribution of individual land parcels to regional surface <span class="hlt">heat</span> island formation could be reduced by approximately 40% through the adoption of specific land use planning policies, such as zoning and subdivision regulations, and with no modifications to the size or albedo of the residential structure.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20770232-investigation-saturated-critical-heat-flux-single-uniformly-heated-microchannel','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20770232-investigation-saturated-critical-heat-flux-single-uniformly-heated-microchannel"><span>Investigation of saturated critical <span class="hlt">heat</span> <span class="hlt">flux</span> in a single, uniformly <span class="hlt">heated</span> microchannel</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wojtan, Leszek; Revellin, Remi; Thome, John R.</p> <p>2006-08-15</p> <p>A series of tests have been performed to determine the saturated critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) in 0.5 and 0.8mm internal diameter microchannel tubes as a function of refrigerant mass velocity, <span class="hlt">heated</span> length, saturation temperature and inlet liquid subcooling. The tested refrigerants were R-134a and R-245fa and the <span class="hlt">heated</span> length of microchannel was varied between 20 and 70mm. The results show a strong dependence of CHF on mass velocity, <span class="hlt">heated</span> length and microchannel diameter but no influence of liquid subcooling (2-15{sup o}C) was observed. The experimental results have been compared to the well-known CHF single-channel correlation of Y. Katto and H.more » Ohno [An improved version of the generalized correlation of critical <span class="hlt">heat</span> <span class="hlt">flux</span> for the forced convective boiling in uniformly <span class="hlt">heated</span> vertical tubes, Int. J. <span class="hlt">Heat</span> and Mass Transfer 27 (9) (1984) 1641-1648] and the multichannel correlation of W. Qu and I. Mudawar [Measurement and correlation of critical <span class="hlt">heat</span> <span class="hlt">flux</span> in two-phase microchannel <span class="hlt">heat</span> sinks, Int. J. <span class="hlt">Heat</span> and Mass Transfer 47 (2004) 2045-2059]. The comparison shows that the correlation of Katto-Ohno predicts microchannel data with a mean absolute error of 32.8% with only 41.2% of the data falling within a +/-15% error band. The correlation of Qu and Mudawar shows the same trends as the CHF data but significantly overpredicts them. Based on the present experimental data, a new microscale version of the Katto-Ohno correlation for the prediction of CHF during saturated boiling in microchannels has been proposed. (author)« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920009517','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920009517"><span>Miniature high temperature plug-type <span class="hlt">heat</span> <span class="hlt">flux</span> gauges</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liebert, Curt H.</p> <p>1992-01-01</p> <p>The objective is to describe continuing efforts to develop methods for measuring surface <span class="hlt">heat</span> <span class="hlt">flux</span>, gauge active surface temperature, and <span class="hlt">heat</span> transfer coefficient quantities. The methodology involves inventing a procedure for fabricating improved plug-type <span class="hlt">heat</span> <span class="hlt">flux</span> gauges and also for formulating inverse <span class="hlt">heat</span> conduction models and calculation procedures. These models and procedures are required for making indirect measurements of these quantities from direct temperature measurements at gauge interior locations. Measurements of these quantities were made in a turbine blade thermal cycling tester (TBT) located at MSFC. The TBT partially simulates the turbopump turbine environment in the Space Shuttle Main Engine. After the TBT test, experiments were performed in an arc lamp to analyze gauge quality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000076807','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000076807"><span><span class="hlt">Radiation</span> <span class="hlt">Heat</span> Transfer Between Diffuse-Gray Surfaces Using Higher Order Finite Elements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gould, Dana C.</p> <p>2000-01-01</p> <p>This paper presents recent work on developing methods for analyzing <span class="hlt">radiation</span> <span class="hlt">heat</span> transfer between diffuse-gray surfaces using p-version finite elements. The work was motivated by a thermal analysis of a High Speed Civil Transport (HSCT) wing structure which showed the importance of <span class="hlt">radiation</span> <span class="hlt">heat</span> transfer throughout the structure. The analysis also showed that refining the finite element mesh to accurately capture the temperature distribution on the internal structure led to very large meshes with unacceptably long execution times. Traditional methods for calculating surface-to-surface <span class="hlt">radiation</span> are based on assumptions that are not appropriate for p-version finite elements. Two methods for determining internal <span class="hlt">radiation</span> <span class="hlt">heat</span> transfer are developed for one and two-dimensional p-version finite elements. In the first method, higher-order elements are divided into a number of sub-elements. Traditional methods are used to determine <span class="hlt">radiation</span> <span class="hlt">heat</span> <span class="hlt">flux</span> along each sub-element and then mapped back to the parent element. In the second method, the <span class="hlt">radiation</span> <span class="hlt">heat</span> transfer equations are numerically integrated over the higher-order element. Comparisons with analytical solutions show that the integration scheme is generally more accurate than the sub-element method. Comparison to results from traditional finite elements shows that significant reduction in the number of elements in the mesh is possible using higher-order (p-version) finite elements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A51T..07D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A51T..07D"><span>Calculating clear-sky <span class="hlt">radiative</span> <span class="hlt">heating</span> rates using the Fu-Liou RTM with inputs from observed and reanalyzed profiles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dolinar, E. K.; Dong, X.; Xi, B.</p> <p>2015-12-01</p> <p>One-dimensional <span class="hlt">radiative</span> transfer models (RTM) are a common tool used for calculating atmospheric <span class="hlt">heating</span> rates and <span class="hlt">radiative</span> <span class="hlt">fluxes</span>. In the forward sense, RTMs use known (or observed) quantities of the atmospheric state and surface characteristics to determine the appropriate surface and top-of-atmosphere (TOA) <span class="hlt">radiative</span> <span class="hlt">fluxes</span>. The NASA CERES science team uses the modified Fu-Liou RTM to calculate atmospheric <span class="hlt">heating</span> rates and surface and TOA <span class="hlt">fluxes</span> using the CERES observed TOA shortwave (SW) and longwave (LW) <span class="hlt">fluxes</span> as constraints to derive global surface and TOA <span class="hlt">radiation</span> budgets using a reanalyzed atmospheric state (e.g. temperature and various greenhouse gases) from the newly developed MERRA-2. However, closure studies have shown that using the reanalyzed state as input to the RTM introduces some disparity between the RTM calculated <span class="hlt">fluxes</span> and surface observed ones. The purpose of this study is to generate a database of observed atmospheric state profiles, from satellite and ground-based sources, at several permanent Atmospheric <span class="hlt">Radiation</span> Measurement (ARM) Program sites, including the Southern Great Plains (SGP), Northern Slope of Alaska (NSA) and Tropical Western Pacific Nauru (TWP-C2), and Eastern North Atlantic (ENA) permanent facilities. Since clouds are a major modulator of <span class="hlt">radiative</span> transfer within the Earth's atmosphere, we will focus on the clear-sky conditions in this study, which will set up the baseline for our cloudy studies in the future. Clear-sky <span class="hlt">flux</span> profiles are calculated using the Edition 4 NASA LaRC modified Fu-Liou RTM. The aforementioned atmospheric profiles generated in-house are used as input into the RTM, as well as from reanalyses. The calculated surface and TOA <span class="hlt">fluxes</span> are compared with ARM surface measured and CERES satellite observed SW and LW <span class="hlt">fluxes</span>, respectively. Clear-sky cases are identified by the ARM radar-lidar observations, as well as satellite observations, at the select ARM sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4199907','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4199907"><span>Estimating Energy Expenditure Using <span class="hlt">Heat</span> <span class="hlt">Flux</span> Measured at Single Body Site</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lyden, Kate; Swibas, Tracy; Catenacci, Victoria; Guo, Ruixin; Szuminsky, Neil; Melanson, Edward L.</p> <p>2014-01-01</p> <p>Introduction The Personal Calorie Monitor (PCM) is a portable direct calorimeter that estimates energy expenditure (EE) from measured <span class="hlt">heat</span> <span class="hlt">flux</span> (i.e. the sum of conductive, convective, <span class="hlt">radiative</span>, and evaporative). Purpose The primary aim of this study was to compare EE estimated from measures of <span class="hlt">heat</span> <span class="hlt">flux</span> to indirect calorimetry in a thermoneutral environment (26°C). A secondary aim was to determine if exposure to ambient temperature below thermoneutral (19°C) influences the accuracy of the PCM. Methods 34 Adults (mean±SD, age = 28±5 y, body mass index = 22.9±2.6 kg.m2) were studied for 5 h in a whole-room indirect calorimeter (IC) in thermoneutral and cool conditions. Participants wore the PCM on their upper arm and completed two, 20-minute treadmill-walking bouts (0% grade, 3 mph). The remaining time was spent sedentary (e.g., watching television, using a computer). Results In thermoneutral, EE (mean (95% CI)) measured by IC and PCM was 560.0 (526.5, 593.5) and 623.3 (535.5, 711.1) kcals, respectively. In cool, EE measured by IC and PCM was 572.5 (540.9, 604.0) and 745.5 (668.1, 822.8) kcals, respectively. Under thermoneutral conditions, mean PCM minute-by-minute EE tracked closely with IC, resulting in a small, non-significant bias (63 kcals (−5.8, 132.4)). During cool conditions, mean PCM minute-by-minute EE did not track IC, resulting in a large bias (173.0 (93.9, 252.1)) (p<0.001). Conclusion This study demonstrated the validity of using measured <span class="hlt">heat</span> <span class="hlt">flux</span> to estimate EE. However, accuracy may be impaired in cool conditions, possibly due to excess <span class="hlt">heat</span> loss from the exposed limbs. PMID:24811326</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28437986','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28437986"><span>Control and design <span class="hlt">heat</span> <span class="hlt">flux</span> bending in thermal devices with transformation optics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Guoqiang; Zhang, Haochun; Jin, Yan; Li, Sen; Li, Yao</p> <p>2017-04-17</p> <p>We propose a fundamental latent function of control <span class="hlt">heat</span> transfer and <span class="hlt">heat</span> <span class="hlt">flux</span> density vectors at random positions on thermal materials by applying transformation optics. The expressions for <span class="hlt">heat</span> <span class="hlt">flux</span> bending are obtained, and the factors influencing them are investigated in both 2D and 3D cloaking schemes. Under certain conditions, more than one degree of freedom of <span class="hlt">heat</span> <span class="hlt">flux</span> bending exists corresponding to the temperature gradients of the 3D domain. The <span class="hlt">heat</span> <span class="hlt">flux</span> path can be controlled in random space based on the geometrical azimuths, radial positions, and thermal conductivity ratios of the selected materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70186946','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70186946"><span><span class="hlt">Heat</span> <span class="hlt">flux</span> from magmatic hydrothermal systems related to availability of fluid recharge</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Harvey, M. C.; Rowland, J.V.; Chiodini, G.; Rissmann, C.F.; Bloomberg, S.; Hernandez, P.A.; Mazot, A.; Viveiros, F.; Werner, Cynthia A.</p> <p>2015-01-01</p> <p>Magmatic hydrothermal systems are of increasing interest as a renewable energy source. Surface <span class="hlt">heat</span> <span class="hlt">flux</span> indicates system resource potential, and can be inferred from soil CO2 <span class="hlt">flux</span> measurements and fumarole gas chemistry. Here we compile and reanalyze results from previous CO2 <span class="hlt">flux</span> surveys worldwide to compare <span class="hlt">heat</span> <span class="hlt">flux</span> from a variety of magma-hydrothermal areas. We infer that availability of water to recharge magmatic hydrothermal systems is correlated with <span class="hlt">heat</span> <span class="hlt">flux</span>. Recharge availability is in turn governed by permeability, structure, lithology, rainfall, topography, and perhaps unsurprisingly, proximity to a large supply of water such as the ocean. The relationship between recharge and <span class="hlt">heat</span> <span class="hlt">flux</span> interpreted by this study is consistent with recent numerical modeling that relates hydrothermal system <span class="hlt">heat</span> output to rainfall catchment area. This result highlights the importance of recharge as a consideration when evaluating hydrothermal systems for electricity generation, and the utility of CO2 <span class="hlt">flux</span> as a resource evaluation tool.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T13B0517B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T13B0517B"><span>A new <span class="hlt">heat</span> <span class="hlt">flux</span> model for the Antarctic Peninsula incorporating spatially variable upper crustal radiogenic <span class="hlt">heat</span> production</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burton-Johnson, A.; Halpin, J.; Whittaker, J. M.; Graham, F. S.; Watson, S. J.</p> <p>2017-12-01</p> <p>We present recently published findings (Burton-Johnson et al., 2017) on the variability of Antarctic sub-glacial <span class="hlt">heat</span> <span class="hlt">flux</span> and the impact from upper crustal geology. Our new method reveals that the upper crust contributes up to 70% of the Antarctic Peninsula's subglacial <span class="hlt">heat</span> <span class="hlt">flux</span>, and that <span class="hlt">heat</span> <span class="hlt">flux</span> values are more variable at smaller spatial resolutions than geophysical methods can resolve. Results indicate a higher <span class="hlt">heat</span> <span class="hlt">flux</span> on the east and south of the Peninsula (mean 81 mWm-2) where silicic rocks predominate, than on the west and north (mean 67 mWm-2) where volcanic arc and quartzose sediments are dominant. Whilst the data supports the contribution of HPE-enriched granitic rocks to high <span class="hlt">heat</span> <span class="hlt">flux</span> values, sedimentary rocks can be of comparative importance dependent on their provenance and petrography. Models of subglacial <span class="hlt">heat</span> <span class="hlt">flux</span> must utilize a heterogeneous upper crust with variable radioactive <span class="hlt">heat</span> production if they are to accurately predict basal conditions of the ice sheet. Our new methodology and dataset facilitate improved numerical model simulations of ice sheet dynamics. The most significant challenge faced remains accurate determination of crustal structure, particularly the depths of the HPE-enriched sedimentary basins and the sub-glacial geology away from exposed outcrops. Continuing research (particularly detailed geophysical interpretation) will better constrain these unknowns and the effect of upper crustal geology on the Antarctic ice sheet. Burton-Johnson, A., Halpin, J.A., Whittaker, J.M., Graham, F.S., and Watson, S.J., 2017, A new <span class="hlt">heat</span> <span class="hlt">flux</span> model for the Antarctic Peninsula incorporating spatially variable upper crustal radiogenic <span class="hlt">heat</span> production: Geophysical Research Letters, v. 44, doi: 10.1002/2017GL073596.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850067082&hterms=Biddle&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DBiddle','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850067082&hterms=Biddle&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DBiddle"><span>Evidence for ion <span class="hlt">heat</span> <span class="hlt">flux</span> in the light ion polar wind</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Biddle, A. P.; Moore, T. E.; Chappell, C. R.</p> <p>1985-01-01</p> <p>Cold flowing hydrogen and helium ions have been observed using the retarding ion mass spectrometer on board the Dynamics Explorer 1 spacecraft in the dayside magnetosphere at subauroral latitudes. The ions show a marked <span class="hlt">flux</span> asymmetry with respect to the relative wind direction. The observed data are fitted by a model of drifting Maxwellian distributions perturbed by a first order-Spritzer-Haerm <span class="hlt">heat</span> <span class="hlt">flux</span> distribution function. It is shown that both ion species are supersonic just equatorward of the auroral zone at L = 14, and the shape of asymmetry and direction of the asymmetry are consistent with the presence of an upward <span class="hlt">heat</span> <span class="hlt">flux</span>. At L = 6, both species evolve smoothly into warmer subsonic upward flows with downward <span class="hlt">heat</span> <span class="hlt">fluxes</span>. In the case of subsonic flows the downward <span class="hlt">heat</span> <span class="hlt">flux</span> implies a significant <span class="hlt">heat</span> source at higher altitudes. Spin curves of the spectrometer count rate versus the spin phase angle are provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930022364','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930022364"><span>Progress in the measurement of SSME turbine <span class="hlt">heat</span> <span class="hlt">flux</span> with plug-type sensors</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liebert, Curt H.</p> <p>1991-01-01</p> <p>Data reduction was completed for tests of plug-type <span class="hlt">heat</span> <span class="hlt">flux</span> sensors (gauges) in a turbine blade thermal cycling tester (TBT) that is located at NASA/Marshall Space Flight Center, and a typical gauge is illustrated. This is the first time that <span class="hlt">heat</span> <span class="hlt">flux</span> has been measured in a Space Shuttle Main Engine (SSME) Turbopump Turbine environment. The development of the concept for the gauge was performed in a <span class="hlt">heat</span> <span class="hlt">flux</span> measurement facility at Lewis. In this facility, transient and steady state absorbed surface <span class="hlt">heat</span> <span class="hlt">flux</span> information was obtained from transient temperature measurements taken at points within the gauge. A schematic of the TBT is presented, and plots of the absorbed surface <span class="hlt">heat</span> <span class="hlt">flux</span> measured on the three blades tested in the TBT are presented. High quality <span class="hlt">heat</span> <span class="hlt">flux</span> values were measured on all three blades. The experiments demonstrated that reliable and durable gauges can be repeatedly fabricated into the airfoils. The experiment <span class="hlt">heat</span> <span class="hlt">flux</span> data are being used for verification of SSME analytical stress, boundary layer, and <span class="hlt">heat</span> transfer design models. Other experimental results and future plans are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A33B0157H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A33B0157H"><span>Distributed Sensible <span class="hlt">Heat</span> <span class="hlt">Flux</span> Measurements for Wireless Sensor Networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huwald, H.; Brauchli, T.; Lehning, M.; Higgins, C. W.</p> <p>2015-12-01</p> <p>The sensible <span class="hlt">heat</span> <span class="hlt">flux</span> component of the surface energy balance is typically computed using eddy covariance or two point profile measurements while alternative approaches such as the <span class="hlt">flux</span> variance method based on convective scaling has been much less explored and applied. <span class="hlt">Flux</span> variance (FV) certainly has a few limitations and constraints but may be an interesting and competitive method in low-cost and power limited wireless sensor networks (WSN) with the advantage of providing spatio-temporal sensible <span class="hlt">heat</span> <span class="hlt">flux</span> over the domain of the network. In a first step, parameters such as sampling frequency, sensor response time, and averaging interval are investigated. Then we explore the applicability and the potential of the FV method for use in WSN in a field experiment. Low-cost sensor systems are tested and compared against reference instruments (3D sonic anemometers) to evaluate the performance and limitations of the sensors as well as the method with respect to the standard calculations. Comparison experiments were carried out at several sites to gauge the <span class="hlt">flux</span> measurements over different surface types (gravel, grass, water) from the low-cost systems. This study should also serve as an example of spatially distributed sensible <span class="hlt">heat</span> <span class="hlt">flux</span> measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1412137Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1412137Z"><span>Urban <span class="hlt">heat</span> <span class="hlt">fluxes</span> in the subsurface of Cologne, Germany</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, K.; Bayer, P.; Blum, P.</p> <p>2012-04-01</p> <p>Urbanization during the last hundred years has led to both environmental and thermal impacts on the subsurface. The urban <span class="hlt">heat</span> island (UHI) effect is mostly described as an atmospheric phenomenon, where the measured aboveground temperatures in cities are elevated in comparison to undisturbed rural regions. However, UHIs can be found below, as well as above ground. A large amount of anthropogenic <span class="hlt">heat</span> migrates into the urban subsurface, which also raises the ground temperature and permanently changes the thermal conditions in shallow aquifers. The main objective of our work is to study and determine the urban <span class="hlt">heat</span> <span class="hlt">fluxes</span> in Cologne, Germany, and to improve our understanding of the dynamics of subsurface energy <span class="hlt">fluxes</span> in UHIs. Ideally, our findings will contribute to strategic and more sustainable geothermal use in cities. For a quantitative analysis of the energy <span class="hlt">fluxes</span> within the subsurface and across the atmospheric boundary, two and three-dimensional coupled numerical flow and <span class="hlt">heat</span> transport models were developed. The simulation results indicate that during the past hundred years, an average vertical urban <span class="hlt">heat</span> <span class="hlt">flux</span> that ranges between 80 and 375 mW m-2 can be deduced. Thermal anomalies have migrated into the local urban aquifer system and they reach a depth of about 150 m. In this context, the influence of the regional groundwater flow on the subsurface <span class="hlt">heat</span> transport and temperature development is comprehensively discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12836556','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12836556"><span>[A review on research of land surface water and <span class="hlt">heat</span> <span class="hlt">fluxes</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sun, Rui; Liu, Changming</p> <p>2003-03-01</p> <p>Many field experiments were done, and soil-vegetation-atmosphere transfer(SVAT) models were stablished to estimate land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span>. In this paper, the processes of experimental research on land surface water and <span class="hlt">heat</span> <span class="hlt">fluxes</span> are reviewed, and three kinds of SVAT model(single layer model, two layer model and multi-layer model) are analyzed. Remote sensing data are widely used to estimate land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span>. Based on remote sensing and energy balance equation, different models such as simplified model, single layer model, extra resistance model, crop water stress index model and two source resistance model are developed to estimate land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> and evapotranspiration. These models are also analyzed in this paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JNuM..258..672M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JNuM..258..672M"><span>On the use of flat tile armour in high <span class="hlt">heat</span> <span class="hlt">flux</span> components</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Merola, M.; Vieider, G.</p> <p>1998-10-01</p> <p>The possibility to have a flat tile geometry for those high <span class="hlt">heat</span> <span class="hlt">flux</span> components subjected to a convective <span class="hlt">heat</span> <span class="hlt">flux</span> (namely the divertor dump target, lower vertical target, and the limiter) has been investigated. Because of the glancing incidence of the power load, if an armour tile falls off an extremely high <span class="hlt">heat</span> <span class="hlt">flux</span> hits the leading edge of the adjacent tile. As a result a rapid temperature increase occurs in the armour-<span class="hlt">heat</span> sink joint. The <span class="hlt">heat</span> <span class="hlt">flux</span> to the water coolant also increases rapidly up to a factor of 1.7 and 2.3 for a beryllium and CFC armour, respectively, thus causing possible critical <span class="hlt">heat</span> <span class="hlt">flux</span> problems. Thermal stresses in the armour-<span class="hlt">heat</span> sink joint double in less than 0.4 s and triplicate after 1 s thus leading to a possible cascade failure. Therefore the use of a flat tile geometry for these components does not seem to be appropriate. In this case a monoblock geometry gives a much more robust solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980018471','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980018471"><span>Tools for Atmospheric <span class="hlt">Radiative</span> Transfer: Streamer and <span class="hlt">Flux</span>Net. Revised</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Key, Jeffrey R.; Schweiger, Axel J.</p> <p>1998-01-01</p> <p>Two tools for the solution of <span class="hlt">radiative</span> transfer problems are presented. Streamer is a highly flexible medium spectral resolution <span class="hlt">radiative</span> transfer model based on the plane-parallel theory of <span class="hlt">radiative</span> transfer. Capable of computing either <span class="hlt">fluxes</span> or radiances, it is suitable for studying <span class="hlt">radiative</span> processes at the surface or within the atmosphere and for the development of remote-sensing algorithms. <span class="hlt">Flux</span>Net is a fast neural network-based implementation of Streamer for computing surface <span class="hlt">fluxes</span>. It allows for a sophisticated treatment of <span class="hlt">radiative</span> processes in the analysis of large data sets and potential integration into geophysical models where computational efficiency is an issue. Documentation and tools for the development of alternative versions of Fluxnet are available. Collectively, Streamer and <span class="hlt">Flux</span>Net solve a wide variety of problems related to <span class="hlt">radiative</span> transfer: Streamer provides the detail and sophistication needed to perform basic research on most aspects of complex <span class="hlt">radiative</span> processes while the efficiency and simplicity of <span class="hlt">Flux</span>Net make it ideal for operational use.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhFl...28i2102V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhFl...28i2102V"><span>Expanding Taylor bubble under constant <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Voirand, Antoine; Benselama, Adel M.; Ayel, Vincent; Bertin, Yves</p> <p>2016-09-01</p> <p>Modelization of non-isothermal bubbles expanding in a capillary, as a contribution to the understanding of the physical phenomena taking place in Pulsating <span class="hlt">Heat</span> Pipes (PHPs), is the scope of this paper. The liquid film problem is simplified and solved, while the thermal problem takes into account a constant <span class="hlt">heat</span> <span class="hlt">flux</span> density applied at the capillary tube wall, exchanging with the liquid film surrounding the bubble and also with the capillary tube outside medium. The liquid slug dynamics is solved using the Lucas-Washburn equation. Mass and energy balance on the vapor phase allow governing equations of bubble expansion to be written. The liquid and vapor phases are coupled only through the saturation temperature associated with the vapor pressure, assumed to be uniform throughout the bubble. Results show an over-<span class="hlt">heating</span> of the vapor phase, although the particular thermal boundary condition used here always ensures an evaporative mass <span class="hlt">flux</span> at the liquid-vapor interface. Global <span class="hlt">heat</span> exchange is also investigated, showing a strong decreasing of the PHP performance to convey <span class="hlt">heat</span> by phase change means for large meniscus velocities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6713305-third-law-thermodynamics-presence-heat-flux','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6713305-third-law-thermodynamics-presence-heat-flux"><span>Third law of thermodynamics in the presence of a <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Camacho, J.</p> <p>1995-01-01</p> <p>Following a maximum entropy formalism, we study a one-dimensional crystal under a <span class="hlt">heat</span> <span class="hlt">flux</span>. We obtain the phonon distribution function and evaluate the nonequilibrium temperature, the specific <span class="hlt">heat</span>, and the entropy as functions of the internal energy and the <span class="hlt">heat</span> <span class="hlt">flux</span>, in both the quantum and the classical limits. Some analogies between the behavior of equilibrium systems at low absolute temperature and nonequilibrium steady states under high values of the <span class="hlt">heat</span> <span class="hlt">flux</span> are shown, which point to a possible generalization of the third law in nonequilibrium situations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920066504&hterms=attractiveness&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dattractiveness','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920066504&hterms=attractiveness&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dattractiveness"><span>Analytical and experimental studies of <span class="hlt">heat</span> pipe <span class="hlt">radiation</span> cooling of hypersonic propulsion systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Martin, R. A.; Merrigan, M. A.; Elder, M. G.; Sena, J. T.; Keddy, E. S.; Silverstein, C. C.</p> <p>1992-01-01</p> <p>Analytical and experimental studies were completed to assess the feasibility of using high-temperature <span class="hlt">heat</span> pipes to cool hypersonic engine components. This new approach involves using <span class="hlt">heat</span> pipes to transport <span class="hlt">heat</span> away from the combustor, nozzle, or inlet regions, and to reject it to the environment by thermal <span class="hlt">radiation</span> from an external <span class="hlt">heat</span> pipe nacelle. For propulsion systems using <span class="hlt">heat</span> pipe <span class="hlt">radiation</span> cooling (HPRC), it is possible to continue to use hydrocarbon fuels into the Mach 4 to Mach 6 speed range, thereby enhancing the economic attractiveness of commercial or military hypersonic flight. In the second-phase feasibility program recently completed, it is found that <span class="hlt">heat</span> loads produced by considering both convection and <span class="hlt">radiation</span> <span class="hlt">heat</span> transfer from the combustion gas can be handled with HPRC design modifications. The application of thermal insulation to ramburner and nozzle walls was also found to reduce the <span class="hlt">heat</span> load by about one-half and to reduce peak HPRC system temperatures to below 2700 F. In addition, the operation of HPRC at cruise conditions of around Mach 4.5 and at an altitude of 90,000 ft lowers the peak hot-section temperatures to around 2800 F. An HPRC <span class="hlt">heat</span> pipe was successfully fabricated and tested at Mach 5 conditions of <span class="hlt">heat</span> <span class="hlt">flux</span>, <span class="hlt">heat</span> load, and temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5445840','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5445840"><span><span class="hlt">Heat</span> Transfer and Geometrical Analysis of Thermoelectric Converters Driven by Concentrated Solar <span class="hlt">Radiation</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Suter, Clemens; Tomeš, Petr; Weidenkaff, Anke; Steinfeld, Aldo</p> <p>2010-01-01</p> <p>A <span class="hlt">heat</span> transfer model that couples <span class="hlt">radiation</span>/conduction/convection <span class="hlt">heat</span> transfer with electrical potential distribution is developed for a thermoelectric converter (TEC) subjected to concentrated solar <span class="hlt">radiation</span>. The 4-leg TEC module consists of two pairs of p-type La1.98Sr0.02CuO4 and n-type CaMn0.98Nb0.02O3 legs that are sandwiched between two ceramic Al2O3 hot/cold plates and connected electrically in series and thermally in parallel. The governing equations for <span class="hlt">heat</span> transfer and electrical potential are formulated, discretized and solved numerically by applying the finite volume (FV) method. The model is validated in terms of experimentally measured temperatures and voltages/power using a set of TEC demonstrator modules, subjected to a peak <span class="hlt">radiative</span> <span class="hlt">flux</span> intensity of 300 suns. The <span class="hlt">heat</span> transfer model is then applied to examine the effect of the geometrical parameters (e.g. length/width of legs) on the solar-to-electricity energy conversion efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/321026-single-side-conduction-modeling-high-heat-flux-coolant-channels','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/321026-single-side-conduction-modeling-high-heat-flux-coolant-channels"><span>Single-side conduction modeling for high <span class="hlt">heat</span> <span class="hlt">flux</span> coolant channels</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Boyd, R.D. Sr.</p> <p></p> <p>In the development of plasma-facing components (PFCs), most investigators have erroneously postulated negligible water critical <span class="hlt">heat</span> <span class="hlt">flux</span> dependence on the coolant channel length-to-diameter (L/D) ratio above a constant value of L/D. Although encouraging results have been obtained in characterizing peaking factors for local two-dimensional boiling curves and critical <span class="hlt">heat</span> <span class="hlt">flux</span>, additional experimental data and theoretical model development are needed to validate the applicability to PFCs. Both these and related issues will affect the flow boiling correlation and data reduction associated with the development of PFCs for fusion reactors and other physical problems that are dependent on conduction modeling in themore » <span class="hlt">heat</span> <span class="hlt">flux</span> spectrum of applications. Both exact solutions and numerical conjugate analyses are presented for a one-side <span class="hlt">heated</span> (OSH) geometry. The results show (a) the coexistence of three flow regimes inside an OSH circular geometry, (b) the correlational dependence of the inside wall <span class="hlt">heat</span> <span class="hlt">flux</span> and temperature, and (c) inaccuracies that could arise in some data reduction procedures.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1373693-gyrokinetic-projection-divertor-heat-flux-width-from-present-tokamaks-iter','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1373693-gyrokinetic-projection-divertor-heat-flux-width-from-present-tokamaks-iter"><span>Gyrokinetic projection of the divertor <span class="hlt">heat-flux</span> width from present tokamaks to ITER</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Chang, Choong Seock; Ku, Seung -Hoe; Loarte, Alberto; ...</p> <p>2017-07-11</p> <p>Here, the XGC1 edge gyrokinetic code is used to study the width of the <span class="hlt">heat-flux</span> to divertor plates in attached plasma condition. The <span class="hlt">flux</span>-driven simulation is performed until an approximate power balance is achieved between the <span class="hlt">heat-flux</span> across the steep pedestal pressure gradient and the <span class="hlt">heat-flux</span> on the divertor plates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21096099','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21096099"><span>Theoretical simulation of the dual-<span class="hlt">heat-flux</span> method in deep body temperature measurements.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huang, Ming; Chen, Wenxi</p> <p>2010-01-01</p> <p>Deep body temperature reveals individual physiological states, and is important in patient monitoring and chronobiological studies. An innovative dual-<span class="hlt">heat-flux</span> method has been shown experimentally to be competitive with the conventional zero-<span class="hlt">heat</span>-flow method in its performance, in terms of measurement accuracy and step response to changes in the deep temperature. We have utilized a finite element method to model and simulate the dynamic process of a dual-<span class="hlt">heat-flux</span> probe in deep body temperature measurements to validate the fundamental principles of the dual-<span class="hlt">heat-flux</span> method theoretically, and to acquire a detailed quantitative description of the thermal profile of the dual-<span class="hlt">heat-flux</span> probe. The simulation results show that the estimated deep body temperature is influenced by the ambient temperature (linearly, at a maximum rate of 0.03 °C/°C) and the blood perfusion rate. The corresponding depth of the estimated temperature in the skin and subcutaneous tissue layer is consistent when using the dual-<span class="hlt">heat-flux</span> probe. Insights in improving the performance of the dual-<span class="hlt">heat-flux</span> method were discussed for further studies of dual-<span class="hlt">heat-flux</span> probes, taking into account structural and geometric considerations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A23M..04W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A23M..04W"><span>How do Greenhouse Gases Warm the Ocean? Investigation of the Response of the Ocean Thermal Skin Layer to Air-Sea Surface <span class="hlt">Heat</span> <span class="hlt">Fluxes</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wong, E.; Minnett, P. J.</p> <p>2016-12-01</p> <p>There is much evidence that the ocean is <span class="hlt">heating</span> due to an increase in concentrations of greenhouse gases (GHG) in the atmosphere from human activities. GHGs absorbs infrared (IR) <span class="hlt">radiation</span> and re-emits the <span class="hlt">radiation</span> back to the ocean's surface which is subsequently absorbed resulting in a rise in the ocean <span class="hlt">heat</span> content. However, the incoming longwave <span class="hlt">radiation</span>, LWin, is absorbed within the top micrometers of the ocean's surface, where the thermal skin layer (TSL) exists and does not directly <span class="hlt">heat</span> the upper few meters of the ocean. We are therefore motivated to investigate the physical mechanism between the absorption of IR <span class="hlt">radiation</span> and its effect on <span class="hlt">heat</span> transfer at the air-sea boundary. The hypothesis is that since <span class="hlt">heat</span> lost through the air-sea interface is controlled by the TSL, which is directly influenced by the absorption and emission of IR <span class="hlt">radiation</span>, the <span class="hlt">heat</span> flow through the TSL adjusts to maintain the surface <span class="hlt">heat</span> loss, and thus modulates the upper ocean <span class="hlt">heat</span> content. This hypothesis is investigated through utilizing clouds to represent an increase in LWin and analyzing retrieved TSL vertical profiles from a shipboard IR spectrometer from two research cruises. The data is limited to night-time, no precipitation and low winds of < 2 m/s to remove effects of solar <span class="hlt">radiation</span>, wind-driven shear and possibilities of TSL disruption. The results show independence between the turbulent <span class="hlt">fluxes</span> and <span class="hlt">radiative</span> <span class="hlt">fluxes</span> which rules out the immediate release of <span class="hlt">heat</span> from the absorption of the cloud infrared irradiance back into the atmosphere through processes such as evaporation. Instead, we observe the surplus energy, from absorbing increasing levels of LWin, adjusts the curvature of the TSL such that there is a lower gradient at the interface between the TSL and the mixed layer. The release of <span class="hlt">heat</span> stored within the mixed layer is therefore hindered while the additional energy within the TSL is cycled back into the atmosphere. This results in <span class="hlt">heat</span> beneath the TSL</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/23962','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/23962"><span>A modified force-restore approach to modeling snow-surface <span class="hlt">heat</span> <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Charles H. Luce; David G. Tarboton</p> <p>2001-01-01</p> <p>Accurate modeling of the energy balance of a snowpack requires good estimates of the snow surface temperature. The snow surface temperature allows a balance between atmospheric <span class="hlt">heat</span> <span class="hlt">fluxes</span> and the conductive <span class="hlt">flux</span> into the snowpack. While the dependency of atmospheric <span class="hlt">fluxes</span> on surface temperature is reasonably well understood and parameterized, conduction of <span class="hlt">heat</span> from...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002mwoc.conf...39M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002mwoc.conf...39M"><span>Contagious Coronal <span class="hlt">Heating</span> from Recurring Emergence of Magnetic <span class="hlt">Flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, R. L.; Falconer, D. A.; Sterling, A. C.</p> <p>2002-01-01</p> <p>For each of six old bipolar active regions, we present and interpret Yohkoh/SXT and SOHO/MDI observations of the development, over several days, of enhanced coronal <span class="hlt">heating</span> in and around the old bipole in response to new magnetic <span class="hlt">flux</span> emergence within the old bipole. The observations show: 1. In each active region, new <span class="hlt">flux</span> emerges in the equatorward side of the old bipole, around a lone remaining leading sunspot and/or on the equatorward end of the neutral line of the old bipole. 2. The emerging field is marked by intense internal coronal <span class="hlt">heating</span>, and enhanced coronal <span class="hlt">heating</span> occurs in extended loops stemming from the emergence site. 3. In five of the six cases, a "rooster tail" of coronal loops in the poleward extent of the old bipole also brightens in response to the <span class="hlt">flux</span> emergence. 4. There are episodes of enhanced coronal <span class="hlt">heating</span> in surrounding magnetic fields that are contiguous with the old bipole but are not directly connected to the emerging field. From these observations, we suggest that the accommodation of localized newly emerged <span class="hlt">flux</span> within an old active region entails far reaching adjustments in the 3D magnetic field throughout the active region and in surrounding fields in which the active region is embedded, and that these adjustments produce the extensive enhanced coronal <span class="hlt">heating</span>. We Also Note That The Reason For The recurrence of <span class="hlt">flux</span> emergence in old active regions may be that active-region <span class="hlt">flux</span> tends to emerge in giant-cell convection downflows. If so, the poleward "rooster tail" is a coronal flag of a long-lasting downflow in the convection zone. This work was funded by NASA's Office of Space Science through the Solar Physics Supporting Research and Technology Program and the Sun-Earth Connection Guest Investigator Program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020022350&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2BFlux','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020022350&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2BFlux"><span>Contagious Coronal <span class="hlt">Heating</span> from Recurring Emergence of Magnetic <span class="hlt">Flux</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moore, Ronald L.; Falconer, David; Sterling, Alphonse; Whitaker, Ann F. (Technical Monitor)</p> <p>2001-01-01</p> <p>For each of six old bipolar active regions, we present and interpret Yohkoh/SXT and SOHO/MDI observations of the development, over several days, of enhanced coronal <span class="hlt">heating</span> in and around the old bipole in response to new magnetic <span class="hlt">flux</span> emerge= within the old bipole. The observations show: 1. In each active region, new <span class="hlt">flux</span> emerges in the equatorward side of the old bipole, around a lone remaining leading sunspot and/or on the equatorward end of the neutral line of the old bipole. 2. The emerging field is marked by intense internal coronal <span class="hlt">heating</span>, and enhanced coronal <span class="hlt">heating</span> occurs in extended loops stemming from the emergence site. 3. In five of the six cases, a "rooster tail" of coronal loops in the poleward extent of the old bipole also brightens in response to the <span class="hlt">flux</span> emergence. 4. There are episodes of enhanced coronal <span class="hlt">heating</span> in surrounding magnetic fields that are contiguous with the old bipole but are not directly connected to the emerging field. From these observations, we suggest that the accommodation of localized newly emerged <span class="hlt">flux</span> within an old active region entails far reaching adjustments in the 3D magnetic field throughout the active region and in surrounding fields in which the active region is embedded, and that these adjustments produce the extensive enhanced coronal <span class="hlt">heating</span>. We also note that the reason for the recurrence of <span class="hlt">flux</span> emergence in old active regions may be that active region <span class="hlt">flux</span> tends to emerge in giant-cell convection downflows. If so, the poleward "rooster tail" is a coronal flag of a long-lasting downflow in the convection zone. This work was funded by NASA's Office of Space Science through the Solar Physics Supporting Research and Technology Program and the Sun-Earth Connection Guest Investigator Program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010086596&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2BFlux','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010086596&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2BFlux"><span>Coronal <span class="hlt">Heating</span> and the Magnetic <span class="hlt">Flux</span> Content of the Network</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.; Whitaker, Ann F. (Technical Monitor)</p> <p>2001-01-01</p> <p>Previously, from analysis of SOHO/EIT coronal images in combination with Kitt Peak magnetograms (Falconer et al 1998, ApJ, 501, 386-396), we found that the quiet corona is the sum of two components: the e-scale corona and the coronal network. The large-scale corona consists of all coronal-temperature (T approx. 10(exp 6) K) structures larger than supergranules (>approx.30,000 km). The coronal network (1) consists of all coronal-temperature structures smaller than supergranules, (2) is rooted in and loosely traces the photospheric magnetic network, (3) has its brightest features seated on polarity dividing fines (neutral lines) in the network magnetic <span class="hlt">flux</span>, and (4) produces only about 5% of the total coronal emission in quiet regions. The <span class="hlt">heating</span> of the coronal network is apparently magnetic in origin. Here, from analysis of EIT coronal images of quiet regions in combination with magnetograms of the same quiet regions from SOHO/MDI and from Kitt Peak, we examine the other 95% of the quiet corona and its relation to the underlying magnetic network. We find: (1) Dividing the large-scale corona into its bright and dim halves divides the area into bright "continents" and dark "oceans" having spans of 2-4 supergranules. (2) These patterns are also present in the photospheric magnetograms: the network is stronger under the bright half and weaker under the dim half. (3) The <span class="hlt">radiation</span> from the large-scale corona increases roughly as the cube root of the magnetic <span class="hlt">flux</span> content of the underlying magnetic network. In contrast, Fisher et A (1998, ApJ, 508, 985-998) found that the coronal <span class="hlt">radiation</span> from an active region increases roughly linearly with the magnetic <span class="hlt">flux</span> content of the active region. We assume, as is widely held, that nearly all of the large-scale corona is magnetically rooted in the network. Our results, together with the result of Fisher et al (1999), suggest that either the coronal <span class="hlt">heating</span> in quiet regions has a large non-magnetic component, or, if the <span class="hlt">heating</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018EPJP..133...24G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018EPJP..133...24G"><span>Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> effect on hydromagnetic <span class="hlt">radiative</span> Oldroyd-B liquid flow across a cone/wedge in the presence of cross-diffusion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gnaneswara Reddy, M.</p> <p>2018-01-01</p> <p>The present article scrutinizes the prominent characteristics of the Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> on magnetohydrodynamic Oldroyd-B <span class="hlt">radiative</span> liquid flow over two different geometries. The effects of cross-diffusion are considered in the modeling of species and energy equations. Similarity transformations are employed to transmute the governing flow, species and energy equations into a set of nonlinear ordinary differential equations (ODEs) with the appropriate boundary conditions. The final system of dimensionless equations is resolved numerically by utilizing the R-K-Fehlberg numerical approach. The behaviors of all physical pertinent flow controlling variables on the three flow distributions are analyzed through plots. The obtained numerical results have been compared with earlier published work and reveal good agreement. The Deborah numbers γ1 and γ2 have quite opposite effects on velocity and energy fields. The increase in thermal relaxation parameter β corresponds to a decrease in the fluid temperature. This study has salient applications in <span class="hlt">heat</span> and mass transfer manufacturing system processing for energy conversion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=311956','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=311956"><span>Neural network analysis on the effect of <span class="hlt">heat</span> <span class="hlt">fluxes</span> on greenhouse gas emissions from anaerobic swine waste treatment lagoon</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>In this study, we examined the various meteorological factors (i.e., air temperatures, solar <span class="hlt">radiation</span>, and <span class="hlt">heat</span> <span class="hlt">fluxes</span>) that potentially affect greenhouse gas (GHG) emissions from swine waste lagoon. GHG concentrations (methane, carbon dioxide, and nitrous oxide) were monitored using a photoacous...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DPPJO5002H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DPPJO5002H"><span><span class="hlt">Heat-Flux</span> Measurements from Collective Thomson-Scattering Spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Henchen, R. J.; Hu, S. X.; Katz, J.; Froula, D. H.; Rozmus, W.</p> <p>2015-11-01</p> <p>Collective Thomson scattering was used to measure <span class="hlt">heat</span> <span class="hlt">flux</span> in coronal plasmas. The relative amplitude of the Thomson-scattered power into the up- and downshifted electron plasma wave features was used to determine the <span class="hlt">flux</span> of electrons moving along the temperature gradient at three to four times the electron thermal velocity. Simultaneously, the ion-acoustic wave features were measured. Their relative amplitude is used to measure the <span class="hlt">flux</span> of the return-current electrons. The frequencies of these ion-acoustic and electron plasma wave features provide local measurements of the electron temperature and density. These spectra were obtained at five locations along the temperature gradient in a laser-produced blowoff plasma. These measurements of plasma parameters are used to infer the Spitzer -Härm <span class="hlt">flux</span> <m:mfenced close=")" open="(" separators="">qSH = - κ∇Te </m:mfenced> and are in good agreement with the values of the <span class="hlt">heat</span> <span class="hlt">flux</span> measured from the scattering-feature asymmetries. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790031213&hterms=Plasma+Shield&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPlasma%2BShield','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790031213&hterms=Plasma+Shield&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPlasma%2BShield"><span><span class="hlt">Radiative</span> cooling in shock-<span class="hlt">heated</span> hydrogen-helium plasmas. [for planetary entry probe <span class="hlt">heat</span> shields</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Poon, P. T. Y.; Stickford, G. H., Jr.</p> <p>1978-01-01</p> <p>Axial and off-axis <span class="hlt">radiative</span> cooling of cylindrical shock-<span class="hlt">heated</span> hydrogen-helium plasmas is investigated theoretically and experimentally. The coupled fluid dynamic-<span class="hlt">radiative</span> transfer equations are solved by a combination of approximation techniques aimed at simplifying the computation of the <span class="hlt">flux</span> divergence term, namely, the quasi-isothermal approximation and the exponential approximation developed for the solid angle integration. The accuracy of the approximation schemes has been assessed and found acceptable for applying the methods to the rapid computation of the <span class="hlt">radiatively</span> coupled flow problem. <span class="hlt">Radiative</span> cooling experiments were conducted in a 6-inch annular arc accelerator shock tube (ANAA) for an initial pressure of 1 torr and shock speeds from 35 to 45 Km/sec. The results indicate that the lateral cooling is small compared with the axial cooling, and that better agreement is achieved between the data and the theoretical results by inclusion of the lateral temperature gradient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860002759','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860002759"><span>Turbine blade and vane <span class="hlt">heat</span> <span class="hlt">flux</span> sensor development, phase 2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Atkinson, W. H.; Cyr, M. A.; Strange, R. R.</p> <p>1985-01-01</p> <p>The development of <span class="hlt">heat</span> <span class="hlt">flux</span> sensors for gas turbine blades and vanes and the demonstration of <span class="hlt">heat</span> transfer measurement methods are reported. The performance of the <span class="hlt">heat</span> <span class="hlt">flux</span> sensors was evaluated in a cylinder in cross flow experiment and compared with two other <span class="hlt">heat</span> <span class="hlt">flux</span> measurement methods, the slug calorimeter and a dynamic method based on fluctuating gas and surface temperature. Two cylinders, each instrumented with an embedded thermocouple sensor, a Gardon gauge, and a slug calorimeter, were fabricated. Each sensor type was calibrated using a quartz lamp bank facility. The instrumented cylinders were then tested in an atmospheric pressure combustor rig at conditions up to gas stream temperatures of 1700K and velocities to Mach 0.74. The test data are compared to other measurements and analytical prediction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC21D0970Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC21D0970Z"><span>Two-wavelength Method Estimates <span class="hlt">Heat</span> <span class="hlt">fluxes</span> over Heterogeneous Surface in North-China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, G.; Zheng, N.; Zhang, J.</p> <p>2017-12-01</p> <p><span class="hlt">Heat</span> <span class="hlt">fluxes</span> is a key process of hydrological and <span class="hlt">heat</span> transfer of soil-plant-atmosphere continuum (SPAC), and now it is becoming an important topic in meteorology, hydrology, ecology and other related research areas. Because the temporal and spatial variation of <span class="hlt">fluxes</span> at regional scale is very complicated, it is still difficult to measure <span class="hlt">fluxes</span> at the kilometer scale over a heterogeneous surface. A technique called "two-wavelength method" which combines optical scintillometer with microwave scintillometer is able to measure both sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> over large spatial scales at the same time. The main purpose of this study is to investigate the <span class="hlt">fluxes</span> over non-uniform terrain in North-China. Estimation of <span class="hlt">heat</span> <span class="hlt">fluxes</span> was carried out with the optical-microwave scintillometer and an eddy covariance (EC) system over heterogeneous surface in Tai Hang Mountains, China. EC method was set as a benchmark in the study. Structure parameters obtained from scintillometer showed that the typical measurement values of Cn2 are around 10-13 m-2/3 for microwave scintillometer, and values of Cn2 were around 10-15 m-2/3 for optical scintillometer. The correlation of <span class="hlt">heat</span> <span class="hlt">fluxes</span> (H) derived from scintillometer and EC system showed as a ratio of 1.05,and with R2=0.75, while the correlation of latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> (LE) showed as 1.29 with R2=0.67. It was also found that <span class="hlt">heat</span> <span class="hlt">fluxes</span> derived from the two system showed good agreement (R2=0.9 for LE, R2=0.97 for H) when the Bowen ratio (β) was 1.03, while discrepancies showed significantly when β=0.75, and RMSD in H was 139.22 W/m2, 230.85 W/m2 in LE respectively.Experiment results in our research shows that, the two-wavelength method gives a larger <span class="hlt">heat</span> <span class="hlt">fluxes</span> over the study area, and a deeper study should be conduct. We expect that our investigate and analysis can be promoted the application of scintillometry method in regional evapotranspiration measurements and relevant disciplines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70159970','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70159970"><span>Automated calculation of surface energy <span class="hlt">fluxes</span> with high-frequency lake buoy data</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Woolway, R. Iestyn; Jones, Ian D; Hamilton, David P.; Maberly, Stephen C; Muroaka, Kohji; Read, Jordan S.; Smyth, Robyn L; Winslow, Luke A.</p> <p>2015-01-01</p> <p>Lake <span class="hlt">Heat</span> <span class="hlt">Flux</span> Analyzer is a program used for calculating the surface energy <span class="hlt">fluxes</span> in lakes according to established literature methodologies. The program was developed in MATLAB for the rapid analysis of high-frequency data from instrumented lake buoys in support of the emerging field of aquatic sensor network science. To calculate the surface energy <span class="hlt">fluxes</span>, the program requires a number of input variables, such as air and water temperature, relative humidity, wind speed, and short-wave <span class="hlt">radiation</span>. Available outputs for Lake <span class="hlt">Heat</span> <span class="hlt">Flux</span> Analyzer include the surface <span class="hlt">fluxes</span> of momentum, sensible <span class="hlt">heat</span> and latent <span class="hlt">heat</span> and their corresponding transfer coefficients, incoming and outgoing long-wave <span class="hlt">radiation</span>. Lake <span class="hlt">Heat</span> <span class="hlt">Flux</span> Analyzer is open source and can be used to process data from multiple lakes rapidly. It provides a means of calculating the surface <span class="hlt">fluxes</span> using a consistent method, thereby facilitating global comparisons of high-frequency data from lake buoys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1953n0142P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1953n0142P"><span>Thermal <span class="hlt">radiation</span> influence on MHD flow of a rotating fluid with <span class="hlt">heat</span> transfer through EFGM solutions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prasad, D. V. V. Krishna; Chaitanya, G. S. Krishna; Raju, R. Srinivasa</p> <p>2018-05-01</p> <p>The aim of this research work is to find the EFGM solutions of the unsteady magnetohydromagnetic natural convection <span class="hlt">heat</span> transfer flow of a rotating, incompressible, viscous, Boussinesq fluid is presented in this study in the presence of <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer. The Rosseland approximation for an optically thick fluid is invoked to describe the <span class="hlt">radiative</span> <span class="hlt">flux</span>. Numerical results obtained show that a decrease in the temperature boundary layer occurs when the Prandtl number and the <span class="hlt">radiation</span> parameter are increased and the flow velocity approaches steady state as the time parameter t is increased. These findings are in quantitative agreement with earlier reported studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhPl...24b2109I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhPl...24b2109I"><span>Transport coefficients and <span class="hlt">heat</span> <span class="hlt">fluxes</span> in non-equilibrium high-temperature flows with electronic excitation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Istomin, V. A.; Kustova, E. V.</p> <p>2017-02-01</p> <p>The influence of electronic excitation on transport processes in non-equilibrium high-temperature ionized mixture flows is studied. Two five-component mixtures, N 2 / N2 + / N / N + / e - and O 2 / O2 + / O / O + / e - , are considered taking into account the electronic degrees of freedom for atomic species as well as the rotational-vibrational-electronic degrees of freedom for molecular species, both neutral and ionized. Using the modified Chapman-Enskog method, the transport coefficients (thermal conductivity, shear viscosity and bulk viscosity, diffusion and thermal diffusion) are calculated in the temperature range 500-50 000 K. Thermal conductivity and bulk viscosity coefficients are strongly affected by electronic states, especially for neutral atomic species. Shear viscosity, diffusion, and thermal diffusion coefficients are not sensible to electronic excitation if the size of excited states is assumed to be constant. The limits of applicability for the Stokes relation are discussed; at high temperatures, this relation is violated not only for molecular species but also for electronically excited atomic gases. Two test cases of strongly non-equilibrium flows behind plane shock waves corresponding to the spacecraft re-entry (Hermes and Fire II) are simulated numerically. Fluid-dynamic variables and <span class="hlt">heat</span> <span class="hlt">fluxes</span> are evaluated in gases with electronic excitation. In inviscid flows without chemical-<span class="hlt">radiative</span> coupling, the flow-field is weakly affected by electronic states; however, in viscous flows, their influence can be more important, in particular, on the convective <span class="hlt">heat</span> <span class="hlt">flux</span>. The contribution of different dissipative processes to the <span class="hlt">heat</span> transfer is evaluated as well as the effect of reaction rate coefficients. The competition of diffusion and <span class="hlt">heat</span> conduction processes reduces the overall effect of electronic excitation on the convective <span class="hlt">heating</span>, especially for the Fire II test case. It is shown that reliable models of chemical reaction rates are of great</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840052365&hterms=coke&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcoke','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840052365&hterms=coke&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcoke"><span>Supercritical convection, critical <span class="hlt">heat</span> <span class="hlt">flux</span>, and coking characteristics of propane</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rousar, D. C.; Gross, R. S.; Boyd, W. C.</p> <p>1984-01-01</p> <p>The <span class="hlt">heat</span> transfer characteristics of propane at subcritical and supercritical pressure were experimentally evaluated using electrically <span class="hlt">heated</span> Monel K-500 tubes. A design correlation for supercritical <span class="hlt">heat</span> transfer coefficient was established using the approach previously applied to supercritical oxygen. Flow oscillations were observed and the onset of these oscillations at supercritical pressures was correlated with wall-to-bulk temperature ratio and velocity. The critical <span class="hlt">heat</span> <span class="hlt">flux</span> measured at subcritical pressure was correlated with the product of velocity and subcooling. Long duration tests at fixed <span class="hlt">heat</span> <span class="hlt">flux</span> conditions were conducted to evaluate coking on the coolant side tube wall and coking rates comparable to RP-1 were observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ACP....18.1241A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ACP....18.1241A"><span>The early summertime Saharan <span class="hlt">heat</span> low: sensitivity of the <span class="hlt">radiation</span> budget and atmospheric <span class="hlt">heating</span> to water vapour and dust aerosol</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alamirew, Netsanet K.; Todd, Martin C.; Ryder, Claire L.; Marsham, John H.; Wang, Yi</p> <p>2018-01-01</p> <p>The Saharan <span class="hlt">heat</span> low (SHL) is a key component of the west African climate system and an important driver of the west African monsoon across a range of timescales of variability. The physical mechanisms driving the variability in the SHL remain uncertain, although water vapour has been implicated as of primary importance. Here, we quantify the independent effects of variability in dust and water vapour on the <span class="hlt">radiation</span> budget and atmospheric <span class="hlt">heating</span> of the region using a <span class="hlt">radiative</span> transfer model configured with observational input data from the Fennec field campaign at the location of Bordj Badji Mokhtar (BBM) in southern Algeria (21.4° N, 0.9° E), close to the SHL core for June 2011. Overall, we find dust aerosol and water vapour to be of similar importance in driving variability in the top-of-atmosphere (TOA) <span class="hlt">radiation</span> budget and therefore the column-integrated <span class="hlt">heating</span> over the SHL (˜ 7 W m-2 per standard deviation of dust aerosol optical depth - AOD). As such, we infer that SHL intensity is likely to be similarly enhanced by the effects of dust and water vapour surge events. However, the details of the processes differ. Dust generates substantial <span class="hlt">radiative</span> cooling at the surface (˜ 11 W m-2 per standard deviation of dust AOD), presumably leading to reduced sensible <span class="hlt">heat</span> <span class="hlt">flux</span> in the boundary layer, which is more than compensated by direct <span class="hlt">radiative</span> <span class="hlt">heating</span> from shortwave (SW) absorption by dust in the dusty boundary layer. In contrast, water vapour invokes a <span class="hlt">radiative</span> warming at the surface of ˜ 6 W m-2 per standard deviation of column-integrated water vapour in kg m-2. Net effects involve a pronounced net atmospheric <span class="hlt">radiative</span> convergence with <span class="hlt">heating</span> rates on average of 0.5 K day-1 and up to 6 K day-1 during synoptic/mesoscale dust events from monsoon surges and convective cold-pool outflows (<q>haboobs</q>). On this basis, we make inferences on the processes driving variability in the SHL associated with <span class="hlt">radiative</span> and advective <span class="hlt">heating</span>/cooling. Depending</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930022365','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930022365"><span>Thin film <span class="hlt">heat</span> <span class="hlt">flux</span> sensor for Space Shuttle Main Engine turbine environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Will, Herbert</p> <p>1991-01-01</p> <p>The Space Shuttle Main Engine (SSME) turbine environment stresses engine components to their design limits and beyond. The extremely high temperatures and rapid temperature cycling can easily cause parts to fail if they are not properly designed. Thin film <span class="hlt">heat</span> <span class="hlt">flux</span> sensors can provide <span class="hlt">heat</span> loading information with almost no disturbance of gas flows or of the blade. These sensors can provide steady state and transient <span class="hlt">heat</span> <span class="hlt">flux</span> information. A thin film <span class="hlt">heat</span> <span class="hlt">flux</span> sensor is described which makes it easier to measure small temperature differences across very thin insulating layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/761855','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/761855"><span>Recent High <span class="hlt">Heat</span> <span class="hlt">Flux</span> Tests on W-Rod-Armored Mockups</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>NYGREN,RICHARD E.; YOUCHISON,DENNIS L.; MCDONALD,JIMMIE M.</p> <p>2000-07-18</p> <p>In the authors initial high <span class="hlt">heat</span> <span class="hlt">flux</span> tests on small mockups armored with W rods, done in the small electron beam facility (EBTS) at Sandia National Laboratories, the mockups exhibited excellent thermal performance. However, to reach high <span class="hlt">heat</span> <span class="hlt">fluxes</span>, they reduced the <span class="hlt">heated</span> area to only a portion ({approximately}25%) of the sample. They have now begun tests in their larger electron beam facility, EB 1200, where the available power (1.2 MW) is more than enough to <span class="hlt">heat</span> the entire surface area of the small mockups. The initial results indicate that, at a given power, the surface temperatures of rods inmore » the EB 1200 tests is somewhat higher than was observed in the EBTS tests. Also, it appears that one mockup (PW-10) has higher surface temperatures than other mockups with similar height (10mm) W rods, and that the previously reported values of absorbed <span class="hlt">heat</span> <span class="hlt">flux</span> on this mockup were too high. In the tests in EB 1200 of a second mockup, PW-4, absorbed <span class="hlt">heat</span> <span class="hlt">fluxes</span> of {approximately}22MW/m{sup 2} were reached but the corresponding surface temperatures were somewhat higher than in EBTS. A further conclusion is that the simple 1-D model initially used in evaluating some of the results from the EBTS testing was not adequate, and 3-D thermal modeling will be needed to interpret the results.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.4569M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.4569M"><span>Mixing rates and vertical <span class="hlt">heat</span> <span class="hlt">fluxes</span> north of Svalbard from Arctic winter to spring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meyer, Amelie; Fer, Ilker; Sundfjord, Arild; Peterson, Algot K.</p> <p>2017-06-01</p> <p>Mixing and <span class="hlt">heat</span> <span class="hlt">flux</span> rates collected in the Eurasian Basin north of Svalbard during the N-ICE2015 drift expedition are presented. The observations cover the deep Nansen Basin, the Svalbard continental slope, and the shallow Yermak Plateau from winter to summer. Mean quiescent winter <span class="hlt">heat</span> <span class="hlt">flux</span> values in the Nansen Basin are 2 W m-2 at the ice-ocean interface, 3 W m-2 in the pycnocline, and 1 W m-2 below the pycnocline. Large <span class="hlt">heat</span> <span class="hlt">fluxes</span> exceeding 300 W m-2 are observed in the late spring close to the surface over the Yermak Plateau. The data consisting of 588 microstructure profiles and 50 days of high-resolution under-ice turbulence measurements are used to quantify the impact of several forcing factors on turbulent dissipation and <span class="hlt">heat</span> <span class="hlt">flux</span> rates. Wind forcing increases turbulent dissipation seven times in the upper 50 m, and doubles <span class="hlt">heat</span> <span class="hlt">fluxes</span> at the ice-ocean interface. The presence of warm Atlantic Water close to the surface increases the temperature gradient in the water column, leading to enhanced <span class="hlt">heat</span> <span class="hlt">flux</span> rates within the pycnocline. Steep topography consistently enhances dissipation rates by a factor of four and episodically increases <span class="hlt">heat</span> <span class="hlt">flux</span> at depth. It is, however, the combination of storms and shallow Atlantic Water that leads to the highest <span class="hlt">heat</span> <span class="hlt">flux</span> rates observed: ice-ocean interface <span class="hlt">heat</span> <span class="hlt">fluxes</span> average 100 W m-2 during peak events and are associated with rapid basal sea ice melt, reaching 25 cm/d.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1175368','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1175368"><span>A model of <span class="hlt">heat</span> flow in the sheep exposed to high levels of solar <span class="hlt">radiation</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vera, R R; Koong, L J; Morris, J G</p> <p>1975-08-01</p> <p>The fleece is an important component in thermoregulation of sheep exposed to high levels of solar <span class="hlt">radiation</span>. A model written in CSMP has been developed which represents the flow of energy between the sheep and its environment. This model is based on a set of differential equations which describe the <span class="hlt">flux</span> of <span class="hlt">heat</span> between the components of the system--fleece, tip, skin, body and environment. It requires as input parameters location, date, time of day, temperature, relative humidity, cloud cover, wind movement, animal weight and linear measurements and fleece length. At each integration interval incoming solar <span class="hlt">radiation</span> and its components, the <span class="hlt">heat</span> arising from the animal's metabolism and the <span class="hlt">heat</span> exchange by long-wave <span class="hlt">radiation</span>, convection, conduction and evaporative cooling are computed. Temperatures at the fleece tip, skin and body core are monitored.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1917050Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1917050Z"><span>Mesoscale eddies control meridional <span class="hlt">heat</span> <span class="hlt">flux</span> variability in the subpolar North Atlantic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Jian; Bower, Amy; Yang, Jiayan; Lin, Xiaopei; Zhou, Chun</p> <p>2017-04-01</p> <p>The meridional <span class="hlt">heat</span> <span class="hlt">flux</span> in the subpolar North Atlantic is vital to the climate of the high-latitude North Atlantic. For the basinwide <span class="hlt">heat</span> <span class="hlt">flux</span> across a section between Greenland and Scotland, much of the variability occurs in the Iceland basin, where the North Atlantic Current (NAC) carries relatively warm and salty water northward. As a component of the Overturning in the Subpolar North Atlantic Program (OSNAP), WHOI and OUC are jointly operating gliders in the Iceland Basin to continuously monitor the circulation and corresponding <span class="hlt">heat</span> <span class="hlt">flux</span> in this eddy-rich region. Based on one year of observations, two circulation regimes in the Iceland basin have been identified: a mesoscale eddy like circulation pattern and northward NAC circulation pattern. When a mesoscale eddy is generated, the rotational currents associated with the eddy lead to both northward and southward flow in the Iceland basin. This is quite different from the broad northward flow associated with the NAC when there is no eddy. The transition between the two regimes coupled with the strong temperature front in the Iceland basin can modify the meridional <span class="hlt">heat</span> <span class="hlt">flux</span> on the order of 0.3PW, which is the dominant source for the <span class="hlt">heat</span> <span class="hlt">flux</span> change the Iceland Basin. According to high-resolution numerical model results, the Iceland Basin has the largest contribution to the meridional <span class="hlt">heat</span> <span class="hlt">flux</span> variability along the section between Greenland and Scotland. Therefore, mesoscale eddies in the Iceland Basin provide important dynamics to control the meridional <span class="hlt">heat</span> <span class="hlt">flux</span> variability in the subpolar North Atlantic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1164318','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1164318"><span>Institute for High <span class="hlt">Heat</span> <span class="hlt">Flux</span> Removal (IHHFR). Phases I, II, and III</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Boyd, Ronald D.</p> <p>2014-08-31</p> <p>The IHHFR focused on interdisciplinary applications as it relates to high <span class="hlt">heat</span> <span class="hlt">flux</span> engineering issues and problems which arise due to engineering systems being miniaturized, optimized, or requiring increased high <span class="hlt">heat</span> <span class="hlt">flux</span> performance. The work in the IHHFR focused on water as a coolant and includes: (1) the development, design, and construction of the high <span class="hlt">heat</span> <span class="hlt">flux</span> flow loop and facility; (2) test section development, design, and fabrication; and, (3) single-side <span class="hlt">heat</span> <span class="hlt">flux</span> experiments to produce 2-D boiling curves and 3-D conjugate <span class="hlt">heat</span> transfer measurements for single-side <span class="hlt">heated</span> test sections. This work provides data for comparisons with previously developed andmore » new single-side <span class="hlt">heated</span> correlations and approaches that address the single-side <span class="hlt">heated</span> effect on <span class="hlt">heat</span> transfer. In addition, this work includes the addition of single-side <span class="hlt">heated</span> circular TS and a monoblock test section with a helical wire insert. Finally, the present work includes: (1) data base expansion for the monoblock with a helical wire insert (only for the latter geometry), (2) prediction and verification using finite element, (3) monoblock model and methodology development analyses, and (4) an alternate model development for a hypervapotron and related conjugate <span class="hlt">heat</span> transfer controlling parameters.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.C43A0587P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.C43A0587P"><span><span class="hlt">Heat</span> <span class="hlt">flux</span> variations over sea-ice observed at the coastal area of the Sejong Station, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, S.; Choi, T.; Kim, S.</p> <p>2012-12-01</p> <p>This study presents variations of sensible <span class="hlt">heat</span> <span class="hlt">flux</span> and latent <span class="hlt">heat</span> <span class="hlt">flux</span> over sea-ice observed in 2011 from the 10-m <span class="hlt">flux</span> tower located at the coast of the Sejong Station on King George Island, Antarctica. A period from June to November was divided into three parts: "Freezing", "Frozen", and "Melting" periods based on daily monitoring of sea state and hourly photos looking at the Marian Cove in front of the Sejong Station. The division of periods enabled us to look into the <span class="hlt">heat</span> <span class="hlt">flux</span> variations depending on the sea-ice conditions. Over freezing sea surface during the freezing period of late June, daily mean sensible <span class="hlt">heat</span> <span class="hlt">flux</span> was -11.9 Wm-2 and daily mean latent <span class="hlt">heat</span> <span class="hlt">flux</span> was +16.3 Wm-2. Over the frozen sea-ice, daily mean sensible <span class="hlt">heat</span> <span class="hlt">flux</span> was -10.4 Wm-2 while daily mean latent <span class="hlt">heat</span> <span class="hlt">flux</span> was +2.4 Wm-2. During the melting period of mid-October to early November, magnitudes of sensible <span class="hlt">heat</span> <span class="hlt">flux</span> increased to -14.2 Wm-2 and latent <span class="hlt">heat</span> <span class="hlt">flux</span> also increased to +13.5 Wm-2. In short, latent <span class="hlt">heat</span> <span class="hlt">flux</span> was usually upward over sea-ice most of the time while sensible <span class="hlt">heat</span> <span class="hlt">flux</span> was downward from atmosphere to sea-ice. Magnitudes of the <span class="hlt">fluxes</span> were small but increased when freezing or melting of sea-ice was occurring. Especially, latent <span class="hlt">heat</span> <span class="hlt">flux</span> increased five to six times compared to that of "frozen" period implying that early melting of sea-ice may cause five to six times larger supply of moisture to the atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160007540','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160007540"><span>Unsteady <span class="hlt">Heat-Flux</span> Measurements of Second-Mode Instability Waves in a Hypersonic Boundary Layer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kergerise, Michael A.; Rufer, Shann J.</p> <p>2016-01-01</p> <p>In this paper we report on the application of the atomic layer thermopile (ALTP) <span class="hlt">heat</span>- <span class="hlt">flux</span> sensor to the measurement of laminar-to-turbulent transition in a hypersonic flat plate boundary layer. The centerline of the flat-plate model was instrumented with a streamwise array of ALTP sensors and the flat-plate model was exposed to a Mach 6 freestream over a range of unit Reynolds numbers. Here, we observed an unstable band of frequencies that are associated with second-mode instability waves in the laminar boundary layer that forms on the flat-plate surface. The measured frequencies, group velocities, phase speeds, and wavelengths of these instability waves are in agreement with data previously reported in the literature. <span class="hlt">Heat</span> <span class="hlt">flux</span> time series, and the Morlet-wavelet transforms of them, revealed the wave-packet nature of the second-mode instability waves. In addition, a laser-based <span class="hlt">radiative</span> <span class="hlt">heating</span> system was developed to measure the frequency response functions (FRF) of the ALTP sensors used in the wind tunnel test. These measurements were used to assess the stability of the sensor FRFs over time and to correct spectral estimates for any attenuation caused by the finite sensor bandwidth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1130204-interaction-between-marine-boundary-layer-cellular-cloudiness-surface-heat-fluxes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1130204-interaction-between-marine-boundary-layer-cellular-cloudiness-surface-heat-fluxes"><span>On the Interaction between Marine Boundary Layer Cellular Cloudiness and Surface <span class="hlt">Heat</span> <span class="hlt">Fluxes</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kazil, J.; Feingold, G.; Wang, Hailong</p> <p>2014-01-02</p> <p>The interaction between marine boundary layer cellular cloudiness and surface uxes of sensible and latent <span class="hlt">heat</span> is investigated. The investigation focuses on the non-precipitating closed-cell state and the precipitating open-cell state at low geostrophic wind speed. The Advanced Research WRF model is used to conduct cloud-system-resolving simulations with interactive surface <span class="hlt">fluxes</span> of sensible <span class="hlt">heat</span>, latent <span class="hlt">heat</span>, and of sea salt aerosol, and with a detailed representation of the interaction between aerosol particles and clouds. The mechanisms responsible for the temporal evolution and spatial distribution of the surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> in the closed- and open-cell state are investigated and explained. Itmore » is found that the horizontal spatial structure of the closed-cell state determines, by entrainment of dry free tropospheric air, the spatial distribution of surface air temperature and water vapor, and, to a lesser degree, of the surface sensible and latent <span class="hlt">heat</span> <span class="hlt">flux</span>. The synchronized dynamics of the the open-cell state drives oscillations in surface air temperature, water vapor, and in the surface <span class="hlt">fluxes</span> of sensible and latent <span class="hlt">heat</span>, and of sea salt aerosol. Open-cell cloud formation, cloud optical depth and liquid water path, and cloud and rain water path are identified as good predictors of the spatial distribution of surface air temperature and sensible <span class="hlt">heat</span> <span class="hlt">flux</span>, but not of surface water vapor and latent <span class="hlt">heat</span> <span class="hlt">flux</span>. It is shown that by enhancing the surface sensible <span class="hlt">heat</span> <span class="hlt">flux</span>, the open-cell state creates conditions by which it is maintained. While the open-cell state under consideration is not depleted in aerosol, and is insensitive to variations in sea-salt <span class="hlt">fluxes</span>, it also enhances the sea-salt <span class="hlt">flux</span> relative to the closed-cell state. In aerosol-depleted conditions, this enhancement may replenish the aerosol needed for cloud formation, and hence contribute to the perpetuation of the open-cell state as well. Spatial homogenization of the surface <span class="hlt">fluxes</span> is found</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MicNa...4....1H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MicNa...4....1H"><span>Nanoporous membrane device for ultra high <span class="hlt">heat</span> <span class="hlt">flux</span> thermal management</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hanks, Daniel F.; Lu, Zhengmao; Sircar, Jay; Salamon, Todd R.; Antao, Dion S.; Bagnall, Kevin R.; Barabadi, Banafsheh; Wang, Evelyn N.</p> <p>2018-02-01</p> <p>High power density electronics are severely limited by current thermal management solutions which are unable to dissipate the necessary <span class="hlt">heat</span> <span class="hlt">flux</span> while maintaining safe junction temperatures for reliable operation. We designed, fabricated, and experimentally characterized a microfluidic device for ultra-high <span class="hlt">heat</span> <span class="hlt">flux</span> dissipation using evaporation from a nanoporous silicon membrane. With 100 nm diameter pores, the membrane can generate high capillary pressure even with low surface tension fluids such as pentane and R245fa. The suspended ultra-thin membrane structure facilitates efficient liquid transport with minimal viscous pressure losses. We fabricated the membrane in silicon using interference lithography and reactive ion etching and then bonded it to a high permeability silicon microchannel array to create a biporous wick which achieves high capillary pressure with enhanced permeability. The back side consisted of a thin film platinum heater and resistive temperature sensors to emulate the <span class="hlt">heat</span> dissipation in transistors and measure the temperature, respectively. We experimentally characterized the devices in pure vapor-ambient conditions in an environmental chamber. Accordingly, we demonstrated <span class="hlt">heat</span> <span class="hlt">fluxes</span> of 665 ± 74 W/cm2 using pentane over an area of 0.172 mm × 10 mm with a temperature rise of 28.5 ± 1.8 K from the <span class="hlt">heated</span> substrate to ambient vapor. This <span class="hlt">heat</span> <span class="hlt">flux</span>, which is normalized by the evaporation area, is the highest reported to date in the pure evaporation regime, that is, without nucleate boiling. The experimental results are in good agreement with a high fidelity model which captures <span class="hlt">heat</span> conduction in the suspended membrane structure as well as non-equilibrium and sub-continuum effects at the liquid-vapor interface. This work suggests that evaporative membrane-based approaches can be promising towards realizing an efficient, high <span class="hlt">flux</span> thermal management strategy over large areas for high-performance electronics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970000389','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970000389"><span>Evaporation on/in Capillary Structures of High <span class="hlt">Heat</span> <span class="hlt">Flux</span> Two-Phase Devices</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Faghri, Amir; Khrustalev, Dmitry</p> <p>1996-01-01</p> <p>Two-phase devices (<span class="hlt">heat</span> pipes, capillary pumped loops, loop <span class="hlt">heat</span> pipes, and evaporators) have become recognized as key elements in thermal control systems of space platforms. Capillary and porous structures are necessary and widely used in these devices, especially in high <span class="hlt">heat</span> <span class="hlt">flux</span> and zero-g applications, to provide fluid transport and enhanced <span class="hlt">heat</span> transfer during vaporization and condensation. However, some unexpected critical phenomena, such as dryout in long <span class="hlt">heat</span> pipe evaporators and high thermal resistance of loop <span class="hlt">heat</span> pipe evaporators with high <span class="hlt">heat</span> <span class="hlt">fluxes</span>, are possible and have been encountered in the use of two-phase devices in the low gravity environment. Therefore, a detailed fundamental investigation is proposed to better understand the fluid behavior in capillary-porous structures during vaporization at high <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The present paper addresses some theoretical aspects of this investigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995SPIE.2586..241X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995SPIE.2586..241X"><span><span class="hlt">Heat</span> <span class="hlt">flux</span> exchange estimation by using ATSR SST data in TOGA area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xue, Yong; Lawrence, Sean P.; Llewellyn-Jones, David T.</p> <p>1995-12-01</p> <p>The study of phenomena such as ENSO requires consideration of the dynamics and thermodynamics of the coupled ocean-atmosphere system. The dynamic and thermal properties of the atmosphere and ocean are directly affected by air-sea transfers of <span class="hlt">fluxes</span> of momentum, <span class="hlt">heat</span> and moisture. In this paper, we present results of turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> calculated by using two years (1992 and 1993) monthly average TOGA data and ATSR SST data in TOGA area. A comparison with published results indicates good qualitative agreement. Also, we compared the results of <span class="hlt">heat</span> <span class="hlt">flux</span> exchange by using ATSR SST data and by using the TOGA bucket SST data. The ATSR SST data set has been shown to be useful in helping to estimate the large space scale <span class="hlt">heat</span> <span class="hlt">flux</span> exchange.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70190499','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70190499"><span>Viscous relaxation of Ganymede's impact craters: Constraints on <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bland, Michael T.; Singer, Kelsi N.; McKinnon, William B.; Schenk, Paul M.</p> <p>2017-01-01</p> <p>Measurement of crater depths in Ganymede’s dark terrain have revealed substantial numbers of unusually shallow craters indicative of viscous relaxation [see companion paper: Singer, K.N., Schenk, P. M., Bland, M.T., McKinnon, W.B., (2017). Relaxed impact craters on Ganymede: Regional variations and high <span class="hlt">heat</span> flow. Icarus, submitted]. These viscously relaxed craters provide insight into the thermal history of the dark terrain: the rate of relaxation depends on the size of the crater and the thermal structure of the lithosphere. Here we use finite element simulations of crater relaxation to constrain the <span class="hlt">heat</span> <span class="hlt">flux</span> within the dark terrain when relaxation occurred. We show that the degree of viscous relaxation observed cannot be achieved through radiogenic <span class="hlt">heating</span> alone, even if all of the relaxed craters are ancient and experienced the high radiogenic <span class="hlt">fluxes</span> present early in the satellite’s history. For craters with diameter ≥ 10 km, <span class="hlt">heat</span> <span class="hlt">fluxes</span> of 40–50 mW m-2−2"> can reproduce the observed crater depths, but only if the <span class="hlt">fluxes</span> are sustained for ∼1 Gyr. These craters can also be explained by shorter-lived “<span class="hlt">heat</span> pulses” with magnitudes of ∼100 mW m-2−2"> and timescales of 10–100 Myr. At small crater diameters (4 km) the observed shallow depths are difficult to achieve even when <span class="hlt">heat</span> <span class="hlt">fluxes</span> as high as 150 mW m-2−2"> are sustained for 1 Gyr. The extreme thermal conditions required to viscously relax small craters may indicate that mechanisms other than viscous relaxation, such as topographic degradation, are also in play at small crater diameters. The timing of the relaxation event(s) is poorly constrained due to the sparsity of adequate topographic information, though it likely occurred in Ganymede’s middle history (neither recently, nor shortly after satellite formation). The consistency between the timing and magnitude of the <span class="hlt">heat</span> <span class="hlt">fluxes</span> derived here and those inferred from other tectonic features suggests that a single event</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Icar..296..275B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Icar..296..275B"><span>Viscous relaxation of Ganymede's impact craters: Constraints on <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bland, Michael T.; Singer, Kelsi N.; McKinnon, William B.; Schenk, Paul M.</p> <p>2017-11-01</p> <p>Measurement of crater depths in Ganymede's dark terrain have revealed substantial numbers of unusually shallow craters indicative of viscous relaxation [see companion paper: Singer, K.N., Schenk, P. M., Bland, M.T., McKinnon, W.B., (2017). Relaxed impact craters on Ganymede: Regional variations and high <span class="hlt">heat</span> flow. Icarus, submitted]. These viscously relaxed craters provide insight into the thermal history of the dark terrain: the rate of relaxation depends on the size of the crater and the thermal structure of the lithosphere. Here we use finite element simulations of crater relaxation to constrain the <span class="hlt">heat</span> <span class="hlt">flux</span> within the dark terrain when relaxation occurred. We show that the degree of viscous relaxation observed cannot be achieved through radiogenic <span class="hlt">heating</span> alone, even if all of the relaxed craters are ancient and experienced the high radiogenic <span class="hlt">fluxes</span> present early in the satellite's history. For craters with diameter ≥ 10 km, <span class="hlt">heat</span> <span class="hlt">fluxes</span> of 40-50 mW m-2 can reproduce the observed crater depths, but only if the <span class="hlt">fluxes</span> are sustained for ∼1 Gyr. These craters can also be explained by shorter-lived "<span class="hlt">heat</span> pulses" with magnitudes of ∼100 mW m-2 and timescales of 10-100 Myr. At small crater diameters (4 km) the observed shallow depths are difficult to achieve even when <span class="hlt">heat</span> <span class="hlt">fluxes</span> as high as 150 mW m-2 are sustained for 1 Gyr. The extreme thermal conditions required to viscously relax small craters may indicate that mechanisms other than viscous relaxation, such as topographic degradation, are also in play at small crater diameters. The timing of the relaxation event(s) is poorly constrained due to the sparsity of adequate topographic information, though it likely occurred in Ganymede's middle history (neither recently, nor shortly after satellite formation). The consistency between the timing and magnitude of the <span class="hlt">heat</span> <span class="hlt">fluxes</span> derived here and those inferred from other tectonic features suggests that a single event caused both Ganymede's tectonic deformation and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC21G1006S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC21G1006S"><span>Urban surface energy <span class="hlt">fluxes</span> based on remotely-sensed data and micrometeorological measurements over the Kansai area, Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sukeyasu, T.; Ueyama, M.; Ando, T.; Kosugi, Y.; Kominami, Y.</p> <p>2017-12-01</p> <p>The urban <span class="hlt">heat</span> island is associated with land cover changes and increases in anthropogenic <span class="hlt">heat</span> <span class="hlt">fluxes</span>. Clear understanding of the surface energy budget at urban area is the most important for evaluating the urban <span class="hlt">heat</span> island. In this study, we develop a model based on remotely-sensed data for the Kansai area in Japan and clarify temporal transitions and spatial distributions of the surface energy <span class="hlt">flux</span> from 2000 to 2016. The model calculated the surface energy <span class="hlt">fluxes</span> based on various satellite and GIS products. The model used land surface temperature, surface emissivity, air temperature, albedo, downward shortwave <span class="hlt">radiation</span> and land cover/use type from the moderate resolution imaging spectroradiometer (MODIS) under cloud free skies from 2000 to 2016 over the Kansai area in Japan (34 to 35 ° N, 135 to 136 ° E). Net <span class="hlt">radiation</span> was estimated by a <span class="hlt">radiation</span> budget of upward/downward shortwave and longwave <span class="hlt">radiation</span>. Sensible <span class="hlt">heat</span> <span class="hlt">flux</span> was estimated by a bulk aerodynamic method. Anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> was estimated by the inventory data. Latent <span class="hlt">heat</span> <span class="hlt">flux</span> was examined with residues of the energy budget and parameterization of bulk transfer coefficients. We validated the model using observed <span class="hlt">fluxes</span> from five eddy-covariance measurement sites: three urban sites and two forested sites. The estimated net <span class="hlt">radiation</span> roughly agreed with the observations, but the sensible <span class="hlt">heat</span> <span class="hlt">flux</span> were underestimated. Based on the modeled spatial distributions of the <span class="hlt">fluxes</span>, the daytime net <span class="hlt">radiation</span> in the forested area was larger than those in the urban area, owing to higher albedo and land surface temperatures in the urban area than the forested area. The estimated anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> was high in the summer and winter periods due to increases in energy-requirements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996APS..DPP..9P42S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996APS..DPP..9P42S"><span>Shock wave as a probe of <span class="hlt">flux</span>-dimited thermal transport in laser-<span class="hlt">heated</span> solids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, K.; Forsman, A.; Chiu, G.</p> <p>1996-11-01</p> <p>Laser-generated shock waves in solids result from the ablation of the target material. Where <span class="hlt">radiation</span> transport is negligible, the ablation process is dominated by electron thermal conduction. This offers an opportunity to probe the degree of transport inhibition (compared with classical <span class="hlt">heat</span> flow) for steep temperature gradients in a dense plasma. Using a 1-dimensional hydrodynamic code, we have examined the effect of <span class="hlt">flux</span>-limited thermal conduction on the amplitude of the resulting shock wave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20050041649&hterms=levels+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DA%2Blevels%2Blaw','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050041649&hterms=levels+law&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DA%2Blevels%2Blaw"><span>Defining Top-of-Atmosphere <span class="hlt">Flux</span> Reference Level for Earth <span class="hlt">Radiation</span> Budget Studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Loeb, N. G.; Kato, S.; Wielicki, B. A.</p> <p>2002-01-01</p> <p>To estimate the earth's <span class="hlt">radiation</span> budget at the top of the atmosphere (TOA) from satellite-measured radiances, it is necessary to account for the finite geometry of the earth and recognize that the earth is a solid body surrounded by a translucent atmosphere of finite thickness that attenuates solar <span class="hlt">radiation</span> differently at different heights. As a result, in order to account for all of the reflected solar and emitted thermal <span class="hlt">radiation</span> from the planet by direct integration of satellite-measured radiances, the measurement viewing geometry must be defined at a reference level well above the earth s surface (e.g., 100 km). This ensures that all <span class="hlt">radiation</span> contributions, including <span class="hlt">radiation</span> escaping the planet along slant paths above the earth s tangent point, are accounted for. By using a field-of- view (FOV) reference level that is too low (such as the surface reference level), TOA <span class="hlt">fluxes</span> for most scene types are systematically underestimated by 1-2 W/sq m. In addition, since TOA <span class="hlt">flux</span> represents a flow of radiant energy per unit area, and varies with distance from the earth according to the inverse-square law, a reference level is also needed to define satellite-based TOA <span class="hlt">fluxes</span>. From theoretical <span class="hlt">radiative</span> transfer calculations using a model that accounts for spherical geometry, the optimal reference level for defining TOA <span class="hlt">fluxes</span> in <span class="hlt">radiation</span> budget studies for the earth is estimated to be approximately 20 km. At this reference level, there is no need to explicitly account for horizontal transmission of solar <span class="hlt">radiation</span> through the atmosphere in the earth <span class="hlt">radiation</span> budget calculation. In this context, therefore, the 20-km reference level corresponds to the effective <span class="hlt">radiative</span> top of atmosphere for the planet. Although the optimal <span class="hlt">flux</span> reference level depends slightly on scene type due to differences in effective transmission of solar <span class="hlt">radiation</span> with cloud height, the difference in <span class="hlt">flux</span> caused by neglecting the scene-type dependence is less than 0.1%. If an inappropriate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AdWR..113..126P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AdWR..113..126P"><span>Water and sediment temperature dynamics in shallow tidal environments: The role of the <span class="hlt">heat</span> <span class="hlt">flux</span> at the sediment-water interface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pivato, M.; Carniello, L.; Gardner, J.; Silvestri, S.; Marani, M.</p> <p>2018-03-01</p> <p>In the present study, we investigate the energy <span class="hlt">flux</span> at the sediment-water interface and the relevance of the <span class="hlt">heat</span> exchanged between water and sediment for the water temperature dynamics in shallow coastal environments. Water and sediment temperature data collected in the Venice lagoon show that, in shallow, temperate lagoons, temperature is uniform within the water column, and enabled us to estimate the net <span class="hlt">heat</span> <span class="hlt">flux</span> at the sediment-water interface. We modeled this <span class="hlt">flux</span> as the sum of a conductive component and of the solar <span class="hlt">radiation</span> reaching the bottom, finding the latter being negligible. We developed a "point" model to describe the temperature dynamics of the sediment-water continuum driven by vertical energy transfer. We applied the model considering conditions characterized by negligible advection, obtaining satisfactory results. We found that the <span class="hlt">heat</span> exchange between water and sediment is crucial for describing sediment temperature but plays a minor role on the water temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JSASS..58...68O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JSASS..58...68O"><span>Effects of Crack on <span class="hlt">Heat</span> <span class="hlt">Flux</span> in Hypersonic Shock/Boundary-Layer Interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ozawa, Hiroshi; Hanai, Katsuhisa; Kitamura, Keiichi; Mori, Koichi; Nakamura, Yoshiaki</p> <p></p> <p>A small crack on body surface led to a tragic accident in 2003, which is the Columbia accident. During the shuttle's re-entry, high temperature gas penetrated crack on leading-edge of the left wing and melted the aluminum structure, finally the Columbia blew up. Since early times, there are many fundamental studies about simple cavity-flow formed on body surface in hypersonic speeds. However, an investigation of Shock/Boundary-Layer Interaction (SBLI) on crack has not been researched. For multistage space transportation vehicle such as TSTO, SBLI is an inevitable problem, and then SBLI on crack becomes a critical issue for TSTO development. In this study, the effects of crack, where SBLI occurs, were investigated for TSTO hypersonic speed (M∞ = 8.1). A square crack locates at SBLI point on the TSTO booster. Results show that a crack and its depth strongly effect on peak <span class="hlt">heat</span> <span class="hlt">flux</span> and aerodynamic interaction flow-field. In the cases of shallow crack (d/C ≤ 0.10), there exist two high <span class="hlt">heat</span> <span class="hlt">flux</span> regions on crack floor, which locates at a flow reattachment region and a back end wall of crack. In this case, a peak <span class="hlt">heat</span> <span class="hlt">flux</span> at flow reattachment region becomes about 2 times as large as the stagnation point <span class="hlt">heat</span> <span class="hlt">flux</span>, which value becomes larger compared with a peak <span class="hlt">heat</span> <span class="hlt">flux</span> in the case of No-Crack TSTO. While in the case of deep crack (d/C = 0.20), overall <span class="hlt">heat</span> <span class="hlt">flux</span> on crack floor decreases to below the stagnation point <span class="hlt">heat</span> <span class="hlt">flux</span>. These results provide useful data for a development of TSTO thermal protection system (TPS) such as thermal protection tile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009HMT....45..967S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009HMT....45..967S"><span>Flow boiling <span class="hlt">heat</span> transfer of R134a and R404A in a microfin tube at low mass <span class="hlt">fluxes</span> and low <span class="hlt">heat</span> <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spindler, Klaus; Müller-Steinhagen, Hans</p> <p>2009-05-01</p> <p>An experimental investigation of flow boiling <span class="hlt">heat</span> transfer in a commercially available microfin tube with 9.52 mm outer diameter has been carried out. The microfin tube is made of copper with a total fin number of 55 and a helix angle of 15°. The fin height is 0.24 mm and the inner tube diameter at fin root is 8.95 mm. The test tube is 1 m long and is electrically <span class="hlt">heated</span>. The experiments have been performed at saturation temperatures between 0 and -20°C. The mass <span class="hlt">flux</span> was varied between 25 and 150 kg/m2s, the <span class="hlt">heat</span> <span class="hlt">flux</span> from 15,000 W/m2 down to 1,000 W/m2. All measurements have been performed at constant inlet vapour quality ranging from 0.1 to 0.7. The measured <span class="hlt">heat</span> transfer coefficients range from 1,300 to 15,700 W/m2K for R134a and from 912 to 11,451 W/m2K for R404A. The mean <span class="hlt">heat</span> transfer coefficient of R134a is in average 1.5 times higher than for R404A. The mean <span class="hlt">heat</span> transfer coefficient has been compared with the correlations by Koyama et al. and by Kandlikar. The deviations are within ±30% and ±15%, respectively. The influence of the mass <span class="hlt">flux</span> on the <span class="hlt">heat</span> transfer is most significant between 25 and 62.5 kg/m2s, where the flow pattern changes from stratified wavy flow to almost annular flow. This flow pattern transition is shifted to lower mass <span class="hlt">fluxes</span> for the microfin tube compared to the smooth tube.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1183661','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1183661"><span>Critical <span class="hlt">Heat</span> <span class="hlt">Flux</span> Phenomena at HighPressure & Low Mass <span class="hlt">Fluxes</span>: NEUP Final Report Part I: Experiments</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Corradini, Michael; Wu, Qiao</p> <p>2015-04-30</p> <p>This report is a preliminary document presenting an overview of the Critical <span class="hlt">Heat</span> <span class="hlt">Flux</span> (CHF) phenomenon, the High Pressure Critical <span class="hlt">Heat</span> <span class="hlt">Flux</span> facility (HPCHF), preliminary CHF data acquired, and the future direction of the research. The HPCHF facility has been designed and built to study CHF at high pressure and low mass <span class="hlt">flux</span> ranges in a rod bundle prototypical of conceptual Small Modular Reactor (SMR) designs. The rod bundle is comprised of four electrically <span class="hlt">heated</span> rods in a 2x2 square rod bundle with a prototypic chopped-cosine axial power profile and equipped with thermocouples at various axial and circumferential positions embeddedmore » in each rod for CHF detection. Experimental test parameters for CHF detection range from pressures of ~80 – 160 bar, mass <span class="hlt">fluxes</span> of ~400 – 1500 kg/m2s, and inlet water subcooling from ~30 – 70°C. The preliminary data base established will be further extended in the future along with comparisons to existing CHF correlations, models, etc. whose application ranges may be applicable to the conditions of SMRs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/128767-two-dimensional-stefan-problem-slightly-varying-heat-flux','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/128767-two-dimensional-stefan-problem-slightly-varying-heat-flux"><span>The two-dimensional Stefan problem with slightly varying <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gammon, J.; Howarth, J.A.</p> <p>1995-09-01</p> <p>The authors solve the two-dimensional stefan problem of solidification in a half-space, where the <span class="hlt">heat</span> <span class="hlt">flux</span> at the wall is a slightly varying function of positioning along the wall, by means of a large Stefan number approximation (which turns out to be equivalent to a small time solution), and then by means of the <span class="hlt">Heat</span> Balance Integral Method, which is valid for all time, and which agrees with the large Stefan number solution for small times. A representative solution is given for a particular form of the <span class="hlt">heat</span> <span class="hlt">flux</span> perturbation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840024719','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840024719"><span>Turbine blade and vane <span class="hlt">heat</span> <span class="hlt">flux</span> sensor development, phase 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Atkinson, W. H.; Cyr, M. A.; Strange, R. R.</p> <p>1984-01-01</p> <p><span class="hlt">Heat</span> <span class="hlt">flux</span> sensors available for installation in the hot section airfoils of advanced aircraft gas turbine engines were developed. Two <span class="hlt">heat</span> <span class="hlt">flux</span> sensors were designed, fabricated, calibrated, and tested. Measurement techniques are compared in an atmospheric pressure combustor rig test. Sensors, embedded thermocouple and the Gordon gauge, were fabricated that met the geometric and fabricability requirements and could withstand the hot section environmental conditions. Calibration data indicate that these sensors yielded repeatable results and have the potential to meet the accuracy goal of measuring local <span class="hlt">heat</span> <span class="hlt">flux</span> to within 5%. Thermal cycle tests and thermal soak tests indicated that the sensors are capable of surviving extended periods of exposure to the environment conditions in the turbine. Problems in calibration of the sensors caused by severe non-one dimensional <span class="hlt">heat</span> flow were encountered. Modifications to the calibration techniques are needed to minimize this problem and proof testing of the sensors in an engine is needed to verify the designs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984pwa..rept.....A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984pwa..rept.....A"><span>Turbine blade and vane <span class="hlt">heat</span> <span class="hlt">flux</span> sensor development, phase 1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Atkinson, W. H.; Cyr, M. A.; Strange, R. R.</p> <p>1984-08-01</p> <p><span class="hlt">Heat</span> <span class="hlt">flux</span> sensors available for installation in the hot section airfoils of advanced aircraft gas turbine engines were developed. Two <span class="hlt">heat</span> <span class="hlt">flux</span> sensors were designed, fabricated, calibrated, and tested. Measurement techniques are compared in an atmospheric pressure combustor rig test. Sensors, embedded thermocouple and the Gordon gauge, were fabricated that met the geometric and fabricability requirements and could withstand the hot section environmental conditions. Calibration data indicate that these sensors yielded repeatable results and have the potential to meet the accuracy goal of measuring local <span class="hlt">heat</span> <span class="hlt">flux</span> to within 5%. Thermal cycle tests and thermal soak tests indicated that the sensors are capable of surviving extended periods of exposure to the environment conditions in the turbine. Problems in calibration of the sensors caused by severe non-one dimensional <span class="hlt">heat</span> flow were encountered. Modifications to the calibration techniques are needed to minimize this problem and proof testing of the sensors in an engine is needed to verify the designs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54..385S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54..385S"><span>Estimation of transient <span class="hlt">heat</span> <span class="hlt">flux</span> density during the <span class="hlt">heat</span> supply of a catalytic wall steam methane reformer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Settar, Abdelhakim; Abboudi, Saïd; Madani, Brahim; Nebbali, Rachid</p> <p>2018-02-01</p> <p>Due to the endothermic nature of the steam methane reforming reaction, the process is often limited by the <span class="hlt">heat</span> transfer behavior in the reactors. Poor thermal behavior sometimes leads to slow reaction kinetics, which is characterized by the presence of cold spots in the catalytic zones. Within this framework, the present work consists on a numerical investigation, in conjunction with an experimental one, on the one-dimensional <span class="hlt">heat</span> transfer phenomenon during the <span class="hlt">heat</span> supply of a catalytic-wall reactor, which is designed for hydrogen production. The studied reactor is inserted in an electric furnace where the <span class="hlt">heat</span> requirement of the endothermic reaction is supplied by electric <span class="hlt">heating</span> system. During the <span class="hlt">heat</span> supply, an unknown <span class="hlt">heat</span> <span class="hlt">flux</span> density, received by the reactive flow, is estimated using inverse methods. In the basis of the catalytic-wall reactor model, an experimental setup is engineered in situ to measure the temperature distribution. Then after, the measurements are injected in the numerical <span class="hlt">heat</span> <span class="hlt">flux</span> estimation procedure, which is based on the Function Specification Method (FSM). The measured and estimated temperatures are confronted and the <span class="hlt">heat</span> <span class="hlt">flux</span> density which crosses the reactor wall is determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910029831&hterms=Hot+papers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DHot%2Bpapers','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910029831&hterms=Hot+papers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DHot%2Bpapers"><span>A unique high <span class="hlt">heat</span> <span class="hlt">flux</span> facility for testing hypersonic engine components</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Melis, Matthew E.; Gladden, Herbert J.</p> <p>1990-01-01</p> <p>This paper describes the Hot Gas Facility, a unique, reliable, and cost-effective high-<span class="hlt">heat-flux</span> facility for testing hypersonic engine components developed at the NASA Lewis Research Center. The Hot Gas Facility is capable of providing <span class="hlt">heat</span> <span class="hlt">fluxes</span> ranging from 200 Btu/sq ft per sec on flat surfaces up to 8000 Btu/sq ft per sec at a leading edge stagnation point. The usefulness of the Hot Gas Facility for the NASP community was demonstrated by testing hydrogen-cooled structures over a range of temperatures and pressures. Ranges of the Reynolds numbers, Prandtl numbers, enthalpy, and <span class="hlt">heat</span> <span class="hlt">fluxes</span> similar to those expected during hypersonic flights were achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22482671-characterization-kw-high-flux-solar-simulator-array-xenon-arc-lamps-capable-concentrations-nearly-suns','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22482671-characterization-kw-high-flux-solar-simulator-array-xenon-arc-lamps-capable-concentrations-nearly-suns"><span>Characterization of a 6 kW high-<span class="hlt">flux</span> solar simulator with an array of xenon arc lamps capable of concentrations of nearly 5000 suns</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gill, Robert; Bush, Evan; Loutzenhiser, Peter, E-mail: peter.loutzenhiser@me.gatech.edu</p> <p>2015-12-15</p> <p>A systematic methodology for characterizing a novel and newly fabricated high-<span class="hlt">flux</span> solar simulator is presented. The high-<span class="hlt">flux</span> solar simulator consists of seven xenon short-arc lamps mounted in truncated ellipsoidal reflectors. Characterization of spatial <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span> distribution was performed using calorimetric measurements of <span class="hlt">heat</span> flow coupled with CCD camera imaging of a Lambertian target mounted in the focal plane. The calorimetric measurements and images of the Lambertian target were obtained in two separate runs under identical conditions. Detailed modeling in the high-<span class="hlt">flux</span> solar simulator was accomplished using Monte Carlo ray tracing to capture <span class="hlt">radiative</span> <span class="hlt">heat</span> transport. A least-squares regression modelmore » was used on the Monte Carlo <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer analysis with the experimental data to account for manufacturing defects. The Monte Carlo ray tracing was calibrated by regressing modeled <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span> as a function of specular error and electric power to <span class="hlt">radiation</span> conversion onto measured <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span> from experimental results. Specular error and electric power to <span class="hlt">radiation</span> conversion efficiency were 5.92 ± 0.05 mrad and 0.537 ± 0.004, respectively. An average <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span> with 95% errors bounds of 4880 ± 223 kW ⋅ m{sup −2} was measured over a 40 mm diameter with a cavity-type calorimeter with an apparent absorptivity of 0.994. The Monte Carlo ray-tracing resulted in an average <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span> of 893.3 kW ⋅ m{sup −2} for a single lamp, comparable to the measured <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">fluxes</span> with 95% error bounds of 892.5 ± 105.3 kW ⋅ m{sup −2} from calorimetry.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvA..91b2121L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvA..91b2121L"><span><span class="hlt">Heat</span> <span class="hlt">flux</span> and quantum correlations in dissipative cascaded systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lorenzo, Salvatore; Farace, Alessandro; Ciccarello, Francesco; Palma, G. Massimo; Giovannetti, Vittorio</p> <p>2015-02-01</p> <p>We study the dynamics of <span class="hlt">heat</span> <span class="hlt">flux</span> in the thermalization process of a pair of identical quantum systems that interact dissipatively with a reservoir in a cascaded fashion. Despite that the open dynamics of the bipartite system S is globally Lindbladian, one of the subsystems "sees" the reservoir in a state modified by the interaction with the other subsystem and hence it undergoes a non-Markovian dynamics. As a consequence, the <span class="hlt">heat</span> flow exhibits a nonexponential time behavior which can greatly deviate from the case where each party is independently coupled to the reservoir. We investigate both thermal and correlated initial states of S and show that the presence of correlations at the beginning can considerably affect the <span class="hlt">heat-flux</span> rate. We carry out our study in two paradigmatic cases—a pair of harmonic oscillators with a reservoir of bosonic modes and two qubits with a reservoir of fermionic modes—and compare the corresponding behaviors. In the case of qubits and for initial thermal states, we find that the trace distance discord is at any time interpretable as the correlated contribution to the total <span class="hlt">heat</span> <span class="hlt">flux</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DPPTP8051M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPTP8051M"><span>Turbulent transport regimes and the SOL <span class="hlt">heat</span> <span class="hlt">flux</span> width</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Myra, J. R.; D'Ippolito, D. A.; Russell, D. A.</p> <p>2014-10-01</p> <p>Understanding the responsible mechanisms and resulting scaling of the scrape-off layer (SOL) <span class="hlt">heat</span> <span class="hlt">flux</span> width is important for predicting viable operating regimes in future tokamaks, and for seeking possible mitigation schemes. Simulation and theory results using reduced edge/SOL turbulence models have produced SOL widths and scalings in reasonable accord with experiments in many cases. In this work, we attempt to qualitatively and conceptually understand various regimes of edge/SOL turbulence and the role of turbulent transport in establishing the SOL <span class="hlt">heat</span> <span class="hlt">flux</span> width. Relevant considerations include the type and spectral characteristics of underlying instabilities, the location of the gradient drive relative to the SOL, the nonlinear saturation mechanism, and the parallel <span class="hlt">heat</span> transport regime. Recent SOLT turbulence code results are employed to understand the roles of these considerations and to develop analytical scalings. We find a <span class="hlt">heat</span> <span class="hlt">flux</span> width scaling with major radius R that is generally positive, consistent with older results reviewed in. The possible relationship of turbulence mechanisms to the heuristic drift mechanism is considered, together with implications for future experiments. Work supported by US DOE grant DE-FG02-97ER54392.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.B23D0602K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.B23D0602K"><span>Use of ordinary kriging to interpolate observations of fire <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span> sampled with airborne imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klauberg Silva, C.; Hudak, A. T.; Bright, B. C.; Dickinson, M. B.; Kremens, R.; Paugam, R.; Mell, W.</p> <p>2016-12-01</p> <p>Biomass burning has impacts on air pollution at local to regional scales and contributes to greenhouse gases and affects carbon balance at the global scale. Therefore, is important to accurately estimate and manage carbon pools (fuels) and <span class="hlt">fluxes</span> (gases and particulate emissions having public health implications) associated with wildland fires. Fire <span class="hlt">radiative</span> energy (FRE) has been shown to be linearly correlated with biomass burned in small-scale experimental fires but not at the landscape level. Characterization of FRE density (FRED) <span class="hlt">flux</span> in J m-2 from a landscape-level fire presents an undersampling problem. Specifically, airborne acquisitions of long-wave infrared <span class="hlt">radiation</span> (LWIR) from a nadir-viewing LWIR camera mounted on board fixed-wing aircraft provide only samples of FRED from a landscape-level fire, because of the time required to turn the plane around between passes, and a fire extent that is broader than the camera field of view. This undersampling in time and space produces apparent firelines in an image of observed FRED, capturing the fire spread only whenever and wherever the scene happened to be imaged. We applied ordinary kriging to images of observed FRED from five prescribed burns collected in forested and non-forested management units burned at Eglin Air Force Base in Florida USA in 2011 and 2012. The three objectives were to: 1. more realistically map FRED, 2. more accurately estimate total FRED as predicted from fuel consumption measurements, and 3. compare the sampled and kriged FRED maps to modeled estimates of fire rate of spread (ROS). Observed FRED was integrated from LWIR images calibrated to units of fire <span class="hlt">radiative</span> <span class="hlt">flux</span> density (FRFD) in W m-2. Iterating the kriging analysis 2-10 times (depending on the burn unit) led to more accurate FRED estimates, both in map form and in terms of total FRED, as corroborated by independent estimates of fuel consumption and ROS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993SPIE.1739..306W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993SPIE.1739..306W"><span>High <span class="hlt">heat</span> <span class="hlt">flux</span> issues for plasma-facing components in fusion reactors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watson, Robert D.</p> <p>1993-02-01</p> <p>Plasma facing components in tokamak fusion reactors are faced with a number of difficult high <span class="hlt">heat</span> <span class="hlt">flux</span> issues. These components include: first wall armor tiles, pumped limiters, diverter plates, rf antennae structure, and diagnostic probes. Peak <span class="hlt">heat</span> <span class="hlt">fluxes</span> are 15 - 30 MW/m2 for diverter plates, which will operate for 100 - 1000 seconds in future tokamaks. Disruption <span class="hlt">heat</span> <span class="hlt">fluxes</span> can approach 100,000 MW/m2 for 0.1 ms. Diverter plates are water-cooled <span class="hlt">heat</span> sinks with armor tiles brazed on to the plasma facing side. <span class="hlt">Heat</span> sink materials include OFHC, GlidcopTM, TZM, Mo-41Re, and niobium alloys. Armor tile materials include: carbon fiber composites, beryllium, silicon carbide, tungsten, and molybdenum. Tile thickness range from 2 - 10 mm, and <span class="hlt">heat</span> sinks are 1 - 3 mm. A twisted tape insert is used to enhance <span class="hlt">heat</span> transfer and increase the burnout safety margin from critical <span class="hlt">heat</span> <span class="hlt">flux</span> limits to 50 - 60 MW/m2 with water at 10 m/s and 4 MPa. Tests using rastered electron beams have shown thermal fatigue failures from cracks at the brazed interface between tiles and the <span class="hlt">heat</span> sink after only 1000 cycles at 10 - 15 MW/m2. These fatigue lifetimes need to be increased an order of magnitude to meet future requirements. Other critical issues for plasma facing components include: surface erosion from sputtering and disruption erosion, eddy current forces and runaway electron impact from disruptions, neutron damage, tritium retention and release, remote maintenance of radioactive components, corrosion-erosion, and loss-of-coolant accidents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880001849','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880001849"><span>Enhancement of surface-atmosphere <span class="hlt">fluxes</span> by desert-fringe vegetation through reduction of surface albedo and of soil <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Otterman, J.</p> <p>1987-01-01</p> <p>Under the arid conditions prevailing at the end of the dry season in the western Negev/northern Sinai region, vegetation causes a sharp increase relative to bare soil in the daytime sensible <span class="hlt">heat</span> <span class="hlt">flux</span> from the surface to the atmosphere. Two mechanisms are involved: the increase in the surface absorptivity and a decrease in the surface <span class="hlt">heat</span> <span class="hlt">flux</span>. By increasing the sensible <span class="hlt">heat</span> <span class="hlt">flux</span> to the atmosphere through the albedo and the soil <span class="hlt">heat</span> <span class="hlt">flux</span> reductions, the desert-fringe vegetation increases the daytime convection and the growth of the planetary boundary layer. Removal of vegetation by overgrazing, by reducing the sensible <span class="hlt">heat</span> <span class="hlt">flux</span>, tends to reduce daytime convective precipitation, producing higher probabilities of drought conditions. This assessment of overgrazing is based on observations in the Sinai/Negev, where the soil albedo is high and where overgrazing produces an essential bare soil. Even if the assessment for the Sinai/Negev does not quantitatively apply throughout Africa, the current practice in many African countries of maintaining a large population of grazing animals, can contribute through the mesoscale mechanisms described to reduce daytime convective precipitation, perpetuating higher probabilities of drought. Time-of-day analysis of precipitation in Africa appears worthwhile, to better assess the role of the surface conditions in contributing to drought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6733B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6733B"><span>Ground <span class="hlt">heat</span> <span class="hlt">flux</span> and power sources of low-enthalpy geothermal systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bayer, Peter; Blum, Philipp; Rivera, Jaime A.</p> <p>2015-04-01</p> <p>Geothermal <span class="hlt">heat</span> pumps commonly extract energy from the shallow ground at depths as low as approximately 400 m. Vertical borehole <span class="hlt">heat</span> exchangers are often applied, which are seasonally operated for decades. During this lifetime, thermal anomalies are induced in the ground and surface-near aquifers, which often grow over the years and which alleviate the overall performance of the geothermal system. As basis for prediction and control of the evolving energy imbalance in the ground, focus is typically set on the ground temperatures. This is reflected in regulative temperature thresholds, and in temperature trends, which serve as indicators for renewability and sustainability. In our work, we examine the fundamental <span class="hlt">heat</span> <span class="hlt">flux</span> and power sources, as well as their temporal and spatial variability during geothermal <span class="hlt">heat</span> pump operation. The underlying rationale is that for control of ground temperature evolution, knowledge of the primary <span class="hlt">heat</span> sources is fundamental. This insight is also important to judge the validity of simplified modelling frameworks. For instance, we reveal that vertical <span class="hlt">heat</span> <span class="hlt">flux</span> from the surface dominates the basal <span class="hlt">heat</span> <span class="hlt">flux</span> towards a borehole. Both <span class="hlt">fluxes</span> need to be accounted for as proper vertical boundary conditions in the model. Additionally, the role of horizontal groundwater advection is inspected. Moreover, by adopting the ground energy deficit and long-term replenishment as criteria for system sustainability, an uncommon perspective is adopted that is based on the primary parameter rather than induced local temperatures. In our synthetic study and dimensionless analysis, we demonstrate that time of ground energy recovery after system shutdown may be longer than what is expected from local temperature trends. In contrast, unrealistically long recovery periods and extreme thermal anomalies are predicted without account for vertical ground <span class="hlt">heat</span> <span class="hlt">fluxes</span> and only when the energy content of the geothermal reservoir is considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhST..170a4071S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhST..170a4071S"><span>Progress in extrapolating divertor <span class="hlt">heat</span> <span class="hlt">fluxes</span> towards large fusion devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sieglin, B.; Faitsch, M.; Eich, T.; Herrmann, A.; Suttrop, W.; Collaborators, JET; the MST1 Team; the ASDEX Upgrade Team</p> <p>2017-12-01</p> <p><span class="hlt">Heat</span> load to the plasma facing components is one of the major challenges for the development and design of large fusion devices such as ITER. Nowadays fusion experiments can operate with <span class="hlt">heat</span> load mitigation techniques, e.g. sweeping, impurity seeding, but do not generally require it. For large fusion devices however, <span class="hlt">heat</span> load mitigation will be essential. This paper presents the current progress of the extrapolation of steady state and transient <span class="hlt">heat</span> loads towards large fusion devices. For transient <span class="hlt">heat</span> loads, so-called edge localized modes are considered a serious issue for the lifetime of divertor components. In this paper, the ITER operation at half field (2.65 T) and half current (7.5 MA) will be discussed considering the current material limit for the divertor peak energy fluence of 0.5 {MJ}/{{{m}}}2. Recent studies were successful in describing the observed energy fluence in the JET, MAST and ASDEX Upgrade using the pedestal pressure prior to the ELM crash. Extrapolating this towards ITER results in a more benign <span class="hlt">heat</span> load compared to previous scalings. In the presence of magnetic perturbation, the axisymmetry is broken and a 2D <span class="hlt">heat</span> <span class="hlt">flux</span> pattern is induced on the divertor target, leading to local increase of the <span class="hlt">heat</span> <span class="hlt">flux</span> which is a concern for ITER. It is shown that for a moderate divertor broadening S/{λ }{{q}}> 0.5 the toroidal peaking of the <span class="hlt">heat</span> <span class="hlt">flux</span> disappears.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PEPI..250...35S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PEPI..250...35S"><span>Dynamos driven by weak thermal convection and heterogeneous outer boundary <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sahoo, Swarandeep; Sreenivasan, Binod; Amit, Hagay</p> <p>2016-01-01</p> <p>We use numerical dynamo models with heterogeneous core-mantle boundary (CMB) <span class="hlt">heat</span> <span class="hlt">flux</span> to show that lower mantle lateral thermal variability may help support a dynamo under weak thermal convection. In our reference models with homogeneous CMB <span class="hlt">heat</span> <span class="hlt">flux</span>, convection is either marginally supercritical or absent, always below the threshold for dynamo onset. We find that lateral CMB <span class="hlt">heat</span> <span class="hlt">flux</span> variations organize the flow in the core into patterns that favour the growth of an early magnetic field. <span class="hlt">Heat</span> <span class="hlt">flux</span> patterns symmetric about the equator produce non-reversing magnetic fields, whereas anti-symmetric patterns produce polarity reversals. Our results may explain the existence of the geodynamo prior to inner core nucleation under a tight energy budget. Furthermore, in order to sustain a strong geomagnetic field, the lower mantle thermal distribution was likely dominantly symmetric about the equator.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PEPI..277...10L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PEPI..277...10L"><span>Linking lowermost mantle structure, core-mantle boundary <span class="hlt">heat</span> <span class="hlt">flux</span> and mantle plume formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Mingming; Zhong, Shijie; Olson, Peter</p> <p>2018-04-01</p> <p>The dynamics of Earth's lowermost mantle exert significant control on the formation of mantle plumes and the core-mantle boundary (CMB) <span class="hlt">heat</span> <span class="hlt">flux</span>. However, it is not clear if and how the variation of CMB <span class="hlt">heat</span> <span class="hlt">flux</span> and mantle plume activity are related. Here, we perform geodynamic model experiments that show how temporal variations in CMB <span class="hlt">heat</span> <span class="hlt">flux</span> and pulses of mantle plumes are related to morphologic changes of the thermochemical piles of large-scale compositional heterogeneities in Earth's lowermost mantle, represented by the large low shear velocity provinces (LLSVPs). We find good correlation between the morphologic changes of the thermochemical piles and the time variation of CMB <span class="hlt">heat</span> <span class="hlt">flux</span>. The morphology of the thermochemical piles is significantly altered during the initiation and ascent of strong mantle plumes, and the changes in pile morphology cause variations in the local and the total CMB <span class="hlt">heat</span> <span class="hlt">flux</span>. Our modeling results indicate that plume-induced episodic variations of CMB <span class="hlt">heat</span> <span class="hlt">flux</span> link geomagnetic superchrons to pulses of surface volcanism, although the relative timing of these two phenomena remains problematic. We also find that the density distribution in thermochemical piles is heterogeneous, and that the piles are denser on average than the surrounding mantle when both thermal and chemical effects are included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070038262&hterms=passive+transport&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpassive%2Btransport','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070038262&hterms=passive+transport&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpassive%2Btransport"><span>Interannual and Decadal Variability of Ocean Surface Latent <span class="hlt">Heat</span> <span class="hlt">Flux</span> as Seen from Passive Microwave Satellite Algorithms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robertson, Franklin R.; Jackson, Darren L.; Wick, Gary A.; Roberts, Brent; Miller, Tim L.</p> <p>2007-01-01</p> <p>Ocean surface turbulent <span class="hlt">fluxes</span> are critical links in the climate system since they mediate energy exchange between the two fluid systems (ocean and atmosphere) whose combined <span class="hlt">heat</span> transport determines the basic character of Earth's climate. Deriving physically-based latent and sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> from satellite is dependent on inferences of near surface moisture and temperature from coarser layer retrievals or satellite radiances. Uncertainties in these "retrievals" propagate through bulk aerodynamic algorithms, interacting as well with error properties of surface wind speed, also provided by satellite. By systematically evaluating an array of passive microwave satellite algorithms, the SEAFLUX project is providing improved understanding of these errors and finding pathways for reducing or eliminating them. In this study we focus on evaluating the interannual variability of several passive microwave-based estimates of latent <span class="hlt">heat</span> <span class="hlt">flux</span> starting from monthly mean gridded data. The algorithms considered range from those based essentially on SSM/I (e.g. HOAPS) to newer approaches that consider additional moisture information from SSM/T-2 or AMSU-B and lower tropospheric temperature data from AMSU-A. On interannual scales, variability arising from ENSO events and time-lagged responses of ocean turbulent and <span class="hlt">radiative</span> <span class="hlt">fluxes</span> in other ocean basins (as well as the extratropical Pacific) is widely recognized, but still not well quantified. Locally, these <span class="hlt">flux</span> anomalies are of order 10-20 W/sq m and present a relevant "target" with which to verify algorithm performance in a climate context. On decadal time scales there is some evidence from reanalyses and remotely-sensed <span class="hlt">fluxes</span> alike that tropical ocean-averaged latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> have increased 5-10 W/sq m since the early 1990s. However, significant uncertainty surrounds this estimate. Our work addresses the origin of these uncertainties and provides statistics on time series of tropical ocean averages, regional space</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1305850-broadening-divertor-heat-flux-profile-increasing-number-elm-filaments-nstx','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1305850-broadening-divertor-heat-flux-profile-increasing-number-elm-filaments-nstx"><span>Broadening of divertor <span class="hlt">heat</span> <span class="hlt">flux</span> profile with increasing number of ELM filaments in NSTX</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Ahn, J. -W.; Maingi, R.; Canik, J. M.; ...</p> <p>2014-11-13</p> <p>Edge localized modes (ELMs) represent a challenge to future fusion devices, owing to cyclical high peak <span class="hlt">heat</span> <span class="hlt">fluxes</span> on divertor plasma facing surfaces. One ameliorating factor has been that the <span class="hlt">heat</span> <span class="hlt">flux</span> characteristic profile width has been observed to broaden with the size of the ELM, as compared with the inter-ELM <span class="hlt">heat</span> <span class="hlt">flux</span> profile. In contrast, the <span class="hlt">heat</span> <span class="hlt">flux</span> profile has been observed to narrow during ELMs under certain conditions in NSTX. Here we show that the ELM <span class="hlt">heat</span> <span class="hlt">flux</span> profile width increases with the number of filamentary striations observed, i.e., profile narrowing is observed with zero or very fewmore » striations. Because NSTX often lies on the long wavelength current-driven mode side of ideal MHD instabilities, few filamentary structures can be expected under many conditions. Lastly, ITER is also projected to lie on the current driven low-n stability boundary, and therefore detailed projections of the unstable modes expected in ITER and the <span class="hlt">heat</span> <span class="hlt">flux</span> driven in ensuing filamentary structures is needed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009APS..DPPPP8020L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009APS..DPPPP8020L"><span>Initial results from divertor <span class="hlt">heat-flux</span> instrumentation on Alcator C-Mod</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Labombard, B.; Brunner, D.; Payne, J.; Reinke, M.; Terry, J. L.; Hughes, J. W.; Lipschultz, B.; Whyte, D.</p> <p>2009-11-01</p> <p>Physics-based plasma transport models that can accurately simulate the <span class="hlt">heat-flux</span> power widths observed in the tokamak boundary are lacking at the present time. Yet this quantity is of fundamental importance for ITER and most critically important for DEMO, a reactor similar to ITER but with ˜4 times the power exhaust. In order to improve our understanding, C-Mod, DIII-D and NSTX will aim experiments in FY10 towards characterizing the divertor ``footprint'' and its connection to conditions ``upstream'' in the boundary and core plasmas [2]. Standard IR-based <span class="hlt">heat-flux</span> measurements are particularly difficult in C-Mod, due to its vertical-oriented divertor targets. To overcome this, a suite of embedded <span class="hlt">heat-flux</span> sensor probes (tile thermocouples, calorimeters, surface thermocouples) combined with IR thermography was installed during the FY09 opening, along with a new divertor bolometer system. This paper will report on initial experiments aimed at unfolding the <span class="hlt">heat-flux</span> dependencies on plasma operating conditions. [2] a proposed US DoE Joint Facilities Milestone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70035239','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70035239"><span>SPECTRAL data-based estimation of soil <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Singh, Ramesh K.; Irmak, A.; Walter-Shea, Elizabeth; Verma, S.B.; Suyker, A.E.</p> <p>2011-01-01</p> <p>Numerous existing spectral-based soil <span class="hlt">heat</span> <span class="hlt">flux</span> (G) models have shown wide variation in performance for maize and soybean cropping systems in Nebraska, indicating the need for localized calibration and model development. The objectives of this article are to develop a semi-empirical model to estimate G from a normalized difference vegetation index (NDVI) and net <span class="hlt">radiation</span> (Rn) for maize (Zea mays L.) and soybean (Glycine max L.) fields in the Great Plains, and present the suitability of the developed model to estimate G under similar and different soil and management conditions. Soil <span class="hlt">heat</span> <span class="hlt">fluxes</span> measured in both irrigated and rainfed fields in eastern and south-central Nebraska were used for model development and validation. An exponential model that uses NDVI and Rn was found to be the best to estimate G based on r2 values. The effect of geographic location, crop, and water management practices were used to develop semi-empirical models under four case studies. Each case study has the same exponential model structure but a different set of coefficients and exponents to represent the crop, soil, and management practices. Results showed that the semi-empirical models can be used effectively for G estimation for nearby fields with similar soil properties for independent years, regardless of differences in crop type, crop rotation, and irrigation practices, provided that the crop residue from the previous year is more than 4000 kg ha-1. The coefficients calibrated from particular fields can be used at nearby fields in order to capture temporal variation in G. However, there is a need for further investigation of the models to account for the interaction effects of crop rotation and irrigation. Validation at an independent site having different soil and crop management practices showed the limitation of the semi-empirical model in estimating G under different soil and environment conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT...tmp..114M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT...tmp..114M"><span>A combined ANN-GA and experimental based technique for the estimation of the unknown <span class="hlt">heat</span> <span class="hlt">flux</span> for a conjugate <span class="hlt">heat</span> transfer problem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>M K, Harsha Kumar; P S, Vishweshwara; N, Gnanasekaran; C, Balaji</p> <p>2018-05-01</p> <p>The major objectives in the design of thermal systems are obtaining the information about thermophysical, transport and boundary properties. The main purpose of this paper is to estimate the unknown <span class="hlt">heat</span> <span class="hlt">flux</span> at the surface of a solid body. A constant area mild steel fin is considered and the base is subjected to constant <span class="hlt">heat</span> <span class="hlt">flux</span>. During <span class="hlt">heating</span>, natural convection <span class="hlt">heat</span> transfer occurs from the fin to ambient. The direct solution, which is the forward problem, is developed as a conjugate <span class="hlt">heat</span> transfer problem from the fin and the steady state temperature distribution is recorded for any assumed <span class="hlt">heat</span> <span class="hlt">flux</span>. In order to model the natural convection <span class="hlt">heat</span> transfer from the fin, an extended domain is created near the fin geometry and air is specified as a fluid medium and Navier Stokes equation is solved by incorporating the Boussinesq approximation. The computational time involved in executing the forward model is then reduced by developing a neural network (NN) between <span class="hlt">heat</span> <span class="hlt">flux</span> values and temperatures based on back propagation algorithm. The conjugate <span class="hlt">heat</span> transfer NN model is now coupled with Genetic algorithm (GA) for the solution of the inverse problem. Initially, GA is applied to the pure surrogate data, the results are then used as input to the Levenberg- Marquardt method and such hybridization is proven to result in accurate estimation of the unknown <span class="hlt">heat</span> <span class="hlt">flux</span>. The hybrid method is then applied for the experimental temperature to estimate the unknown <span class="hlt">heat</span> <span class="hlt">flux</span>. A satisfactory agreement between the estimated and actual <span class="hlt">heat</span> <span class="hlt">flux</span> is achieved by incorporating the hybrid method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890000356&hterms=Rhodium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DRhodium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890000356&hterms=Rhodium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DRhodium"><span><span class="hlt">Heat-Flux</span> Sensor For Hot Engine Cylinders</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kim, Walter S.; Barrows, Richard F.; Smith, Floyd A.; Koch, John</p> <p>1989-01-01</p> <p><span class="hlt">Heat-flux</span> sensor includes buried wire thermocouple and thin-film surface thermocouple, made of platinum and platinum with 13 percent rhodium. Sensor intended for use in ceramic-insulated, low-<span class="hlt">heat</span>-rejection diesel engine at temperatures of about 1,000 K. Thermocouple junction resists environment in cylinder of advanced high-temperature diesel engine created by depositing overlapping films of Pt and 0.87 Pt/0.13 Rh on iron plug. Plug also contains internal thermocouple.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120004033','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120004033"><span><span class="hlt">Heat</span> Rejection from a Variable Conductance <span class="hlt">Heat</span> Pipe <span class="hlt">Radiator</span> Panel</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jaworske, D. A.; Gibson, M. A.; Hervol, D. S.</p> <p>2012-01-01</p> <p>A titanium-water <span class="hlt">heat</span> pipe <span class="hlt">radiator</span> having an innovative proprietary evaporator configuration was evaluated in a large vacuum chamber equipped with liquid nitrogen cooled cold walls. The <span class="hlt">radiator</span> was manufactured by Advanced Cooling Technologies, Inc. (ACT), Lancaster, PA, and delivered as part of a Small Business Innovative Research effort. The <span class="hlt">radiator</span> panel consisted of five titanium-water <span class="hlt">heat</span> pipes operating as thermosyphons, sandwiched between two polymer matrix composite face sheets. The five variable conductance <span class="hlt">heat</span> pipes were purposely charged with a small amount of non-condensable gas to control <span class="hlt">heat</span> flow through the condenser. <span class="hlt">Heat</span> rejection was evaluated over a wide range of inlet water temperature and flow conditions, and <span class="hlt">heat</span> rejection was calculated in real-time utilizing a data acquisition system programmed with the Stefan-Boltzmann equation. Thermography through an infra-red transparent window identified <span class="hlt">heat</span> flow across the panel. Under nominal operation, a maximum <span class="hlt">heat</span> rejection value of over 2200 Watts was identified. The thermal vacuum evaluation of <span class="hlt">heat</span> rejection provided critical information on understanding the <span class="hlt">radiator</span> s performance, and in steady state and transient scenarios provided useful information for validating current thermal models in support of the Fission Power Systems Project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790008611','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790008611"><span>A method of exploration of the atmosphere of Titan. [hot air balloon <span class="hlt">heated</span> by solar <span class="hlt">radiation</span> or planetary thermal <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Blamont, J.</p> <p>1978-01-01</p> <p>A hot-air balloon, with the air <span class="hlt">heated</span> by natural sources, is described. Buoyancy is accomplished by either solar <span class="hlt">heating</span> or by utilizing the IR thermal <span class="hlt">flux</span> of the planet to <span class="hlt">heat</span> the gas in the balloon. Altitude control is provided by a valve which is opened and closed by a barometer. The balloon is made of an organic material which has to absorb radiant energy and to emit as little as possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54.1511N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54.1511N"><span>Effect of surface <span class="hlt">radiation</span> on natural convection in an asymmetrically <span class="hlt">heated</span> channel-chimney system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nasri, Zied; Derouich, Youssef; Laatar, Ali Hatem; Balti, Jalloul</p> <p>2018-05-01</p> <p>In this paper, a more realistic numerical approach that takes into account the effect of surface <span class="hlt">radiation</span> on the laminar air flow induced by natural convection in a channel-chimney system asymmetrically <span class="hlt">heated</span> at uniform <span class="hlt">heat</span> <span class="hlt">flux</span> is used. The aim is to enrich the results given in Nasri et al. (Int J Therm Sci 90:122-134, 2015) by varying all the geometric parameters of the system and by taking into account the effect of surface <span class="hlt">radiation</span> on the flows. The numerical results are first validated against experimental and numerical data available in the literature. The computations have allowed the determination of optimal configurations that maximize the mass flow rate and the convective <span class="hlt">heat</span> transfer and minimize the <span class="hlt">heated</span> wall temperatures. The analysis of the temperature fields with the streamlines and the pressure fields has helped to explain the effects of surface <span class="hlt">radiation</span> and of the different thermo-geometrical parameters on the system performances to improve the mass flow rate and the <span class="hlt">heat</span> transfer with respect to the simple channel. It is shown that the thermal performance of the channel-chimney system in terms of lower <span class="hlt">heated</span> wall temperatures is little affected by the surface <span class="hlt">radiation</span>. At the end, simple correlation equations have been proposed for quickly and easily predict the optimal configurations as well as the corresponding enhancement rates of the induced mass flow rate and the convective <span class="hlt">heat</span> transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DPPJP2043P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DPPJP2043P"><span>Scaling Relationships for ELM Diverter <span class="hlt">Heat</span> <span class="hlt">Flux</span> on DIII D</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peters, E. A.; Makowski, M. A.; Leonard, A. W.</p> <p>2015-11-01</p> <p>Edge Localized Modes (ELMs) are periodic plasma instabilities that occur during H-mode operation in tokamaks. Left unmitigated, these instabilities result in concentrated particle and <span class="hlt">heat</span> <span class="hlt">fluxes</span> at the divertor and stand to cause serious damage to the plasma facing components of tokamaks. The purpose of this research is to find scaling relationships that predict divertor <span class="hlt">heat</span> <span class="hlt">flux</span> due to ELMs based on plasma parameters at the time of instability. This will be accomplished by correlating characteristic ELM parameters with corresponding plasma measurements and analyzing the data for trends. One early assessment is the effect of the <span class="hlt">heat</span> transmission coefficient ? on the in/out asymmetry of the calculated ELM <span class="hlt">heat</span> <span class="hlt">fluxes</span>. Using IR camera data, further assessments in this study will continue to emphasize in/out asymmetry in ELMs, as this has important implications for ITER operation. Work supported in part by the US DOE, DE-AC52-07NA27344, DE-FC02-04ER54698, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internships Program (SULI).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NucFu..57k6016X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NucFu..57k6016X"><span>Divertor <span class="hlt">heat</span> <span class="hlt">flux</span> simulations in ELMy H-mode discharges of EAST</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, T. Y.; Xu, X. Q.; Wu, Y. B.; Huang, Y. Q.; Wang, L.; Zheng, Z.; Liu, J. B.; Zang, Q.; Li, Y. Y.; Zhao, D.; EAST Team</p> <p>2017-11-01</p> <p>This paper presents <span class="hlt">heat</span> <span class="hlt">flux</span> simulations for the ELMy H-mode on the Experimental Advanced Superconducting Tokamak (EAST) using a six-field two-fluid model in BOUT++. Three EAST ELMy H-mode discharges with different plasma currents I p and geometries are studied. The trend of the scrape-off layer width λq with I p is reproduced by the simulation. The simulated width is only half of that derived from the EAST scaling law, but agrees well with the international multi-machine scaling law. Note that there is no radio-frequency (RF) <span class="hlt">heating</span> scheme in the simulations, and RF <span class="hlt">heating</span> can change the boundary topology and increase the <span class="hlt">flux</span> expansion. Anomalous electron transport is found to contribute to the divertor <span class="hlt">heat</span> <span class="hlt">fluxes</span>. A coherent mode is found in the edge region in simulations. The frequency and poloidal wave number kθ are in the range of the edge coherent mode in EAST. The magnetic fluctuations of the mode are smaller than the electric field fluctuations. Statistical analysis of the type of turbulence shows that the turbulence transport type (blobby or turbulent) does not influence the <span class="hlt">heat</span> <span class="hlt">flux</span> width scaling. The two-point model differs from the simulation results but the drift-based model shows good agreement with simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNG21A0138D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNG21A0138D"><span>The Influence of <span class="hlt">Heat</span> <span class="hlt">Flux</span> Boundary Heterogeneity on <span class="hlt">Heat</span> Transport in Earth's Core</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davies, C. J.; Mound, J. E.</p> <p>2017-12-01</p> <p>Rotating convection in planetary systems can be subjected to large lateral variations in <span class="hlt">heat</span> <span class="hlt">flux</span> from above; for example, due to the interaction between the metallic cores of terrestrial planets and their overlying silicate mantles. The boundary anomalies can significantly reorganise the pattern of convection and influence global diagnostics such as the Nusselt number. We have conducted a suite of numerical simulations of rotating convection in a spherical shell geometry comparing convection with homogeneous boundary conditions to that with two patterns of <span class="hlt">heat</span> <span class="hlt">flux</span> variation at the outer boundary: one hemispheric pattern, and one derived from seismic tomographic imaging of Earth's lower mantle. We consider Ekman numbers down to 10-6 and <span class="hlt">flux</span>-based Rayleigh numbers up to 800 times critical. The heterogeneous boundary conditions tend to increase the Nusselt number relative to the equivalent homogeneous case by altering both the flow and temperature fields, particularly near the top of the convecting region. The enhancement in Nusselt number tends to increase as the amplitude and wavelength of the boundary heterogeneity is increased and as the system becomes more supercritical. In our suite of models, the increase in Nusselt number can be as large as 25%. The slope of the Nusselt-Rayleigh scaling also changes when boundary heterogeneity is included, which has implications when extrapolating to planetary conditions. Additionally, regions of effective thermal stratification can develop when strongly heterogeneous <span class="hlt">heat</span> <span class="hlt">flux</span> conditions are applied at the outer boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730019076','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730019076"><span>Extended hydrodynamic theory of the peak and minimum pool boiling <span class="hlt">heat</span> <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Linehard, J. H.; Dhir, V. K.</p> <p>1973-01-01</p> <p>The hydrodynamic theory of the extreme pool boiling <span class="hlt">heat</span> <span class="hlt">fluxes</span> is expanded to embrace a variety of problems that have not previously been analyzed. These problems include the prediction of the peak <span class="hlt">heat</span> <span class="hlt">flux</span> on a variety of finite heaters, the influence of viscosity on the Taylor and Helmoltz instability mechanisms with application to film boiling and to the peak <span class="hlt">heat</span> <span class="hlt">flux</span> in viscous liquids, the formalization of the analogy between high-current-density electrolysis and boiling, and the description of boiling in the low-gravity limit. The predictions are verified with a large number of new data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/19747','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/19747"><span>An inverse method to estimate stem surface <span class="hlt">heat</span> <span class="hlt">flux</span> in wildland fires</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Anthony S. Bova; Matthew B. Dickinson</p> <p>2009-01-01</p> <p>Models of wildland fire-induced stem <span class="hlt">heating</span> and tissue necrosis require accurate estimates of inward <span class="hlt">heat</span> <span class="hlt">flux</span> at the bark surface. Thermocouple probes or <span class="hlt">heat</span> <span class="hlt">flux</span> sensors placed at a stem surface do not mimic the thermal response of tree bark to flames.We show that data from thin thermocouple probes inserted just below the bark can be used, by means of a one-...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.661a2055K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.661a2055K"><span>Numerical simulation of <span class="hlt">heat</span> <span class="hlt">fluxes</span> in a two-temperature plasma at shock tube walls</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuznetsov, E. A.; Poniaev, S. A.</p> <p>2015-12-01</p> <p>Numerical simulation of a two-temperature three-component Xenon plasma flow is presented. A solver based on the OpenFOAM CFD software package is developed. The <span class="hlt">heat</span> <span class="hlt">flux</span> at the shock tube end wall is calculated and compared with experimental data. It is shown that the <span class="hlt">heat</span> <span class="hlt">flux</span> due to electrons can be as high as 14% of the total <span class="hlt">heat</span> <span class="hlt">flux</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..DPPTP9069B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..DPPTP9069B"><span>Measurements of plasma sheath <span class="hlt">heat</span> <span class="hlt">flux</span> in the Alcator C-Mod divertor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brunner, Dan; Labombard, Brian; Terry, Jim; Reinke, Matt</p> <p>2010-11-01</p> <p><span class="hlt">Heat</span> <span class="hlt">flux</span> is one of the most important parameters controlling the lifetime of first-wall components in fusion experiments and reactors. The sheath <span class="hlt">heat</span> <span class="hlt">flux</span> coefficient (γ) is a parameter relating <span class="hlt">heat</span> <span class="hlt">flux</span> (from a plasma to a material surface) to the electron temperature and ion saturation current. Being such a simple expression for a kinetic process, it is of great interest to plasma edge fluid modelers. Under the assumptions of equal ion and electron temperatures, no secondary electron emission, and no net current to the surface the value of γ is approximately 7 [1]. Alcator C-Mod provides a unique opportunity among today's experiments to measure reactor-relevant <span class="hlt">heat</span> <span class="hlt">fluxes</span> (100's of MW/m^2 parallel to the magnetic field) in reactor-like divertor geometry. Motivated by the DoE 2010 joint milestone to measure <span class="hlt">heat</span> <span class="hlt">flux</span> footprints, the lower outer divertor of Alcator has been instrumented with a suite of Langmuir probes, novel surface thermocouples, and calorimeters in tiles purposefully ramped to eliminate shadowing; all within view of an IR camera. Initial results indicate that the experimentally inferred values of γ are found to agree with simple theory in the sheath limited regime and diverges to lower values as the density increases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AIPC.1547..746C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AIPC.1547..746C"><span>Numerical research of dynamic characteristics in tower solar cavity receiver based on step-change <span class="hlt">radiation</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Zhengwei; Wang, Yueshe; Hao, Yun; Wang, Qizhi</p> <p>2013-07-01</p> <p>The solar cavity receiver is an important light-energy to thermal-energy convector in the tower solar thermal power plant system. The <span class="hlt">heat</span> <span class="hlt">flux</span> in the inner surface of the cavity will show the characteristics of non-continuous step change especially in non-normal and transient weather conditions, which may result in a continuous dynamic variation of the characteristic parameters. Therefore, the research of dynamic characteristics of the receiver plays a very important role in the operation and the control safely in solar cavity receiver system. In this paper, based on the non-continuous step change of <span class="hlt">radiation</span> <span class="hlt">flux</span>, a non-linear dynamic model is put forward to obtain the effects of the non-continuous step change <span class="hlt">radiation</span> <span class="hlt">flux</span> and step change feed water flow on the receiver performance by sequential modular approach. The subject investigated in our study is a 1MW solar power station constructed in Yanqing County, Beijing. This study has obtained the dynamic responses of the characteristic parameters in the cavity receiver, such as drum pressure, drum water level, main steam flow and main steam enthalpy under step change <span class="hlt">radiation</span> <span class="hlt">flux</span>. And the influence law of step-change feed water flow to the dynamic characteristics in the receiver also has been analyzed. The results have a reference value for the safe operation and the control in solar cavity receiver system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840008426','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840008426"><span>Effects of broadened property fuels on radiant <span class="hlt">heat</span> <span class="hlt">flux</span> to gas turbine combustor liners</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Haggard, J. B., Jr.</p> <p>1983-01-01</p> <p>The effects of fuel type, inlet air pressure, inlet air temperature, and fuel/air ratio on the combustor <span class="hlt">radiation</span> were investigated. Combustor liner radiant <span class="hlt">heat</span> <span class="hlt">flux</span> measurements were made in the spectral region between 0.14 and 6.5 microns at three locations in a modified commercial aviation can combustor. Two fuels, Jet A and a heavier distillate research fuel called ERBS were used. The use of ERBS fuel as opposed to Jet A under similar operating conditions resulted in increased <span class="hlt">radiation</span> to the combustor liner and hence increased backside liner temperature. This increased <span class="hlt">radiation</span> resulted in liner temperature increases always less than 73 C. The increased <span class="hlt">radiation</span> is shown by way of calculations to be the result of increased soot concentrations in the combustor. The increased liner temperatures indicated can substantially affect engine maintenance costs by reducing combustor liner life up to 1/3 because of the rapid decay in liner material properties when operated beyond their design conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ResPh...9..779M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ResPh...9..779M"><span>Nonlinear unsteady convection on micro and nanofluids with Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mamatha Upadhya, S.; Raju, C. S. K.; Mahesha; Saleem, S.</p> <p>2018-06-01</p> <p>This is a theoretical study of unsteady nonlinear convection on magnetohydrodynamic fluid in a suspension of dust and graphene nanoparticles. For boosting the <span class="hlt">heat</span> transport phenomena we consider the Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> and thermal <span class="hlt">radiation</span>. Dispersal of graphene nanoparticles in dusty fluids finds applications in biocompatibility, bio-imaging, biosensors, detection and cancer treatment, in monitoring stem cells differentiation etc. Initially the simulation is performed by amalgamation of dust (micron size) and nanoparticles into base fluid. Primarily existing partial differential system (PDEs) is changed to ordinary differential system (ODEs) with the support of usual similarity transformations. Consequently, the highly nonlinear ODEs are solved numerically through Runge-Kutta and Shooting method. The computational results for Non-dimensional temperature and velocity profiles are offered through graphs (ϕ = 0 and ϕ = 0.05) cases. Additionally, the numerical values of friction factor and <span class="hlt">heat</span> transfer rate are tabulated numerically for various physical parameters obtained. We also validated the current outcomes with previously available study and found to be extremely acceptable. From this study we conclude that in the presence of nanofluid <span class="hlt">heat</span> transfer rate and temperature distribution is higher compared to micro fluid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA469754','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA469754"><span>Electromagnetic Control of High <span class="hlt">Heat-Flux</span> Spray Impingement Boiling Under Microgravity Conditions</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2007-03-01</p> <p>impingement boiling ( Mudawar , 2000; Chow et al., 1997; Tilton, 1989). With water as the working fluid, spray cooling has achieved a <span class="hlt">heat</span> <span class="hlt">flux</span> on the...Stebbins, C. J., and Mudawar , I., 1996. "Mapping of Impact and <span class="hlt">Heat</span> Transfer Regimes of Water Drops Impinging on a Polished Surface," Int. J. <span class="hlt">Heat</span> and Mass...34 Proceedings of SAE 2004 Power Systems Conference, 2004-01-3204, Reno NV, November, pp. 309-317. Mudawar , 1., 2000. "Assessment of High-<span class="hlt">heat</span> <span class="hlt">Flux</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1356713-analysis-edge-stability-models-heat-flux-width','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1356713-analysis-edge-stability-models-heat-flux-width"><span>Analysis of edge stability for models of <span class="hlt">heat</span> <span class="hlt">flux</span> width</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Makowski, Michael A.; Lasnier, Charles J.; Leonard, Anthony W.; ...</p> <p>2017-05-12</p> <p>Detailed measurements of the n e, and T e, and T i profiles in the vicinity of the separatrix of ELMing H-mode discharges have been used to examine plasma stability at the extreme edge of the plasma and assess stability dependent models of the <span class="hlt">heat</span> <span class="hlt">flux</span> width. The results are strongly contrary to the critical gradient model, which posits that a ballooning instability determines a gradient scale length related to the <span class="hlt">heat</span> <span class="hlt">flux</span> width. The results of this analysis are not sensitive to the choice of location to evaluate stability. Significantly, it is also found that the results are completelymore » consistent with the heuristic drift model for the <span class="hlt">heat</span> <span class="hlt">flux</span> width. Here the edge pressure gradient scales with plasma density and is proportional to the pressure gradient inferred from the equilibrium in accordance with the predictions of that theory.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..DPPPI2005M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..DPPPI2005M"><span>Analysis of a Multi-Machine Database on Divertor <span class="hlt">Heat</span> <span class="hlt">Fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Makowski, M. A.</p> <p>2011-10-01</p> <p>A coordinated effort to measure divertor <span class="hlt">heat</span> <span class="hlt">flux</span> characteristics in fully attached, similarly shaped H-mode plasmas on C-Mod, DIII-D and NSTX was carried out in 2010 in order to construct a predictive scaling relation applicable to next step devices including ITER, FNSF, and DEMO. Few published scaling laws are available and those that have been published were obtained under widely varying conditions and divertor geometries, leading to conflicting predictions for this critically important quantity. This study was designed to overcome these deficiencies. Corresponding plasma parameters were systematically varied in each tokamak, resulting in a combined data set in which Ip varies by a factor 3, Bt varies by a factor of 14.5, and major radius varies by a factor of 2.6. The derived scaling relation consistently predicts narrower <span class="hlt">heat</span> <span class="hlt">flux</span> widths than relations currently in use. Analysis of the combined data set reveals that the primary dependence of the parallel <span class="hlt">heat</span> <span class="hlt">flux</span> width is robustly inverse with Ip. All three tokamaks independently demonstrate this dependence. The midplane SOL profiles in DIII-D are also found to steepen with higher Ip, similar to the divertor <span class="hlt">heat</span> <span class="hlt">flux</span> profiles. Weaker dependencies on the toroidal field and normalized Greenwald density, fGW, are also found, but vary across devices and with the measure of the <span class="hlt">heat</span> <span class="hlt">flux</span> width used, either FWHM or integral width. In the combined data set, the strongest size scaling is with minor radius resulting in an approximately linear dependence on a /Ip . This suggests a scaling correlated with the inverse of the poloidal field, as would be expected for critical gradient or drift-based transport. Supported by the US DOE under DE-AC52-07NA27344 and DE-FC02-04ER54698.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11874138','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11874138"><span>Methodology for estimation of time-dependent surface <span class="hlt">heat</span> <span class="hlt">flux</span> due to cryogen spray cooling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tunnell, James W; Torres, Jorge H; Anvari, Bahman</p> <p>2002-01-01</p> <p>Cryogen spray cooling (CSC) is an effective technique to protect the epidermis during cutaneous laser therapies. Spraying a cryogen onto the skin surface creates a time-varying <span class="hlt">heat</span> <span class="hlt">flux</span>, effectively cooling the skin during and following the cryogen spurt. In previous studies mathematical models were developed to predict the human skin temperature profiles during the cryogen spraying time. However, no studies have accounted for the additional cooling due to residual cryogen left on the skin surface following the spurt termination. We formulate and solve an inverse <span class="hlt">heat</span> conduction (IHC) problem to predict the time-varying surface <span class="hlt">heat</span> <span class="hlt">flux</span> both during and following a cryogen spurt. The IHC formulation uses measured temperature profiles from within a medium to estimate the surface <span class="hlt">heat</span> <span class="hlt">flux</span>. We implement a one-dimensional sequential function specification method (SFSM) to estimate the surface <span class="hlt">heat</span> <span class="hlt">flux</span> from internal temperatures measured within an in vitro model in response to a cryogen spurt. Solution accuracy and experimental errors are examined using simulated temperature data. <span class="hlt">Heat</span> <span class="hlt">flux</span> following spurt termination appears substantial; however, it is less than that during the spraying time. The estimated time-varying <span class="hlt">heat</span> <span class="hlt">flux</span> can subsequently be used in forward <span class="hlt">heat</span> conduction models to estimate temperature profiles in skin during and following a cryogen spurt and predict appropriate timing for onset of the laser pulse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DPPBO7015H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DPPBO7015H"><span><span class="hlt">Heat-Flux</span> Measurements in Laser-Produced Plasmas Using Thomson Scattering from Electron Plasma Waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Henchen, R. J.; Goncharov, V. N.; Cao, D.; Katz, J.; Froula, D. H.; Rozmus, W.</p> <p>2017-10-01</p> <p>An experiment was designed to measure <span class="hlt">heat</span> <span class="hlt">flux</span> in coronal plasmas using collective Thomson scattering. Adjustments to the electron distribution function resulting from <span class="hlt">heat</span> <span class="hlt">flux</span> affect the shape of the collective Thomson scattering features through wave-particle resonance. The amplitude of the Spitzer-Härm electron distribution function correction term (f1) was varied to match the data and determines the value of the <span class="hlt">heat</span> <span class="hlt">flux</span>. Independent measurements of temperature and density obtained from Thomson scattering were used to infer the classical <span class="hlt">heat</span> <span class="hlt">flux</span> (q = - κ∇Te) . Time-resolved Thomson-scattering data were obtained at five locations in the corona along the target normal in a blowoff plasma formed from a planar Al target with 1.5 kJ of 351-nm laser light in a 2-ns square pulse. The <span class="hlt">flux</span> measured through the Thomson-scattering spectra is a factor of 5 less than the κ∇Te measurements. The lack of collisions of <span class="hlt">heat</span>-carrying electrons suggests a nonlocal model is needed to accurately describe the <span class="hlt">heat</span> <span class="hlt">flux</span>. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyC..530..133S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyC..530..133S"><span><span class="hlt">Heat</span> loss analysis-based design of a 12 MW wind power generator module having an HTS <span class="hlt">flux</span> pump exciter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sung, Hae-Jin; Go, Byeong-Soo; Jiang, Zhenan; Park, Minwon; Yu, In-Keun</p> <p>2016-11-01</p> <p>The development of an effective high-temperature superconducting (HTS) generator is currently a research focus; however, the reduction of <span class="hlt">heat</span> loss of a large-scale HTS generator is a challenge. This study deals with a <span class="hlt">heat</span> loss analysis-based design of a 12 MW wind power generator module having an HTS <span class="hlt">flux</span> pump exciter. The generator module consists of an HTS rotor of the generator and an HTS <span class="hlt">flux</span> pump exciter. The specifications of the module were described, and the detailed configuration of the module was illustrated. For the <span class="hlt">heat</span> loss analysis of the module, the excitation loss of the <span class="hlt">flux</span> pump exciter, eddy current loss of all of the structures in the module, <span class="hlt">radiation</span> loss, and conduction loss of an HTS coil supporter were assessed using a 3D finite elements method program. In the case of the conduction loss, different types of the supporters were compared to find out the supporter of the lowest conduction loss in the module. The <span class="hlt">heat</span> loss analysis results of the module were reflected in the design of the generator module and discussed in detail. The results will be applied to the design of large-scale superconducting generators for wind turbines including a cooling system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/813610','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/813610"><span>Infrared Camera Diagnostic for <span class="hlt">Heat</span> <span class="hlt">Flux</span> Measurements on NSTX</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>D. Mastrovito; R. Maingi; H.W. Kugel</p> <p>2003-03-25</p> <p>An infrared imaging system has been installed on NSTX (National Spherical Torus Experiment) at the Princeton Plasma Physics Laboratory to measure the surface temperatures on the lower divertor and center stack. The imaging system is based on an Indigo Alpha 160 x 128 microbolometer camera with 12 bits/pixel operating in the 7-13 {micro}m range with a 30 Hz frame rate and a dynamic temperature range of 0-700 degrees C. From these data and knowledge of graphite thermal properties, the <span class="hlt">heat</span> <span class="hlt">flux</span> is derived with a classic one-dimensional conduction model. Preliminary results of <span class="hlt">heat</span> <span class="hlt">flux</span> scaling are reported.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820009925','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820009925"><span>Sensitivity of a climatologically-driven sea ice model to the ocean <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parkinson, C. L.; Good, M. R.</p> <p>1982-01-01</p> <p>Ocean <span class="hlt">heat</span> <span class="hlt">flux</span> sensitivity was studied on a numerical model of sea ice covering the Weddell Sea region of the southern ocean. The model is driven by mean monthly climatological atmospheric variables. For each model run, the ocean <span class="hlt">heat</span> <span class="hlt">flux</span> is uniform in both space and time. Ocean <span class="hlt">heat</span> <span class="hlt">fluxes</span> below 20 W m to the minus 2 power do not provide sufficient energy to allow the ice to melt to its summertime thicknesses and concentrations by the end of the 14 month simulation, whereas ocean <span class="hlt">heat</span> <span class="hlt">fluxes</span> of 30 W m to the minus 2 power and above result in too much ice melt, producing the almost total disappearance of ice in the Weddell Sea by the end of the 14 months. These results are dependent on the atmospheric forcing fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122..726R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122..726R"><span>Surface <span class="hlt">flux</span> and ocean <span class="hlt">heat</span> transport convergence contributions to seasonal and interannual variations of ocean <span class="hlt">heat</span> content</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roberts, C. D.; Palmer, M. D.; Allan, R. P.; Desbruyeres, D. G.; Hyder, P.; Liu, C.; Smith, D.</p> <p>2017-01-01</p> <p>We present an observation-based <span class="hlt">heat</span> budget analysis for seasonal and interannual variations of ocean <span class="hlt">heat</span> content (H) in the mixed layer (Hmld) and full-depth ocean (Htot). Surface <span class="hlt">heat</span> <span class="hlt">flux</span> and ocean <span class="hlt">heat</span> content estimates are combined using a novel Kalman smoother-based method. Regional contributions from ocean <span class="hlt">heat</span> transport convergences are inferred as a residual and the dominant drivers of Hmld and Htot are quantified for seasonal and interannual time scales. We find that non-Ekman ocean <span class="hlt">heat</span> transport processes dominate Hmld variations in the equatorial oceans and regions of strong ocean currents and substantial eddy activity. In these locations, surface temperature anomalies generated by ocean dynamics result in turbulent <span class="hlt">flux</span> anomalies that drive the overlying atmosphere. In addition, we find large regions of the Atlantic and Pacific oceans where <span class="hlt">heat</span> transports combine with local air-sea <span class="hlt">fluxes</span> to generate mixed layer temperature anomalies. In all locations, except regions of deep convection and water mass transformation, interannual variations in Htot are dominated by the internal rearrangement of <span class="hlt">heat</span> by ocean dynamics rather than the loss or addition of <span class="hlt">heat</span> at the surface. Our analysis suggests that, even in extratropical latitudes, initialization of ocean dynamical processes could be an important source of skill for interannual predictability of Hmld and Htot. Furthermore, we expect variations in Htot (and thus thermosteric sea level) to be more predictable than near surface temperature anomalies due to the increased importance of ocean <span class="hlt">heat</span> transport processes for full-depth <span class="hlt">heat</span> budgets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140016851','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140016851"><span>Impacts of Soil-aquifer <span class="hlt">Heat</span> and Water <span class="hlt">Fluxes</span> on Simulated Global Climate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Krakauer, N.Y.; Puma, Michael J.; Cook, B. I.</p> <p>2013-01-01</p> <p>Climate models have traditionally only represented <span class="hlt">heat</span> and water <span class="hlt">fluxes</span> within relatively shallow soil layers, but there is increasing interest in the possible role of <span class="hlt">heat</span> and water exchanges with the deeper subsurface. Here, we integrate an idealized 50m deep aquifer into the land surface module of the GISS ModelE general circulation model to test the influence of aquifer-soil moisture and <span class="hlt">heat</span> exchanges on climate variables. We evaluate the impact on the modeled climate of aquifer-soil <span class="hlt">heat</span> and water <span class="hlt">fluxes</span> separately, as well as in combination. The addition of the aquifer to ModelE has limited impact on annual-mean climate, with little change in global mean land temperature, precipitation, or evaporation. The seasonal amplitude of deep soil temperature is strongly damped by the soil-aquifer <span class="hlt">heat</span> <span class="hlt">flux</span>. This not only improves the model representation of permafrost area but propagates to the surface, resulting in an increase in the seasonal amplitude of surface air temperature of >1K in the Arctic. The soil-aquifer water and <span class="hlt">heat</span> <span class="hlt">fluxes</span> both slightly decrease interannual variability in soil moisture and in landsurface temperature, and decrease the soil moisture memory of the land surface on seasonal to annual timescales. The results of this experiment suggest that deepening the modeled land surface, compared to modeling only a shallower soil column with a no-<span class="hlt">flux</span> bottom boundary condition, has limited impact on mean climate but does affect seasonality and interannual persistence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3995107','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3995107"><span>Estimation of Surface <span class="hlt">Heat</span> <span class="hlt">Flux</span> and Surface Temperature during Inverse <span class="hlt">Heat</span> Conduction under Varying Spray Parameters and Sample Initial Temperature</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Aamir, Muhammad; Liao, Qiang; Zhu, Xun; Aqeel-ur-Rehman; Wang, Hong</p> <p>2014-01-01</p> <p>An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface <span class="hlt">heat</span> <span class="hlt">flux</span>, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck's sequential function specification method was utilized to estimate surface <span class="hlt">heat</span> <span class="hlt">flux</span> and surface temperature. Inlet pressure has a positive effect on surface <span class="hlt">heat</span> <span class="hlt">flux</span> (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface <span class="hlt">heat</span> <span class="hlt">flux</span> as high as 0.4024 MW/m2 was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface <span class="hlt">heat</span> <span class="hlt">flux</span> and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface <span class="hlt">heat</span> <span class="hlt">flux</span> and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa. PMID:24977219</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950048882&hterms=solar+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bradiation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950048882&hterms=solar+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bradiation"><span>Solar <span class="hlt">radiation</span>, phytoplankton pigments and the radiant <span class="hlt">heating</span> of the equatorial Pacific warm pool</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siegel, David A.; Ohlmann, J. Carter; Washburn, Libe; Bidigare, Robert R.; Nosse, Craig T.; Fields, Erik; Zhou, Yimei</p> <p>1995-01-01</p> <p>Recent optical, physical, and biological oceanographic observations are used to assess the magnitude and variability of the penetrating <span class="hlt">flux</span> of solar <span class="hlt">radiation</span> through the mixed layer of the warm water pool (WWP) of the western equatorial Pacific Ocean. Typical values for the penetrative solar <span class="hlt">flux</span> at the climatological mean mixed layer depth for the WWP (30 m) are approx. 23 W/sq m and are a large fraction of the climatological mean net air-sea <span class="hlt">heat</span> <span class="hlt">flux</span> (approx. 40 W/sq m). The penetrating solar <span class="hlt">flux</span> can vary significantly on synoptic timescales. Following a sustained westerly wind burst in situ solar <span class="hlt">fluxes</span> were reduced in response to a near tripling of mixed layer phytoplankton pigment concentrations. This results in a reduction in the penetrative <span class="hlt">flux</span> at depth (5.6 W/sq m at 30 m) and corresponds to a biogeochemically mediated increase in the mixed layer radiant <span class="hlt">heating</span> rate of 0.13 C per month. These observations demonstrate a significant role of biogeochemical processes on WWP thermal climate. We speculate that this biogeochemically mediated feedback process may play an important role in enhancing the rate at which the WWP climate system returns to normal conditions following a westerly wind burst event.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/491560','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/491560"><span>Critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) phenomenon on a downward facing curved surface</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cheung, F.B.; Haddad, K.H.; Liu, Y.C.</p> <p>1997-06-01</p> <p>This report describes a theoretical and experimental study of the boundary layer boiling and critical <span class="hlt">heat</span> <span class="hlt">flux</span> phenomena on a downward facing curved <span class="hlt">heating</span> surface, including both hemispherical and toroidal surfaces. A subscale boundary layer boiling (SBLB) test facility was developed to measure the spatial variation of the critical <span class="hlt">heat</span> <span class="hlt">flux</span> and observe the underlying mechanisms. Transient quenching and steady-state boiling experiments were performed in the SBLB facility under both saturated and subcooled conditions to obtain a complete database on the critical <span class="hlt">heat</span> <span class="hlt">flux</span>. To complement the experimental effort, an advanced hydrodynamic CHF model was developed from the conservation lawsmore » along with sound physical arguments. The model provides a clear physical explanation for the spatial variation of the CHF observed in the SBLB experiments and for the weak dependence of the CHF data on the physical size of the vessel. Based upon the CHF model, a scaling law was established for estimating the local critical <span class="hlt">heat</span> <span class="hlt">flux</span> on the outer surface of a <span class="hlt">heated</span> hemispherical vessel that is fully submerged in water. The scaling law, which compares favorably with all the available local CHF data obtained for various vessel sizes, can be used to predict the local CHF limits on large commercial-size vessels. This technical information represents one of the essential elements that is needed in assessing the efficacy of external cooling of core melt by cavity flooding as a severe accident management strategy. 83 figs., 3 tabs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA266086','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA266086"><span>Boiling <span class="hlt">Heat</span>-Transfer Processes and Their Application in the Cooling of High <span class="hlt">Heat</span> <span class="hlt">Flux</span> Devices</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1993-06-01</p> <p>1991, pp. 395-397. 385. Galloway, J. E. and Mudawar , 1. "Critical <span class="hlt">Heat</span> <span class="hlt">Flux</span> Enhancement by Means of Liquid Subcooling and Centrifugal Force Induced...Flow Boiling <span class="hlt">Heat</span> Transfer for a Spirally Fluted Tube." <span class="hlt">Heat</span> Tran~ler Engineering, Vol. 13, No.1, 1992, pp. 42-52. 390. Willingham, T. C. and Mudawar</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920018134','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920018134"><span>Turbulent <span class="hlt">heat</span> <span class="hlt">flux</span> measurements in a transitional boundary layer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sohn, K. H.; Zaman, K. B. M. Q.; Reshotko, E.</p> <p>1992-01-01</p> <p>During an experimental investigation of the transitional boundary layer over a <span class="hlt">heated</span> flat plate, an unexpected result was encountered for the turbulent <span class="hlt">heat</span> <span class="hlt">flux</span> (bar-v't'). This quantity, representing the correlation between the fluctuating normal velocity and the temperature, was measured to be negative near the wall under certain conditions. The result was unexpected as it implied a counter-gradient <span class="hlt">heat</span> transfer by the turbulent fluctuations. Possible reasons for this anomalous result were further investigated. The possible causes considered for this negative bar-v't' were: (1) plausible measurement error and peculiarity of the flow facility, (2) large probe size effect, (3) 'streaky structure' in the near wall boundary layer, and (4) contributions from other terms usually assumed negligible in the energy equation including the Reynolds <span class="hlt">heat</span> <span class="hlt">flux</span> in the streamwise direction (bar-u't'). Even though the energy balance has remained inconclusive, none of the items (1) to (3) appear to be contributing directly to the anomaly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850046194&hterms=magnetic+cooling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dmagnetic%2Bcooling','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850046194&hterms=magnetic+cooling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dmagnetic%2Bcooling"><span>On the <span class="hlt">heating</span> mechanism of magnetic <span class="hlt">flux</span> loops in the solar atmosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Song, M. T.; Wu, S. T.</p> <p>1984-01-01</p> <p>An investigation is conducted of physical <span class="hlt">heating</span> mechanisms due to the ponderomotive forces exerted by turbulent waves along the solar atmosphere's curved magnetic <span class="hlt">flux</span> loops. Results indicate that the temperature difference between the inside and outside of the <span class="hlt">flux</span> loop can be classified into three parts, two of which represent the cooling or <span class="hlt">heating</span> effect exerted by the ponderomotive force, while the third is the <span class="hlt">heating</span> effect due to turbulent energy conversion from the localized plasma. This <span class="hlt">heating</span> mechanism is used to illustrate solar atmospheric <span class="hlt">heating</span> by means of an example that leads to the formulation of plages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28410347','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28410347"><span>Accuracy of Zero-<span class="hlt">Heat-Flux</span> Cutaneous Temperature in Intensive Care Adults.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dahyot-Fizelier, Claire; Lamarche, Solène; Kerforne, Thomas; Bénard, Thierry; Giraud, Benoit; Bellier, Rémy; Carise, Elsa; Frasca, Denis; Mimoz, Olivier</p> <p>2017-07-01</p> <p>To compare accuracy of a continuous noninvasive cutaneous temperature using zero-<span class="hlt">heat-flux</span> method to esophageal temperature and arterial temperature. Prospective study. ICU and NeuroICU, University Hospital. Fifty-two ICU patients over a 4-month period who required continuous temperature monitoring were included in the study, after informed consent. All patients had esophageal temperature probe and a noninvasive cutaneous device to monitor their core temperature continuously. In seven patients who required cardiac output monitoring, continuous iliac arterial temperature was collected. Simultaneous core temperatures were recorded from 1 to 5 days. Comparison to the esophageal temperature, considered as the reference in this study, used the Bland and Altman method with adjustment for multiple measurements per patient. The esophageal temperature ranged from 33°C to 39.7°C, 61,298 pairs of temperature using zero-<span class="hlt">heat-flux</span> and esophageal temperature were collected and 1,850 triple of temperature using zero-<span class="hlt">heat-flux</span>, esophageal temperature, and arterial temperature. Bias and limits of agreement for temperature using zero-<span class="hlt">heat-flux</span> were 0.19°C ± 0.53°C compared with esophageal temperature with an absolute difference of temperature pairs equal to or lower than 0.5°C of 92.6% (95% CI, 91.9-93.4%) of cases and equal to or lower than 1°C for 99.9% (95% CI, 99.7-100.0%) of cases. Compared with arterial temperature, bias and limits of agreement were -0.00°C ± 0.36°C with an absolute difference of temperature pairs equal to or lower than 0.5°C of 99.8% (95% CI, 95.3-100%) of cases. All absolute difference of temperature pairs between temperature using zero-<span class="hlt">heat-flux</span> and arterial temperature and between arterial temperature and esophageal temperature were equal to or lower than 1°C. No local or systemic serious complication was observed. These results suggest a comparable reliability of the cutaneous sensor using the zero-<span class="hlt">heat-flux</span> method compared with esophageal or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5381797','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5381797"><span>Darcy-Forchheimer flow with Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> and homogeneous-heterogeneous reactions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hayat, Tasawar; Haider, Farwa; Alsaedi, Ahmed</p> <p>2017-01-01</p> <p>Here Darcy-Forchheimer flow of viscoelastic fluids has been analyzed in the presence of Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> and homogeneous-heterogeneous reactions. Results for two viscoelastic fluids are obtained and compared. A linear stretching surface has been used to generate the flow. Flow in porous media is characterized by considering the Darcy-Forchheimer model. Modified version of Fourier's law through Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> is employed. Equal diffusion coefficients are employed for both reactants and auto catalyst. Optimal homotopy scheme is employed for solutions development of nonlinear problems. Solutions expressions of velocity, temperature and concentration fields are provided. Skin friction coefficient and <span class="hlt">heat</span> transfer rate are computed and analyzed. Here the temperature and thermal boundary layer thickness are lower for Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> model in comparison to classical Fourier's law of <span class="hlt">heat</span> conduction. Moreover, the homogeneous and heterogeneous reactions parameters have opposite behaviors for concentration field. PMID:28380014</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPNO6011L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPNO6011L"><span>Particle-In-Cell simulation concerning <span class="hlt">heat-flux</span> mitigation using electromagnetic fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lüskow, Karl Felix; Duras, Julia; Kemnitz, Stefan; Kahnfeld, Daniel; Matthias, Paul; Bandelow, Gunnas; Schneider, Ralf; Konigorski, Detlev</p> <p>2016-10-01</p> <p>In space missions enormous amount of money is spent for the thermal protection system for re-entry. To avoid complex materials and save money one idea is to reduce the <span class="hlt">heat-flux</span> towards the spacecraft. The partially-ionized gas can be controlled by electromagnetic fields. For first-principle tests partially ionized argon flow from an arc-jet was used to measure the <span class="hlt">heat-flux</span> mitigation created by an external magnetic field. In the successful experiment a reduction of 85% was measured. In this work the Particle-in-Cell (PIC) method was used to simulate this experiment. PIC is able to reproduce the <span class="hlt">heat</span> <span class="hlt">flux</span> mitigation qualitatively. The main mechanism is identified as a changed electron transport and by this, modified electron density due to the reaction to the applied magnetic field. Ions follow due to quasi-neutrality and influence then strongly by charge exchange collisions the neutrals dynamics and <span class="hlt">heat</span> deposition. This work was supported by the German Space Agency DLR through Project 50RS1508.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhPl...22d2516M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhPl...22d2516M"><span>Turbulent transport regimes and the scrape-off layer <span class="hlt">heat</span> <span class="hlt">flux</span> width</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Myra, J. R.; D'Ippolito, D. A.; Russell, D. A.</p> <p>2015-04-01</p> <p>Understanding the responsible mechanisms and resulting scaling of the scrape-off layer (SOL) <span class="hlt">heat</span> <span class="hlt">flux</span> width is important for predicting viable operating regimes in future tokamaks and for seeking possible mitigation schemes. In this paper, we present a qualitative and conceptual framework for understanding various regimes of edge/SOL turbulence and the role of turbulent transport as the mechanism for establishing the SOL <span class="hlt">heat</span> <span class="hlt">flux</span> width. Relevant considerations include the type and spectral characteristics of underlying instabilities, the location of the gradient drive relative to the SOL, the nonlinear saturation mechanism, and the parallel <span class="hlt">heat</span> transport regime. We find a <span class="hlt">heat</span> <span class="hlt">flux</span> width scaling with major radius R that is generally positive, consistent with the previous findings [Connor et al., Nucl. Fusion 39, 169 (1999)]. The possible relationship of turbulence mechanisms to the neoclassical orbit width or heuristic drift mechanism in core energy confinement regimes known as low (L) mode and high (H) mode is considered, together with implications for the future experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16711925','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16711925"><span>Effect of <span class="hlt">heat</span> <span class="hlt">flux</span> on differential rotation in turbulent convection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kleeorin, Nathan; Rogachevskii, Igor</p> <p>2006-04-01</p> <p>We studied the effect of the turbulent <span class="hlt">heat</span> <span class="hlt">flux</span> on the Reynolds stresses in a rotating turbulent convection. To this end we solved a coupled system of dynamical equations which includes the equations for the Reynolds stresses, the entropy fluctuations, and the turbulent <span class="hlt">heat</span> <span class="hlt">flux</span>. We used a spectral tau approximation in order to close the system of dynamical equations. We found that the ratio of the contributions to the Reynolds stresses caused by the turbulent <span class="hlt">heat</span> <span class="hlt">flux</span> and the anisotropic eddy viscosity is of the order of approximately 10(L rho/l0)2, where l0 is the maximum scale of turbulent motions and L rho is the fluid density variation scale. This effect is crucial for the formation of the differential rotation and should be taken into account in the theories of the differential rotation of the Sun, stars, and planets. In particular, we demonstrated that this effect may cause the differential rotation which is comparable with the typical solar differential rotation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040171125&hterms=climate+change+evidence&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dclimate%2Bchange%2Bevidence','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040171125&hterms=climate+change+evidence&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dclimate%2Bchange%2Bevidence"><span>How Well are Recent Climate Variability Signals Resolved by Satellite <span class="hlt">Radiative</span> <span class="hlt">Flux</span> Estimates?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robertson, Franklin R.; Lu, H.-L.</p> <p>2004-01-01</p> <p>One notable aspect of Earth s climate is that although the planet appears to be very close to <span class="hlt">radiative</span> balance at top-of-atmosphere (TOA), the atmosphere itself and underlying surface are not. Profound exchanges of energy between the atmosphere and oceans, land and cryosphere occur over a range of time scales. Recent evidence from broadband satellite measurements suggests that even these TOA <span class="hlt">fluxes</span> contain some detectable variations. Our ability to measure and reconstruct <span class="hlt">radiative</span> <span class="hlt">fluxes</span> at the surface and at the top of atmosphere is improving rapidly. Understanding the character of <span class="hlt">radiative</span> <span class="hlt">flux</span> estimates and relating them to variations in other energy <span class="hlt">fluxes</span> and climate state variables is key to improving our understanding of climate. In this work we will evaluate several recently released estimates of <span class="hlt">radiative</span> <span class="hlt">fluxes</span>, focusing primarily on surface estimates. The International Satellite Cloud Climatology Project FD <span class="hlt">radiative</span> <span class="hlt">flux</span> profiles are available from rnid-1983 to near present and have been constructed by driving the <span class="hlt">radiative</span> transfer physics from the Goddard Institute for Space Studies (GISS) global model with ISCCP clouds and HlRS operational soundings profiles. Full and clear sky SW and LW <span class="hlt">fluxes</span> are produced. A similar product from the NASA/GEWEX Surface <span class="hlt">Radiation</span> Budget Project using different <span class="hlt">radiative</span> <span class="hlt">flux</span> codes and thermodynamics from the NASA/Goddard Earth Observing System assimilation model makes a similar calculation of surface <span class="hlt">fluxes</span>. However this data set currently extends only through 1995. Several estimates of downward LW <span class="hlt">flux</span> at the surface inferred from microwave data are also examined. Since these products have been evaluated with Baseline Surface <span class="hlt">Radiation</span> Network data over land we focus over ocean regions and use the DOE/NOAA/NASA Shipboard Ocean Atmospheric <span class="hlt">Radiation</span> (SOAR) surface <span class="hlt">flux</span> measurements to characterize performance of these data sets under both clear and cloudy conditions. Some aspects of performance are stratified</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.8178B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.8178B"><span>Measured and parameterized energy <span class="hlt">fluxes</span> estimated for Atlantic transects of RV Polarstern</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bumke, Karl; Macke, Andreas; Kalisch, John; Kleta, Henry</p> <p>2013-04-01</p> <p>Even to date energy <span class="hlt">fluxes</span> over the oceans are difficult to assess. As an example the relative paucity of evaporation observations and the uncertainties of currently employed empirical approaches lead to large uncertainties of evaporation products over the ocean (e.g. Large and Yeager, 2009). Within the frame of OCEANET (Macke et al., 2010) we performed such measurements on Atlantic transects between Bremerhaven (Germany) and Cape Town (South Africa) or Punta Arenas (Chile) onboard RV Polarstern during the recent years. The basic measurements of sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> are inertial-dissipation (e.g. Dupuis et al., 1997) <span class="hlt">flux</span> estimates and measurements of the bulk variables. Turbulence measurements included a sonic anemometer and an infrared hygrometer, both mounted on the crow's nest. Mean meteorological sensors were those of the ship's operational measurement system. The global <span class="hlt">radiation</span> and the down terrestrial <span class="hlt">radiation</span> were measured on the OCEANET container placed on the monkey island. At least about 1000 time series of 1 h length were analyzed to derive bulk transfer coefficients for the <span class="hlt">fluxes</span> of sensible and latent <span class="hlt">heat</span>. The bulk transfer coefficients were applied to the ship's meteorological data to derive the <span class="hlt">heat</span> <span class="hlt">fluxes</span> at the sea surface. The reflected solar <span class="hlt">radiation</span> was estimated from measured global <span class="hlt">radiation</span>. The up terrestrial <span class="hlt">radiation</span> was derived from the skin temperature according to the Stefan-Boltzmann law. Parameterized <span class="hlt">heat</span> <span class="hlt">fluxes</span> were compared to the widely used COARE-parameterization (Fairall et al., 2003), the agreement is excellent. Measured and parameterized <span class="hlt">heat</span> and <span class="hlt">radiation</span> <span class="hlt">fluxes</span> gave the total energy budget at the air sea interface. As expected the mean total <span class="hlt">flux</span> is positive, but there are also areas, where it is negative, indicating an energy loss of the ocean. It could be shown that the variations in the energy budget are mainly due to insolation and evaporation. A comparison between the mean values of measured and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1175972','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1175972"><span><span class="hlt">Radiation</span> detector system having <span class="hlt">heat</span> pipe based cooling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Iwanczyk, Jan S.; Saveliev, Valeri D.; Barkan, Shaul</p> <p>2006-10-31</p> <p>A <span class="hlt">radiation</span> detector system having a <span class="hlt">heat</span> pipe based cooling. The <span class="hlt">radiation</span> detector system includes a <span class="hlt">radiation</span> detector thermally coupled to a thermo electric cooler (TEC). The TEC cools down the <span class="hlt">radiation</span> detector, whereby <span class="hlt">heat</span> is generated by the TEC. A <span class="hlt">heat</span> removal device dissipates the <span class="hlt">heat</span> generated by the TEC to surrounding environment. A <span class="hlt">heat</span> pipe has a first end thermally coupled to the TEC to receive the <span class="hlt">heat</span> generated by the TEC, and a second end thermally coupled to the <span class="hlt">heat</span> removal device. The <span class="hlt">heat</span> pipe transfers the <span class="hlt">heat</span> generated by the TEC from the first end to the second end to be removed by the <span class="hlt">heat</span> removal device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ExFl...57..130K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ExFl...57..130K"><span>Unsteady <span class="hlt">heat-flux</span> measurements of second-mode instability waves in a hypersonic flat-plate boundary layer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kegerise, Michael A.; Rufer, Shann J.</p> <p>2016-08-01</p> <p>In this paper, we report on the application of the atomic layer thermopile (ALTP) <span class="hlt">heat-flux</span> sensor to the measurement of laminar-to-turbulent transition in a hypersonic flat-plate boundary layer. The centerline of the flat-plate model was instrumented with a streamwise array of ALTP sensors, and the flat-plate model was exposed to a Mach 6 freestream over a range of unit Reynolds numbers. Here, we observed an unstable band of frequencies that are associated with second-mode instability waves in the laminar boundary layer that forms on the flat-plate surface. The measured frequencies, group velocities, phase speeds, and wavelengths of these instability waves are consistent with data previously reported in the literature. <span class="hlt">Heat</span> <span class="hlt">flux</span> time series, and the Morlet wavelet transforms of them, revealed the wave-packet nature of the second-mode instability waves. In addition, a laser-based <span class="hlt">radiative</span> <span class="hlt">heating</span> system was used to measure the frequency response functions (FRF) of the ALTP sensors used in the wind tunnel test. These measurements were used to assess the stability of the sensor FRFs over time and to correct spectral estimates for any attenuation caused by the finite sensor bandwidth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvE..97b2122S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvE..97b2122S"><span>Hyperbolic <span class="hlt">heat</span> conduction, effective temperature, and third law for nonequilibrium systems with <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sobolev, S. L.</p> <p>2018-02-01</p> <p>Some analogies between different nonequilibrium <span class="hlt">heat</span> conduction models, particularly random walk, the discrete variable model, and the Boltzmann transport equation with the single relaxation time approximation, have been discussed. We show that, under an assumption of a finite value of the <span class="hlt">heat</span> carrier velocity, these models lead to the hyperbolic <span class="hlt">heat</span> conduction equation and the modified Fourier law with relaxation term. Corresponding effective temperature and entropy have been introduced and analyzed. It has been demonstrated that the effective temperature, defined as a geometric mean of the kinetic temperatures of the <span class="hlt">heat</span> carriers moving in opposite directions, acts as a criterion for thermalization and is a nonlinear function of the kinetic temperature and <span class="hlt">heat</span> <span class="hlt">flux</span>. It is shown that, under highly nonequilibrium conditions when the <span class="hlt">heat</span> <span class="hlt">flux</span> tends to its maximum possible value, the effective temperature, <span class="hlt">heat</span> capacity, and local entropy go to zero even at a nonzero equilibrium temperature. This provides a possible generalization of the third law to nonequilibrium situations. Analogies and differences between the proposed effective temperature and some other definitions of a temperature in nonequilibrium state, particularly for active systems, disordered semiconductors under electric field, and adiabatic gas flow, have been shown and discussed. Illustrative examples of the behavior of the effective temperature and entropy during nonequilibrium <span class="hlt">heat</span> conduction in a monatomic gas and a strong shockwave have been analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JIEIC.tmp..264S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JIEIC.tmp..264S"><span>Prediction of Experimental Surface <span class="hlt">Heat</span> <span class="hlt">Flux</span> of Thin Film Gauges using ANFIS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarma, Shrutidhara; Sahoo, Niranjan; Unal, Aynur</p> <p>2018-05-01</p> <p>Precise quantification of surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> in highly transient environment is of paramount importance from the design point of view of several engineering equipment like thermal protection or cooling systems. Such environments are simulated in experimental facilities by exposing the surface with transient <span class="hlt">heat</span> loads typically step/impulsive in nature. The surface <span class="hlt">heating</span> rates are then determined from highly transient temperature history captured by efficient surface temperature sensors. The classical approach is to use thin film gauges (TFGs) in which temperature variations are acquired within milliseconds, thereby allowing calculation of surface <span class="hlt">heat</span> <span class="hlt">flux</span>, based on the theory of one-dimensional <span class="hlt">heat</span> conduction on a semi-infinite body. With recent developments in the soft computing methods, the present study is an attempt for the application of intelligent system technique, called adaptive neuro fuzzy inference system (ANFIS) to recover surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> from a given temperature history recorded by TFGs without having the need to solve lengthy analytical equations. Experiments have been carried out by applying known quantity of `impulse <span class="hlt">heat</span> load' through laser beam on TFGs. The corresponding voltage signals have been acquired and surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> are estimated through classical analytical approach. These signals are then used to `train' the ANFIS model, which later predicts output for `test' values. Results from both methods have been compared and these surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> are used to predict the non-linear relationship between thermal and electrical properties of the gauges that are exceedingly pertinent to the design of efficient TFGs. Further, surface plots have been created to give an insight about dimensionality effect of the non-linear dependence of thermal/electrical parameters on each other. Later, it is observed that a properly optimized ANFIS model can predict the impulsive <span class="hlt">heat</span> profiles with significant accuracy. This paper thus shows the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050209932','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050209932"><span>Benchmark Wall <span class="hlt">Heat</span> <span class="hlt">Flux</span> Data for a GO2/GH2 Single Element Combustor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Marshall, William M.; Pal, Sibtosh; Woodward, Roger d.; Santoro, Robert J.</p> <p>2005-01-01</p> <p>Wall <span class="hlt">heat</span> <span class="hlt">flux</span> measurements in a 1.5 in. diameter circular cross-section rocket chamber for a uni-element shear coaxial injector element operating on gaseous oxygen (GOz)/gaseous hydrogen (GH,) propellants are presented. The wall <span class="hlt">heat</span> <span class="hlt">flux</span> measurements were made using arrays of Gardon type <span class="hlt">heat</span> <span class="hlt">flux</span> gauges and coaxial thermocouple instrumentation. Wall <span class="hlt">heat</span> <span class="hlt">flux</span> measurements were made for two cases. For the first case, GOZ/GHz oxidizer-rich (O/F=l65) and fuel-rich preburners (O/F=1.09) integrated with the main chamber were utilized to provide vitiated hot fuel and oxidizer to the study shear coaxial injector element. For the second case, the preburners were removed and ambient temperature gaseous oxygen/gaseous hydrogen propellants were supplied to the study injector. Experiments were conducted at four chamber pressures of 750, 600, 450 and 300psia for each case. The overall mixture ratio for the preburner case was 6.6, whereas for the ambient propellant case, the mixture ratio was 6.0. Total propellant flow was nominally 0.27-0.29 Ibm/s for the 750 psia case with flowrates scaled down linearly for lower chamber pressures. The axial <span class="hlt">heat</span> <span class="hlt">flux</span> profile results for both the preburner and ambient propellant cases show peak <span class="hlt">heat</span> <span class="hlt">flux</span> levels a t axial locations between 2.0 and 3.0 in. from the injector face. The maximum <span class="hlt">heat</span> <span class="hlt">flux</span> level was about two times greater for the preburner case. This is attributed to the higher injector fuel-to-oxidizer momentum <span class="hlt">flux</span> ratio that promotes mixing and higher initial propellant temperature for the preburner case which results in a shorter reaction zone. The axial <span class="hlt">heat</span> <span class="hlt">flux</span> profiles were also scaled with respect to the chamber pressure to the power 0.8. The results at the four chamber pressures for both cases collapsed to a single profile indicating that at least to first approximation, the basic fluid dynamic structures in the flow field are pressure independent as long as the chamber/njector/nozzle geometry and injection velocities</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011MeScT..22j5402O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011MeScT..22j5402O"><span>High-resolution hot-film measurement of surface <span class="hlt">heat</span> <span class="hlt">flux</span> to an impinging jet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>O'Donovan, T. S.; Persoons, T.; Murray, D. B.</p> <p>2011-10-01</p> <p>To investigate the complex coupling between surface <span class="hlt">heat</span> transfer and local fluid velocity in convective <span class="hlt">heat</span> transfer, advanced techniques are required to measure the surface <span class="hlt">heat</span> <span class="hlt">flux</span> at high spatial and temporal resolution. Several established flow velocity techniques such as laser Doppler anemometry, particle image velocimetry and hot wire anemometry can measure fluid velocities at high spatial resolution (µm) and have a high-frequency response (up to 100 kHz) characteristic. Equivalent advanced surface <span class="hlt">heat</span> transfer measurement techniques, however, are not available; even the latest advances in high speed thermal imaging do not offer equivalent data capture rates. The current research presents a method of measuring point surface <span class="hlt">heat</span> <span class="hlt">flux</span> with a hot film that is flush mounted on a <span class="hlt">heated</span> flat surface. The film works in conjunction with a constant temperature anemometer which has a bandwidth of 100 kHz. The bandwidth of this technique therefore is likely to be in excess of more established surface <span class="hlt">heat</span> <span class="hlt">flux</span> measurement techniques. Although the frequency response of the sensor is not reported here, it is expected to be significantly less than 100 kHz due to its physical size and capacitance. To demonstrate the efficacy of the technique, a cooling impinging air jet is directed at the <span class="hlt">heated</span> surface, and the power required to maintain the hot-film temperature is related to the local <span class="hlt">heat</span> <span class="hlt">flux</span> to the fluid air flow. The technique is validated experimentally using a more established surface <span class="hlt">heat</span> <span class="hlt">flux</span> measurement technique. The thermal performance of the sensor is also investigated numerically. It has been shown that, with some limitations, the measurement technique accurately measures the surface <span class="hlt">heat</span> transfer to an impinging air jet with improved spatial resolution for a wide range of experimental parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28063826','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28063826"><span>Evaluation of <span class="hlt">Heat</span> <span class="hlt">Flux</span> Measurement as a New Process Analytical Technology Monitoring Tool in Freeze Drying.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vollrath, Ilona; Pauli, Victoria; Friess, Wolfgang; Freitag, Angelika; Hawe, Andrea; Winter, Gerhard</p> <p>2017-05-01</p> <p>This study investigates the suitability of <span class="hlt">heat</span> <span class="hlt">flux</span> measurement as a new technique for monitoring product temperature and critical end points during freeze drying. The <span class="hlt">heat</span> <span class="hlt">flux</span> sensor is tightly mounted on the shelf and measures non-invasively (no contact with the product) the <span class="hlt">heat</span> transferred from shelf to vial. <span class="hlt">Heat</span> <span class="hlt">flux</span> data were compared to comparative pressure measurement, thermocouple readings, and Karl Fischer titration as current state of the art monitoring techniques. The whole freeze drying process including freezing (both by ramp freezing and controlled nucleation) and primary and secondary drying was considered. We found that direct measurement of the transferred <span class="hlt">heat</span> enables more insights into thermodynamics of the freezing process. Furthermore, a vial <span class="hlt">heat</span> transfer coefficient can be calculated from <span class="hlt">heat</span> <span class="hlt">flux</span> data, which ultimately provides a non-invasive method to monitor product temperature throughout primary drying. The end point of primary drying determined by <span class="hlt">heat</span> <span class="hlt">flux</span> measurements was in accordance with the one defined by thermocouples. During secondary drying, <span class="hlt">heat</span> <span class="hlt">flux</span> measurements could not indicate the progress of drying as monitoring the residual moisture content. In conclusion, <span class="hlt">heat</span> <span class="hlt">flux</span> measurements are a promising new non-invasive tool for lyophilization process monitoring and development using energy transfer as a control parameter. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AIPC.1959e0009D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AIPC.1959e0009D"><span>Investigation of <span class="hlt">heat</span> <span class="hlt">flux</span> on aerodynamic body in supersonic gas flow with local energy deposition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dobrov, Y. V.; Lashkov, V. A.; Mashek, I. Ch.; Khoronzhuk, R. S.</p> <p>2018-05-01</p> <p>Existence and intensive growth of <span class="hlt">heat</span> <span class="hlt">flux</span> on a vehicle is one of the main problems in hypersonic flight. Experimental study of <span class="hlt">heat</span> <span class="hlt">flux</span> in the stagnation point of a blunt cylinder in supersonic flow was made using gradient <span class="hlt">heat</span> <span class="hlt">flux</span> sensor. It was found that a transfer function of the measuring system should be used for obtaining data at fast-changing <span class="hlt">heat</span> <span class="hlt">flux</span> measurements. It was established that it was possible to produce a short-term <span class="hlt">heat</span> transfer from the surface of streamlined body with the help of microwave discharge. Numerical simulation showed that it is possible to change nature of the flow by means of local energy deposition in case of streamlined wedge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060047645','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060047645"><span>Local <span class="hlt">Heat</span> <span class="hlt">Flux</span> Measurements with Single Element Coaxial Injectors</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jones, Gregg; Protz, Christopher; Bullard, Brad; Hulka, James</p> <p>2006-01-01</p> <p>To support the mission for the NASA Vision for Space Exploration, the NASA Marshall Space Flight Center conducted a program in 2005 to improve the capability to predict local thermal compatibility and <span class="hlt">heat</span> transfer in liquid propellant rocket engine combustion devices. The ultimate objective was to predict and hence reduce the local peak <span class="hlt">heat</span> <span class="hlt">flux</span> due to injector design, resulting in a significant improvement in overall engine reliability and durability. Such analyses are applicable to combustion devices in booster, upper stage, and in-space engines, as well as for small thrusters with few elements in the injector. In this program, single element and three-element injectors were hot-fire tested with liquid oxygen and ambient temperature gaseous hydrogen propellants at The Pennsylvania State University Cryogenic Combustor Laboratory from May to August 2005. Local <span class="hlt">heat</span> <span class="hlt">fluxes</span> were measured in a 1-inch internal diameter <span class="hlt">heat</span> sink combustion chamber using Medtherm coaxial thermocouples and Gardon <span class="hlt">heat</span> <span class="hlt">flux</span> gauges. Injectors were tested with shear coaxial and swirl coaxial elements, including recessed, flush and scarfed oxidizer post configurations, and concentric and non-concentric fuel annuli. This paper includes general descriptions of the experimental hardware, instrumentation, and results of the hot-fire testing for three of the single element injectors - recessed-post shear coaxial with concentric fuel, flush-post swirl coaxial with concentric fuel, and scarfed-post swirl coaxial with concentric fuel. Detailed geometry and test results will be published elsewhere to provide well-defined data sets for injector development and model validatation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900017062','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900017062"><span>Measuring and modeling near-surface reflected and emitted <span class="hlt">radiation</span> <span class="hlt">fluxes</span> at the FIFE site</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Blad, Blaine L.; Walter-Shea, Elizabeth A.; Starks, Patrick J.; Vining, Roel C.; Hays, Cynthia J.; Mesarch, Mark A.</p> <p>1990-01-01</p> <p>Information is presented pertaining to the measurement and estimation of reflected and emitted components of the <span class="hlt">radiation</span> balance. Information is included about reflectance and transmittance of solar <span class="hlt">radiation</span> from and through the leaves of some grass and forb prairie species, bidirectional reflectance from a prairie canopy is discussed and measured and estimated <span class="hlt">fluxes</span> are described of incoming and outgoing longwave and shortwave <span class="hlt">radiation</span>. Results of the study showed only very small differences in reflectances and transmittances for the adaxial and abaxial surfaces of grass species in the visible and infrared wavebands, but some differences in the infrared wavebands were noted for the forbs. Reflectance from the prairie canopy changed as a function of solar and view zenith angles in the solar principal plane with definite asymmetry about nadir. The surface temperature of prairie canopies was found to vary by as much as 5 C depending on view zenith and azimuth position and on the solar azimuth. Aerodynamic temperature calculated from measured sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> ranged from 0 to 3 C higher than nadir-viewed temperatures. Models were developed to estimate incoming and reflected shortwave <span class="hlt">radiation</span> from data collected with a Barnes Modular Multiband Radiometer. Several algorithms for estimating incoming longwave <span class="hlt">radiation</span> were evaluated and compared to actual measures of that parameter. Net <span class="hlt">radiation</span> was calculated using the estimated components of the shortwave <span class="hlt">radiation</span> streams, determined from the algorithms developed, and from the longwave <span class="hlt">radiation</span> streams provided by the Brunt, modified Deacon, and the Stefan-Boltzmann models. Estimates of net <span class="hlt">radiation</span> were compared to measured values and found to be within the measurement error of the net radiometers used in the study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22708930','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22708930"><span>A low-frequency wave motion mechanism enables efficient energy transport in carbon nanotubes at high <span class="hlt">heat</span> <span class="hlt">fluxes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Xiaoliang; Hu, Ming; Poulikakos, Dimos</p> <p>2012-07-11</p> <p>The great majority of investigations of thermal transport in carbon nanotubes (CNTs) in the open literature focus on low <span class="hlt">heat</span> <span class="hlt">fluxes</span>, that is, in the regime of validity of the Fourier <span class="hlt">heat</span> conduction law. In this paper, by performing nonequilibrium molecular dynamics simulations we investigated thermal transport in a single-walled CNT bridging two Si slabs under constant high <span class="hlt">heat</span> <span class="hlt">flux</span>. An anomalous wave-like kinetic energy profile was observed, and a previously unexplored, wave-dominated energy transport mechanism is identified for high <span class="hlt">heat</span> <span class="hlt">fluxes</span> in CNTs, originated from excited low frequency transverse acoustic waves. The transported energy, in terms of a one-dimensional low frequency mechanical wave, is quantified as a function of the total <span class="hlt">heat</span> <span class="hlt">flux</span> applied and is compared to the energy transported by traditional Fourier <span class="hlt">heat</span> conduction. The results show that the low frequency wave actually overtakes traditional Fourier <span class="hlt">heat</span> conduction and efficiently transports the energy at high <span class="hlt">heat</span> <span class="hlt">flux</span>. Our findings reveal an important new mechanism for high <span class="hlt">heat</span> <span class="hlt">flux</span> energy transport in low-dimensional nanostructures, such as one-dimensional (1-D) nanotubes and nanowires, which could be very relevant to high <span class="hlt">heat</span> <span class="hlt">flux</span> dissipation such as in micro/nanoelectronics applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25045862','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25045862"><span>An evaluation of a zero-<span class="hlt">heat-flux</span> cutaneous thermometer in cardiac surgical patients.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Eshraghi, Yashar; Nasr, Vivian; Parra-Sanchez, Ivan; Van Duren, Albert; Botham, Mark; Santoscoy, Thomas; Sessler, Daniel I</p> <p>2014-09-01</p> <p>Although core temperature can be measured invasively, there are currently no widely available, reliable, noninvasive thermometers for its measurement. We thus compared a prototype zero-<span class="hlt">heat-flux</span> thermometer with simultaneous measurements from a pulmonary artery catheter. Specifically, we tested the hypothesis that zero-<span class="hlt">heat-flux</span> temperatures are sufficiently accurate for routine clinical use. Core temperature was measured from the thermistor of a standard pulmonary artery catheter and with a prototype zero-<span class="hlt">heat-flux</span> deep-tissue thermometer in 105 patients having nonemergent cardiac surgery. Zero-<span class="hlt">heat-flux</span> probes were positioned on the lateral forehead and lateral neck. Skin surface temperature probes were attached to the forehead just adjacent to the zero-<span class="hlt">heat-flux</span> probe. Temperatures were recorded at 1-minute intervals, excluding the period of cardiopulmonary bypass, and for the first 4 postoperative hours. Zero-<span class="hlt">heat-flux</span> and pulmonary artery temperatures were compared with bias analysis; differences exceeding 0.5°C were considered to be potentially clinically important. The mean duration in the operating room was 279 ± 75 minutes, and the mean cross-clamp time was 118 ± 50 minutes. All subjects were monitored for an additional 4 hours in the intensive care unit. The average overall difference between forehead zero-<span class="hlt">heat-flux</span> and pulmonary artery temperatures (i.e., forehead minus pulmonary artery) was -0.23°C (95% limits of agreement of ±0.82); 78% of the differences were ≤0.5°C. The average intraoperative temperature difference was -0.08°C (95% limits of agreement of ±0.88); 84% of the differences were ≤0.5°C. The average postoperative difference was -0.32°C (95% limits of agreement of ±0.75); 84% of the differences were ≤0.5°C. Bias and precision values for neck site were similar to the forehead values. Uncorrected forehead skin temperature showed an increasing negative bias as core temperature decreased. Core temperature can be noninvasively</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy..tmp.2382T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy..tmp.2382T"><span>Impact of air-sea drag coefficient for latent <span class="hlt">heat</span> <span class="hlt">flux</span> on large scale climate in coupled and atmosphere stand-alone simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torres, Olivier; Braconnot, Pascale; Marti, Olivier; Gential, Luc</p> <p>2018-05-01</p> <p>The turbulent <span class="hlt">fluxes</span> across the ocean/atmosphere interface represent one of the principal driving forces of the global atmospheric and oceanic circulation. Despite decades of effort and improvements, representation of these <span class="hlt">fluxes</span> still presents a challenge due to the small-scale acting turbulent processes compared to the resolved scales of the models. Beyond this subgrid parameterization issue, a comprehensive understanding of the impact of air-sea interactions on the climate system is still lacking. In this paper we investigates the large-scale impacts of the transfer coefficient used to compute turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> with the IPSL-CM4 climate model in which the surface bulk formula is modified. Analyzing both atmosphere and coupled ocean-atmosphere general circulation model (AGCM, OAGCM) simulations allows us to study the direct effect and the mechanisms of adjustment to this modification. We focus on the representation of latent <span class="hlt">heat</span> <span class="hlt">flux</span> in the tropics. We show that the <span class="hlt">heat</span> transfer coefficients are highly similar for a given parameterization between AGCM and OAGCM simulations. Although the same areas are impacted in both kind of simulations, the differences in surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> are substantial. A regional modification of <span class="hlt">heat</span> transfer coefficient has more impact than uniform modification in AGCM simulations while in OAGCM simulations, the opposite is observed. By studying the global energetics and the atmospheric circulation response to the modification, we highlight the role of the ocean in dampening a large part of the disturbance. Modification of the <span class="hlt">heat</span> exchange coefficient modifies the way the coupled system works due to the link between atmospheric circulation and SST, and the different feedbacks between ocean and atmosphere. The adjustment that takes place implies a balance of net incoming solar <span class="hlt">radiation</span> that is the same in all simulations. As there is no change in model physics other than drag coefficient, we obtain similar latent <span class="hlt">heat</span> <span class="hlt">flux</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930019430','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930019430"><span>Small hydrogen/oxygen rocket flowfield behavior from <span class="hlt">heat</span> <span class="hlt">flux</span> measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reed, Brian D.</p> <p>1993-01-01</p> <p>The mixing and <span class="hlt">heat</span> transfer phenomena in small rocket flow fields with fuel film cooling is not well understood. An instrumented, water-cooled chamber with a gaseous hydrogen/gaseous oxygen injector was used to gather steady-state inner and outer wall temperature profiles. The chamber was tested at 414 kPa (60 psia) chamber pressure, from mixture ratios of 3.41 to 8.36. Sixty percent of the fuel was used for film cooling. These temperature profiles were used as boundary conditions in a finite element analysis program, MSC/NASTRAN, to calculate the local radial and axial <span class="hlt">heat</span> <span class="hlt">fluxes</span> in the chamber wall. The normal <span class="hlt">heat</span> <span class="hlt">fluxes</span> were then calculated and used as a diagnostic of the rocket's flow field behavior. The normal <span class="hlt">heat</span> <span class="hlt">fluxes</span> determined were on the order of 1.0 to 3.0 MW/meters squared (0.6 to 1.8 Btu/sec-inches squared). In the cases where mixture ratio was 5 or above, there was a sharp local <span class="hlt">heat</span> <span class="hlt">flux</span> maximum in the barrel section of the chamber. This local maximum seems to indicate a reduction or breakdown of the fuel film cooling layer, possibly due to increased mixing in the shear layer between the film and core flows. However, the flow was thought to be completely laminar, as the throat Reynolds numbers were below 50,000 for all the cases. The increased mixing in the shear layer in the higher mixture ratio cases appeared not to be due to the transition of the flow from laminar to turbulent, but rather due to increased reactions between the hydrogen film and oxidizer-rich core flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7377945','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7377945"><span>Wheelchair cushion effect on skin temperature, <span class="hlt">heat</span> <span class="hlt">flux</span>, and relative humidity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stewart, S F; Palmieri, V; Cochran, G V</p> <p>1980-05-01</p> <p>For patients subject to decubitus ulcers, wheelchair cushions should be prescribed with knowledge of the cushion's effect on the thermal as well as mechanical environment of the skin. To define thermal effects that may be encountered during routine use, tests werr made on 24 commercially available cushions. Skin temperature, <span class="hlt">heat</span> <span class="hlt">flux</span> and relative humidity were measured under the ischial tuberosities of a normal 24-year-old man during a 1-hour period of sitting on each cushion. After 1 hour, skin temperatures increased by means of 3.4 C and 2.8 C on foams and viscoelastic foams and there were slight decreases in <span class="hlt">heat</span> <span class="hlt">flux</span> as compared with control values in air. On gels, skin temperatures remained constant and <span class="hlt">heat</span> <span class="hlt">flux</span> increased, while water "floatation" pads caused a mean skin temperature decreased of 2.7 C along with a marked increase in <span class="hlt">heat</span> <span class="hlt">flux</span>. Relative humidity at the skin cushion interface increased by 10.4%, 22.8% and 19.8% on foams, gels and water floatation pads, as compared with room air values. Representative cushions from each of the general types (foam, viscoelastic foam, gel and water floatation) also were subjected to 2-hour tests which indicated the measured parameters continued to change asymptotically.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JEnvM.127..300K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JEnvM.127..300K"><span>Skyglow effects in UV and visible spectra: <span class="hlt">Radiative</span> <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kocifaj, Miroslav; Solano Lamphar, Hector Antonio</p> <p>2013-09-01</p> <p>Several studies have tried to understand the mechanisms and effects of <span class="hlt">radiative</span> transfer under different night-sky conditions. However, most of these studies are limited to the various effects of visible spectra. Nevertheless, the invisible parts of the electromagnetic spectrum can pose a more profound threat to nature. One visible threat is from what is popularly termed skyglow. Such skyglow is caused by injudiciously situated or designed artificial night lighting systems which degrade desired sky viewing. Therefore, since lamp emissions are not limited to visible electromagnetic spectra, it is necessary to consider the complete spectrum of such lamps in order to understand the physical behaviour of diffuse <span class="hlt">radiation</span> at terrain level. In this paper, the downward diffuse <span class="hlt">radiative</span> <span class="hlt">flux</span> is computed in a two-stream approximation and obtained ultraviolet spectral <span class="hlt">radiative</span> <span class="hlt">fluxes</span> are inter-related with luminous <span class="hlt">fluxes</span>. Such a method then permits an estimate of ultraviolet <span class="hlt">radiation</span> if the traditionally measured illuminance on a horizontal plane is available. The utility of such a comparison of two spectral bands is shown, using the different lamp types employed in street lighting. The data demonstrate that it is insufficient to specify lamp type and its visible <span class="hlt">flux</span> production independently of each other. Also the UV emissions have to be treated by modellers and environmental scientists because some light sources can be fairly important pollutants in the near ultraviolet. Such light sources can affect both the living organisms and ambient environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPYO8001H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPYO8001H"><span>Classical <span class="hlt">Heat-Flux</span> Measurements in Coronal Plasmas from Collective Thomson-Scattering Spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Henchen, R. J.; Hu, S. X.; Katz, J.; Froula, D. H.; Rozmus, W.</p> <p>2016-10-01</p> <p>Collective Thomson scattering was used to measure <span class="hlt">heat</span> <span class="hlt">flux</span> in coronal plasmas. The relative amplitude of the Thomson-scattered power into the up- and downshifted electron plasma wave features was used to determine the <span class="hlt">flux</span> of electrons moving along the temperature gradient at three to four times the electron thermal velocity. Simultaneously, the ion-acoustic wave features were measured. Their relative amplitude was used to measure the <span class="hlt">flux</span> of the return-current electrons. The frequencies of these ion-acoustic and electron plasma wave features provide local measurements of the electron temperature and density. These spectra were obtained at five locations along the temperature gradient in a laser-produced blowoff plasma. These measurements of plasma parameters are used to infer the Spitzer-Härm <span class="hlt">flux</span> (qSH = - κ∇Te ) and are in good agreement with the values of the <span class="hlt">heat</span> <span class="hlt">flux</span> measured from the scattering-feature asymmetries. Additional experiments probed plasma waves perpendicular to the temperature gradient. The data show small effects resulting from <span class="hlt">heat</span> <span class="hlt">flux</span> compared to probing waves along the temperature gradient. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960033254','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960033254"><span>Research concerning the net <span class="hlt">flux</span> of <span class="hlt">radiation</span> in the atmosphere of Jupiter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tomasko, M. G.</p> <p>1996-01-01</p> <p>The plan of the NFR (Net <span class="hlt">Flux</span> of <span class="hlt">Radiation</span>) team is for the data from the two solar channels (B and E) of NFR to be reduced with the goal of determining the solar <span class="hlt">heating</span> rate. In order to determine the solar <span class="hlt">heating</span> rate from the NFR measurements, effects due to the instrument's spatial and spectral response functions, to the temperature variation of the instrument (and associated drift of calibration), to the setting sun, and to the rotation of the probe (initially at a rate comparable to the NFR sampling frequency), all must be well modelled. In the past year, a forward modeling routine was created to simulate NFR data return in the B and E channels. The effects of varying parameters describing the atmospheric model (such as cloud location and thickness) and the descent profile (such as rotation rate) were investigated and an inversion routine was developed. For the forward modeling, existing <span class="hlt">radiative</span> transfer codes were used to determine intensity fields within the Jovian atmosphere. A routine was developed to determine instantaneous instrument response by integrating the intensity field over the instrument response functions. A second routine was developed to determine the actual output of the NFR by integrating along an arbitrary descent trajectory. Near the top of the atmosphere, the upflux data alone are used to constrain the cloud structure of he atmosphere. To accomplish this, models are used to describe the variation in up <span class="hlt">flux</span> between consecutive measurements in terms of variations of cloud opacity and variations in known parameters such as the solar zenith angle. This allows us to develop a zero-order model of cloud structure. Lower in the atmosphere, at levels where there is little or no azimuthal structure to the net <span class="hlt">flux</span> measurements, both the up <span class="hlt">flux</span> and net <span class="hlt">flux</span> are used to derive layer transmission and reflection functions, which then determine layer opacity and single scattering albedo. A preliminary analysis of the data began in December 1995</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PhDT........82R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PhDT........82R"><span>Multiplate <span class="hlt">Radiation</span> Shields: Investigating <span class="hlt">Radiational</span> <span class="hlt">Heating</span> Errors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richardson, Scott James</p> <p>1995-01-01</p> <p>Multiplate <span class="hlt">radiation</span> shield errors are examined using the following techniques: (1) analytic <span class="hlt">heat</span> transfer analysis, (2) optical ray tracing, (3) numerical fluid flow modeling, (4) laboratory testing, (5) wind tunnel testing, and (6) field testing. Guidelines for reducing <span class="hlt">radiational</span> <span class="hlt">heating</span> errors are given that are based on knowledge of the temperature sensor to be used, with the shield being chosen to match the sensor design. Small, reflective sensors that are exposed directly to the air stream (not inside a filter as is the case for many temperature and relative humidity probes) should be housed in a shield that provides ample mechanical and rain protection while impeding the air flow as little as possible; protection from <span class="hlt">radiation</span> sources is of secondary importance. If a sensor does not meet the above criteria (i.e., is large or absorbing), then a standard Gill shield performs reasonably well. A new class of shields, called part-time aspirated multiplate <span class="hlt">radiation</span> shields, are introduced. This type of shield consists of a multiplate design usually operated in a passive manner but equipped with a fan-forced aspiration capability to be used when necessary (e.g., low wind speed). The fans used here are 12 V DC that can be operated with a small dedicated solar panel. This feature allows the fan to operate when global solar <span class="hlt">radiation</span> is high, which is when the largest <span class="hlt">radiational</span> <span class="hlt">heating</span> errors usually occur. A prototype shield was constructed and field tested and an example is given in which <span class="hlt">radiational</span> <span class="hlt">heating</span> errors were reduced from 2 ^circC to 1.2 ^circC. The fan was run continuously to investigate night-time low wind speed errors and the prototype shield reduced errors from 1.6 ^ circC to 0.3 ^circC. Part-time aspirated shields are an inexpensive alternative to fully aspirated shields and represent a good compromise between cost, power consumption, reliability (because they should be no worse than a standard multiplate shield if the fan fails), and accuracy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28789058','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28789058"><span>Overcoming limits to near-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer in uniform planar media through multilayer optimization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jin, Weiliang; Messina, Riccardo; Rodriguez, Alejandro W</p> <p>2017-06-26</p> <p><span class="hlt">Radiative</span> <span class="hlt">heat</span> transfer between uniform plates is bounded by the narrow range and limited contribution of surface waves. Using a combination of analytical calculations and numerical gradient-based optimization, we show that such a limitation can be overcome in complicated multilayer geometries, allowing the scattering and coupling rates of slab resonances to be altered over a broad range of evanescent wavevectors. We conclude that while the <span class="hlt">radiative</span> <span class="hlt">flux</span> between two inhomogeneous slabs can only be weakly enhanced, the <span class="hlt">flux</span> between a dipolar particle and an inhomogeneous slab-proportional to the local density of states-can be orders of magnitude larger, albeit at the expense of increased frequency selectivity. A brief discussion of hyperbolic metamaterials shows that they provide far less enhancement than optimized inhomogeneous slabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22299979','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22299979"><span>Dynamic thermomechanical response of bimaterial microcantilevers to periodic <span class="hlt">heating</span> by infrared <span class="hlt">radiation</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kwon, Beomjin; Rosenberger, Matthew; Bhargava, Rohit; Cahill, David G; King, William P</p> <p>2012-01-01</p> <p>This paper investigates the dynamic thermomechanical response of bimaterial microcantilevers to periodic <span class="hlt">heating</span> by an infrared laser operating at a wavelenegth of 10.35 μm. A model relates incident <span class="hlt">radiation</span>, <span class="hlt">heat</span> transfer, temperature distribution in the cantilever, and thermal expansion mismatch to find the cantilever displacement. Experiments were conducted on two custom-fabricated bimaterial cantilevers and two commercially available bimaterial microcantilevers. The cantilever response was measured as a function of the modulation frequency of the laser over the range of 0.01-30 kHz. The model and the method of cantilever displacement calibration can be applied for bimaterial cantilever with thick coating layer. The sensitivity and signal-to-noise of bimaterial cantilevers were evaluated in terms of either total incident power or incident <span class="hlt">flux</span>. The custom-fabricated bimaterial cantilevers showed 9X or 190X sensitivity improvement compared to commercial cantilevers. The detection limit on incident <span class="hlt">flux</span> is as small as 0.10 pW μm(-2) Hz(-1/2).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H54C..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H54C..03L"><span>Mapping surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> by assimilating GOES land surface temperature and SMAP products</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Y.; Steele-Dunne, S. C.; Van De Giesen, N.</p> <p>2017-12-01</p> <p>Surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> significantly affect the land-atmosphere interaction, but their modelling is often hindered by the lack of in-situ measurements and the high spatial heterogeneity. Here, we propose a hybrid particle assimilation strategy to estimate surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> by assimilating GOES land surface temperature (LST) data and SMAP products into a simple dual-source surface energy balance model, in which the requirement for in-situ data is minimized. The study aims to estimate two key parameters: a neutral bulk <span class="hlt">heat</span> transfer coefficient (CHN) and an evaporative fraction (EF). CHN scales the sum of surface energy <span class="hlt">fluxes</span>, and EF represents the partitioning between <span class="hlt">flux</span> components. To bridge the huge resolution gap between GOES and SMAP data, SMAP data are assimilated using a particle filter to update soil moisture which constrains EF, and GOES data are assimilated with an adaptive particle batch smoother to update CHN. The methodology is applied to an area in the US Southern Great Plains with forcing data from NLDAS-2 and the GPM mission. Assessment against in-situ observations suggests that the sensible and latent <span class="hlt">heat</span> <span class="hlt">flux</span> estimates are greatly improved at both daytime and 30-min scale after assimilation, particularly for latent <span class="hlt">heat</span> <span class="hlt">fluxes</span>. Comparison against an LST-only assimilation case demonstrates that despite the coarse resolution, assimilating SMAP data is not only beneficial but also crucial for successful and robust <span class="hlt">flux</span> estimation, particularly when the modelling uncertainties are large. Since the methodology is independent on in-situ data, it can be easily applied to other areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990009879&hterms=afterburning&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dafterburning','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990009879&hterms=afterburning&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dafterburning"><span>Delta Clipper-Experimental In-Ground Effect on Base-<span class="hlt">Heating</span> Environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Ten-See</p> <p>1998-01-01</p> <p>A quasitransient in-ground effect method is developed to study the effect of vertical landing on a launch vehicle base-<span class="hlt">heating</span> environment. This computational methodology is based on a three-dimensional, pressure-based, viscous flow, chemically reacting, computational fluid dynamics formulation. Important in-ground base-flow physics such as the fountain-jet formation, plume growth, air entrainment, and plume afterburning are captured with the present methodology. Convective and <span class="hlt">radiative</span> base-<span class="hlt">heat</span> <span class="hlt">fluxes</span> are computed for comparison with those of a flight test. The influence of the laminar Prandtl number on the convective <span class="hlt">heat</span> <span class="hlt">flux</span> is included in this study. A <span class="hlt">radiative</span> direction-dependency test is conducted using both the discrete ordinate and finite volume methods. Treatment of the plume afterburning is found to be very important for accurate prediction of the base-<span class="hlt">heat</span> <span class="hlt">fluxes</span>. Convective and <span class="hlt">radiative</span> base-<span class="hlt">heat</span> <span class="hlt">fluxes</span> predicted by the model using a finite rate chemistry option compared reasonably well with flight-test data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/864118','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/864118"><span>Method and apparatus for determining vertical <span class="hlt">heat</span> <span class="hlt">flux</span> of geothermal field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Poppendiek, Heinz F.</p> <p>1982-01-01</p> <p>A method and apparatus for determining vertical <span class="hlt">heat</span> <span class="hlt">flux</span> of a geothermal field, and mapping the entire field, is based upon an elongated <span class="hlt">heat-flux</span> transducer (10) comprised of a length of tubing (12) of relatively low thermal conductivity with a thermopile (20) inside for measuring the thermal gradient between the ends of the transducer after it has been positioned in a borehole for a period sufficient for the tube to reach thermal equilibrium. The transducer is thermally coupled to the surrounding earth by a fluid annulus, preferably water or mud. A second transducer comprised of a length of tubing of relatively high thermal conductivity is used for a second thermal gradient measurement. The ratio of the first measurement to the second is then used to determine the earth's thermal conductivity, k.sub..infin., from a precalculated graph, and using the value of thermal conductivity thus determined, then determining the vertical earth temperature gradient, b, from predetermined steady state <span class="hlt">heat</span> balance equations which relate the undisturbed vertical earth temperature distributions at some distance from the borehole and earth thermal conductivity to the temperature gradients in the transducers and their thermal conductivity. The product of the earth's thermal conductivity, k.sub..infin., and the earth's undisturbed vertical temperature gradient, b, then determines the earth's vertical <span class="hlt">heat</span> <span class="hlt">flux</span>. The process can be repeated many times for boreholes of a geothermal field to map vertical <span class="hlt">heat</span> <span class="hlt">flux</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NucFu..57c6021E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NucFu..57c6021E"><span>Numerical investigation of plasma edge transport and limiter <span class="hlt">heat</span> <span class="hlt">fluxes</span> in Wendelstein 7-X startup plasmas with EMC3-EIRENE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Effenberg, F.; Feng, Y.; Schmitz, O.; Frerichs, H.; Bozhenkov, S. A.; Hölbe, H.; König, R.; Krychowiak, M.; Pedersen, T. Sunn; Reiter, D.; Stephey, L.; W7-X Team</p> <p>2017-03-01</p> <p>The results of a first systematic assessment of plasma edge transport processes for the limiter startup configuration at Wendelstein 7-X are presented. This includes an investigation of transport from intrinsic and externally injected impurities and their impact on the power balance and limiter <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The fully 3D coupled plasma fluid and kinetic neutral transport Monte Carlo code EMC3-EIRENE is used. The analysis of the magnetic topology shows that the poloidally and toroidally localized limiters cause a 3D helical scrape-off layer (SOL) consisting of magnetic <span class="hlt">flux</span> tubes of three different connection lengths L C. The transport in the helical SOL is governed by L C as topological scale length for the parallel plasma loss channel to the limiters. A clear modulation of the plasma pressure with L C is seen. The helical <span class="hlt">flux</span> tube topology results in counter streaming sonic plasma flows. The heterogeneous SOL plasma structure yields an uneven limiter <span class="hlt">heat</span> load distribution with localized peaking. Assuming spatially constant anomalous transport coefficients, increasing plasma density yields a reduction of the maximum peak <span class="hlt">heat</span> loads from 12 MWm-2 to 7.5 MWm-2 and a broadening of the deposited <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The impact of impurities on the limiter <span class="hlt">heat</span> loads is studied by assuming intrinsic carbon impurities eroded from the limiter surfaces with a gross chemical sputtering yield of 2 % . The resulting <span class="hlt">radiative</span> losses account for less than 10% of the input power in the power balance with marginal impact on the limiter <span class="hlt">heat</span> loads. It is shown that a significant mitigation of peak <span class="hlt">heat</span> loads, 40-50%, can be achieved with controlled impurity seeding with nitrogen and neon, which is a method of particular interest for the later island divertor phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSHE12A..03H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSHE12A..03H"><span>Energy and variance budgets of a diffusive staircase with implications for <span class="hlt">heat</span> <span class="hlt">flux</span> scaling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hieronymus, M.; Carpenter, J. R.</p> <p>2016-02-01</p> <p>Diffusive convection, the mode of double-diffusive convection that occur when both temperature and salinity increase with increasing depth, is commonplace throughout the high latitude oceans and diffusive staircases constitute an important <span class="hlt">heat</span> transport process in the Arctic Ocean. <span class="hlt">Heat</span> and buoyancy <span class="hlt">fluxes</span> through these staircases are often estimated using <span class="hlt">flux</span> laws deduced either from laboratory experiments, or from simplified energy or variance budgets. We have done direct numerical simulations of double-diffusive convection at a range of Rayleigh numbers and quantified the energy and variance budgets in detail. This allows us to compare the <span class="hlt">fluxes</span> in our simulations to those derived using known <span class="hlt">flux</span> laws and to quantify how well the simplified energy and variance budgets approximate the full budgets. The <span class="hlt">fluxes</span> are found to agree well with earlier estimates at high Rayleigh numbers, but we find large deviations at low Rayleigh numbers. The close ties between the <span class="hlt">heat</span> and buoyancy <span class="hlt">fluxes</span> and the budgets of thermal variance and energy have been utilized to derive <span class="hlt">heat</span> <span class="hlt">flux</span> scaling laws in the field of thermal convection. The result is the so called GL-theory, which has been found to give accurate <span class="hlt">heat</span> <span class="hlt">flux</span> scaling laws in a very wide parameter range. Diffusive convection has many similarities to thermal convection and an extension of the GL-theory to diffusive convection is also presented and its predictions are compared to the results from our numerical simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/gewex/available-data','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/gewex/available-data"><span>GEWEX <span class="hlt">Radiative</span> <span class="hlt">Flux</span> Assessment Available Data</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2016-05-31</p> <p>... ERBE--ERBS-NOAA10_EdXXX ERBE/ERBS + NOAA 10 Scanner 2.5 degree monthly mean data from 02/87 to 05/89 ... GEWEX <span class="hlt">Radiative</span> <span class="hlt">Flux</span> Assessment data were obtained from the NASA Langley Research Center Atmospheric Science Data Center. " In addition, ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A53G2365S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A53G2365S"><span>CERES Fast Longwave And SHortwave <span class="hlt">Radiative</span> <span class="hlt">Flux</span> (FLASHFlux) Version4A.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sawaengphokhai, P.; Stackhouse, P. W., Jr.; Kratz, D. P.; Gupta, S. K.</p> <p>2017-12-01</p> <p>The agricultural, renewable energy management, and science communities need global surface and top-of-atmosphere (TOA) <span class="hlt">radiative</span> <span class="hlt">fluxes</span> on a low latency basis. The Clouds and Earth's Radiant Energy System (CERES) FLASHFlux (Fast Longwave and SHortwave <span class="hlt">radiative</span> <span class="hlt">Flux</span>) data products address this need by enhancing the speed of CERES processing using simplified calibration and parameterized model of surface <span class="hlt">fluxes</span> to provide a daily global <span class="hlt">radiative</span> <span class="hlt">fluxes</span> data set within one week of satellite observations. The CERES FLASHFlux provides two data products: 1) an overpass swath Level 2 Single Scanner Footprint (SSF) data products separately for both Aqua and Terra observations, and 2) a daily Level 3 Time Interpolated and Spatially Averaged (TISA) 1o x 1o gridded data that combines Aqua and Terra observations. The CERES FLASHFlux data product is being promoted to Version4A. Updates to FLASHFlux Version4A include a new cloud retrieval algorithm and an improved shortwave surface <span class="hlt">flux</span> parameterization. We inter-compared FLASHFlux Version4A, FLASHFlux Version3C, CERES Edition 4 Syn1Deg and at the monthly scale CERES Edition4 EBAF (Energy Balanced and Filled) Top-of-Atmosphere and Edition 4 Surface EBAF <span class="hlt">fluxes</span> to evaluate these improvements. We also analyze the impact of the new inputs and cloud algorithm to the surface shortwave and longwave <span class="hlt">radiative</span> <span class="hlt">fluxes</span> using ground sites measurement provided by CAVE (CERES/ARM Validation Experiment).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JQSRT.151...67C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JQSRT.151...67C"><span>Evaluation of FSK models for <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer under oxyfuel conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clements, Alastair G.; Porter, Rachael; Pranzitelli, Alessandro; Pourkashanian, Mohamed</p> <p>2015-01-01</p> <p>Oxyfuel is a promising technology for carbon capture and storage (CCS) applied to combustion processes. It would be highly advantageous in the deployment of CCS to be able to model and optimise oxyfuel combustion, however the increased concentrations of CO2 and H2O under oxyfuel conditions modify several fundamental processes of combustion, including <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer. This study uses benchmark narrow band <span class="hlt">radiation</span> models to evaluate the influence of assumptions in global full-spectrum k-distribution (FSK) models, and whether they are suitable for modelling <span class="hlt">radiation</span> in computational fluid dynamics (CFD) calculations of oxyfuel combustion. The statistical narrow band (SNB) and correlated-k (CK) models are used to calculate benchmark data for the <span class="hlt">radiative</span> source term and <span class="hlt">heat</span> <span class="hlt">flux</span>, which are then compared to the results calculated from FSK models. Both the full-spectrum correlated k (FSCK) and the full-spectrum scaled k (FSSK) models are applied using up-to-date spectral data. The results show that the FSCK and FSSK methods achieve good agreement in the test cases. The FSCK method using a five-point Gauss quadrature scheme is recommended for CFD calculations in oxyfuel conditions, however there are still potential inaccuracies in cases with very wide variations in the ratio between CO2 and H2O concentrations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930048596&hterms=scala&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dscala','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930048596&hterms=scala&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dscala"><span><span class="hlt">Heating</span>, moisture, and water budgets of tropical and midlatitude squall lines - Comparisons and sensitivity to longwave <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tao, W.-K.; Simpson, J.; Sui, C.-H.; Ferrier, B.; Lang, S.; Scala, J.; Chou, M.-D.; Pickering, K.</p> <p>1993-01-01</p> <p>A 2D time-dependent and nonhydrostatic numerical cloud model is presently used to estimate the <span class="hlt">heating</span>, moisture, and water budgets in the convective and stratiform regions for both a tropical and a midlatitude squall line. The model encompasses a parameterized, three-class ice phase microphysical scheme and longwave <span class="hlt">radiative</span> transfer process. It is noted that the convective region plays an important role in the generation of stratiform rainfall for both cases. While a midlevel minimum in the moisture profile for the tropical case is due to vertical eddy transport in the convective region, the contribution to the <span class="hlt">heating</span> budget by the cloud-scale <span class="hlt">fluxes</span> is minor; by contrast, the vertical eddy <span class="hlt">heat-flux</span> is relatively important for the midlatitude case due to the stronger vertical velocities present in the convective cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1910765G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1910765G"><span>Surface energy budget and turbulent <span class="hlt">fluxes</span> at Arctic terrestrial sites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grachev, Andrey; Persson, Ola; Uttal, Taneil; Konopleva-Akish, Elena; Crepinsek, Sara; Cox, Christopher; Fairall, Christopher; Makshtas, Alexander; Repina, Irina</p> <p>2017-04-01</p> <p>Determination of the surface energy budget (SEB) and all SEB components at the air-surface interface are required in a wide variety of applications including atmosphere-land/snow simulations and validation of the surface <span class="hlt">fluxes</span> predicted by numerical models over different spatial and temporal scales. Here, comparisons of net surface energy budgets at two Arctic sites are made using long-term near-continuous measurements of hourly averaged surface <span class="hlt">fluxes</span> (turbulent, <span class="hlt">radiation</span>, and soil conduction). One site, Eureka (80.0 N; Nunavut, Canada), is located in complex topography near a fjord about 200 km from the Arctic Ocean. The other site, Tiksi (71.6 N; Russian East Siberia), is located on a relatively flat coastal plain less than 1 km from the shore of Tiksi Bay, a branch of the Arctic Ocean. We first analyzed diurnal and annual cycles of basic meteorological parameters and key SEB components at these locations. Although Eureka and Tiksi are located on different continents and at different latitudes, the annual course of the surface meteorology and SEB components are qualitatively similar. Surface energy balance closure is a formulation of the conservation of energy principle. Our direct measurements of energy balance for both Arctic sites show that the sum of the turbulent sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> and the ground (conductive) <span class="hlt">heat</span> <span class="hlt">flux</span> systematically underestimate the net <span class="hlt">radiation</span> by about 25-30%. This lack of energy balance closure is a fundamental and pervasive problem in micrometeorology. We discuss a variety of factors which may be responsible for the lack of SEB closure. In particular, various storage terms (e.g., air column energy storage due to <span class="hlt">radiative</span> and/or sensible <span class="hlt">heat</span> <span class="hlt">flux</span> divergence, ground <span class="hlt">heat</span> storage above the soil <span class="hlt">flux</span> plate, energy used in photosynthesis, canopy biomass <span class="hlt">heat</span> storage). For example, our observations show that the photosynthesis storage term is relatively small (about 1-2% of the net <span class="hlt">radiation</span>), but about 8-12% of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10444E..1PN','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10444E..1PN"><span>Satellite data based approach for the estimation of anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> over urban areas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nitis, Theodoros; Tsegas, George; Moussiopoulos, Nicolas; Gounaridis, Dimitrios; Bliziotis, Dimitrios</p> <p>2017-09-01</p> <p>Anthropogenic effects in urban areas influence the thermal conditions in the environment and cause an increase of the atmospheric temperature. The cities are sources of <span class="hlt">heat</span> and pollution, affecting the thermal structure of the atmosphere above them which results to the urban <span class="hlt">heat</span> island effect. In order to analyze the urban <span class="hlt">heat</span> island mechanism, it is important to estimate the anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> which has a considerable impact on the urban energy budget. The anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> is the result of man-made activities (i.e. traffic, industrial processes, <span class="hlt">heating</span>/cooling) and thermal releases from the human body. Many studies have underlined the importance of the Anthropogenic <span class="hlt">Heat</span> <span class="hlt">Flux</span> to the calculation of the urban energy budget and subsequently, the estimation of mesoscale meteorological fields over urban areas. Therefore, spatially disaggregated anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> data, at local and city scales, are of major importance for mesoscale meteorological models. The main objectives of the present work are to improve the quality of such data used as input for mesoscale meteorological models simulations and to enhance the application potential of GIS and remote sensing in the fields of climatology and meteorology. For this reason, the Urban Energy Budget concept is proposed as the foundation for an accurate determination of the anthropogenic <span class="hlt">heat</span> discharge as a residual term in the surface energy balance. The methodology is applied to the cities of Athens and Paris using the Landsat ETM+ remote sensing data. The results will help to improve our knowledge on Anthropogenic <span class="hlt">Heat</span> <span class="hlt">Flux</span>, while the potential for further improvement of the methodology is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27176779','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27176779"><span>A Comparative Study for Flow of Viscoelastic Fluids with Cattaneo-Christov <span class="hlt">Heat</span> <span class="hlt">Flux</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hayat, Tasawar; Muhammad, Taseer; Alsaedi, Ahmed; Mustafa, Meraj</p> <p>2016-01-01</p> <p>This article examines the impact of Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> in flows of viscoelastic fluids. Flow is generated by a linear stretching sheet. Influence of thermal relaxation time in the considered <span class="hlt">heat</span> <span class="hlt">flux</span> is seen. Mathematical formulation is presented for the boundary layer approach. Suitable transformations lead to a nonlinear differential system. Convergent series solutions of velocity and temperature are achieved. Impacts of various influential parameters on the velocity and temperature are sketched and discussed. Numerical computations are also performed for the skin friction coefficient and <span class="hlt">heat</span> transfer rate. Our findings reveal that the temperature profile has an inverse relationship with the thermal relaxation parameter and the Prandtl number. Further the temperature profile and thermal boundary layer thickness are lower for Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> model in comparison to the classical Fourier's law of <span class="hlt">heat</span> conduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030062133&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMagnetic%2BFlux','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030062133&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMagnetic%2BFlux"><span>Solar Coronal <span class="hlt">Heating</span> and the Magnetic <span class="hlt">Flux</span> Content of the Network</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.</p> <p>2003-01-01</p> <p>We investigate the <span class="hlt">heating</span> of the quiet corona by measuring the increase of coronal luminosity with the amount of magnetic <span class="hlt">flux</span> in the underlying network at solar minimum when there were no active regions on the face of the Sun. The coronal luminosity is measured from Fe IX/X-Fe XII pairs of coronal images from SOHO/EIT. The network magnetic <span class="hlt">flux</span> content is measured from SOHO/MDI magnetograms. We find that the luminosity of the corona in our quiet regions increases roughly in proportion to the square root of the magnetic <span class="hlt">flux</span> content of the network and roughly in proportion to the length of the perimeter of the network magnetic <span class="hlt">flux</span> clumps. From (1) this result, (2) other observations of many fine-scale explosive events at the edges of network <span class="hlt">flux</span> clumps, and (3) a demonstration that it is energetically feasible for the <span class="hlt">heating</span> of the corona in quiet regions to be driven by explosions of granule-sized sheared-core magnetic bipoles embedded in the edges of network <span class="hlt">flux</span> clumps, we infer that in quiet regions that are not influenced by active regions the corona is mainly <span class="hlt">heated</span> by such magnetic activity in the edges of the network <span class="hlt">flux</span> clumps. Our observational results together with our feasibility analysis allow us to predict that (1) at the edges of the network <span class="hlt">flux</span> clumps there are many transient sheared-core bipoles of the size and lifetime of granules and having transverse field strengths > approx. 100 G, (2) approx. 30 of these bipoles are present per supergranule, and (3) most spicules are produced by explosions of these bipoles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030062034&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMagnetic%2BFlux','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030062034&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMagnetic%2BFlux"><span>Solar Coronal <span class="hlt">Heating</span> and the Magnetic <span class="hlt">Flux</span> Content of the Network</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moore, R. L.; Falconer, D. A.; Porter, J. G.; Hathaway, D. H.</p> <p>2003-01-01</p> <p>We investigate the <span class="hlt">heating</span> of the quiet corona by measuring the increase of coronal luminosity with the amount of magnetic <span class="hlt">flux</span> in the underlying network at solar minimum when there were no active regions on the face of the Sun. The coronal luminosity is measured from Fe IX/X-Fe XII pairs of coronal images from SOHO/EIT. The network magnetic <span class="hlt">flux</span> content is measured from SOHO/MDI magnetograms. We find that the luminosity of the corona in our quiet regions increases roughly in proportion to the square root of the magnetic <span class="hlt">flux</span> content of the network and roughly in proportion to the length of the perimeter of the network magnetic <span class="hlt">flux</span> clumps. From (1) this result, (2) other observations of many fine-scale explosive events at the edges of network <span class="hlt">flux</span> clumps, and (3) a demonstration that it is energetically feasible for the <span class="hlt">heating</span> of the corona in quiet regions to be driven by explosions of granule-sized sheared-core magnetic bipoles embedded in the edges of network <span class="hlt">flux</span> clumps, we infer that in quiet regions that are not influenced by active regions the corona is mainly <span class="hlt">heated</span> by such magnetic activity in the edges of the network <span class="hlt">flux</span> clumps. Our observational results together with our feasibility analysis allow us to predict that (1) at the edges of the network <span class="hlt">flux</span> clumps there are many transient sheared-core bipoles of the size and lifetime of granules and having transverse field strengths greater than approximately - 100 G, (2) approximately 30 of these bipoles are present per supergranule, and (3) most spicules are produced by explosions of these bipoles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870053663&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dworlds%2Boceans','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870053663&hterms=worlds+oceans&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dworlds%2Boceans"><span>Mass, <span class="hlt">heat</span> and freshwater <span class="hlt">fluxes</span> in the South Indian Ocean</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fu, Lee-Lueng</p> <p>1986-01-01</p> <p>Six hydrographic sections were used to examine the circulation and property <span class="hlt">fluxes</span> in the South Indian Ocean from 10 to 32 deg S. The calculations were made by applying an inverse method to the data. In the interior of the South Indian Ocean, the geostrophic flow is generally northward. At 18 deg S, the northward interior mass <span class="hlt">flux</span> is balanced by the southward Ekman mass <span class="hlt">flux</span> at the surface, whereas at 32 deg S the northward interior mass <span class="hlt">flux</span> is balanced by the southward mass <span class="hlt">flux</span> of the Agulhas Current. There is a weak, southward mass <span class="hlt">flux</span> of 6 x 10 to the 9th kg/s in the Mozambique Channel. The rate of water exchange between the Pacific Ocean and the Indian Ocean is dependent on the choice of the initial reference level used in the inverse calculation. The choice of 1500 m, the depth of the deep oxygen minimum, has led to a <span class="hlt">flux</span> of water from the Pacific Ocean to the Indian Ocean at a rate of 6.6 x 10 to the 9th kg/s. <span class="hlt">Heat</span> <span class="hlt">flux</span> calculations indicate that the Indian Ocean is exporting <span class="hlt">heat</span> to the rest of the world's oceans at a rate of -0.69 x 10 to the 15th W at 18 deg S and -0.25 x 10 to the 15th W at 32 deg S (negative values being southward).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000085968','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000085968"><span>Investigation of Instabilities and <span class="hlt">Heat</span> Transfer Phenomena in Supercritical Fuels at High <span class="hlt">Heat</span> <span class="hlt">Flux</span> and Temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Linne, Diane L.; Meyer, Michael L.; Braun, Donald C.; Keller, Dennis J.</p> <p>2000-01-01</p> <p>A series of <span class="hlt">heated</span> tube experiments was performed to investigate fluid instabilities that occur during <span class="hlt">heating</span> of supercritical fluids. In these tests, JP-7 flowed vertically through small diameter tubes at supercritical pressures. Test section <span class="hlt">heated</span> length, diameter, mass flow rate, inlet temperature, and <span class="hlt">heat</span> <span class="hlt">flux</span> were varied in an effort to determine the range of conditions that trigger the instabilities. <span class="hlt">Heat</span> <span class="hlt">flux</span> was varied up to 4 BTU/sq in./s, and test section wall temperatures reached as high as 1950 F. A statistical model was generated to explain the trends and effects of the control variables. The model included no direct linear effect of <span class="hlt">heat</span> <span class="hlt">flux</span> on the occurrence of the instabilities. All terms involving inlet temperature were negative, and all terms involving mass flow rate were positive. Multiple tests at conditions that produced instabilities provided inconsistent results. These inconsistencies limit the use of the model as a predictive tool. Physical variables that had been previously postulated to control the onset of the instabilities, such as film temperature, velocity, buoyancy, and wall-to-bulk temperature ratio, were evaluated here. Film temperatures at or near critical occurred during both stable and unstable tests. All tests at the highest velocity were stable, but there was no functional relationship found between the instabilities and velocity, or a combination of velocity and temperature ratio. Finally, all of the unstable tests had significant buoyancy at the inlet of the test section, but many stable tests also had significant buoyancy forces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720018905','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720018905"><span>Combined buoyancy and flow direction effects on saturated boiling critical <span class="hlt">heat</span> <span class="hlt">flux</span> in liquid nitrogen</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Papell, S. S.</p> <p>1972-01-01</p> <p>Buoyancy effects on the critical <span class="hlt">heat</span> <span class="hlt">flux</span> and general data trends for a liquid nitrogen internal flow system were determined by comparison of upflow and downflow data under identical test conditions. The test section had a 1.28 cm diameter flow passage and a 30.5 cm <span class="hlt">heated</span> length which was subjected to uniform <span class="hlt">heat</span> <span class="hlt">fluxes</span> through resistance <span class="hlt">heating</span>. Test conditions covered a range of pressures from 3.4 to 10.2 atm, inlet velocities from 0.23 to 3.51 m/sec, with the liquid nitrogen temperature at saturated inlet conditions. Data comparisons showed that the critical <span class="hlt">heat</span> <span class="hlt">flux</span> for downflow could be up to 36 percent lower than for upflow. A nonmonotonic relationship between the critical <span class="hlt">heat</span> <span class="hlt">flux</span> and velocity was determined for upflow but not for downflow. A limiting inlet velocity of 4.12 m/sec was determined to be the minimum velocity required to completely suppress the influence of buoyancy on the critical <span class="hlt">heat</span> <span class="hlt">flux</span> for this saturated inlet flow system. A correlation of this limiting fluid velocity is presented that was developed from previously published subcooled liquid nitrogen data and the saturated data of this investigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23521268','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23521268"><span>How the propagation of <span class="hlt">heat-flux</span> modulations triggers E × B flow pattern formation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kosuga, Y; Diamond, P H; Gürcan, O D</p> <p>2013-03-08</p> <p>We propose a novel mechanism to describe E×B flow pattern formation based upon the dynamics of propagation of <span class="hlt">heat-flux</span> modulations. The E × B flows of interest are staircases, which are quasiregular patterns of strong, localized shear layers and profile corrugations interspersed between regions of avalanching. An analogy of staircase formation to jam formation in traffic flow is used to develop an extended model of <span class="hlt">heat</span> avalanche dynamics. The extension includes a <span class="hlt">flux</span> response time, during which the instantaneous <span class="hlt">heat</span> <span class="hlt">flux</span> relaxes to the mean <span class="hlt">heat</span> <span class="hlt">flux</span>, determined by symmetry constraints. The response time introduced here is the counterpart of the drivers' response time in traffic, during which drivers adjust their speed to match the background traffic flow. The finite response time causes the growth of mesoscale temperature perturbations, which evolve to form profile corrugations. The length scale associated with the maximum growth rate scales as Δ(2) ~ (v(thi)/λT(i))ρ(i)sqrt[χ(neo)τ], where λT(i) is a typical <span class="hlt">heat</span> pulse speed, χ(neo) is the neoclassical thermal diffusivity, and τ is the response time of the <span class="hlt">heat</span> <span class="hlt">flux</span>. The connection between the scale length Δ(2) and the staircase interstep scale is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016amsf.conf..335Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016amsf.conf..335Y"><span>Effect of Na2O on Crystallisation Behaviour and <span class="hlt">Heat</span> Transfer of Fluorine-Free Mould <span class="hlt">Fluxes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Jian; Zhang, Jianqiang; Sasaki, Yasushi; Ostrovski, Oleg; Zhang, Chen; Cai, Dexiang; Kashiwaya, Yoshiaki</p> <p></p> <p>Most of the commercial mould <span class="hlt">fluxes</span> contain fluorides which bring about serious environmental problems. The major challenge in the application of fluorine-free mould <span class="hlt">fluxes</span> is to control the <span class="hlt">heat</span> transfer from the strand to copper mould which is closely related to crystallisation behaviour. In this study, the effects of Na2O on the crystallisation behaviour and <span class="hlt">heat</span> transfer of CaO-SiO2-Na2O-B2O3-TiO2-Al2O3-MgO-Li2O mould <span class="hlt">fluxes</span> were investigated using single /double hot thermocouple technique (SHTT/DHTT) and infrared emitter technique (IET), respectively. Continuous cooling transformation (CCT) and time-temperature transformation (TTT) diagrams constructed using SHTT showed that the increase of Na2O concentration led to higher critical cooling rate and shorter incubation time. The crystallisation behaviour in a thermal gradient was examined using DHTT. The <span class="hlt">heat</span> <span class="hlt">flux</span> measured by IET showed that the increase of Na2O concentration decreased the <span class="hlt">heat</span> <span class="hlt">flux</span> when Na2O was lower than 9 mass% but the further increase of Na2O raised the <span class="hlt">heat</span> <span class="hlt">flux</span>. The relationship between <span class="hlt">flux</span> crystallisation and <span class="hlt">heat</span> transfer was also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890052278&hterms=heat+exchange&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dheat%2Bexchange','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890052278&hterms=heat+exchange&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dheat%2Bexchange"><span>A study of oceanic surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> in the Greenland, Norwegian, and Barents Seas</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hakkinen, Sirpa; Cavalieri, Donald J.</p> <p>1989-01-01</p> <p>This study examines oceanic surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> in the Norwegian, Greenland, and Barents seas using the gridded Navy Fleet Numerical Oceanography Central surface analysis and the First GARP Global Experiment (FGGE) IIc cloudiness data bases. Monthly and annual means of net and turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> are computed for the FGGE year 1979. The FGGE IIb data base consisting of individual observations provides particularly good data coverage in this region for a comparison with the gridded Navy winds and air temperatures. The standard errors of estimate between the Navy and FGGE IIb winds and air temperatures are 3.6 m/s and 2.5 C, respectively. The computations for the latent and sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> are based on bulk formulas with the same constant <span class="hlt">heat</span> exchange coefficient of 0.0015. The results show extremely strong wintertime <span class="hlt">heat</span> <span class="hlt">fluxes</span> in the northern Greenland Sea and especially in the Barents Sea in contrast to previous studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740003624','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740003624"><span>Effect of gage size on the measurement of local <span class="hlt">heat</span> <span class="hlt">flux</span>. [formulas for determining gage averaging errors</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baumeister, K. J.; Papell, S. S.</p> <p>1973-01-01</p> <p>General formulas are derived for determining gage averaging errors of strip-type <span class="hlt">heat</span> <span class="hlt">flux</span> meters used in the measurement of one-dimensional <span class="hlt">heat</span> <span class="hlt">flux</span> distributions. In addition, a correction procedure is presented which allows a better estimate for the true value of the local <span class="hlt">heat</span> <span class="hlt">flux</span>. As an example of the technique, the formulas are applied to the cases of <span class="hlt">heat</span> transfer to air slot jets impinging on flat and concave surfaces. It is shown that for many practical problems, the use of very small <span class="hlt">heat</span> <span class="hlt">flux</span> gages is often unnecessary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011A%26A...531A.162K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011A%26A...531A.162K"><span>Reynolds stress and <span class="hlt">heat</span> <span class="hlt">flux</span> in spherical shell convection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Käpylä, P. J.; Mantere, M. J.; Guerrero, G.; Brandenburg, A.; Chatterjee, P.</p> <p>2011-07-01</p> <p>Context. Turbulent <span class="hlt">fluxes</span> of angular momentum and enthalpy or <span class="hlt">heat</span> due to rotationally affected convection play a key role in determining differential rotation of stars. Their dependence on latitude and depth has been determined in the past from convection simulations in Cartesian or spherical simulations. Here we perform a systematic comparison between the two geometries as a function of the rotation rate. Aims: Here we want to extend the earlier studies by using spherical wedges to obtain turbulent angular momentum and <span class="hlt">heat</span> transport as functions of the rotation rate from stratified convection. We compare results from spherical and Cartesian models in the same parameter regime in order to study whether restricted geometry introduces artefacts into the results. In particular, we want to clarify whether the sharp equatorial profile of the horizontal Reynolds stress found in earlier Cartesian models is also reproduced in spherical geometry. Methods: We employ direct numerical simulations of turbulent convection in spherical and Cartesian geometries. In order to alleviate the computational cost in the spherical runs, and to reach as high spatial resolution as possible, we model only parts of the latitude and longitude. The rotational influence, measured by the Coriolis number or inverse Rossby number, is varied from zero to roughly seven, which is the regime that is likely to be realised in the solar convection zone. Cartesian simulations are performed in overlapping parameter regimes. Results: For slow rotation we find that the radial and latitudinal turbulent angular momentum <span class="hlt">fluxes</span> are directed inward and equatorward, respectively. In the rapid rotation regime the radial <span class="hlt">flux</span> changes sign in accordance with earlier numerical results, but in contradiction with theory. The latitudinal <span class="hlt">flux</span> remains mostly equatorward and develops a maximum close to the equator. In Cartesian simulations this peak can be explained by the strong "banana cells". Their effect in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19740030181&hterms=heat+insulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dheat%2Binsulation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19740030181&hterms=heat+insulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dheat%2Binsulation"><span>Solid motor aft closure insulation erosion. [<span class="hlt">heat</span> <span class="hlt">flux</span> correlation for rate analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stampfl, E.; Landsbaum, E. M.</p> <p>1973-01-01</p> <p>The erosion rate of aft closure insulation in a number of large solid propellant motors was empirically analyzed by correlating the average ablation rate with a number of variables that had previously been demonstrated to affect <span class="hlt">heat</span> <span class="hlt">flux</span>. The main correlating parameter was a <span class="hlt">heat</span> <span class="hlt">flux</span> based on the simplified Bartz <span class="hlt">heat</span> transfer coefficient corrected for two-dimensional effects. A multiplying group contained terms related to port-to-throat ratio, local wall angle, grain geometry and nozzle cant angle. The resulting equation gave a good correlation and is a useful design tool.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890056315&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddropout','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890056315&hterms=dropout&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddropout"><span>Electron <span class="hlt">heat</span> <span class="hlt">flux</span> dropouts in the solar wind - Evidence for interplanetary magnetic field reconnection?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mccomas, D. J.; Gosling, J. T.; Phillips, J. L.; Bame, S. J.; Luhmann, J. G.; Smith, E. J.</p> <p>1989-01-01</p> <p>An examination of ISEE-3 data from 1978 reveal 25 electron <span class="hlt">heat</span> <span class="hlt">flux</span> dropout events ranging in duration from 20 min to over 11 hours. The <span class="hlt">heat</span> <span class="hlt">flux</span> dropouts are found to occur in association with high plasma densities, low plasma velocities, low ion and electron temperatures, and low magnetic field magnitudes. It is suggested that the <span class="hlt">heat</span> <span class="hlt">flux</span> dropout intervals may indicate that the spacecraft is sampling plasma regimes which are magnetically disconnected from the sun and instead are connected to the outer heliosphere at both ends.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.472.3749O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.472.3749O"><span>Super-Eddington stellar winds: unifying <span class="hlt">radiative</span>-enthalpy versus <span class="hlt">flux</span>-driven models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Owocki, Stanley P.; Townsend, Richard H. D.; Quataert, Eliot</p> <p>2017-12-01</p> <p>We derive semi-analytic solutions for optically thick, super-Eddington stellar winds, induced by an assumed steady energy addition Δ {\\dot{E}} concentrated around a near-surface <span class="hlt">heating</span> radius R in a massive star of central luminosity L*. We show that obtaining steady wind solutions requires both that the resulting total luminosity L_o = L_\\ast + Δ {\\dot{E}} exceed the Eddington luminosity, Γo ≡ Lo/LEdd > 1, and that the induced mass-loss rate be such that the 'photon-tiring' parameter, m ≡ {\\dot{M}} GM/R L_o ≤ 1-1/Γ _o, ensuring the luminosity is sufficient to overcome the gravitational potential GM/R. Our analysis unifies previous super-Eddington wind models that either: (1) assumed a direct <span class="hlt">radiative</span> <span class="hlt">flux</span>-driving without accounting for the advection of <span class="hlt">radiative</span> enthalpy that can become important in such an optically thick flow; or (2) assumed that such super-Eddington outflows are adiabatic, neglecting the effects of the diffusive <span class="hlt">radiative</span> <span class="hlt">flux</span>. We show that these distinct models become applicable in the asymptotic limits of small versus large values of mΓo, respectively. By solving the coupled differential equations for <span class="hlt">radiative</span> diffusion and wind momentum, we obtain general solutions that effectively bridge the behaviours of these limiting models. Two key scaling results are for the terminal wind speed to escape speed, which is found to vary as v_∞^2/v_esc^2 = Γ _o/(1+m Γ _o) -1, and for the final observed luminosity Lobs, which for all allowed steady-solutions with m < 1 - 1/Γo exceeds the Eddington luminosity, Lobs > LEdd. Our super-Eddington wind solutions have potential applicability for modelling phases of eruptive mass-loss from massive stars, classical novae, and the remnants of stellar mergers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGP41A0954M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGP41A0954M"><span>New geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> map of Greenland and the Iceland hotspot track</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martos, Y. M.; Jordan, T. A.; Catalan, M.; Jordan, T. M.; Bamber, J. L.; Vaughan, D. G.</p> <p>2017-12-01</p> <p>Greenland is the second largest reservoir of water on Earth and about 80% of its surface is covered by ice. It is mainly composed of Archean blocks that collided during the Early Proterozoic. Indirect methods have been used to study its subglacial thermal conditions, geology and lithospheric structure. Numerous regions of basal melting are identified in the central and north Greenland but their relationship with geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> is not yet clear. Crustal thickness derived by seismology and gravity data are consistent, showing no significant lateral variations, and providing average values of about 40 and 36 km respectively. Even though Greenland is considered a craton its crust has been affected by the presume passage of the Iceland hotspot since at least 100 Ma. Here we present the newest and highest resolution Curie Depth and geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> maps for Greenland as well as their associated uncertainties. For estimating the Curie Depths we applied spectral methods to aeromagnetic data from the World Digital Magnetic Anomaly Map WDMAM2.0. Calculated Curie Depths vary from 25 to 50 km with shallower values located to the east. A thermal model is built based on the 1D <span class="hlt">heat</span> conduction equation and considering steady state conditions. The thermal parameters are then optimized using local values derived from direct measurements, temperature profiles and more indirect methods such as radar imaging. The <span class="hlt">heat</span> <span class="hlt">flux</span> distribution shows higher spatial variability and a very different pattern than previously proposed and with values of 50-80 mW/m2. We identify a NW-SE high <span class="hlt">heat</span> <span class="hlt">flux</span> feature crossing Greenland which we correlate with the Iceland hotspot track. Additionally, to evaluate the lithospheric structure we calculate the Bouguer anomaly from GOCO5s satellite free air data and construct several gravity models across the proposed hotspot track. We show that a dense lower crust body in the same location the high <span class="hlt">heat</span> <span class="hlt">flux</span> trend is permissible from a gravimetric</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvA..97d2508R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvA..97d2508R"><span>Landauer's formula breakdown for <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer and nonequilibrium Casimir forces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rubio López, Adrián E.; Poggi, Pablo M.; Lombardo, Fernando C.; Giannini, Vincenzo</p> <p>2018-04-01</p> <p>In this work, we analyze the incidence of the plates' thickness on the Casimir force and <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer for a configuration of parallel plates in a nonequilibrium scenario, relating to Lifshitz's and Landauer's formulas. From a first-principles canonical quantization scheme for the study of the matter-field interaction, we give closed-form expressions for the nonequilibrium Casimir force and the <span class="hlt">heat</span> transfer between plates of thicknesses dL,dR . We distinguish three different contributions to the Casimir force and the <span class="hlt">heat</span> transfer in the general nonequilibrium situation: two associated with each of the plates and one to the initial state of the field. We analyze the dependence of the Casimir force and <span class="hlt">heat</span> transfer with the plate thickness (setting dL=dR≡d ), showing the scale at which each magnitude converges to the value of infinite thickness (d →+∞ ) and how to correctly reproduce the nonequilibrium Lifshitz's formula. For the <span class="hlt">heat</span> transfer, we show that Landauer's formula does not apply to every case (where the three contributions are present), but it is correct for some specific situations. We also analyze the interplay of the different contributions for realistic experimental and nanotechnological conditions, showing the impact of the thickness in the measurements. For small thicknesses (compared to the separation distance), the plates act to decrease the background blackbody <span class="hlt">flux</span>, while for large thicknesses the <span class="hlt">heat</span> is given by the baths' contribution only. The combination of these behaviors allows for the possibility, on one hand, of having a tunable minimum in the <span class="hlt">heat</span> transfer that is experimentally attainable and observable for metals and, on the other hand, of having vanishing <span class="hlt">heat</span> <span class="hlt">flux</span> in the gap when those difference are of opposite signs (thermal shielding). These features turns out to be relevant for nanotechnological applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54..363K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54..363K"><span>An experimental investigation devoted to determine <span class="hlt">heat</span> transfer characteristics in a radiant ceiling <span class="hlt">heating</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koca, Aliihsan; Acikgoz, Ozgen; Çebi, Alican; Çetin, Gürsel; Dalkilic, Ahmet Selim; Wongwises, Somchai</p> <p>2018-02-01</p> <p>Investigations on <span class="hlt">heated</span> ceiling method can be considered as a new research area in comparison to the common wall <span class="hlt">heating</span>-cooling and cooled ceiling methods. In this work, <span class="hlt">heat</span> transfer characteristics of a <span class="hlt">heated</span> radiant ceiling system was investigated experimentally. There were different configurations for a single room design in order to determine the convective and <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer rates. Almost all details on the arrangement of the test chamber, hydraulic circuit and radiant panels, the measurement equipment and experimental method including uncertainty analysis were revealed in detail indicating specific international standards. Total <span class="hlt">heat</span> transfer amount from the panels were calculated as the sum of <span class="hlt">radiation</span> to the unheated surfaces, convection to the air, and conduction <span class="hlt">heat</span> loss from the backside of the panels. Integral expression of the view factors was calculated by means of the numerical evaluations using Matlab code. By means of this experimental chamber, the <span class="hlt">radiative</span>, convective and total <span class="hlt">heat</span>-transfer coefficient values along with the <span class="hlt">heat</span> <span class="hlt">flux</span> values provided from the ceiling to the unheated surrounding surfaces have been calculated. Moreover, the details of 28 different experimental case study measurements from the experimental chamber including the convective, <span class="hlt">radiative</span> and total <span class="hlt">heat</span> <span class="hlt">flux</span>, and <span class="hlt">heat</span> output results are given in a Table for other researchers to validate their theoretical models and empirical correlations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872555','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872555"><span>Method of fission <span class="hlt">heat</span> <span class="hlt">flux</span> determination from experimental data</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Paxton, Frank A.</p> <p>1999-01-01</p> <p>A method is provided for determining the fission <span class="hlt">heat</span> <span class="hlt">flux</span> of a prime specimen inserted into a specimen of a test reactor. A pair of thermocouple test specimens are positioned at the same level in the holder and a determination is made of various experimental data including the temperature of the thermocouple test specimens, the temperature of bulk water channels located in the test holder, the gamma scan count ratios for the thermocouple test specimens and the prime specimen, and the thicknesses of the outer clads, the fuel fillers, and the backclad of the thermocouple test specimen. Using this experimental data, the absolute value of the fission <span class="hlt">heat</span> <span class="hlt">flux</span> for the thermocouple test specimens and prime specimen can be calculated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840016704','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840016704"><span>Performance of thermal barrier coatings in high <span class="hlt">heat</span> <span class="hlt">flux</span> environments</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, R. A.; Berndt, C. C.</p> <p>1984-01-01</p> <p>Thermal barrier coatings were exposed to the high temperature and high <span class="hlt">heat</span> <span class="hlt">flux</span> produced by a 30 kW plasma torch. Analysis of the specimen <span class="hlt">heating</span> rates indicates that the temperature drop across the thickness of the 0.038 cm ceramic layer was about 1100 C after 0.5 sec in the flame. An as-sprayed ZrO2-8%Y2O3 specimens survived 3000 of the 0.5 sec cycles with failing. Surface spalling was observed when 2.5 sec cycles were employed but this was attributed to uneven <span class="hlt">heating</span> caused by surface roughness. This surface spalling was prevented by smoothing the surface with silicon carbide paper or by laser glazing. A coated specimen with no surface modification but which was <span class="hlt">heat</span> treated in argon also did not surface spall. <span class="hlt">Heat</span> treatment in air led to spalling in as early as 2 cycle from <span class="hlt">heating</span> stresses. Failures at edges were investigated and shown to be a minor source of concern. Ceramic coatings formed from ZrO2-12%Y2O3 or ZrO2-20%Y2O3 were shown to be unsuited for use under the high <span class="hlt">heat</span> <span class="hlt">flux</span> conditions of this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24360191','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24360191"><span>Assessment of land surface temperature and <span class="hlt">heat</span> <span class="hlt">fluxes</span> over Delhi using remote sensing data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chakraborty, Surya Deb; Kant, Yogesh; Mitra, Debashis</p> <p>2015-01-15</p> <p>Surface energy processes has an essential role in urban weather, climate and hydrosphere cycles, as well in urban <span class="hlt">heat</span> redistribution. The research was undertaken to analyze the potential of Landsat and MODIS data in retrieving biophysical parameters in estimating land surface temperature & <span class="hlt">heat</span> <span class="hlt">fluxes</span> diurnally in summer and winter seasons of years 2000 and 2010 and understanding its effect on anthropogenic <span class="hlt">heat</span> disturbance over Delhi and surrounding region. Results show that during years 2000-2010, settlement and industrial area increased from 5.66 to 11.74% and 4.92 to 11.87% respectively which in turn has direct effect on land surface temperature (LST) and <span class="hlt">heat</span> <span class="hlt">fluxes</span> including anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span>. Based on the energy balance model for land surface, a method to estimate the increase in anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> (Has) has been proposed. The settlement and industrial areas has higher amounts of energy consumed and has high values of Has in all seasons. The comparison of satellite derived LST with that of field measured values show that Landsat estimated values are in close agreement within error of ±2 °C than MODIS with an error of ±3 °C. It was observed that, during 2000 and 2010, the average change in surface temperature using Landsat over settlement & industrial areas of both seasons is 1.4 °C & for MODIS data is 3.7 °C. The seasonal average change in anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> (Has) estimated using Landsat & MODIS is up by around 38 W/m(2) and 62 W/m(2) respectively while higher change is observed over settlement and concrete structures. The study reveals that the dynamic range of Has values has increased in the 10 year period due to the strong anthropogenic influence over the area. The study showed that anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> is an indicator of the strength of urban <span class="hlt">heat</span> island effect, and can be used to quantify the magnitude of the urban <span class="hlt">heat</span> island effect. Copyright © 2013 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920002282&hterms=asphalt&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dasphalt','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920002282&hterms=asphalt&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dasphalt"><span>Urban <span class="hlt">heat</span> island</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kim, Hongsuk H.</p> <p>1991-01-01</p> <p>The phenomenon of urban <span class="hlt">heat</span> island was investigated by the use of LANDSAT Thematic Mapper data sets collected over the metropolitan area of Washington DC (U.S.). By combining the retrieved spectral albedos and temperatures, urban modification on <span class="hlt">radiation</span> budgets of five surface categories were analyzed. The surface <span class="hlt">radiation</span> budget imagery of the area show that urban <span class="hlt">heating</span> is attributable to a large <span class="hlt">heat</span> <span class="hlt">flux</span> from the rapidly <span class="hlt">heating</span> surfaces of asphalt, bare soil and short grass. In summer, symptoms of diurnal <span class="hlt">heating</span> begin to appear by mid morning and can be about 10 degrees warmer than nearby woodlands in summer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H41D0901Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H41D0901Z"><span>Comparison of Sensible <span class="hlt">Heat</span> <span class="hlt">Flux</span> from Eddy Covariance and Scintillometer over different land surface conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zeweldi, D. A.; Gebremichael, M.; Summis, T.; Wang, J.; Miller, D.</p> <p>2008-12-01</p> <p>The large source of uncertainty in satellite-based evapotranspiration algorithm results from the estimation of sensible <span class="hlt">heat</span> <span class="hlt">flux</span> H. Traditionally eddy covariance sensors, and recently large-aperture scintillometers, have been used as ground truth to evaluate satellite-based H estimates. The two methods rely on different physical measurement principles, and represent different foot print sizes. In New Mexico, we conducted a field campaign during summer 2008 to compare H estimates obtained from the eddy covariance and scintillometer methods. During this field campaign, we installed sonic anemometers; one propeller eddy covariance (OPEC) equipped with net radiometer and soil <span class="hlt">heat</span> <span class="hlt">flux</span> sensors; large aperture scintillometer (LAS); and weather station consisting of wind speed, direction and <span class="hlt">radiation</span> sensors over three different experimental areas consisting of different roughness conditions (desert, irrigated area and lake). Our results show the similarities and differences in H estimates obtained from these various methods over the different land surface conditions. Further, our results show that the H estimates obtained from the LAS agree with those obtained from the eddy covariance method when high frequency thermocouple temperature, instead of the typical weather station temperature measurements, is used in the LAS analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.214..265V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.214..265V"><span>Temperature and <span class="hlt">heat</span> <span class="hlt">flux</span> scaling laws for isoviscous, infinite Prandtl number mixed <span class="hlt">heating</span> convection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vilella, Kenny; Deschamps, Frédéric</p> <p>2018-07-01</p> <p>Thermal evolution of terrestrial planets is controlled by <span class="hlt">heat</span> transfer through their silicate mantles. A suitable framework for modelling this <span class="hlt">heat</span> transport is a system including bottom <span class="hlt">heating</span> (from the core) and internal <span class="hlt">heating</span>, for example, generated by secular cooling or by the decay of radioactive isotopes. The mechanism of <span class="hlt">heat</span> transfer depends on the physical properties of the system. In systems where convection is able to operate, two different regimes are possible depending on the relative amount of bottom and internal <span class="hlt">heating</span>. For moderate internal <span class="hlt">heating</span> rates, the system is composed of active hot upwellings and cold downwellings. For large internal <span class="hlt">heating</span> rates, the bottom <span class="hlt">heat</span> <span class="hlt">flux</span> becomes negative and the system is only composed of active cold downwellings. Here, we build theoretical scaling laws for both convective regimes following the approach of Vilella & Kaminski (2017), which links the surface <span class="hlt">heat</span> <span class="hlt">flux</span> and the temperature jump across both the top and the bottom thermal boundary layer (TBL) to the Rayleigh number and the dimensionless internal <span class="hlt">heating</span> rate. Theoretical predictions are then verified against numerical simulations performed in 2-D and 3-D Cartesiangeometry, and covering a large range of the parameter space. Our theoretical scaling laws are more successful in predicting the thermal structure of systems with large internal <span class="hlt">heating</span> rates than that of systems with no or moderate internal <span class="hlt">heating</span>. The differences between moderate and large internal <span class="hlt">heating</span> rates are interpreted as differences in the mechanisms generating thermal instabilities. We identified three mechanisms: conductive growth of the TBL, instability impacting, and TBL erosion, the last two being present only for moderate internal <span class="hlt">heating</span> rates, in which hot plumes are generated at the bottom of the system and are able to reach the surface. Finally, we apply our scaling laws to the evolution of the early Earth, proposing a new model for the cooling of the primordial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.tmp..134V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.tmp..134V"><span>Temperature and <span class="hlt">heat</span> <span class="hlt">flux</span> scaling laws for isoviscous, infinite Prandtl number mixed <span class="hlt">heating</span> convection.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vilella, Kenny; Deschamps, Frederic</p> <p>2018-04-01</p> <p>Thermal evolution of terrestrial planets is controlled by <span class="hlt">heat</span> transfer through their silicate mantles. A suitable framework for modelling this <span class="hlt">heat</span> transport is a system including bottom <span class="hlt">heating</span> (from the core) and internal <span class="hlt">heating</span>, e.g., generated by secular cooling or by the decay of radioactive isotopes. The mechanism of <span class="hlt">heat</span> transfer depends on the physical properties of the system. In systems where convection is able to operate, two different regimes are possible depending on the relative amount of bottom and internal <span class="hlt">heating</span>. For moderate internal <span class="hlt">heating</span> rates, the system is composed of active hot upwellings and cold downwellings. For large internal <span class="hlt">heating</span> rates, the bottom <span class="hlt">heat</span> <span class="hlt">flux</span> becomes negative and the system is only composed of active cold downwellings. Here, we build theoretical scaling laws for both convective regimes following the approach of Vilella & Kaminski (2017), which links the surface <span class="hlt">heat</span> <span class="hlt">flux</span> and the temperature jump across both the top and bottom thermal boundary layer (TBL) to the Rayleigh number and the dimensionless internal <span class="hlt">heating</span> rate. Theoretical predictions are then verified against numerical simulations performed in 2D and 3D-Cartesian geometry, and covering a large range of the parameter space. Our theoretical scaling laws are more successful in predicting the thermal structure of systems with large internal <span class="hlt">heating</span> rates than that of systems with no or moderate internal <span class="hlt">heating</span>. The differences between moderate and large internal <span class="hlt">heating</span> rates are interpreted as differences in the mechanisms generating thermal instabilities. We identified three mechanisms: conductive growth of the TBL, instability impacting, and TBL erosion, the last two being present only for moderate internal <span class="hlt">heating</span> rates, in which hot plumes are generated at the bottom of the system and are able to reach the surface. Finally, we apply our scaling laws to the evolution of the early Earth, proposing a new model for the cooling of the primordial magma ocean</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3373A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3373A"><span>Estimating sensible <span class="hlt">heat</span> <span class="hlt">flux</span> in agricultural screenhouses by the <span class="hlt">flux</span>-variance and half-order time derivative methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Achiman, Ori; Mekhmandarov, Yonatan; Pirkner, Moran; Tanny, Josef</p> <p>2016-04-01</p> <p>Previous studies have established that the eddy covariance (EC) technique is reliable for whole canopy <span class="hlt">flux</span> measurements in agricultural crops covered by porous screens, i.e., screenhouses. Nevertheless, the eddy covariance technique remains difficult to apply in the farm due to costs, operational complexity, and post-processing of data - thereby inviting alternative techniques to be developed. The subject of this research was estimating the sensible <span class="hlt">heat</span> <span class="hlt">flux</span> by two turbulent transport techniques, namely, <span class="hlt">Flux</span>-Variance (FV) and Half-order Time Derivative (HTD) whose instrumentation needs and operational demands are not as elaborate as the EC. The FV is based on the standard deviation of high frequency temperature measurements and a similarity constant CT. The HTD method requires mean air temperature and air velocity data. Measurements were carried out in two types of screenhouses: (i) a banana plantation in a light shading (8%) screenhouse; (ii) a pepper crop in a dense insect-proof (50-mesh) screenhouse. In each screenhouse an EC system was deployed for reference and high frequency air temperature measurements were conducted using miniature thermocouples installed at several levels to identify the optimal measurement height. Quality control analysis showed that turbulence development and flow stationarity conditions in the two structures were suitable for <span class="hlt">flux</span> measurements by the EC technique. Energy balance closure slopes in the two screenhouses were larger than 0.71, in agreement with results for open fields. Regressions between sensible <span class="hlt">heat</span> <span class="hlt">flux</span> measured by EC and estimated by FV resulted with CT values that were usually larger than 1, the typical value for open field. In both shading and insect-proof screenhouses the CT value generally increased with height. The optimal measurement height, defined as the height with maximum R2 of the regression between EC and FV sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span>, was just above the screen. CT value at optimal height was 2.64 and 1.52 for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRC..121.8419K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRC..121.8419K"><span>Reconciling estimates of the ratio of <span class="hlt">heat</span> and salt <span class="hlt">fluxes</span> at the ice-ocean interface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keitzl, T.; Mellado, J. P.; Notz, D.</p> <p>2016-12-01</p> <p>The <span class="hlt">heat</span> exchange between floating ice and the underlying ocean is determined by the interplay of diffusive <span class="hlt">fluxes</span> directly at the ice-ocean interface and turbulent <span class="hlt">fluxes</span> away from it. In this study, we examine this interplay through direct numerical simulations of free convection. Our results show that an estimation of the interface <span class="hlt">flux</span> ratio based on direct measurements of the turbulent <span class="hlt">fluxes</span> can be difficult because the <span class="hlt">flux</span> ratio varies with depth. As an alternative, we present a consistent evaluation of the <span class="hlt">flux</span> ratio based on the total <span class="hlt">heat</span> and salt <span class="hlt">fluxes</span> across the boundary layer. This approach allows us to reconcile previous estimates of the ice-ocean interface conditions. We find that the ratio of <span class="hlt">heat</span> and salt <span class="hlt">fluxes</span> directly at the interface is 83-100 rather than 33 as determined by previous turbulence measurements in the outer layer. This can cause errors in the estimated ice-ablation rate from field measurements of up to 40% if they are based on the three-equation formulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27285827','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27285827"><span>Experimental Methodology for Estimation of Local <span class="hlt">Heat</span> <span class="hlt">Fluxes</span> and Burning Rates in Steady Laminar Boundary Layer Diffusion Flames.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Singh, Ajay V; Gollner, Michael J</p> <p>2016-06-01</p> <p>Modeling the realistic burning behavior of condensed-phase fuels has remained out of reach, in part because of an inability to resolve the complex interactions occurring at the interface between gas-phase flames and condensed-phase fuels. The current research provides a technique to explore the dynamic relationship between a combustible condensed fuel surface and gas-phase flames in laminar boundary layers. Experiments have previously been conducted in both forced and free convective environments over both solid and liquid fuels. A unique methodology, based on the Reynolds Analogy, was used to estimate local mass burning rates and flame <span class="hlt">heat</span> <span class="hlt">fluxes</span> for these laminar boundary layer diffusion flames utilizing local temperature gradients at the fuel surface. Local mass burning rates and convective and <span class="hlt">radiative</span> <span class="hlt">heat</span> feedback from the flames were measured in both the pyrolysis and plume regions by using temperature gradients mapped near the wall by a two-axis traverse system. These experiments are time-consuming and can be challenging to design as the condensed fuel surface burns steadily for only a limited period of time following ignition. The temperature profiles near the fuel surface need to be mapped during steady burning of a condensed fuel surface at a very high spatial resolution in order to capture reasonable estimates of local temperature gradients. Careful corrections for <span class="hlt">radiative</span> <span class="hlt">heat</span> losses from the thermocouples are also essential for accurate measurements. For these reasons, the whole experimental setup needs to be automated with a computer-controlled traverse mechanism, eliminating most errors due to positioning of a micro-thermocouple. An outline of steps to reproducibly capture near-wall temperature gradients and use them to assess local burning rates and <span class="hlt">heat</span> <span class="hlt">fluxes</span> is provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850007787','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850007787"><span>High temperature thermocouple and <span class="hlt">heat</span> <span class="hlt">flux</span> gauge using a unique thin film-hardware hot juncture</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liebert, C. H.; Holanda, R.; Hippensteele, S. A.; Andracchio, C. A.</p> <p>1984-01-01</p> <p>A special thin film-hardware material thermocouple (TC) and <span class="hlt">heat</span> <span class="hlt">flux</span> gauge concept for a reasonably high temperature and high <span class="hlt">flux</span> flat plate <span class="hlt">heat</span> transfer experiment was fabricated and tested to gauge temperatures of 911 K. This concept was developed for minimal disturbance of boundary layer temperature and flow over the plates and minimal disturbance of <span class="hlt">heat</span> <span class="hlt">flux</span> through the plates. Comparison of special <span class="hlt">heat</span> <span class="hlt">flux</span> gauge Stanton number output at steady-state conditions with benchmark literature data was good and agreement was within a calculated uncertainty of the measurement system. Also, good agreement of special TC and standard TC outputs was obtained and the results are encouraging. Oxidation of thin film thermoelements was a primary failure mode after about 5 of operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860028321&hterms=911&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D911','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860028321&hterms=911&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D911"><span>High-temperature thermocouple and <span class="hlt">heat</span> <span class="hlt">flux</span> gauge using a unique thin film-hardware hot junction</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liebert, C. H.; Holanda, R.; Hippensteele, S. A.; Andracchio, C. A.</p> <p>1985-01-01</p> <p>A special thin film-hardware material thermocouple (TC) and <span class="hlt">heat</span> <span class="hlt">flux</span> gauge concept for a reasonably high temperature and high <span class="hlt">flux</span> flat plate <span class="hlt">heat</span> transfer experiment was fabricated and tested to gauge temperatures of 911 K. This concept was developed for minimal disturbance of boundary layer temperature and flow over the plates and minimal disturbance of <span class="hlt">heat</span> <span class="hlt">flux</span> through the plates. Comparison of special <span class="hlt">heat</span> <span class="hlt">flux</span> gauge Stanton number output at steady-state conditions with benchmark literature data was good and agreement was within a calculated uncertainty of the measurement system. Also, good agreement of special TC and standard TC outputs was obtained and the results are encouraging. Oxidation of thin film thermoelements was a primary failure mode after about 5 of operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009HESSD...6.4619M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009HESSD...6.4619M"><span>Estimating surface <span class="hlt">fluxes</span> over middle and upper streams of the Heihe River Basin with ASTER imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, W.; Ma, Y.; Hu, Z.; Su, B.; Wang, J.; Ishikawa, H.</p> <p>2009-06-01</p> <p>Surface <span class="hlt">fluxes</span> are important boundary conditions for climatological modeling and the Asian monsoon system. Recent availability of high-resolution, multi-band imagery from the ASTER (Advanced Space-borne Thermal Emission and Reflection Radiometer) sensor has enabled us to estimate surface <span class="hlt">fluxes</span> to bridge the gap between local scale <span class="hlt">flux</span> measurements using micrometeorological instruments and regional scale land-atmosphere exchanges of water and <span class="hlt">heat</span> <span class="hlt">fluxes</span> that are fundamental for the understanding of the water cycle in the Asian monsoon system. A Surface Energy Balance System (SEBS) method based on ASTER data and field observations has been proposed and tested for deriving net <span class="hlt">radiation</span> <span class="hlt">flux</span> (Rn), soil <span class="hlt">heat</span> <span class="hlt">flux</span> (G0), sensible <span class="hlt">heat</span> <span class="hlt">flux</span> (H) and latent <span class="hlt">heat</span> <span class="hlt">flux</span> (λ E) over heterogeneous land surface in this paper. As a case study, the methodology was applied to the experimental area of the WATER (Watershed Allied Telemetry Experimental Research), located at the mid-to-upstream sections of the Heihe River, northwest China. The ASTER data of 3 May and 4 June in 2008 was used in this paper for the case of mid-to-upstream sections of the Heihe River Basin. To validate the proposed methodology, the ground-measured land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> (net <span class="hlt">radiation</span> <span class="hlt">flux</span> (Rn), soil <span class="hlt">heat</span> <span class="hlt">flux</span> (G0), sensible <span class="hlt">heat</span> <span class="hlt">flux</span> (H) and latent <span class="hlt">heat</span> <span class="hlt">flux</span> (λ E)) were compared to the ASTER derived values. The results show that the derived surface variables and land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> in different months over the study area are in good accordance with the land surface status. It is therefore concluded that the proposed methodology is successful for the retrieval of land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> using the ASTER data and filed observation over the study area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/111422','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/111422"><span>General correlation for prediction of critical <span class="hlt">heat</span> <span class="hlt">flux</span> ratio in water cooled channels</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Pernica, R.; Cizek, J.</p> <p>1995-09-01</p> <p>The paper present the general empirical Critical <span class="hlt">Heat</span> <span class="hlt">Flux</span> Ration (CHFR) correlation which is valid for vertical water upflow through tubes, internally <span class="hlt">heated</span> concentric annuli and rod bundles geometries with both wide and very tight square and triangular rods lattices. The proposed general PG correlation directly predicts the CHFR, it comprises axial and radial non-uniform <span class="hlt">heating</span>, and is valid in a wider range of thermal hydraulic conditions than previously published critical <span class="hlt">heat</span> <span class="hlt">flux</span> correlations. The PG correlation has been developed using the critical <span class="hlt">heat</span> <span class="hlt">flux</span> Czech data bank which includes more than 9500 experimental data on tubes, 7600 data onmore » rod bundles and 713 data on internally <span class="hlt">heated</span> concentric annuli. Accuracy of the CHFR prediction, statistically assessed by the constant dryout conditions approach, is characterized by the mean value nearing 1.00 and the standard deviation less than 0.06. Moverover, a subchannel form of the PG correlations is statistically verified on Westinghouse and Combustion Engineering rod bundle data bases, i.e. more than 7000 experimental CHF points of Columbia University data bank were used.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70032127','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70032127"><span>Using <span class="hlt">heat</span> to characterize streambed water <span class="hlt">flux</span> variability in four stream reaches</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Essaid, H.I.; Zamora, C.M.; McCarthy, K.A.; Vogel, J.R.; Wilson, J.T.</p> <p>2008-01-01</p> <p>Estimates of streambed water <span class="hlt">flux</span> are needed for the interpretation of streambed chemistry and reactions. Continuous temperature and head monitoring in stream reaches within four agricultural watersheds (Leary Weber Ditch, IN; Maple Creek, NE; DR2 Drain, WA; and Merced River, CA) allowed <span class="hlt">heat</span> to be used as a tracer to study the temporal and spatial variability of <span class="hlt">fluxes</span> through the streambed. Synoptic methods (seepage meter and differential discharge measurements) were compared with estimates obtained by using <span class="hlt">heat</span> as a tracer. Water <span class="hlt">flux</span> was estimated by modeling one-dimensional vertical flow of water and <span class="hlt">heat</span> using the model VS2DH. <span class="hlt">Flux</span> was influenced by physical heterogeneity of the stream channel and temporal variability in stream and ground-water levels. During most of the study period (April-December 2004), <span class="hlt">flux</span> was upward through the streambeds. At the IN, NE, and CA sites, high-stage events resulted in rapid reversal of flow direction inducing short-term surface-water flow into the streambed. During late summer at the IN site, regional ground-water levels dropped, leading to surface-water loss to ground water that resulted in drying of the ditch. Synoptic measurements of <span class="hlt">flux</span> generally supported the model <span class="hlt">flux</span> estimates. Water flow through the streambed was roughly an order of magnitude larger in the humid basins (IN and NE) than in the arid basins (WA and CA). Downward <span class="hlt">flux</span>, in response to sudden high streamflows, and seasonal variability in <span class="hlt">flux</span> was most pronounced in the humid basins and in high conductivity zones in the streambed. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012Cryo...52..505I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012Cryo...52..505I"><span>Integrated computational study of ultra-high <span class="hlt">heat</span> <span class="hlt">flux</span> cooling using cryogenic micro-solid nitrogen spray</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ishimoto, Jun; Oh, U.; Tan, Daisuke</p> <p>2012-10-01</p> <p>A new type of ultra-high <span class="hlt">heat</span> <span class="hlt">flux</span> cooling system using the atomized spray of cryogenic micro-solid nitrogen (SN2) particles produced by a superadiabatic two-fluid nozzle was developed and numerically investigated for application to next generation super computer processor thermal management. The fundamental characteristics of <span class="hlt">heat</span> transfer and cooling performance of micro-solid nitrogen particulate spray impinging on a <span class="hlt">heated</span> substrate were numerically investigated and experimentally measured by a new type of integrated computational-experimental technique. The employed Computational Fluid Dynamics (CFD) analysis based on the Euler-Lagrange model is focused on the cryogenic spray behavior of atomized particulate micro-solid nitrogen and also on its ultra-high <span class="hlt">heat</span> <span class="hlt">flux</span> cooling characteristics. Based on the numerically predicted performance, a new type of cryogenic spray cooling technique for application to a ultra-high <span class="hlt">heat</span> power density device was developed. In the present integrated computation, it is clarified that the cryogenic micro-solid spray cooling characteristics are affected by several factors of the <span class="hlt">heat</span> transfer process of micro-solid spray which impinges on <span class="hlt">heated</span> surface as well as by atomization behavior of micro-solid particles. When micro-SN2 spraying cooling was used, an ultra-high cooling <span class="hlt">heat</span> <span class="hlt">flux</span> level was achieved during operation, a better cooling performance than that with liquid nitrogen (LN2) spray cooling. As micro-SN2 cooling has the advantage of direct latent <span class="hlt">heat</span> transport which avoids the film boiling state, the ultra-short time scale <span class="hlt">heat</span> transfer in a thin boundary layer is more possible than in LN2 spray. The present numerical prediction of the micro-SN2 spray cooling <span class="hlt">heat</span> <span class="hlt">flux</span> profile can reasonably reproduce the measurement results of cooling wall <span class="hlt">heat</span> <span class="hlt">flux</span> profiles. The application of micro-solid spray as a refrigerant for next generation computer processors is anticipated, and its ultra-high <span class="hlt">heat</span> <span class="hlt">flux</span> technology is expected</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19880733','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19880733"><span>Transectional <span class="hlt">heat</span> transfer in thermoregulating bigeye tuna (Thunnus obesus) - a 2D <span class="hlt">heat</span> <span class="hlt">flux</span> model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boye, Jess; Musyl, Michael; Brill, Richard; Malte, Hans</p> <p>2009-11-01</p> <p>We developed a 2D <span class="hlt">heat</span> <span class="hlt">flux</span> model to elucidate routes and rates of <span class="hlt">heat</span> transfer within bigeye tuna Thunnus obesus Lowe 1839 in both steady-state and time-dependent settings. In modeling the former situation, we adjusted the efficiencies of <span class="hlt">heat</span> conservation in the red and the white muscle so as to make the output of the model agree as closely as possible with observed cross-sectional isotherms. In modeling the latter situation, we applied the <span class="hlt">heat</span> exchanger efficiencies from the steady-state model to predict the distribution of temperature and <span class="hlt">heat</span> <span class="hlt">fluxes</span> in bigeye tuna during their extensive daily vertical excursions. The simulations yielded a close match to the data recorded in free-swimming fish and strongly point to the importance of the <span class="hlt">heat</span>-producing and <span class="hlt">heat</span>-conserving properties of the white muscle. The best correspondence between model output and observed data was obtained when the countercurrent <span class="hlt">heat</span> exchangers in the blood flow pathways to the red and white muscle retained 99% and 96% (respectively) of the <span class="hlt">heat</span> produced in these tissues. Our model confirms that the ability of bigeye tuna to maintain elevated muscle temperatures during their extensive daily vertical movements depends on their ability to rapidly modulate <span class="hlt">heating</span> and cooling rates. This study shows that the differential cooling and <span class="hlt">heating</span> rates could be fully accounted for by a mechanism where blood flow to the swimming muscles is either exclusively through the <span class="hlt">heat</span> exchangers or completely shunted around them, depending on the ambient temperature relative to the body temperature. Our results therefore strongly suggest that such a mechanism is involved in the extensive physiological thermoregulatory abilities of endothermic bigeye tuna.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhPl...23e2502Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhPl...23e2502Y"><span>The study of <span class="hlt">heat</span> <span class="hlt">flux</span> for disruption on experimental advanced superconducting tokamak</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Zhendong; Fang, Jianan; Gong, Xianzu; Gan, Kaifu; Luo, Jiarong; Zhao, Hailin; Cui, Zhixue; Zhang, Bin; Chen, Meiwen</p> <p>2016-05-01</p> <p>Disruption of the plasma is one of the most dangerous instabilities in tokamak. During the disruption, most of the plasma thermal energy is lost, which causes damages to the plasma facing components. Infrared (IR) camera is an effective tool to detect the temperature distribution on the first wall, and the energy deposited on the first wall can be calculated from the surface temperature profile measured by the IR camera. This paper concentrates on the characteristics of <span class="hlt">heat</span> <span class="hlt">flux</span> distribution onto the first wall under different disruptions, including the minor disruption and the vertical displacement events (VDE) disruption. Several minor disruptions have been observed before the major disruption under the high plasma density in experimental advanced superconducting tokamak. During the minor disruption, the <span class="hlt">heat</span> <span class="hlt">fluxes</span> are mainly deposited on the upper/lower divertors. The magnetic configuration prior to the minor disruption is a lower single null with the radial distance between the two separatrices in the outer midplane dRsep = -2 cm, while it changes to upper single null (dRsep = 1.4 cm) during the minor disruption. As for the VDE disruption, the spatial distribution of <span class="hlt">heat</span> <span class="hlt">flux</span> exhibits strong toroidal and radial nonuniformity, and the maximum <span class="hlt">heat</span> <span class="hlt">flux</span> received on the dome plate can be up to 11 MW/m2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040161241','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040161241"><span>Effects of <span class="hlt">Heat</span> <span class="hlt">Flux</span>, Oxygen Concentration and Glass Fiber Volume Fraction on Pyrolysate Mass <span class="hlt">Flux</span> from Composite Solids</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rich, D. B.; Lautenberger, C. W.; Yuan, Z.; Fernandez-Pello, A. C.</p> <p>2004-01-01</p> <p>Experimental work on the effects of <span class="hlt">heat</span> <span class="hlt">flux</span>, oxygen concentration and glass fiber volume fraction on pyrolysate mass <span class="hlt">flux</span> from samples of polypropylene/glass fiber composite (PP/G) is underway. The research is conducted as part of a larger project to develop a test methodology for flammability of materials, particularly composites, in the microgravity and variable oxygen concentration environment of spacecraft and space structures. Samples of PP/G sized at 30 x 30 x 10 mm are flush mounted in a flow tunnel, which provides a flow of oxidizer over the surface of the samples at a fixed value of 1 m/s and oxygen concentrations varying between 18 and 30%. Each sample is exposed to a constant external radiant <span class="hlt">heat</span> <span class="hlt">flux</span> at a given value, which varies between tests from 10 to 24 kW/sq m. Continuous sample mass loss and surface temperature measurements are recorded for each test. Some tests are conducted with an igniter and some are not. In the former case, the research goal is to quantify the critical mass <span class="hlt">flux</span> at ignition for the various environmental and material conditions described above. The later case generates a wider range of mass <span class="hlt">flux</span> rates than those seen prior to ignition, providing an opportunity to examine the protective effects of blowing on oxidative pyrolysis and <span class="hlt">heating</span> of the surface. Graphs of surface temperature and sample mass loss vs. time for samples of 30% PPG at oxygen concentrations of 18 and 21% are presented in the figures below. These figures give a clear indication of the lower pyrolysis rate and extended time to ignition that accompany a lower oxygen concentration. Analysis of the mass <span class="hlt">flux</span> rate at the time of ignition gives good repeatability but requires further work to provide a clear indication of mass <span class="hlt">flux</span> trends accompanying changes in environmental and material properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040084193','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040084193"><span>Effects of <span class="hlt">Heat</span> <span class="hlt">Flux</span>, Oxygen Concentration and Glass Fiber Volume Fraction on Pyrolysate Mass <span class="hlt">Flux</span> from Composite Solids</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rich, D. B.; Lautenberger, C. W.; Yuan, Z.; Fernandez-Pello, A. C.</p> <p>2004-01-01</p> <p>Experimental work on the effects of <span class="hlt">heat</span> <span class="hlt">flux</span>, oxygen concentration and glass fiber volume fraction on pyrolysate mass <span class="hlt">flux</span> from samples of polypropylene/glass fiber composite (PP/G) is underway. The research is conducted as part of a larger project to develop a test methodology for flammability of materials, particularly composites, in the microgravity and variable oxygen concentration environment of spacecraft and space structures. Samples of PP/G sized at 30x30x10 mm are flush mounted in a flow tunnel, which provides a flow of oxidizer over the surface of the samples at a fixed value of 1 m/s and oxygen concentrations varying between 18 and 30%. Each sample is exposed to a constant external radiant <span class="hlt">heat</span> <span class="hlt">flux</span> at a given value, which varies between tests from 10 to 24 kW/m2. Continuous sample mass loss and surface temperature measurements are recorded for each test. Some tests are conducted with an igniter and some are not. In the former case, the research goal is to quantify the critical mass <span class="hlt">flux</span> at ignition for the various environmental and material conditions described above. The later case generates a wider range of mass <span class="hlt">flux</span> rates than those seen prior to ignition, providing an opportunity to examine the protective effects of blowing on oxidative pyrolysis and <span class="hlt">heating</span> of the surface. Graphs of surface temperature and sample mass loss vs. time for samples of 30% PPG at oxygen concentrations of 18 and 21% are presented in the figures below. These figures give a clear indication of the lower pyrolysis rate and extended time to ignition that accompany a lower oxygen concentration. Analysis of the mass <span class="hlt">flux</span> rate at the time of ignition gives good repeatability but requires further work to provide a clear indication of mass <span class="hlt">flux</span> trends accompanying changes in environmental and material properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993eash.book.....A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993eash.book.....A"><span>Experimental and analytical studies of high <span class="hlt">heat</span> <span class="hlt">flux</span> components for fusion experimental reactor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Araki, Masanori</p> <p>1993-03-01</p> <p>In this report, the experimental and analytical results concerning the development of plasma facing components of ITER are described. With respect to developing high <span class="hlt">heat</span> removal structures for the divertor plates, an externally-finned swirl tube was developed based on the results of critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) experiments on various tube structures. As the result, the burnout <span class="hlt">heat</span> <span class="hlt">flux</span>, which also indicates incident CHF, of 41 (+/-) 1 MW/sq m was achieved in the externally-finned swirl tube. The applicability of existing CHF correlations based on uniform <span class="hlt">heating</span> conditions was evaluated by comparing the CHF experimental data with the smooth and the externally-finned tubes under one-sided <span class="hlt">heating</span> condition. As the results, experimentally determined CHF data for straight tube show good agreement, for the externally-finned tube, no existing correlations are available for prediction of the CHF. With respect to the evaluation of the bonds between carbon-based material and <span class="hlt">heat</span> sink metal, results of brazing tests were compared with the analytical results by three dimensional model with temperature-dependent thermal and mechanical properties. Analytical results showed that residual stresses from brazing can be estimated by the analytical three directional stress values instead of the equivalent stress value applied. In the analytical study on the separatrix sweeping for effectively reducing surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> on the divertor plate, thermal response of the divertor plate was analyzed under ITER relevant <span class="hlt">heat</span> <span class="hlt">flux</span> conditions and has been tested. As the result, it has been demonstrated that application of the sweeping technique is very effective for improvement in the power handling capability of the divertor plate and that the divertor mock-up has withstood a large number of additional cyclic <span class="hlt">heat</span> loads.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110008740','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110008740"><span>Monitoring Delamination of Thermal Barrier Coatings During Interrupted High-<span class="hlt">Heat-Flux</span> Laser Testing using Luminescence Imaging</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Eldridge, Jeffrey I.; Zhu, Dongming; Wolfe, Douglas E.</p> <p>2011-01-01</p> <p>This presentation showed progress made in extending luminescence-base delamination monitoring to TBCs exposed to high <span class="hlt">heat</span> <span class="hlt">fluxes</span>, which is an environment that much better simulates actual turbine engine conditions. This was done by performing upconversion luminescence imaging during interruptions in laser testing, where a high-power CO2 laser was employed to create the desired <span class="hlt">heat</span> <span class="hlt">flux</span>. Upconverison luminescence refers to luminescence where the emission is at a higher energy (shorter wavelength) than the excitation. Since there will be negligible background emission at higher energies than the excitation, this methods produces superb contrast. Delamination contrast is produced because both the excitation and emission wavelengths are reflected at delamination cracks so that substantially higher luminescence intensity is observed in regions containing delamination cracks. Erbium was selected as the dopant for luminescence specifically because it exhibits upconversion luminescence. The high power CO2 10.6 micron wavelength laser facility at NASA GRC was used to produce the <span class="hlt">heat</span> <span class="hlt">flux</span> in combination with forced air backside cooling. Testing was performed at a lower (95 W/sq cm) and higher (125 W/sq cm) <span class="hlt">heat</span> <span class="hlt">flux</span> as well as furnace cycling at 1163C for comparison. The lower <span class="hlt">heat</span> <span class="hlt">flux</span> showed the same general behavior as furnace cycling, a gradual, "spotty" increase in luminescence associated with debond progression; however, a significant difference was a pronounced incubation period followed by acceleration delamination progression. These results indicate that extrapolating behavior from furnace cycling measurements will grossly overestimate remaining life under high <span class="hlt">heat</span> <span class="hlt">flux</span> conditions. The higher <span class="hlt">heat</span> <span class="hlt">flux</span> results were not only accelerated, but much different in character. Extreme bond coat rumpling occurred, and delamination propagation extended over much larger areas before precipitating macroscopic TBC failure. This indicates that under the higher <span class="hlt">heat</span> <span class="hlt">flux</span> (and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC21D0969Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC21D0969Z"><span>Uncertainty analysis of scintillometers methods in measuring sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> of forest ecosystem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zheng, N.</p> <p>2017-12-01</p> <p>Sensible <span class="hlt">heat</span> <span class="hlt">flux</span> (H) is one of the driving factors of surface turbulent motion and energy exchange. Therefore, it is particularly important to measure sensible <span class="hlt">heat</span> <span class="hlt">flux</span> accurately at the regional scale. However, due to the heterogeneity of the underlying surface, hydrothermal regime, and different weather conditions, it is difficult to estimate the represented <span class="hlt">flux</span> at the kilometer scale. The scintillometer have been developed into an effective and universal equipment for deriving <span class="hlt">heat</span> <span class="hlt">flux</span> at the regional-scale which based on the turbulence effect of light in the atmosphere since the 1980s. The parameter directly obtained by the scintillometer is the structure parameter of the refractive index of air based on the changes of light intensity fluctuation. Combine with parameters such as temperature structure parameter, zero-plane displacement, surface roughness, wind velocity, air temperature and the other meteorological data <span class="hlt">heat</span> <span class="hlt">fluxes</span> can be derived. These additional parameters increase the uncertainties of <span class="hlt">flux</span> because the difference between the actual feature of turbulent motion and the applicable conditions of turbulence theory. Most previous studies often focused on the constant <span class="hlt">flux</span> layers that are above the rough sub-layers and homogeneous flat surfaces underlying surfaces with suitable weather conditions. Therefore, the criteria and modified forms of key parameters are invariable. In this study, we conduct investment over the hilly area of northern China with different plants, such as cork oak, cedar-black and locust. On the basis of key research on the threshold and modified forms of saturation with different turbulence intensity, modified forms of Bowen ratio with different drying-and-wetting conditions, universal function for the temperature structure parameter under different atmospheric stability, the dominant sources of uncertainty will be determined. The above study is significant to reveal influence mechanism of uncertainty and explore influence</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160000481','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160000481"><span>Comparison of Turbulent <span class="hlt">Heat</span>-Transfer Results for Uniform Wall <span class="hlt">Heat</span> <span class="hlt">Flux</span> and Uniform Wall Temperature</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siegel, R.; Sparrow, E. M.</p> <p>1960-01-01</p> <p>The purpose of this note is to examine in a more precise way how the Nusselt numbers for turbulent <span class="hlt">heat</span> transfer in both the fully developed and thermal entrance regions of a circular tube are affected by two different wall boundary conditions. The comparisons are made for: (a) Uniform wall temperature (UWT); and (b) uniform wall <span class="hlt">heat</span> <span class="hlt">flux</span> (UHF). Several papers which have been concerned with the turbulent thermal entrance region problem are given. 1 Although these analyses have all utilized an eigenvalue formulation for the thermal entrance region there were differences in the choices of eddy diffusivity expressions, velocity distributions, and methods for carrying out the numerical solutions. These differences were also found in the fully developed analyses. Hence when making a comparison of the analytical results for uniform wall temperature and uniform wall <span class="hlt">heat</span> <span class="hlt">flux</span>, it was not known if differences in the Nusselt numbers could be wholly attributed to the difference in wall boundary conditions, since all the analytical results were not obtained in a consistent way. To have results which could be directly compared, computations were carried out for the uniform wall temperature case, using the same eddy diffusivity, velocity distribution, and digital computer program employed for uniform wall <span class="hlt">heat</span> <span class="hlt">flux</span>. In addition, the previous work was extended to a lower Reynolds number range so that comparisons could be made over a wide range of both Reynolds and Prandtl numbers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130011353','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130011353"><span>Two-Dimensional Thermal Boundary Layer Corrections for Convective <span class="hlt">Heat</span> <span class="hlt">Flux</span> Gauges</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kandula, Max; Haddad, George</p> <p>2007-01-01</p> <p>This work presents a CFD (Computational Fluid Dynamics) study of two-dimensional thermal boundary layer correction factors for convective <span class="hlt">heat</span> <span class="hlt">flux</span> gauges mounted in flat plate subjected to a surface temperature discontinuity with variable properties taken into account. A two-equation k - omega turbulence model is considered. Results are obtained for a wide range of Mach numbers (1 to 5), gauge radius ratio, and wall temperature discontinuity. Comparisons are made for correction factors with constant properties and variable properties. It is shown that the variable-property effects on the <span class="hlt">heat</span> <span class="hlt">flux</span> correction factors become significant</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1918509L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918509L"><span>An eddy covariance system to characterize the atmospheric surface layer and turbulent latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> over a debris-covered Himalayan glacier.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Litt, Maxime; Steiner, Jakob F.; Stigter, Emmy E.; Immerzeel, Walter; Shea, Joseph Michael</p> <p>2017-04-01</p> <p>Over debris-covered glaciers, water content variations in the debris layer can drive significant changes in its thermal conductivity and significantly impact melt rates. Since sublimation and evaporation are favoured in high-altitude conditions, e.g., low atmospheric pressure and high wind speeds, they are expected to strongly influence the water balance of the debris-layer. Dedicated latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> measurements at the debris surface are essential to characterize the debris <span class="hlt">heat</span> conductivity in order to assess underlying ice melt. Furthermore, the contribution of the turbulent <span class="hlt">fluxes</span> in the surface energy balance over debris covered glacier remains uncertain since they are generally evaluated through similarity methods which might not be valid in complex terrain. We present the first results of a 15-day eddy-covariance experiment installed at the end of the monsoon (September-October) on a 3-m tower above the debris-covered Lirung glacier in Nepal. The tower also included measurements of the 4 <span class="hlt">radiation</span> components. The eddy covariance measurements allowed for the characterization of the turbulence in the atmospheric surface layer, as well as the direct measurements of evaporation, sublimation and turbulent sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The experiment helps us to evaluate the contribution of turbulent <span class="hlt">fluxes</span> to the surface energy balance over this debris-covered glacier, through a precise characterization of the overlying turbulent atmospheric surface layer. It also helps to study the role of the debris-layer water content changes through evaporation and sublimation and its feedback on <span class="hlt">heat</span> conduction in this layer. The large observed turbulent <span class="hlt">fluxes</span> play a significant role in the energy balance at the debris surface and significantly influence debris moisture, conductivity and subsequently underlying ice melt.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT.......289C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT.......289C"><span>The <span class="hlt">Radiative</span> <span class="hlt">Heat</span> Transfer Properties of Molten Salts and Their Relevance to the Design of Advanced Reactors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaleff, Ethan Solomon</p> <p></p> <p>Molten salts, such as the fluoride salt eutectic LiF-NaF-KF (FLiNaK) or the transition metal fluoride salt KF-ZrF4, have been proposed as coolants for numerous advanced reactor concepts. These reactors are designed to operate at high temperatures where <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer may play a significant role. If this is the case, the <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer properties of the salt coolants are required to be known for <span class="hlt">heat</span> transfer calculations to be performed accurately. Chapter 1 describes the existing literature and experimental efforts pertaining to <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer in molten salts. The physics governing photon absorption by halide salts is discussed first, followed by a more specific description of experimental results pertaining to salts of interest. The phonon absorption edge in LiF-based salts such as FLiNaK is estimated and the technique described for potential use in other salts. A description is given of various spectral measurement techniques which might plausibly be employed in the present effort, as well as an argument for the use of integral techniques. Chapter 2 discusses the mathematical treatments required to approximate and solve for the <span class="hlt">radiative</span> <span class="hlt">flux</span> in participating materials. The differential approximation and the exact solutions to the <span class="hlt">radiative</span> <span class="hlt">flux</span> are examined, and methods are given to solve <span class="hlt">radiative</span> and energy equations simultaneously. A coupled solution is used to examine <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer to molten salt coolants. A map is generated of pipe diameters, wall temperatures, and average absorption coefficients where <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer will increase expected <span class="hlt">heat</span> transfer by more than 10% compared to convective methods alone. Chapter 3 presents the design and analysis of the Integral <span class="hlt">Radiative</span> Absorption Chamber (IRAC). The IRAC employs an integral technique for the measurement of the entire electromagnetic spectrum, negating some of the challenges associated with the methods discussed in Chapter 1 at the loss of spectral</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950044721&hterms=Lamb&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DLamb','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950044721&hterms=Lamb&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DLamb"><span>Critical <span class="hlt">radiation</span> <span class="hlt">fluxes</span> and luminosities of black holes and relativistic stars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lamb, Frederick K.; Miller, M. Coleman</p> <p>1995-01-01</p> <p>The critial luminosity at which the outward force of <span class="hlt">radiation</span> balances the inward force of gravity plays an important role in many astrophysical systems. We present expressions for the <span class="hlt">radiation</span> force on particles with arbitrary cross sections and analyze the <span class="hlt">radiation</span> field produced by <span class="hlt">radiating</span> matter, such as a disk, ring, boundary layer, or stellar surface, that rotates slowly around a slowly rotating gravitating mass. We then use these results to investigate the critical <span class="hlt">radiation</span> <span class="hlt">flux</span> and, where possible, the critical luminosity of such a system in genral relativity. We demonstrate that if the <span class="hlt">radiation</span> source is axisymmetric and emission is back-front symmetric with repect to the local direction of motion of the <span class="hlt">radiating</span> matter, as seen in the comoving frame, then the radial component of the <span class="hlt">radiation</span> <span class="hlt">flux</span> and the diagonal components of the <span class="hlt">radiation</span> stress-energy tensor outside the source are the same, to first order in the rotation rates, as they would be if the <span class="hlt">radiation</span> source and gravitating mass were not rotating. We argue that the critical <span class="hlt">radiation</span> <span class="hlt">flux</span> for matter at rest in the locally nonrotating frame is often satisfactory as an astrophysical benchmark <span class="hlt">flux</span> and show that if this benchmark is adopted, many of the complications potentially introduced by rotation of the <span class="hlt">radiation</span> source and the gravitating mass are avoided. We show that if the <span class="hlt">radiation</span> field in the absence of rotation would be spherically symmetric and the opacity is independent of frequency and direction, one can define a critical luminosity for the system that is independent of frequency and direction, one can define a critical luminosity for the system that is independent of the spectrum and angular size of the <span class="hlt">radiation</span> source and is unaffected by rotation of the source and mass and orbital motion of the matter, to first order. Finally, we analyze the conditions under which the maximum possible luminosity of a star or black hole powered by steady spherically symmetric radial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910011011','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910011011"><span>Self-pressurization of a flightweight liquid hydrogen storage tank subjected to low <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hasan, M. M.; Lin, C. S.; Vandresar, N. T.</p> <p>1991-01-01</p> <p>Results are presented for an experimental investigation of self-pressurization and thermal stratification of a 4.89 cu m liquid hydrogen (LH2) storage tank subjected to low <span class="hlt">heat</span> <span class="hlt">flux</span> (0.35, 2.0, and 3.5 W/sq m) under normal gravity conditions. Tests were performed at fill levels of 83 to 84 percent (by volume). The LH2 tank was representative of future spacecraft tankage, having a low mass-to-volume ratio and high performance multilayer thermal insulation. Results show that the pressure rise rate and thermal stratification increase with increasing <span class="hlt">heat</span> <span class="hlt">flux</span>. At the lowest <span class="hlt">heat</span> <span class="hlt">flux</span>, the pressure rise rate is comparable to the homogenous rate, while at the highest <span class="hlt">heat</span> <span class="hlt">flux</span>, the rate is more than three times the homogeneous rate. It was found that initial conditions have a significant impact on the initial pressure rise rate. The quasi-steady pressure rise rates are nearly independent of the initial condition after an initial transient period has passed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.P53A1845G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.P53A1845G"><span>Counterintuitive Constraints on Chaos Formation Set by <span class="hlt">Heat</span> <span class="hlt">Flux</span> through Europa's Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goodman, J. C.</p> <p>2013-12-01</p> <p>Models for the formation of disruptive chaos features on the icy surface of Europa fall into two broad categories: either chaos is formed when basal <span class="hlt">heating</span> causes localized melting and thinning of the ice shell, or basal <span class="hlt">heating</span> drives diapiric convection within the ice shell. We argue that in both of these cases, <span class="hlt">heating</span> of the ice shell from below does not lead to chaos formation at the location of <span class="hlt">heating</span>. If chaos is formed when a localized oceanic <span class="hlt">heat</span> source, such as a hydrothermal plume, "melts through" the ice crust, we must consider what happens to the melted liquid. If Europa's ocean is salty, the melt will form a buoyant pool inside the melted cavity, leading to a stable interface between cold fresh meltwater and warm salty seawater. This stable interface acts like an ablative <span class="hlt">heat</span> shield, protecting the ice from further damage. Some <span class="hlt">heat</span> can be transferred across the stable layer by double diffusion, but this transfer is very inefficient. We calculate that local ocean <span class="hlt">heating</span> cannot be balanced by local <span class="hlt">flux</span> through the stable layer: instead, the warm ocean water must spread laterally until it is delivering <span class="hlt">heat</span> to the ice base on a regional or global scale (a <span class="hlt">heating</span> zone hundreds or thousands of km across, for conservative parameters.) If chaos is formed by diapiric solid-state convection within the ice shell, many investigators have assumed that diapirism and chaos should be most prevalent where the basal <span class="hlt">heat</span> <span class="hlt">flux</span> is strongest. We argue that this is not the case. In Rayleigh-Benard convection, increasing the <span class="hlt">heat</span> <span class="hlt">flux</span> will make convection more vigorous --- if and only if the convecting layer thickness does not change. We argue that increased basal <span class="hlt">heat</span> <span class="hlt">flux</span> will thin the ice shell, reducing its Rayleigh number and making convection less likely, not more. This insight allows us to reverse the logic of recent discussions of the relationship between ocean circulation and chaos (for instance, Soderlund et al, 2013 LPSC). We argue that global oceanic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20527160','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20527160"><span>[Characteristics of CO2 <span class="hlt">flux</span> before and in the <span class="hlt">heating</span> period at urban complex underlying surface area].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jia, Qing-yu; Zhou, Guang-sheng; Wang, Yu; Liu, Xiao-mei</p> <p>2010-04-01</p> <p>Urban areas were significant contributors to global carbon dioxide emissions. The eddy covariance (EC) was used to measure carbon dioxide (CO2) concentration and <span class="hlt">flux</span> data at urban area in Shenyang. This research analyzed the characteristics of atmospheric CO2 concentration and <span class="hlt">flux</span> in October 2008 to November 2008 period before and in the <span class="hlt">heating</span> period. The results showed that the daily variation of CO2 concentration was two-peak curve. The first peak time appeared as same as sunrise time, while the second peak time impacted by vehicles and <span class="hlt">heating</span>. The result of CO2 <span class="hlt">flux</span> showed that urban atmospheric CO2 was net emissions, vegetation photosynthesis absorbed CO2 of traffic, the CO2 <span class="hlt">flux</span> peak appeared at 17:15-18:15 in the <span class="hlt">heating</span> period, CO2 emission increased 29.37 g x (m2 x d)(-1) in the <span class="hlt">heating</span> period than that before the <span class="hlt">heating</span> period; there was corresponding relationship between CO2 <span class="hlt">flux</span> and the time when temperature peak and sensible <span class="hlt">heating</span> <span class="hlt">flux</span> (Hc) turn positive. The results also indicated that atmospheric CO2 concentration and its <span class="hlt">flux</span> were affected seriously by both wind direction and carbon sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.108w3901B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.108w3901B"><span>Pool boiling with high <span class="hlt">heat</span> <span class="hlt">flux</span> enabled by a porous artery structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bai, Lizhan; Zhang, Lianpei; Lin, Guiping; Peterson, G. P.</p> <p>2016-06-01</p> <p>A porous artery structure utilizing the concept of "phase separation and modulation" is proposed to enhance the critical <span class="hlt">heat</span> <span class="hlt">flux</span> of pool boiling. A series of experiments were conducted on a range of test articles in which multiple rectangular arteries were machined directly into the top surface of a 10.0 mm diameter copper rod. The arteries were then covered by a 2.0 mm thickness microporous copper plate through silver brazing. The pool wall was fabricated from transparent Pyrex glass to allow a visualization study, and water was used as the working fluid. Experimental results confirmed that the porous artery structure provided individual flow paths for the liquid supply and vapor venting, and avoided the detrimental effects of the liquid/vapor counter flow. As a result, a maximum <span class="hlt">heat</span> <span class="hlt">flux</span> of 610 W/cm2 over a <span class="hlt">heating</span> area of 0.78 cm2 was achieved with no indication of dryout, prior to reaching the heater design temperature limit. Following the experimental tests, the mechanisms responsible for the boiling critical <span class="hlt">heat</span> <span class="hlt">flux</span> and performance enhancement of the porous artery structure were analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH32A..04S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH32A..04S"><span>Control Mechanisms of the Electron <span class="hlt">Heat</span> <span class="hlt">Flux</span> in the Solar Wind: Observations in Comparison to Numerical Simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stverak, S.; Hellinger, P.; Landi, S.; Travnicek, P. M.; Maksimovic, M.</p> <p>2017-12-01</p> <p>Recent understanding of the <span class="hlt">heat</span> transport and dissipation in the expanding solar wind propose number of complex control mechanisms down to the electron kinetic scales. We investigate the evolution of electron <span class="hlt">heat</span> <span class="hlt">flux</span> properties and constraints along the expansion using in situ observations from Helios spacecraft in comparison to numerical kinetic simulations. In particular we focus on the roles of Coulomb collisions and wave-particle interactions in shaping the electron velocity distribution functions and thus controlling the <span class="hlt">heat</span> transported by the electron <span class="hlt">heat</span> <span class="hlt">flux</span>. We show the general evolution of the electron <span class="hlt">heat</span> <span class="hlt">flux</span> to be driven namely by the Coulomb collisions. Locally we demonstrate the wave-particle interactions related to the kinetic plasma instabilities to be providing effective constraints in case of extreme <span class="hlt">heat</span> <span class="hlt">flux</span> levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720011318','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720011318"><span>Pyrotechnic hazards classification and evaluation program test report. <span class="hlt">Heat</span> <span class="hlt">flux</span> study of deflagrating pyrotechnic munitions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fassnacht, P. O.</p> <p>1971-01-01</p> <p>A <span class="hlt">heat</span> <span class="hlt">flux</span> study of deflagrating pyrotechnic munitions is presented. Three tests were authorized to investigate whether <span class="hlt">heat</span> <span class="hlt">flux</span> measurements may be used as effective hazards evaluation criteria to determine safe quantity distances for pyrotechnics. A passive sensor study was conducted simultaneously to investigate their usefulness in recording events and conditions. It was concluded that <span class="hlt">heat</span> <span class="hlt">flux</span> measurements can effectively be used to evaluate hazards criteria and that passive sensors are an inexpensive tool to record certain events in the vicinity of deflagrating pyrotechnic stacks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16118893','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16118893"><span>Finger <span class="hlt">heat</span> <span class="hlt">flux</span>/temperature as an indicator of thermal imbalance with application for extravehicular activity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Koscheyev, Victor S; Leon, Gloria R; Coca, Aitor</p> <p>2005-11-01</p> <p>The designation of a simple, non-invasive, and highly precise method to monitor the thermal status of astronauts is important to enhance safety during extravehicular activities (EVA) and onboard emergencies. Finger temperature (Tfing), finger <span class="hlt">heat</span> <span class="hlt">flux</span>, and indices of core temperature (Tc) [rectal (Tre), ear canal (Tec)] were assessed in 3 studies involving different patterns of <span class="hlt">heat</span> removal/insertion from/to the body by a multi-compartment liquid cooling/warming garment (LCWG). Under both uniform and nonuniform temperature conditions on the body surface, Tfing and finger <span class="hlt">heat</span> <span class="hlt">flux</span> were highly correlated with garment <span class="hlt">heat</span> <span class="hlt">flux</span>, and also highly correlated with each other. Tc responses did not adequately reflect changes in thermal balance during the ongoing process of <span class="hlt">heat</span> insertion/removal from the body. Overall, Tfing/finger <span class="hlt">heat</span> <span class="hlt">flux</span> adequately reflected the initial destabilization of thermal balance, and therefore appears to have significant potential as a useful index for monitoring and maintaining thermal balance and comfort in extreme conditions in space as well as on Earth. c2005 Elsevier Ltd. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930036590&hterms=carbon+footprint&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcarbon%2Bfootprint','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930036590&hterms=carbon+footprint&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcarbon%2Bfootprint"><span>Aircraft- and tower-based <span class="hlt">fluxes</span> of carbon dioxide, latent, and sensible <span class="hlt">heat</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Desjardins, R. L.; Hart, R. L.; Macpherson, J. I.; Schuepp, P. H.; Verma, S. B.</p> <p>1992-01-01</p> <p><span class="hlt">Fluxes</span> of carbon dioxide, water vapor, and sensible <span class="hlt">heat</span> obtained over a grassland ecosystem, during the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE), using an aircraft- and two tower-based systems are compared for several days in 1987 and in 1989. The tower-based cospectral estimates of CO2, sensible <span class="hlt">heat</span>, water vapor, and momentum, expressed as a function of wavenumber K times sampling height z, are relatively similar to the aircraft-based estimates for K x z greater than 0.1. A measurable contribution to the <span class="hlt">fluxes</span> is observed by tower-based systems at K x z less than 0.01 but not by the aircraft-based system operating at an altitude of approximately 100 m over a 15 x 15 km area. Using all available simultaneous aircraft and tower data, <span class="hlt">flux</span> estimates by both systems were shown to be highly correlated. As expected from the spatial variations of the greenness index, surface extrapolation of airborne <span class="hlt">flux</span> estimates tended to lie between those of the two tower sites. The average <span class="hlt">fluxes</span> obtained, on July 11, 1987, and August 4, 1989, by flying a grid pattern over the FIFE site agreed with the two tower data sets for CO2, but sensible and latent <span class="hlt">heat</span> were smaller than those obtained by the tower-based systems. However, in general, except for a small underestimation due to the long wavelength contributions and due to <span class="hlt">flux</span> divergence with height, the differences between the aircraft- and tower-based surface estimates of <span class="hlt">fluxes</span> appear to be mainly attributable to differences in footprint, that is, differences in the area contributing to the surface <span class="hlt">flux</span> estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130000651','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130000651"><span>Surface Catalysis and Oxidation on Stagnation Point <span class="hlt">Heat</span> <span class="hlt">Flux</span> Measurements in High Enthalpy Arc Jets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nawaz, Anuscheh; Driver, David M.; Terrazas-Salinas</p> <p>2013-01-01</p> <p><span class="hlt">Heat</span> <span class="hlt">flux</span> sensors are routinely used in arc jet facilities to determine <span class="hlt">heat</span> transfer rates from plasma plume. The goal of this study is to assess the impact of surface composition changes on these <span class="hlt">heat</span> <span class="hlt">flux</span> sensors. Surface compositions can change due to oxidation and material deposition from the arc jet. Systematic surface analyses of the sensors were conducted before and after exposure to plasma. Currently copper is commonly used as surface material. Other surface materials were studied including nickel, constantan gold, platinum and silicon dioxide. The surfaces were exposed to plasma between 0.3 seconds and 3 seconds. Surface changes due to oxidation as well as copper deposition from the arc jets were observed. Results from changes in measured <span class="hlt">heat</span> <span class="hlt">flux</span> as a function of surface catalycity is given, along with a first assessment of enthalpy for these measurements. The use of cupric oxide is recommended for future <span class="hlt">heat</span> <span class="hlt">flux</span> measurements, due to its consistent surface composition arc jets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RScI...83c3501B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RScI...83c3501B"><span>Surface thermocouples for measurement of pulsed <span class="hlt">heat</span> <span class="hlt">flux</span> in the divertor of the Alcator C-Mod tokamak</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brunner, D.; LaBombard, B.</p> <p>2012-03-01</p> <p>A novel set of thermocouple sensors has been developed to measure <span class="hlt">heat</span> <span class="hlt">fluxes</span> arriving at divertor surfaces in the Alcator C-Mod tokamak, a magnetic confinement fusion experiment. These sensors operate in direct contact with the divertor plasma, which deposits <span class="hlt">heat</span> <span class="hlt">fluxes</span> in excess of ˜10 MW/m2 over an ˜1 s pulse. Thermoelectric EMF signals are produced across a non-standard bimetallic junction: a 50 μm thick 74% tungsten-26% rhenium ribbon embedded in a 6.35 mm diameter molybdenum cylinder. The unique coaxial geometry of the sensor combined with its single-point electrical ground contact minimizes interference from the plasma/magnetic environment. Incident <span class="hlt">heat</span> <span class="hlt">fluxes</span> are inferred from surface temperature evolution via a 1D thermal <span class="hlt">heat</span> transport model. For an incident <span class="hlt">heat</span> <span class="hlt">flux</span> of 10 MW/m2, surface temperatures rise ˜1000 °C/s, corresponding to a <span class="hlt">heat</span> <span class="hlt">flux</span> flowing along the local magnetic field of ˜200 MW/m2. Separate calorimeter sensors are used to independently confirm the derived <span class="hlt">heat</span> <span class="hlt">fluxes</span> by comparing total energies deposited during a plasma pulse. Langmuir probes in close proximity to the surface thermocouples are used to test plasma-sheath <span class="hlt">heat</span> transmission theory and to identify potential sources of discrepancies among physical models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28794447','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28794447"><span>The role of local <span class="hlt">heating</span> in the 2015 Indian <span class="hlt">Heat</span> Wave.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ghatak, Debjani; Zaitchik, Benjamin; Hain, Christopher; Anderson, Martha</p> <p>2017-08-09</p> <p>India faced a major <span class="hlt">heat</span> wave during the summer of 2015. Temperature anomalies peaked in the dry period before the onset of the summer monsoon, suggesting that local land-atmosphere feedbacks involving desiccated soils and vegetation might have played a role in driving the <span class="hlt">heat</span> extreme. Upon examination of in situ data, reanalysis, satellite observations, and land surface models, we find that the <span class="hlt">heat</span> wave included two distinct peaks: one in late May, and a second in early June. During the first peak we find that clear skies led to a positive net <span class="hlt">radiation</span> anomaly at the surface, but there is no significant sensible <span class="hlt">heat</span> <span class="hlt">flux</span> anomaly within the core of the <span class="hlt">heat</span> wave affected region. By the time of the second peak, however, soil moisture had dropped to anomalously low levels in the core <span class="hlt">heat</span> wave region, net surface <span class="hlt">radiation</span> was anomalously high, and a significant positive sensible <span class="hlt">heat</span> <span class="hlt">flux</span> anomaly developed. This led to a substantial local forcing on air temperature that contributed to the intensity of the event. The analysis indicates that the highly agricultural landscape of North and Central India can reinforce <span class="hlt">heat</span> extremes under dry conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/20643911-role-electron-heat-flux-guide-field-magnetic-reconnection','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/20643911-role-electron-heat-flux-guide-field-magnetic-reconnection"><span>The role of electron <span class="hlt">heat</span> <span class="hlt">flux</span> in guide-field magnetic reconnection</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hesse, Michael; Kuznetsova, Masha; Birn, Joachim</p> <p>2004-12-01</p> <p>A combination of analytical theory and particle-in-cell simulations are employed in order to investigate the electron dynamics near and at the site of guide field magnetic reconnection. A detailed analysis of the contributions to the reconnection electric field shows that both bulk inertia and pressure-based quasiviscous processes are important for the electrons. Analytic scaling demonstrates that conventional approximations for the electron pressure tensor behavior in the dissipation region fail, and that <span class="hlt">heat</span> <span class="hlt">flux</span> contributions need to be accounted for. Based on the evolution equation of the <span class="hlt">heat</span> <span class="hlt">flux</span> three tensor, which is derived in this paper, an approximate form ofmore » the relevant <span class="hlt">heat</span> <span class="hlt">flux</span> contributions to the pressure tensor is developed, which reproduces the numerical modeling result reasonably well. Based on this approximation, it is possible to develop a scaling of the electron current layer in the central dissipation region. It is shown that the pressure tensor contributions become important at the scale length defined by the electron Larmor radius in the guide magnetic field.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080006072','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080006072"><span>High-<span class="hlt">Heat-Flux</span> Cyclic Durability of Thermal and Environmental Barrier Coatings</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhu, Dongming; Ghosn, Louis L.; Miller, Robert A.</p> <p>2007-01-01</p> <p>Advanced ceramic thermal and environmental barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to protect the engine components and further raise engine temperatures. For the supersonic vehicles currently envisioned in the NASA fundamental aeronautics program, advanced gas turbine engines will be used to provide high power density thrust during the extended supersonic flight of the aircraft, while meeting stringent low emission requirements. Advanced ceramic coating systems are critical to the performance, life and durability of the hot-section components of the engine systems. In this work, the laser and burner rig based high-<span class="hlt">heat-flux</span> testing approaches were developed to investigate the coating cyclic response and failure mechanisms under simulated supersonic long-duration cruise mission. The accelerated coating cracking and delamination mechanism under the engine high-<span class="hlt">heat-flux</span>, and extended supersonic cruise time conditions will be addressed. A coating life prediction framework may be realized by examining the crack initiation and propagation in conjunction with environmental degradation under high-<span class="hlt">heat-flux</span> test conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730022520','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730022520"><span>Viscous hydrodynamic instability theory of the peak and minimum pool boiling <span class="hlt">heat</span> <span class="hlt">fluxes</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dhir, V. K.</p> <p>1972-01-01</p> <p>Liquid viscosity was included in the Bellman-Pennington theory of the Taylor wave in a liquid vapor interface. Predictions of the most susceptible wavelength, and of the wave frequency, were made as a function of a liquid viscosity parameter and the Bond number. The stability of a gas jet in a viscous liquid was studied and the result is used to predict the peak <span class="hlt">heat</span> <span class="hlt">flux</span> on large horizontal heaters. Experimental measurements of the dominant Taylor wave and its growth rate were made during the film boiling of cyclohexanol on cylindrical heaters. The results bear out the predictions quite well. The thickness of the vapor blanket surrounding a cylindrical heater was measured and a correlation suggested. The effect of large <span class="hlt">fluxes</span> of vapor volume on the dominant wavelength was also noted. Theoretical results of the peak <span class="hlt">heat</span> <span class="hlt">flux</span> are compared with the experimental data, and the effect of finite geometry of flat plate heaters on the peak <span class="hlt">heat</span> <span class="hlt">flux</span> is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160003590&hterms=strengthening&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstrengthening','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160003590&hterms=strengthening&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstrengthening"><span>The Impact of Trends in the Large Scale Atmospheric Circulation on Mediterranean Surface Turbulent <span class="hlt">Heat</span> <span class="hlt">Fluxes</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Romanski, Joy; Hameed, Sultan</p> <p>2015-01-01</p> <p>Interannual variations of latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> (LHF) and sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> (SHF) over the Mediterranean for the boreal winter season (DJF) show positive trends during 1958-2011. Using reanalysis and satellite-based products, the variability and trends in the <span class="hlt">heat</span> <span class="hlt">fluxes</span> are compared with variations in three atmospheric teleconnection patterns: the North Atlantic Oscillation (NAO), the pressure and position of the Azores High (AH), and the East Atlantic-West Russia teleconnection pattern (EAWR). Comparison of correlations between the <span class="hlt">heat</span> <span class="hlt">fluxes</span> and teleconnections, along with analysis of composites of surface temperature, humidity, and wind fields for different teleconnection states, demonstrates that the AH explains the <span class="hlt">heat</span> <span class="hlt">flux</span> changes more successfully than NAO and EAWR. Trends in pressure and longitude of the Azores High show a strengthening and an eastward shift. Variations of the Azores High occur along an axis defined by lower pressure and westward location at one extreme and higher pressure and eastward location at the other extreme. The shift of the AH from predominance of the low/west state to the high/east state induces trends in Mediterranean Sea surface winds, temperature, and moisture. These, combined with sea surface warming trends, produce trends in wintertime sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...846..165U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...846..165U"><span>Modeling Coronal Response in Decaying Active Regions with Magnetic <span class="hlt">Flux</span> Transport and Steady <span class="hlt">Heating</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ugarte-Urra, Ignacio; Warren, Harry P.; Upton, Lisa A.; Young, Peter R.</p> <p>2017-09-01</p> <p>We present new measurements of the dependence of the extreme ultraviolet (EUV) radiance on the total magnetic <span class="hlt">flux</span> in active regions as obtained from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Using observations of nine active regions tracked along different stages of evolution, we extend the known radiance—magnetic <span class="hlt">flux</span> power-law relationship (I\\propto {{{Φ }}}α ) to the AIA 335 Å passband, and the Fe xviii 93.93 Å spectral line in the 94 Å passband. We find that the total unsigned magnetic <span class="hlt">flux</span> divided by the polarity separation ({{Φ }}/D) is a better indicator of radiance for the Fe xviii line with a slope of α =3.22+/- 0.03. We then use these results to test our current understanding of magnetic <span class="hlt">flux</span> evolution and coronal <span class="hlt">heating</span>. We use magnetograms from the simulated decay of these active regions produced by the Advective <span class="hlt">Flux</span> Transport model as boundary conditions for potential extrapolations of the magnetic field in the corona. We then model the hydrodynamics of each individual field line with the Enthalpy-based Thermal Evolution of Loops model with steady <span class="hlt">heating</span> scaled as the ratio of the average field strength and the length (\\bar{B}/L) and render the Fe xviii and 335 Å emission. We find that steady <span class="hlt">heating</span> is able to partially reproduce the magnitudes and slopes of the EUV radiance—magnetic <span class="hlt">flux</span> relationships and discuss how impulsive <span class="hlt">heating</span> can help reconcile the discrepancies. This study demonstrates that combined models of magnetic <span class="hlt">flux</span> transport, magnetic topology, and <span class="hlt">heating</span> can yield realistic estimates for the decay of active region radiances with time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26641312','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26641312"><span><span class="hlt">Radiative</span> <span class="hlt">heat</span> transfer in the extreme near field.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Kyeongtae; Song, Bai; Fernández-Hurtado, Víctor; Lee, Woochul; Jeong, Wonho; Cui, Longji; Thompson, Dakotah; Feist, Johannes; Reid, M T Homer; García-Vidal, Francisco J; Cuevas, Juan Carlos; Meyhofer, Edgar; Reddy, Pramod</p> <p>2015-12-17</p> <p><span class="hlt">Radiative</span> transfer of energy at the nanometre length scale is of great importance to a variety of technologies including <span class="hlt">heat</span>-assisted magnetic recording, near-field thermophotovoltaics and lithography. Although experimental advances have enabled elucidation of near-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer in gaps as small as 20-30 nanometres (refs 4-6), quantitative analysis in the extreme near field (less than 10 nanometres) has been greatly limited by experimental challenges. Moreover, the results of pioneering measurements differed from theoretical predictions by orders of magnitude. Here we use custom-fabricated scanning probes with embedded thermocouples, in conjunction with new microdevices capable of periodic temperature modulation, to measure <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer down to gaps as small as two nanometres. For our experiments we deposited suitably chosen metal or dielectric layers on the scanning probes and microdevices, enabling direct study of extreme near-field <span class="hlt">radiation</span> between silica-silica, silicon nitride-silicon nitride and gold-gold surfaces to reveal marked, gap-size-dependent enhancements of <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer. Furthermore, our state-of-the-art calculations of <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer, performed within the theoretical framework of fluctuational electrodynamics, are in excellent agreement with our experimental results, providing unambiguous evidence that confirms the validity of this theory for modelling <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer in gaps as small as a few nanometres. This work lays the foundations required for the rational design of novel technologies that leverage nanoscale <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54..985A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54..985A"><span>Thermal performance analysis of a flat <span class="hlt">heat</span> pipe working with carbon nanotube-water nanofluid for cooling of a high <span class="hlt">heat</span> <span class="hlt">flux</span> heater</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arya, A.; Sarafraz, M. M.; Shahmiri, S.; Madani, S. A. H.; Nikkhah, V.; Nakhjavani, S. M.</p> <p>2018-04-01</p> <p>Experimental investigation on the thermal performance of a flat <span class="hlt">heat</span> pipe working with carbon nanotube nanofluid is conducted. It is used for cooling a heater working at high <span class="hlt">heat</span> <span class="hlt">flux</span> conditions up to 190 kW/m2. The <span class="hlt">heat</span> pipe is fabricated from aluminium and is equipped with rectangular fin for efficient cooling of condenser section. Inside the <span class="hlt">heat</span> pipe, a screen mesh was inserted as a wick structure to facilitate the capillary action of working fluid. Influence of different operating parameters such as <span class="hlt">heat</span> <span class="hlt">flux</span>, mass concentration of carbon nanotubes and filling ratio of working fluid on thermal performance of <span class="hlt">heat</span> pipe and its thermal resistance are investigated. Results showed that with an increase in <span class="hlt">heat</span> <span class="hlt">flux</span>, the <span class="hlt">heat</span> transfer coefficient in evaporator section of the <span class="hlt">heat</span> pipe increases. For filling ratio, however, there is an optimum value, which was 0.8 for the test <span class="hlt">heat</span> pipe. In addition, CNT/water enhanced the <span class="hlt">heat</span> transfer coefficient up to 40% over the deionized water. Carbon nanotubes intensified the thermal performance of wick structure by creating a fouling layer on screen mesh structure, which changes the contact angle of liquid with the surface, intensifying the capillary forces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120002868','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120002868"><span>Characterization of Turbulent Latent and Sensible <span class="hlt">Heat</span> <span class="hlt">Flux</span> Exchange Between the Atmosphere and Ocean in MERRA</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robert, J. Brent; Robertson, Franklin R.; Clayson, Carol Anne; Bosilovich, Michael G.</p> <p>2012-01-01</p> <p>Turbulent <span class="hlt">fluxes</span> of <span class="hlt">heat</span> and moisture across the atmosphere-ocean interface are fundamental components of the Earth's energy and water balance. Characterizing both the spatiotemporal variability and the fidelity of these exchanges of <span class="hlt">heat</span> and moisture is critical to understanding the global water and energy cycle variations, quantifying atmosphere-ocean feedbacks, and improving model predictability. This study examines the veracity of the recently completed NASA Modern-Era Retrospective analysis for Research and Applications (MERRA) product with respect to its representation of the surface turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span>. A validation of MERRA turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> and near-surface bulk variables at local, high-resolution space and time scales is achieved by making comparisons to a large suite of direct observations. Both in situ and satellite-observed gridded surface <span class="hlt">heat</span> <span class="hlt">flux</span> estimates are employed to investigate the spatial and temporal variability of the surface <span class="hlt">fluxes</span> with respect to their annual mean climatologies, their seasonal covariability of near-surface bulk parameters, and their representation of extremes. The impact of data assimilation on the near-surface parameters is assessed through evaluation of incremental analysis update tendencies produced by the assimilation procedure. It is found that MERRA turbulent surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> are relatively accurate for typical conditions but have systematically weak vertical gradients in moisture and temperature and have a weaker covariability between the near-surface gradients and wind speed than found in observations. This results in an underestimate of the surface latent and sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> over the western boundary current and storm track regions. The assimilation of observations mostly acts to bring MERRA closer to observational products by increasing moisture and temperature near the surface and decreasing the near-surface wind speeds. The major patterns of spatial and temporal variability of the turbulent <span class="hlt">heat</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120007430','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120007430"><span>Characterization of Turbulent Latent and Sensible <span class="hlt">Heat</span> <span class="hlt">Flux</span> Exchange Between the Atmosphere and Ocean in MERRA</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roberts, J. Brent; Robertson, Franklin R.; Clayson, Carol Anne; Bosilovich, Michael G.</p> <p>2012-01-01</p> <p>Turbulent <span class="hlt">fluxes</span> of <span class="hlt">heat</span> and moisture across the atmosphere-ocean interface are fundamental components of the Earth s energy and water balance. Characterizing both the spatiotemporal variability and the fidelity of these exchanges of <span class="hlt">heat</span> and moisture is critical to understanding the global water and energy cycle variations, quantifying atmosphere-ocean feedbacks, and improving model predictability. This study examines the veracity of the recently completed NASA Modern-Era Retrospective analysis for Research and Applications (MERRA) product with respect to its representation of the surface turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span>. A validation of MERRA turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> and near-surface bulk variables at local, high-resolution space and time scales is achieved by making comparisons to a large suite of direct observations. Both in situ and satellite-observed gridded surface <span class="hlt">heat</span> <span class="hlt">flux</span> estimates are employed to investigate the spatial and temporal variability of the surface <span class="hlt">fluxes</span> with respect to their annual mean climatologies, their seasonal covariability of near-surface bulk parameters, and their representation of extremes. The impact of data assimilation on the near-surface parameters is assessed through evaluation of incremental analysis update tendencies produced by the assimilation procedure. It is found that MERRA turbulent surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> are relatively accurate for typical conditions but have systematically weak vertical gradients in moisture and temperature and have a weaker covariability between the near-surface gradients and wind speed than found in observations. This results in an underestimate of the surface latent and sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> over the western boundary current and storm track regions. The assimilation of observations mostly acts to bring MERRA closer to observational products by increasing moisture and temperature near the surface and decreasing the near-surface wind speeds. The major patterns of spatial and temporal variability of the turbulent <span class="hlt">heat</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780018913&hterms=heat+exchange&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dheat%2Bexchange','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780018913&hterms=heat+exchange&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dheat%2Bexchange"><span><span class="hlt">Heat</span> transfer evaluation in a plasma core reactor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, D. E.; Smith, T. M.; Stoenescu, M. L.</p> <p>1976-01-01</p> <p>Numerical evaluations of <span class="hlt">heat</span> transfer in a fissioning uranium plasma core reactor cavity, operating with seeded hydrogen propellant, was performed. A two-dimensional analysis is based on an assumed flow pattern and cavity wall <span class="hlt">heat</span> exchange rate. Various iterative schemes were required by the nature of the <span class="hlt">radiative</span> field and by the solid seed vaporization. Approximate formulations of the <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span> are generally used, due to the complexity of the solution of a rigorously formulated problem. The present work analyzes the sensitivity of the results with respect to approximations of the <span class="hlt">radiative</span> field, geometry, seed vaporization coefficients and flow pattern. The results present temperature, <span class="hlt">heat</span> <span class="hlt">flux</span>, density and optical depth distributions in the reactor cavity, acceptable simplifying assumptions, and iterative schemes. The present calculations, performed in cartesian and spherical coordinates, are applicable to any most general <span class="hlt">heat</span> transfer problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22600185-study-heat-flux-disruption-experimental-advanced-superconducting-tokamak','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22600185-study-heat-flux-disruption-experimental-advanced-superconducting-tokamak"><span>The study of <span class="hlt">heat</span> <span class="hlt">flux</span> for disruption on experimental advanced superconducting tokamak</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yang, Zhendong, E-mail: dongyz@ipp.ac.cn, E-mail: jafang@dhu.edu.cn; Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031; Fang, Jianan, E-mail: dongyz@ipp.ac.cn, E-mail: jafang@dhu.edu.cn</p> <p></p> <p>Disruption of the plasma is one of the most dangerous instabilities in tokamak. During the disruption, most of the plasma thermal energy is lost, which causes damages to the plasma facing components. Infrared (IR) camera is an effective tool to detect the temperature distribution on the first wall, and the energy deposited on the first wall can be calculated from the surface temperature profile measured by the IR camera. This paper concentrates on the characteristics of <span class="hlt">heat</span> <span class="hlt">flux</span> distribution onto the first wall under different disruptions, including the minor disruption and the vertical displacement events (VDE) disruption. Several minor disruptionsmore » have been observed before the major disruption under the high plasma density in experimental advanced superconducting tokamak. During the minor disruption, the <span class="hlt">heat</span> <span class="hlt">fluxes</span> are mainly deposited on the upper/lower divertors. The magnetic configuration prior to the minor disruption is a lower single null with the radial distance between the two separatrices in the outer midplane dR{sub sep} = −2 cm, while it changes to upper single null (dR{sub sep} = 1.4 cm) during the minor disruption. As for the VDE disruption, the spatial distribution of <span class="hlt">heat</span> <span class="hlt">flux</span> exhibits strong toroidal and radial nonuniformity, and the maximum <span class="hlt">heat</span> <span class="hlt">flux</span> received on the dome plate can be up to 11 MW/m{sup 2}.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A52B..07D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A52B..07D"><span>A method for obtaining distributed surface <span class="hlt">flux</span> measurements in complex terrain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Daniels, M. H.; Pardyjak, E.; Nadeau, D. F.; Barrenetxea, G.; Brutsaert, W. H.; Parlange, M. B.</p> <p>2011-12-01</p> <p>Sonic anemometers and gas analyzers can be used to measure <span class="hlt">fluxes</span> of momentum, <span class="hlt">heat</span>, and moisture over flat terrain, and with the proper corrections, over sloping terrain as well. While this method of obtaining <span class="hlt">fluxes</span> is currently the most accurate available, the instruments themselves are costly, making installation of many stations impossible for most campaign budgets. Small, commercial automatic weather stations (Sensorscope) are available at a fraction of the cost of sonic anemometers or gas analyzers. Sensorscope stations use slow-response instruments to measure standard meteorological variables, including wind speed and direction, air temperature, humidity, surface skin temperature, and incoming solar <span class="hlt">radiation</span>. The method presented here makes use of one sonic anemometer and one gas analyzer along with a dozen Sensorscope stations installed throughout the Val Ferret catchment in southern Switzerland in the summers of 2009, 2010 and 2011. Daytime <span class="hlt">fluxes</span> are calculated using Monin-Obukhov similarity theory in conjunction with the surface energy balance at each Sensorscope station as well as at the location of the sonic anemometer and gas analyzer, where a suite of additional slow-response instruments were co-located. Corrections related to slope angle were made for wind speeds and incoming shortwave <span class="hlt">radiation</span> measured by the horizontally-mounted cup anemometers and incoming solar <span class="hlt">radiation</span> sensors respectively. A temperature correction was also applied to account for daytime <span class="hlt">heating</span> inside the <span class="hlt">radiation</span> shield on the slow-response temperature/humidity sensors. With these corrections, we find a correlation coefficient of 0.77 between u* derived using Monin-Obukhov similarity theory and that of the sonic anemometer. Calculated versus measured <span class="hlt">heat</span> <span class="hlt">fluxes</span> also compare well and local patterns of latent <span class="hlt">heat</span> <span class="hlt">flux</span> and measured surface soil moisture are correlated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4927748','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4927748"><span>Experimental Methodology for Estimation of Local <span class="hlt">Heat</span> <span class="hlt">Fluxes</span> and Burning Rates in Steady Laminar Boundary Layer Diffusion Flames</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Singh, Ajay V.; Gollner, Michael J.</p> <p>2016-01-01</p> <p>Modeling the realistic burning behavior of condensed-phase fuels has remained out of reach, in part because of an inability to resolve the complex interactions occurring at the interface between gas-phase flames and condensed-phase fuels. The current research provides a technique to explore the dynamic relationship between a combustible condensed fuel surface and gas-phase flames in laminar boundary layers. Experiments have previously been conducted in both forced and free convective environments over both solid and liquid fuels. A unique methodology, based on the Reynolds Analogy, was used to estimate local mass burning rates and flame <span class="hlt">heat</span> <span class="hlt">fluxes</span> for these laminar boundary layer diffusion flames utilizing local temperature gradients at the fuel surface. Local mass burning rates and convective and <span class="hlt">radiative</span> <span class="hlt">heat</span> feedback from the flames were measured in both the pyrolysis and plume regions by using temperature gradients mapped near the wall by a two-axis traverse system. These experiments are time-consuming and can be challenging to design as the condensed fuel surface burns steadily for only a limited period of time following ignition. The temperature profiles near the fuel surface need to be mapped during steady burning of a condensed fuel surface at a very high spatial resolution in order to capture reasonable estimates of local temperature gradients. Careful corrections for <span class="hlt">radiative</span> <span class="hlt">heat</span> losses from the thermocouples are also essential for accurate measurements. For these reasons, the whole experimental setup needs to be automated with a computer-controlled traverse mechanism, eliminating most errors due to positioning of a micro-thermocouple. An outline of steps to reproducibly capture near-wall temperature gradients and use them to assess local burning rates and <span class="hlt">heat</span> <span class="hlt">fluxes</span> is provided. PMID:27285827</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160007555','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160007555"><span>Comparison of <span class="hlt">Heat</span> <span class="hlt">Flux</span> Gages for High Enthalpy Flows - NASA Ames and IRS</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Loehle, Stefan; Nawaz, Anuscheh; Herdrich, Georg; Fasoulas, Stefanos; Martinez, Edward; Raiche, George</p> <p>2016-01-01</p> <p>This article is a companion to a paper on <span class="hlt">heat</span> <span class="hlt">flux</span> measurements as initiated under a Space Act Agreement in 2011. The current focus of this collaboration between the Institute of Space Systems (IRS) of the University of Stuttgart and NASA Ames Research Center is the comparison and refinement of diagnostic measurements. A first experimental campaign to test different <span class="hlt">heat</span> <span class="hlt">flux</span> gages in the NASA Interaction <span class="hlt">Heating</span> Facility (IHF) and the Plasmawindkanaele (PWK) at IRS was established. This paper focuses on the results of the measurements conducted at IRS. The tested gages included a at face and hemispherical probe head, a 4" hemispherical slug calorimeter, a null-point calorimeter from Ames and a null-point calorimeter developed for this purpose at IRS. The Ames null-point calorimeter was unfortunately defective upon arrival. The measured <span class="hlt">heat</span> <span class="hlt">fluxes</span> agree fairly well with each other. The reason for discrepancies can be attributed to signal-to-noise levels and the probe geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97d5408F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97d5408F"><span>Super-Planckian far-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fernández-Hurtado, V.; Fernández-Domínguez, A. I.; Feist, J.; García-Vidal, F. J.; Cuevas, J. C.</p> <p>2018-01-01</p> <p>We present here a theoretical analysis that demonstrates that the far-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer between objects with dimensions smaller than the thermal wavelength can overcome the Planckian limit by orders of magnitude. To guide the search for super-Planckian far-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer, we make use of the theory of fluctuational electrodynamics and derive a relation between the far-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer and the directional absorption efficiency of the objects involved. Guided by this relation, and making use of state-of-the-art numerical simulations, we show that the far-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer between highly anisotropic objects can largely overcome the black-body limit when some of their dimensions are smaller than the thermal wavelength. In particular, we illustrate this phenomenon in the case of suspended pads made of polar dielectrics like SiN or SiO2. These structures are widely used to measure the thermal transport through nanowires and low-dimensional systems and can be employed to test our predictions. Our work illustrates the dramatic failure of the classical theory to predict the far-field <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer between micro- and nanodevices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4497480','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4497480"><span>Simulation of high-energy <span class="hlt">radiation</span> belt electron <span class="hlt">fluxes</span> using NARMAX-VERB coupled codes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pakhotin, I P; Drozdov, A Y; Shprits, Y Y; Boynton, R J; Subbotin, D A; Balikhin, M A</p> <p>2014-01-01</p> <p>This study presents a fusion of data-driven and physics-driven methodologies of energetic electron <span class="hlt">flux</span> forecasting in the outer <span class="hlt">radiation</span> belt. Data-driven NARMAX (Nonlinear AutoRegressive Moving Averages with eXogenous inputs) model predictions for geosynchronous orbit <span class="hlt">fluxes</span> have been used as an outer boundary condition to drive the physics-based Versatile Electron <span class="hlt">Radiation</span> Belt (VERB) code, to simulate energetic electron <span class="hlt">fluxes</span> in the outer <span class="hlt">radiation</span> belt environment. The coupled system has been tested for three extended time periods totalling several weeks of observations. The time periods involved periods of quiet, moderate, and strong geomagnetic activity and captured a range of dynamics typical of the <span class="hlt">radiation</span> belts. The model has successfully simulated energetic electron <span class="hlt">fluxes</span> for various magnetospheric conditions. Physical mechanisms that may be responsible for the discrepancies between the model results and observations are discussed. PMID:26167432</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016552','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016552"><span>Improved Finite-Volume Method for <span class="hlt">Radiative</span> Hydrodynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wray, Alan</p> <p>2012-01-01</p> <p>Fully coupled simulations of hydrodynamics and <span class="hlt">radiative</span> transfer are essential to a number of fields ranging from astrophysics to engineering applications. Of particular interest in this work are hypersonic atmospheric entries and associated experimental apparatus, e.g., shock tubes and high enthalpy testing facilities. The <span class="hlt">radiative</span> transfer calculations must supply to the CFD a <span class="hlt">heating</span> term in the energy equation in the form of the divergence of the <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span> and the <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">fluxes</span> to bounding surfaces. It is most efficient to solve the <span class="hlt">radiative</span> transfer equation on the same grid as the CFD solution, and this work presents an algorithm with improved accuracy for such simulations on structured and unstructured grids compared to more conventional approaches. Results will be shown for shock <span class="hlt">radiation</span> during hypersonic reentry. Issues of parallelization within a <span class="hlt">radiation</span> sweep will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5455404','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5455404"><span>Influence of Orientation and <span class="hlt">Radiative</span> <span class="hlt">Heat</span> Transfer on Aluminum Foams in Buoyancy-Induced Convection</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Billiet, Marijn; De Schampheleire, Sven; Huisseune, Henk; De Paepe, Michel</p> <p>2015-01-01</p> <p>Two differently-produced open-cell aluminum foams were compared to a commercially available finned <span class="hlt">heat</span> sink. Further, an aluminum plate and block were tested as a reference. All <span class="hlt">heat</span> sinks have the same base plate dimensions of four by six inches. The first foam was made by investment casting of a polyurethane preform and has a porosity of 0.946 and a pore density of 10 pores per linear inch. The second foam is manufactured by casting over a solvable core and has a porosity of 0.85 and a pore density of 2.5 pores per linear inch. The effects of orientation and <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer are experimentally investigated. The <span class="hlt">heat</span> sinks are tested in a vertical and horizontal orientation. The effect of <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer is investigated by comparing a painted/anodized <span class="hlt">heat</span> sink with an untreated one. The <span class="hlt">heat</span> <span class="hlt">flux</span> through the <span class="hlt">heat</span> sink for a certain temperature difference between the environment and the <span class="hlt">heat</span> sink’s base plate is used as the performance indicator. For temperature differences larger than 30 ∘C, the finned <span class="hlt">heat</span> sink outperforms the in-house-made aluminum foam <span class="hlt">heat</span> sink on average by 17%. Furthermore, the in-house-made aluminum foam dissipates on average 12% less <span class="hlt">heat</span> than the other aluminum foam for a temperature difference larger than 40 ∘C. By painting/anodizing the <span class="hlt">heat</span> sinks, the <span class="hlt">heat</span> transfer rate increased on average by 10% to 50%. Finally, the thermal performance of the horizontal in-house-made aluminum foam <span class="hlt">heat</span> sink is up to 18% larger than the one of the vertical aluminum foam <span class="hlt">heat</span> sink. PMID:28793601</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28793601','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28793601"><span>Influence of Orientation and <span class="hlt">Radiative</span> <span class="hlt">Heat</span> Transfer on Aluminum Foams in Buoyancy-Induced Convection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Billiet, Marijn; De Schampheleire, Sven; Huisseune, Henk; De Paepe, Michel</p> <p>2015-10-09</p> <p>Two differently-produced open-cell aluminum foams were compared to a commercially available finned <span class="hlt">heat</span> sink. Further, an aluminum plate and block were tested as a reference. All <span class="hlt">heat</span> sinks have the same base plate dimensions of four by six inches. The first foam was made by investment casting of a polyurethane preform and has a porosity of 0.946 and a pore density of 10 pores per linear inch. The second foam is manufactured by casting over a solvable core and has a porosity of 0.85 and a pore density of 2.5 pores per linear inch. The effects of orientation and <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer are experimentally investigated. The <span class="hlt">heat</span> sinks are tested in a vertical and horizontal orientation. The effect of <span class="hlt">radiative</span> <span class="hlt">heat</span> transfer is investigated by comparing a painted/anodized <span class="hlt">heat</span> sink with an untreated one. The <span class="hlt">heat</span> <span class="hlt">flux</span> through the <span class="hlt">heat</span> sink for a certain temperature difference between the environment and the <span class="hlt">heat</span> sink's base plate is used as the performance indicator. For temperature differences larger than 30 °C, the finned <span class="hlt">heat</span> sink outperforms the in-house-made aluminum foam <span class="hlt">heat</span> sink on average by 17%. Furthermore, the in-house-made aluminum foam dissipates on average 12% less <span class="hlt">heat</span> than the other aluminum foam for a temperature difference larger than 40 °C. By painting/anodizing the <span class="hlt">heat</span> sinks, the <span class="hlt">heat</span> transfer rate increased on average by 10% to 50%. Finally, the thermal performance of the horizontal in-house-made aluminum foam <span class="hlt">heat</span> sink is up to 18% larger than the one of the vertical aluminum foam <span class="hlt">heat</span> sink.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JQSRT.182..264A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JQSRT.182..264A"><span><span class="hlt">Radiative</span> <span class="hlt">heat</span> transfer in strongly forward scattering media of circulating fluidized bed combustors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ates, Cihan; Ozen, Guzide; Selçuk, Nevin; Kulah, Gorkem</p> <p>2016-10-01</p> <p>Investigation of the effect of particle scattering on <span class="hlt">radiative</span> incident <span class="hlt">heat</span> <span class="hlt">fluxes</span> and source terms is carried out in the dilute zone of the lignite-fired 150 kWt Middle East Technical University Circulating Fluidized Bed Combustor (METU CFBC) test rig. The dilute zone is treated as an axisymmetric cylindrical enclosure containing grey/non-grey, absorbing, emitting gas with absorbing, emitting non/isotropically/anisotropically scattering particles surrounded by grey diffuse walls. A two-dimensional axisymmetric <span class="hlt">radiation</span> model based on Method of Lines (MOL) solution of Discrete Ordinates Method (DOM) coupled with Grey Gas (GG)/Spectral Line-Based Weighted Sum of Grey Gases Model (SLW) and Mie theory/geometric optics approximation (GOA) is extended for incorporation of anisotropic scattering by using normalized Henyey-Greenstein (HG)/transport approximation for the phase function. Input data for the <span class="hlt">radiation</span> model is obtained from predictions of a comprehensive model previously developed and benchmarked against measurements on the same CFBC burning low calorific value indigenous lignite with high volatile matter/fixed carbon (VM/FC) ratio in its own ash. Predictive accuracy and computational efficiency of nonscattering, isotropic scattering and forward scattering with transport approximation are tested by comparing their predictions with those of forward scattering with HG. GG and GOA based on reflectivity with angular dependency are found to be accurate and CPU efficient. Comparisons reveal that isotropic assumption leads to under-prediction of both incident <span class="hlt">heat</span> <span class="hlt">fluxes</span> and source terms for which discrepancy is much larger. On the other hand, predictions obtained by neglecting scattering were found to be in favorable agreement with those of forward scattering at significantly less CPU time. Transport approximation is as accurate and CPU efficient as HG. These findings indicate that negligence of scattering is a more practical choice in solution of the <span class="hlt">radiative</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title16-vol2/pdf/CFR-2010-title16-vol2-part1209-subpartA-app8.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title16-vol2/pdf/CFR-2010-title16-vol2-part1209-subpartA-app8.pdf"><span>16 CFR Figure 8 to Subpart A of... - Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile 8... PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 8 Figure 8 to Subpart A of Part 1209—Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile EC03OC91...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title16-vol2/pdf/CFR-2011-title16-vol2-part1209-subpartA-app8.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title16-vol2/pdf/CFR-2011-title16-vol2-part1209-subpartA-app8.pdf"><span>16 CFR Figure 8 to Subpart A of... - Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-01-01</p> <p>... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile 8... PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 8 Figure 8 to Subpart A of Part 1209—Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile EC03OC91...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title16-vol2/pdf/CFR-2013-title16-vol2-part1209-subpartA-app8.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title16-vol2/pdf/CFR-2013-title16-vol2-part1209-subpartA-app8.pdf"><span>16 CFR Figure 8 to Subpart A of... - Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-01-01</p> <p>... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile 8... PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 8 Figure 8 to Subpart A of Part 1209—Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile EC03OC91...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title16-vol2/pdf/CFR-2012-title16-vol2-part1209-subpartA-app8.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title16-vol2/pdf/CFR-2012-title16-vol2-part1209-subpartA-app8.pdf"><span>16 CFR Figure 8 to Subpart A of... - Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-01-01</p> <p>... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile 8... PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 8 Figure 8 to Subpart A of Part 1209—Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile EC03OC91...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title16-vol2/pdf/CFR-2014-title16-vol2-part1209-subpartA-app8.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title16-vol2/pdf/CFR-2014-title16-vol2-part1209-subpartA-app8.pdf"><span>16 CFR Figure 8 to Subpart A of... - Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-01-01</p> <p>... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile 8... PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt. A, Fig. 8 Figure 8 to Subpart A of Part 1209—Standard Radiant <span class="hlt">Heat</span> Energy <span class="hlt">Flux</span> Profile EC03OC91...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812884M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812884M"><span>The <span class="hlt">radiative</span> <span class="hlt">heating</span> response to climate change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maycock, Amanda</p> <p>2016-04-01</p> <p>The structure and magnitude of <span class="hlt">radiative</span> <span class="hlt">heating</span> rates in the atmosphere can change markedly in response to climate forcings; diagnosing the causes of these changes can aid in understanding parts of the large-scale circulation response to climate change. This study separates the relative drivers of projected changes in longwave and shortwave <span class="hlt">radiative</span> <span class="hlt">heating</span> rates over the 21st century into contributions from <span class="hlt">radiatively</span> active gases, such as carbon dioxide, ozone and water vapour, and from changes in atmospheric and surface temperatures. Results are shown using novel <span class="hlt">radiative</span> diagnostics applied to timeslice experiments from the UM-UKCA chemistry-climate model; these online estimates are compared to offline <span class="hlt">radiative</span> transfer calculations. Line-by-line calculations showing spectrally-resolved changes in <span class="hlt">heating</span> rates due to different gases will also be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000056863','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000056863"><span>Critical <span class="hlt">Heat</span> <span class="hlt">Flux</span> in Pool Boiling on Metal-Graphite Composite Surfaces</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhang, Nengli; Yang, Wen-Jei; Chao, David F.; Chao, David F. (Technical Monitor)</p> <p>2000-01-01</p> <p>A study is conducted on high <span class="hlt">heat-flux</span> pool boiling of pentane on micro-configured composite surfaces. The boiling surfaces are copper-graphite (Cu-Gr) and aluminum-graphite (Al-Gr) composites with a fiber volume concentration of 50%. The micro-graphite fibers embedded in the matrix contribute to a substantial enhancement in boiling <span class="hlt">heat</span>-transfer performance. Correlation equations are obtained for both the isolated and coalesced bubble regimes, utilizing a mathematical model based on a metal-graphite, two-tier configuration with the aid of experimental data. A new model to predict the critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) on the composites is proposed to explain the fundamental aspects of the boiling phenomena. Three different factors affecting the CHF are considered in the model. Two of them are expected to become the main agents driving vapor volume detachment under microgravity conditions, using the metal-graphite composite surfaces as the <span class="hlt">heating</span> surface and using liquids with an unusual Marangoni effect as the working fluid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000BoLMe..95..271O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000BoLMe..95..271O"><span>Stability Effects on <span class="hlt">Heat</span> and Moisture <span class="hlt">Fluxes</span> at Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oost, W. A.; Jacobs, C. M. J.; van Oort, C.</p> <p></p> <p>During the 1996 ASGAMAGE experiment we measured windspeed, air temperature Ta, watertemperature Ts, humidity and the momentum,<span class="hlt">heat</span> and moisture <span class="hlt">fluxes</span> at a research platform offthe Dutch coast. For each quantity we used several(sets of) instruments simultaneously. This allowed usto make an extensive assessment of the quality of themeasurements and to find optimal values for thevarious quantities for each run. From these values wecalculated CH and CE, theStanton and Dalton numbers, and reduced them to 10-mheight and neutral conditions. For this reductionwe made a separate analysis for the effect ofinclusion or non-inclusion of the assumption that theroughness length for <span class="hlt">heat</span> or moisture is the same forthe neutral and non-neutral cases. Differences inthe reduced data due to this assumption turned out tobe well within the measurement error.For CH we distinguished three separategroups of data: stable (A), unstable witha s (B) and unstablewith thetas;a > s (C), with indicating the potential temperature.The stable data separate into two groups, depending onwater temperature and/or the wave field. The data ofgroup B showed a relation with wave age. The data ofgroup C consistently gave negative values forCH, a result that might indicate conversion oflatent <span class="hlt">heat</span> into sensible <span class="hlt">heat</span> through condensation ofwater vapour just above the water surface. An attemptto re-analyse the data in terms of density <span class="hlt">fluxes</span>,combining the effects of <span class="hlt">heat</span> and moisture, still gavenegative transfer coefficients for group C.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhDT.......232H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhDT.......232H"><span>Critical <span class="hlt">heat</span> <span class="hlt">flux</span> in subcooled flow boiling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hall, David Douglas</p> <p></p> <p>The critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) phenomenon was investigated for water flow in tubes with particular emphasis on the development of methods for predicting CHF in the subcooled flow boiling regime. The Purdue University Boiling and Two-Phase Flow Laboratory (PU-BTPFL) CHF database for water flow in a uniformly <span class="hlt">heated</span> tube was compiled from the world literature dating back to 1949 and represents the largest CHF database ever assembled with 32,544 data points from over 100 sources. The superiority of this database was proven via a detailed examination of previous databases. The PU-BTPFL CHF database is an invaluable tool for the development of CHF correlations and mechanistic models that are superior to existing ones developed with smaller, less comprehensive CHF databases. In response to the many inaccurate and inordinately complex correlations, two nondimensional, subcooled CHF correlations were formulated, containing only five adjustable constants and whose unique functional forms were determined without using a statistical analysis but rather using the parametric trends observed in less than 10% of the subcooled CHF data. The correlation based on inlet conditions (diameter, <span class="hlt">heated</span> length, mass velocity, pressure, inlet quality) was by far the most accurate of all known subcooled CHF correlations, having mean absolute and root-mean-square (RMS) errors of 10.3% and 14.3%, respectively. The outlet (local) conditions correlation was the most accurate correlation based on local CHF conditions (diameter, mass velocity, pressure, outlet quality) and may be used with a nonuniform axial <span class="hlt">heat</span> <span class="hlt">flux</span>. Both correlations proved more accurate than a recent CHF look-up table commonly employed in nuclear reactor thermal hydraulic computer codes. An interfacial lift-off, subcooled CHF model was developed from a consideration of the instability of the vapor-liquid interface and the fraction of <span class="hlt">heat</span> required for liquid-vapor conversion as opposed to that for bulk liquid <span class="hlt">heating</span>. Severe</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/5978','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/5978"><span>Charring rate of wood exposed to a constant <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>R. H. White; H. C. Tran</p> <p>1996-01-01</p> <p>A critical factor in the fire endurance of a wood member is its rate of charring. Most available charring rate data have been obtained using the time-temperature curves of the standard fire resistance tests (ASTM E 119 and ISO 834) to define the fire exposure. The increased use of <span class="hlt">heat</span> release calorimeters using exposures of constant <span class="hlt">heat</span> <span class="hlt">flux</span> levels has broadened the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910007159','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910007159"><span>An inter-comparison of surface energy <span class="hlt">flux</span> measurement systems used during FIFE, 1987</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nie, D.; Kanemasu, E. T.; Fritschen, L. J.; Weaver, H.; Smith, E. A.; Verma, S. B.; Field, R. T.; Kustas, W.; Stewart, J. B.</p> <p>1990-01-01</p> <p>During the first International Satellite Land Surface Climatology Program Field Experiment (FIFE-87), surface energy <span class="hlt">fluxes</span> were measured at 22 <span class="hlt">flux</span> sites by nine groups of scientists using different measuring systems. A rover Bowen ratio station was taken to nearly all the <span class="hlt">flux</span> stations to serve as a reference for estimating the instrument related differences. The rover system was installed within a few meters from the host instrument of a site. Net <span class="hlt">radiation</span>, Bowen ratio, and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> were compared between the rover and the host for the stations visited. Linear regression analysis was used to examine the relationship between rover measurements and host measurements. These inter-comparisons are needed to examine the influence of instrumentation on measurement uncertainty. Highly significant effects of instrument type were detected from these comparisons. Instruments of the same type showed average differences of less than 5 percent for net <span class="hlt">radiation</span>, 10 percent for Bowen ratio, and 6 percent for latent <span class="hlt">heat</span> <span class="hlt">flux</span>. The corresponding average differences for different types of instruments can be up to 10, 30, and 20 percent respectively. The Didcot net radiometer gave higher net <span class="hlt">radiation</span> while the Swissteco type showed lower values, as compared to the corrected REBS model. The 4-way components methed and the Thornswaite type give similar values to the REBS. The SERBS type Bowen ratio systems exhibit slightly lower Bowen ratios and thus higher latent <span class="hlt">heat</span> <span class="hlt">fluxes</span>, compared to the AZET systems. Eddy correlation systems showed slightly lower latent <span class="hlt">heat</span> <span class="hlt">flux</span> in comparison to the Bowen ratio systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010BGeo....7..301L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010BGeo....7..301L"><span><span class="hlt">Heat</span> storage in forest biomass improves energy balance closure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lindroth, A.; Mölder, M.; Lagergren, F.</p> <p>2010-01-01</p> <p>Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the <span class="hlt">heat</span> storage in the tree biomass. The estimated <span class="hlt">heat</span> <span class="hlt">flux</span> in the sample trees and data on biomass distributions were used to scale up to stand level biomass <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The rate of change of sensible and latent <span class="hlt">heat</span> storage in the air layer below the level of the <span class="hlt">flux</span> measurements was estimated from air temperature and humidity profile measurements and soil <span class="hlt">heat</span> <span class="hlt">flux</span> was estimated from <span class="hlt">heat</span> <span class="hlt">flux</span> plates and soil temperature measurements. The <span class="hlt">fluxes</span> of sensible and latent <span class="hlt">heat</span> from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass <span class="hlt">heat</span> <span class="hlt">flux</span> was the largest of the estimated storage components and varied between 40 and -35 W m-2 on summer days with nice weather. Averaged over two months the diurnal maximum of total <span class="hlt">heat</span> storage was 45 W m-2 and the minimum was -35 W m-2. The soil <span class="hlt">heat</span> <span class="hlt">flux</span> and the sensible <span class="hlt">heat</span> storage in air were out of phase with the biomass <span class="hlt">flux</span> and they reached maximum values that were about 75% of the maximum of the tree biomass <span class="hlt">heat</span> storage. The energy balance closure improved significantly when the total <span class="hlt">heat</span> storage was added to the turbulent <span class="hlt">fluxes</span>. The slope of a regression line with sum of <span class="hlt">fluxes</span> and storage as independent and net <span class="hlt">radiation</span> as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible <span class="hlt">heat</span> <span class="hlt">flux</span> dropped to nearly zero, the total storage matched the net <span class="hlt">radiation</span> very well. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. -0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy covariance</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1038927-heat-flux-analysis-reacting-thermite-spray-impingent-substrate','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1038927-heat-flux-analysis-reacting-thermite-spray-impingent-substrate"><span><span class="hlt">Heat</span> <span class="hlt">Flux</span> Analysis of a Reacting Thermite Spray Impingent on a Substrate</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Eric S. Collins; Michelle L. Pantoya; Michael A. Daniels</p> <p>2012-03-01</p> <p>Spray combustion from a thermite reaction is a new area of research relevant to localized energy generation applications, such as welding or cutting. In this study, we characterized the <span class="hlt">heat</span> <span class="hlt">flux</span> of combustion spray impinging on a target from a nozzle for three thermite mixtures. The reactions studied include aluminum (Al) with iron oxide (Fe2O3), Al with copper oxide (CuO), and Al with molybdenum oxide (MoO3). Several standoff distances (i.e., distance from the nozzle exit to the target) were analyzed. A fast response <span class="hlt">heat</span> <span class="hlt">flux</span> sensor was engineered for this purpose and is discussed in detail. Results correlated substrate damagemore » to a threshold <span class="hlt">heat</span> <span class="hlt">flux</span> of 4550 W/cm2 for a fixed-nozzle configuration. Also, higher gas-generating thermites were shown to produce a widely dispersed spray and be less effective at imparting kinetic energy damage to a target. These results provide an understanding of the role of thermal and physical properties (i.e., such as <span class="hlt">heat</span> of combustion, gas generation, and particle size) on thermite spray combustion performance measured by damaging a target substrate.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JPFR...75..594K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JPFR...75..594K"><span>Development of High-Z Materials with Improved Toughness for High <span class="hlt">Heat</span> <span class="hlt">Flux</span> Components</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurishita, Hiroaki; Kitsunai, Yuji; Kuwabara, Tetsuya; Hasegawa, Masayuki; Hiraoka, Yutaka; Takida, Tomohiro; Igarashi, Tadashi</p> <p></p> <p>Tungsten is superior to other materials in physical and mechanical properties for use as high <span class="hlt">heat</span> <span class="hlt">flux</span> components in future fusion reactors. The key issue of the metal is to improve the low temperature embrittlement, the recrystallization embrittlement and the irradiation embrittlement. An alloy design and microstructure control for achieving simultaneous and significant improvements in those embrittlements are described and are applied to tungsten and molybdenum which has quite similar properties as tungsten. The result of the application is presented for each of the embrittlement, with considerable success. Emphasis is placed on the occurrence of RIDU (<span class="hlt">Radiation</span> Induced Ductilization) because RIDU is expected to provide the scenario to overcome severe irradiation embrittlement that is the most crucial problem for structure materials exposed in fusion environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO51D..01B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO51D..01B"><span>Intercomparison of Air-Sea <span class="hlt">Fluxes</span> in the Bay of Bengal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buckley, J.; Weller, R. A.; Farrar, J. T.; Tandon, A.</p> <p>2016-02-01</p> <p><span class="hlt">Heat</span> and momentum exchange between the air and sea in the Bay of Bengal is an important driver of atmospheric convection during the Asian Monsoon. Warm sea surface temperatures resulting from salinity stratified shallow mixed layers trigger widespread showers and thunderstorms. In this study, we compare atmospheric reanalysis <span class="hlt">flux</span> products to air-sea <span class="hlt">flux</span> values calculated from shipboard observations from four cruises and an air-sea <span class="hlt">flux</span> mooring in the Bay of Bengal as part of the Air-Sea Interactions in the Northern Indian Ocean (ASIRI) experiment. Comparisons with months of mooring data show that most long timescale reanalysis error arises from the overestimation of longwave and shortwave <span class="hlt">radiation</span>. Ship observations and select data from the air-sea <span class="hlt">flux</span> mooring reveals significant errors on shorter timescales (2-4 weeks) which are greatly influenced by errors in shortwave <span class="hlt">radiation</span> and latent and sensible <span class="hlt">heat</span>. During these shorter periods, the reanalyses fail to properly show sharp decreases in air temperature, humidity, and shortwave <span class="hlt">radiation</span> associated with mesoscale convective systems. Simulations with the Price-Weller-Pinkel (PWP) model show upper ocean mixing and deepening mixed layers during these events that effect the long term upper ocean stratification. Mesoscale convective systems associated with cloudy skies and cold and dry air can reduce net <span class="hlt">heat</span> into the ocean for minutes to a few days, significantly effecting air-sea <span class="hlt">heat</span> transfer, upper ocean stratification, and ocean surface temperature and salinity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9038Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9038Z"><span>Comparison of 37 months global net <span class="hlt">radiation</span> <span class="hlt">flux</span> derived from PICARD-BOS over the same period observations of CERES and ARGO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Ping; Wild, Martin</p> <p>2016-04-01</p> <p>The absolute level of the global net <span class="hlt">radiation</span> <span class="hlt">flux</span> (NRF) is fixed at the level of [0.5-1.0] Wm-2 based on the ocean <span class="hlt">heat</span> content measurements [1]. The space derived global NRF is at the same order of magnitude than the ocean [2]. Considering the atmosphere has a negligible effects on the global NRF determination, the surface global NRF is consistent with the values determined from space [3]. Instead of studying the absolute level of the global NRF, we focus on the interannual variation of global net <span class="hlt">radiation</span> <span class="hlt">flux</span>, which were derived from the PICARD-BOS experiment and its comparison with values over the same period but obtained from the NASA-CERES system and inferred from the ocean <span class="hlt">heat</span> content survey by ARGO network. [1] Allan, Richard P., Chunlei Liu, Norman G. Loeb, Matthew D. Palmer, Malcolm Roberts, Doug Smith, and Pier-Luigi Vidale (2014), Changes in global net <span class="hlt">radiative</span> imbalance 1985-2012, Geophysical Research Letters, 41 (no.15), 5588-5597. [2] Loeb, Norman G., John M. Lyman, Gregory C. Johnson, Richard P. Allan, David R. Doelling, Takmeng Wong, Brian J. Soden, and Graeme L. Stephens (2012), Observed changes in top-of-the-atmosphere <span class="hlt">radiation</span> and upper-ocean <span class="hlt">heating</span> consistent within uncertainty, Nature Geoscience, 5 (no.2), 110-113. [3] Wild, Martin, Doris Folini, Maria Z. Hakuba, Christoph Schar, Sonia I. Seneviratne, Seiji Kato, David Rutan, Christof Ammann, Eric F. Wood, and Gert Konig-Langlo (2015), the energy balance over land and oceans: an assessment based on direct observations and CMIP5 climate models, Climate Dynamics, 44 (no.11-12), 3393-3429.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123.1381R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123.1381R"><span>Coordinates for Representing <span class="hlt">Radiation</span> Belt Particle <span class="hlt">Flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roederer, Juan G.; Lejosne, Solène</p> <p>2018-02-01</p> <p>Fifty years have passed since the parameter "L-star" was introduced in geomagnetically trapped particle dynamics. It is thus timely to review the use of adiabatic theory in present-day studies of the <span class="hlt">radiation</span> belts, with the intention of helping to prevent common misinterpretations and the frequent confusion between concepts like "distance to the equatorial point of a field line," McIlwain's L-value, and the trapped particle's adiabatic L* parameter. And too often do we miss in the recent literature a proper discussion of the extent to which some observed time and space signatures of particle <span class="hlt">flux</span> could simply be due to changes in magnetospheric field, especially insofar as off-equatorial particles are concerned. We present a brief review on the history of <span class="hlt">radiation</span> belt parameterization, some "recipes" on how to compute adiabatic parameters, and we illustrate our points with a real event in which magnetospheric disturbance is shown to adiabatically affect the particle <span class="hlt">fluxes</span> measured onboard the Van Allen Probes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NuPhS.248..118P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NuPhS.248..118P"><span>Optimization of the Mu2e Production Solenoid <span class="hlt">Heat</span> and <span class="hlt">Radiation</span> Shield</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pronskikh, V. S.; Coleman, R.; Glenzinski, D.; Kashikhin, V. V.; Mokhov, N. V.</p> <p>2014-03-01</p> <p>The Mu2e experiment at Fermilab is designed to study the conversion of a negative muon to electron in the field of a nucleus without emission of neutrinos. Observation of this process would provide unambiguous evidence for physics beyond the Standard Model, and can point to new physics beyond the reach of the LHC. The main parts of the Mu2e apparatus are its superconducting solenoids: Production Solenoid (PS), Transport Solenoid (TS), and Detector Solenoid (DS). Being in the vicinity of the beam, PS magnets are most subjected to the <span class="hlt">radiation</span> damage. In order for the PS superconducting magnet to operate reliably, the peak neutron <span class="hlt">flux</span> in the PS coils must be reduced by 3 orders of magnitude by means of sophisticatedly designed massive <span class="hlt">Heat</span> and <span class="hlt">Radiation</span> Shield (HRS), optimized for the performance and cost. An issue with <span class="hlt">radiation</span> damage is related to large residual electrical resistivity degradation in the superconducting coils, especially its Al stabilizer. A detailed MARS15 analysis and optimization of the HRS has been carried out both to satisfy the Mu2e requirements to the <span class="hlt">radiation</span> quantities (such as displacements per atom, peak temperature and power density in the coils, absorbed dose in the insulation, and dynamic <span class="hlt">heat</span> load) and cost. Results of MARS15 simulations of these <span class="hlt">radiation</span> quantities are reported and optimized HRS models are presented; it is shown that design levels satisfy all requirements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770055598&hterms=Bacillus+subtilis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DBacillus%2Bsubtilis','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770055598&hterms=Bacillus+subtilis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DBacillus%2Bsubtilis"><span>Effect of combined <span class="hlt">heat</span> and <span class="hlt">radiation</span> on microbial destruction</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fisher, D. A.; Pflug, I. J.</p> <p>1977-01-01</p> <p>A series of experiments at several levels of relative humidity and <span class="hlt">radiation</span> dose rates was carried out using spores of Bacillus subtilis var. niger to evaluate the effect of <span class="hlt">heat</span> alone, <span class="hlt">radiation</span> alone, and a combination of <span class="hlt">heat</span> and <span class="hlt">radiation</span>. Combined <span class="hlt">heat</span> and <span class="hlt">radiation</span> treatment of microorganisms yields a destruction rate greater than the additive rates of the independent agents. The synergistic mechanism shows a proportional dependency on <span class="hlt">radiation</span> dose rate, an Arrhenius dependence on temperature, and a dependency on relative humidity. Maximum synergism occurs under conditions where <span class="hlt">heat</span> and <span class="hlt">radiation</span> individually destroy microorganisms at approximately equal rates. Larger synergistic advantage is possible at low relative humidities rather than at high relative humidities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930036602&hterms=four+seasons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dfour%2Bseasons','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930036602&hterms=four+seasons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dfour%2Bseasons"><span>Surface energy <span class="hlt">fluxes</span> on four slope sites during FIFE 1988</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nie, D.; Demetriades-Shah, T.; Kanemasu, E. T.</p> <p>1992-01-01</p> <p>Four slopes (facing north, south, east, and west) in the Konza Prairie Research Natural Area were selected to study the effect of topography on surface energy balance and other micrometeorological variables. Energy <span class="hlt">fluxes</span>, air temperature, and vapor pressure were measured on the slopes throughout the 1988 growing season. Net <span class="hlt">radiation</span> was highest on the south facing slope and lowest on the north facing slope, and the difference was more than 150 W/sq m (20-30 percent) at solar noon. For daily averages the difference was about 25 W/sq m (15 percent) early in the season and increased to about 60 W/sq m (30-50 percent) in September. Soil <span class="hlt">heat</span> <span class="hlt">fluxes</span> were similar for all the slopes. The absolute values of sensible <span class="hlt">heat</span> <span class="hlt">flux</span> were consistently lower on the north facing slope compared with other slopes. The south facing slope had the greatest day-to-day fluctuation in latent <span class="hlt">heat</span> <span class="hlt">flux</span> as a result of the interaction of net <span class="hlt">radiation</span>, soil moisture, and green leaf area. Differences were found in the partitioning of the available energy among the slopes, and the north facing slope had a higher percentage of energy dissipated into latent <span class="hlt">heat</span> <span class="hlt">flux</span>. The north facing slope had higher air temperatures during the day and higher vapor pressures both during the day and at night when the wind was from the south.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/5724910','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/5724910"><span>GRAY: a program to calculate gray-body <span class="hlt">radiation</span> <span class="hlt">heat</span>-transfer view factors from black-body view factors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wong, R. L.</p> <p>1976-06-14</p> <p>Program GRAY is written to perform the matrix manipulations necessary to convert black-body <span class="hlt">radiation</span> <span class="hlt">heat</span>-transfer view factors to gray-body view factors as required by thermal analyzer codes. The black-body view factors contain only geometric relationships. Program GRAY allows the effects of multiple gray-body reflections to be included. The resulting effective gray-body factors can then be used with the corresponding fourth-power temperature differences to obtain the net <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span>. The program is written to accept a matrix input or the card image output generated by the black-body view factor program CNVUFAC. The resulting card image output generated by GRAY ismore » in a form usable by the TRUMP thermal analyzer.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011WRR....47.5545M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011WRR....47.5545M"><span>Estimation of evaporation and sensible <span class="hlt">heat</span> <span class="hlt">flux</span> from open water using a large-aperture scintillometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McJannet, D. L.; Cook, F. J.; McGloin, R. P.; McGowan, H. A.; Burn, S.</p> <p>2011-05-01</p> <p>The use of scintillometers to determine sensible and latent <span class="hlt">heat</span> <span class="hlt">flux</span> is becoming increasingly common because of their ability to quantify convective <span class="hlt">fluxes</span> over distances of hundreds of meters to several kilometers. The majority of investigations using scintillometry have focused on processes above land surfaces, but here we propose a new methodology for obtaining sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> from a scintillometer deployed over open water. This methodology has been tested by comparison with eddy covariance measurements and through comparison with alternative scintillometer calculation approaches that are commonly used in the literature. The methodology is based on linearization of the Bowen ratio, which is a common assumption in models such as Penman's model and its derivatives. Comparison of latent <span class="hlt">heat</span> <span class="hlt">flux</span> estimates from the eddy covariance system and the scintillometer showed excellent agreement across a range of weather conditions and <span class="hlt">flux</span> rates, giving a high level of confidence in scintillometry-derived latent <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The proposed approach produced better estimates than other scintillometry calculation methods because of the reliance of alternative methods on measurements of water temperature or water body <span class="hlt">heat</span> storage, which are both notoriously hard to quantify. The proposed methodology requires less instrumentation than alternative scintillometer calculation approaches, and the spatial scales of required measurements are arguably more compatible. In addition to scintillometer measurements of the structure parameter of the refractive index of air, the only measurements required are atmospheric pressure, air temperature, humidity, and wind speed at one height over the water body.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810005654','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810005654"><span>New methods to detect particle velocity and mass <span class="hlt">flux</span> in arc-<span class="hlt">heated</span> ablation/erosion facilities</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brayton, D. B.; Bomar, B. W.; Seibel, B. L.; Elrod, P. D.</p> <p>1980-01-01</p> <p>Arc-<span class="hlt">heated</span> flow facilities with injected particles are used to simulate the erosive and ablative/erosive environments encountered by spacecraft re-entry through fog, clouds, thermo-nuclear explosions, etc. Two newly developed particle diagnostic techniques used to calibrate these facilities are discussed. One technique measures particle velocity and is based on the detection of thermal <span class="hlt">radiation</span> and/or chemiluminescence from the hot seed particles in a model ablation/erosion facility. The second technique measures a local particle rate, which is proportional to local particle mass <span class="hlt">flux</span>, in a dust erosion facility by photodetecting and counting the interruptions of a focused laser beam by individual particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.7262B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.7262B"><span>Anthropogenic <span class="hlt">heat</span> <span class="hlt">fluxes</span> over Moscow agglomeration and other Russian and world cities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belova, Iya; Ginzburg, Alexander</p> <p>2010-05-01</p> <p>Urbanization, particularly with respect to its sustainability, remains to be a great challenge in all regions of the world. Urbanization has an influence on soils, hydrology, and climate, these changes have effect on global climate, pollution, increase of anthropogenic greenhouse gases in the earth's atmosphere and human health. Thus anthropogenic <span class="hlt">heat</span> <span class="hlt">flux</span> is an important factor for estimation of development of global climate. The simple formula for anthropogenic <span class="hlt">heat</span> <span class="hlt">fluxes</span> (AHF) was proposed in the EGU General Assembly 2008 presentation [1] AHF = k × PD × EC, were PD is urban population density and EC is total energy consumption per capita. It was estimated that two of the world megacities - Seoul and Moscow - have the highest AHF values - 83 and 56 W/m2 correspondently. In presented paper it was studied the reasons of such high anthropogenic <span class="hlt">heat</span> <span class="hlt">fluxes</span> within Moscow region as well as AHF over the major Russian cities. It was shown that main reason of this circumstance is the administrative divisions in Moscow region. Moscow is ringed by Moscow circle motor road. Accordingly the city has sharply defined boundaries and densely populated residential suburbs are cut off and don't included in Moscow city administrative area. It was constructed the special graph to illuminate why Moscow city has such a high anthropogenic <span class="hlt">heat</span> factor and how much Moscow agglomeration AHF could be if consider not only Moscow city itself but also the nearest suburb towns. Using the data from World Bank [2] and Russian governmental statistic agency [3] anthropogenic <span class="hlt">heat</span> <span class="hlt">fluxes</span> for Russian cities with population more than 500 000 were estimated. Energy consumption data for different Russian regions were calculated by special routine using in the Web-atlas [4]. This research is supported by RAS Fundamental Research Project 'Influence of anthropogenic <span class="hlt">heat</span> <span class="hlt">fluxes</span> and aerosol pollution on <span class="hlt">heat</span> balance and climate of urbanized areas'. Other results of this project is presented in paper [5</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080014091&hterms=heat+exchanger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dheat%2Bexchanger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080014091&hterms=heat+exchanger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dheat%2Bexchanger"><span>A Freezable <span class="hlt">Heat</span> Exchanger for Space Suit <span class="hlt">Radiator</span> Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nabity, James A.; Mason, Georgia R.; Copeland, Robert J.; Trevino, Luis a.</p> <p>2008-01-01</p> <p>During an ExtraVehicular Activity (EVA), both the <span class="hlt">heat</span> generated by the astronaut s metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The <span class="hlt">heat</span> sources include the <span class="hlt">heat</span> of adsorption of metabolic CO2, the <span class="hlt">heat</span> of condensation of water, the <span class="hlt">heat</span> removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 1.58 kg (3.48 lbm), an additional 3.6 kg (8 lbm) of water are loaded into the unit, most of which is sublimated and lost to space, thus becoming the single largest expendable during an eight-hour EVA. Using a <span class="hlt">radiator</span> to reject <span class="hlt">heat</span> from the astronaut during an EVA can reduce the amount of expendable water consumed in the sublimator. <span class="hlt">Radiators</span> have no moving parts and are thus highly reliable. Past freezable <span class="hlt">radiators</span> have been too heavy, but the weight can be greatly reduced by placing a small and freeze tolerant <span class="hlt">heat</span> exchanger between the astronaut and <span class="hlt">radiator</span>, instead of making the very large <span class="hlt">radiator</span> freeze tolerant. Therefore, the key technological innovation to improve space suit <span class="hlt">radiator</span> performance was the development of a lightweight and freezable <span class="hlt">heat</span> exchanger that accommodates the variable <span class="hlt">heat</span> load generated by the astronaut. Herein, we present the <span class="hlt">heat</span> transfer performance of a newly designed <span class="hlt">heat</span> exchanger that endured several freeze / thaw cycles without any apparent damage. The <span class="hlt">heat</span> exchanger was also able to continuously turn down or turn up the <span class="hlt">heat</span> rejection to follow the variable load.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000APS..DPPWP1060H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000APS..DPPWP1060H"><span>Polar <span class="hlt">Radiation-Flux</span> Symmetry Measurements in Z-Pinch-Driven Hohlraums with Symmetric Double-Pinch Drive</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hanson, D. L.; Vesey, R. A.; Cuneo Porter, M. E., Jr.; Chandler, G. A.; Ruggles, L. E.; Simpson, W. W.; Seamen, H.; Primm, P.; Torres, J.; McGurn, J.; Gilliland, T. L.; Reynolds, P.; Hebron, D. E.; Dropinski, S. C.; Schroen-Carey, D. G.; Hammer, J. H.; Landen, O.; Koch, J.</p> <p>2000-10-01</p> <p>We are currently exploring symmetry requirements of the z-pinch-driven hohlraum concept [1] for high-yield inertial confinement fusion. In experiments on the Z accelerator, the burnthrough of a low-density self-backlit foam ball has been used to diagnose the large time-dependent <span class="hlt">flux</span> asymmetry of several single-sided-drive hohlraum geometries [2]. We are currently applying this technique to study polar <span class="hlt">radiation</span> <span class="hlt">flux</span> symmetry in a symmetric double z-pinch geometry. Wire arrays on opposite ends of the hohlraum, connected in series to a single current drive of 18 MA, implode and stagnate on axis, efficiently <span class="hlt">radiating</span> about 100 TW of x rays which <span class="hlt">heat</span> the secondary to 75 eV. Comparisons with 3-D radiosity and 2-D rad-hydro models of hohlraum symmetry performance will be presented. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000. 1 J. H. Hammer et al., Phys. Plasmas 6, 2129 (1999). 2 D. L. Hanson et al., Bull. Am. Phys. Soc. 44, 40 (1999).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGC23H1204B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGC23H1204B"><span>Influence of Solar and Thermal <span class="hlt">Radiation</span> on Future <span class="hlt">Heat</span> Stress Using CMIP5 Archive Driving the Community Land Model Version 4.5</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buzan, J. R.; Huber, M.</p> <p>2015-12-01</p> <p>The summer of 2015 has experienced major <span class="hlt">heat</span> waves on 4 continents, and <span class="hlt">heat</span> stress left ~4000 people dead in India and Pakistan. <span class="hlt">Heat</span> stress is caused by a combination of meteorological factors: temperature, humidity, and <span class="hlt">radiation</span>. The International Organization for Standardization (ISO) uses Wet Bulb Globe Temperature (WBGT)—an empirical metric this is calibrated with temperature, humidity, and radiation—for determining labor capacity during <span class="hlt">heat</span> stress. Unfortunately, most literature studying global <span class="hlt">heat</span> stress focuses on extreme temperature events, and a limited number of studies use the combination of temperature and humidity. Recent global assessments use WBGT, yet omit the <span class="hlt">radiation</span> component without recalibrating the metric.Here we explicitly calculate future WBGT within a land surface model, including <span class="hlt">radiative</span> <span class="hlt">fluxes</span> as produced by a modeled globe thermometer. We use the Community Land Model version 4.5 (CLM4.5), which is a component model of the Community Earth System Model (CESM), and is maintained by the National Center for Atmospheric Research (NCAR). To drive our CLM4.5 simulations, we use greenhouse gasses Representative Concentration Pathway 8.5 (business as usual), and atmospheric output from the CMIP5 Archive. Humans work in a variety of environments, and we place the modeled globe thermometer in a variety of environments. We modify CLM4.5 code to calculate solar and thermal <span class="hlt">radiation</span> <span class="hlt">fluxes</span> below and above canopy vegetation, and in bare ground. To calculate wet bulb temperature, we implemented the HumanIndexMod into CLM4.5. The temperature, wet bulb temperature, and <span class="hlt">radiation</span> fields are calculated at every model time step and are outputted 4x Daily. We use these fields to calculate WBGT and labor capacity for two time slices: 2026-2045 and 2081-2100.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EL....11964001P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EL....11964001P"><span>Local rectification of <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pons, M.; Cui, Y. Y.; Ruschhaupt, A.; Simón, M. A.; Muga, J. G.</p> <p>2017-09-01</p> <p>We present a chain-of-atoms model where <span class="hlt">heat</span> is rectified, with different <span class="hlt">fluxes</span> from the hot to the cold baths located at the chain boundaries when the temperature bias is reversed. The chain is homogeneous except for boundary effects and a local modification of the interactions at one site, the “impurity”. The rectification mechanism is due here to the localized impurity, the only asymmetrical element of the structure, apart from the externally imposed temperature bias, and does not rely on putting in contact different materials or other known mechanisms such as grading or long-range interactions. The effect survives if all interaction forces are linear except the ones for the impurity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...48.1089L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...48.1089L"><span>A multi-model ensemble view of winter <span class="hlt">heat</span> <span class="hlt">flux</span> dynamics and the dipole mode in the Mediterranean Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liguori, Giovanni; Di Lorenzo, Emanuele; Cabos, William</p> <p>2017-02-01</p> <p>Changes in surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> affect several climate processes controlling the Mediterranean climate. These include the winter formation of deep waters, which is the primary driver of the Mediterranean Sea overturning circulation. Previous studies that characterize the spatial and temporal variability of surface <span class="hlt">heat</span> <span class="hlt">flux</span> anomalies over the basin reveal the existence of two statistically dominant patterns of variability: a monopole of uniform sign and an east-west dipole of opposite signs. In this work, we use the 12 regional climate model ensemble from the EU-FP6 ENSEMBLES project to diagnose the large-scale atmospheric processes that control the variability of <span class="hlt">heat</span> <span class="hlt">fluxes</span> over the Mediterranean Sea from interannual to decadal timescales (here defined as timescales > 6 year). Our findings suggest that while the monopole structure captures variability in the winter-to-winter domain-average net <span class="hlt">heat</span> <span class="hlt">flux</span>, the dipole pattern tracks changes in the Mediterranean climate that are connected to the East Atlantic/Western Russia (EA/WR) atmospheric teleconnection pattern. Furthermore, while the monopole exhibits significant differences in the spatial structure across the multi-model ensemble, the dipole pattern is very robust and more clearly identifiable in the anomaly maps of individual years. A <span class="hlt">heat</span> budget analysis of the dipole pattern reveals that changes in winds associated with the EA/WR pattern exert dominant control through both a direct effect on the latent <span class="hlt">heat</span> <span class="hlt">flux</span> (i.e., wind speed) and an indirect effect through specific humidity (e.g., wind advection). A simple reconstruction of the <span class="hlt">heat</span> <span class="hlt">flux</span> variability over the deep-water formation regions of the Gulf of Lion and the Aegean Sea reveals that the combination of the monopole and dipole time series explains over 90 % of the <span class="hlt">heat</span> <span class="hlt">flux</span> variance in these regions. Given the important role that surface <span class="hlt">heat</span> <span class="hlt">flux</span> anomalies play in deep-water formation and the regional climate, improving our knowledge on the dynamics</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012266','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012266"><span>Spacecraft <span class="hlt">Radiator</span> Freeze Protection Using a Regenerative <span class="hlt">Heat</span> Exchanger</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ungar, Eugene K.; Schunk, Richard G.</p> <p>2011-01-01</p> <p>An active thermal control system architecture has been modified to include a regenerative <span class="hlt">heat</span> exchanger (regenerator) inboard of the <span class="hlt">radiator</span>. Rather than using a <span class="hlt">radiator</span> bypass valve a regenerative <span class="hlt">heat</span> exchanger is placed inboard of the <span class="hlt">radiators</span>. A regenerator cold side bypass valve is used to set the return temperature. During operation, the regenerator bypass flow is varied, mixing cold <span class="hlt">radiator</span> return fluid and warm regenerator outlet fluid to maintain the system setpoint. At the lowest <span class="hlt">heat</span> load for stable operation, the bypass flow is closed off, sending all of the flow through the regenerator. This lowers the <span class="hlt">radiator</span> inlet temperature well below the system set-point while maintaining full flow through the <span class="hlt">radiators</span>. By using a regenerator bypass flow control to maintain system setpoint, the required minimum <span class="hlt">heat</span> load to avoid <span class="hlt">radiator</span> freezing can be reduced by more than half compared to a <span class="hlt">radiator</span> bypass system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRD..121.7853K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRD..121.7853K"><span>Re-examining the roles of surface <span class="hlt">heat</span> <span class="hlt">flux</span> and latent <span class="hlt">heat</span> release in a "hurricane-like" polar low over the Barents Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolstad, Erik W.; Bracegirdle, Thomas J.; Zahn, Matthias</p> <p>2016-07-01</p> <p>Polar lows are intense mesoscale cyclones that occur at high latitudes in both hemispheres during winter. Their sometimes evidently convective nature, fueled by strong surface <span class="hlt">fluxes</span> and with cloud-free centers, have led to some polar lows being referred to as "arctic hurricanes." Idealized studies have shown that intensification by hurricane development mechanisms is theoretically possible in polar winter atmospheres, but the lack of observations and realistic simulations of actual polar lows have made it difficult to ascertain if this occurs in reality. Here the roles of surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> and latent <span class="hlt">heat</span> release in the development of a Barents Sea polar low, which in its cloud structures showed some similarities to hurricanes, are studied with an ensemble of sensitivity experiments, where latent <span class="hlt">heating</span> and/or surface <span class="hlt">fluxes</span> of sensible and latent <span class="hlt">heat</span> were switched off before the polar low peaked in intensity. To ensure that the polar lows in the sensitivity runs did not track too far away from the actual environmental conditions, a technique known as spectral nudging was applied. This was shown to be crucial for enabling comparisons between the different model runs. The results presented here show that (1) no intensification occurred during the mature, postbaroclinic stage of the simulated polar low; (2) surface <span class="hlt">heat</span> <span class="hlt">fluxes</span>, i.e., air-sea interaction, were crucial processes both in order to attain the polar low's peak intensity during the baroclinic stage and to maintain its strength in the mature stage; and (3) latent <span class="hlt">heat</span> release played a less important role than surface <span class="hlt">fluxes</span> in both stages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990080915','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990080915"><span>Diffusion, <span class="hlt">Fluxes</span>, Friction Forces, and Joule <span class="hlt">Heating</span> in Two-Temperature Multicomponent Magnetohydrodynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chang, C. H.</p> <p>1999-01-01</p> <p>The relationship between Joule <span class="hlt">heating</span>, diffusion <span class="hlt">fluxes</span>, and friction forces has been studied for both total and electron thermal energy equations, using general expressions for multicomponent diffusion in two-temperature plasmas with the velocity dependent Lorentz force acting on charged species in a magnetic field. It is shown that the derivation of Joule <span class="hlt">heating</span> terms requires both diffusion <span class="hlt">fluxes</span> and friction between species which represents the resistance experienced by the species moving at different relative velocities. It is also shown that the familiar Joule <span class="hlt">heating</span> term in the electron thermal energy equation includes artificial effects produced by switching the convective velocity from the species velocity to the mass-weighted velocity, and thus should not be ignored even when there is no net energy dissipation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A33B2351M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A33B2351M"><span>Development of a New Methodology for Computing Surface Sensible <span class="hlt">Heat</span> <span class="hlt">Fluxes</span> using Thermal Imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morrison, T. J.; Calaf, M.; Fernando, H. J.; Price, T. A.; Pardyjak, E.</p> <p>2017-12-01</p> <p>Current numerical weather predication models utilize similarity to characterize momentum, moisture, and <span class="hlt">heat</span> <span class="hlt">fluxes</span>. Such formulations are only valid under the ideal assumptions of spatial homogeneity, statistical stationary, and zero subsidence. However, recent surface temperature measurements from the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program on the Salt Flats of Utah's West desert, show that even under the most a priori ideal conditions, heterogeneity of the aforementioned variables exists. We present a new method to extract spatially-distributed measurements of surface sensible <span class="hlt">heat</span> <span class="hlt">flux</span> from thermal imagery. The approach consists of using a surface energy budget, where the ground <span class="hlt">heat</span> <span class="hlt">flux</span> is easily computed from limited measurements using a force-restore-type methodology, the latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> are neglected, and the energy storage is computed using a lumped capacitance model. Preliminary validation of the method is presented using experimental data acquired from a nearby sonic anemometer during the MATERHORN campaign. Additional evaluation is required to confirm the method's validity. Further decomposition analysis of on-site instrumentation (thermal camera, cold-hotwire probes, and sonic anemometers) using Proper Orthogonal Decomposition (POD), and wavelet analysis, reveals time scale similarity between the flow and surface fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1076472-reduced-model-simulations-scrape-off-layer-heat-flux-width-comparison-experiment','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1076472-reduced-model-simulations-scrape-off-layer-heat-flux-width-comparison-experiment"><span>Reduced model simulations of the scrape-off-layer <span class="hlt">heat-flux</span> width and comparison with experiment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Myra, J. R.; Russell, D. A.; D’Ippolito, D. A.; ...</p> <p>2011-01-01</p> <p>Reduced model simulations of turbulence in the edge and scrape-off-layer (SOL) region of a spherical torus or tokamak plasma are employed to address the physics of the scrape-off-layer <span class="hlt">heat</span> <span class="hlt">flux</span> width. The simulation model is an electrostatic two-dimensional fluid turbulence model, applied in the plane perpendicular to the magnetic field at the outboard midplane of the torus. The model contains curvature-driven-interchange modes, sheath losses, and both perpendicular turbulent diffusive and convective (blob) transport. These transport processes compete with classical parallel transport to set the SOL width. Midplane SOL profiles of density, temperature and parallel <span class="hlt">heat</span> <span class="hlt">flux</span> are obtained from themore » simulation and compared with experimental results from the National Spherical Torus Experiment (NSTX) to study the scaling of the <span class="hlt">heat</span> <span class="hlt">flux</span> width with power and plasma current. It is concluded that midplane turbulence is the main contributor to the SOL <span class="hlt">heat</span> <span class="hlt">flux</span> width for the low power H-mode discharges studied, while additional physics is required to explain the plasma current scaling of the SOL <span class="hlt">heat</span> <span class="hlt">flux</span> width observed experimentally in higher power discharges. Intermittent separatrix spanning convective cells are found to be the main mechanism that sets the near-SOL width in the simulations. The roles of sheared flows and blob trapping vs. emission are discussed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AIPC..766..551H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AIPC..766..551H"><span>Simplified Analysis of Airspike <span class="hlt">Heat</span> <span class="hlt">Flux</span> Into Lightcraft Thermal Management System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Head, Dean R.; Seo, Junghwa; Cassenti, Brice N.; Myrabo, Leik N.</p> <p>2005-04-01</p> <p>An approximate method is presented for estimating the airspike <span class="hlt">heat</span> <span class="hlt">flux</span> into a 9-meter diameter lightcraft, integrated over its flight to low Earth orbit. The super-pressure lightcraft's exotic twin-hull, sandwich structure is assumed to be fabricated from SiC/SiC thin-film ceramic matrix composites of semiconductor grade purity, giving superior structural properties while being transparent to 35-GHz microwave <span class="hlt">radiation</span>. The vehicle's MHD slipstream accelerator engine is energized by an annular microwave power beam — converted on-board into DC electric power by two concentric, water-cooled microwave rectenna arrays. The vehicle's airspike is created by a central 3-m diameter laser beam that sustains a laser-supported detonation wave at a distance of 10-m ahead of the craft; the LSD wave propagates up the beam with a velocity that matches the lightcraft's flight speed. The simplified analysis, which is based on aerodynamic <span class="hlt">heating</span> during re-entry, shows that helium flowing at a velocity of 10 m/s through the lightcraft's double-hull is sufficient to keep the outer, 0.13-mm thick SiC skin safely under its maximum service temperature. The interior helium pressurant that maintains the structural integrity of this exotic pressure-airship, increases in temperature by only 25 K during the flight to LEO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760015408','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760015408"><span><span class="hlt">Heat</span> pipe <span class="hlt">radiators</span> for space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sellers, J. P.</p> <p>1976-01-01</p> <p>Analysis of the data <span class="hlt">heat</span> pipe <span class="hlt">radiator</span> systems tested in both vacuum and ambient environments was continued. The systems included (1) a feasibility VCHP header <span class="hlt">heat</span>-pipe panel, (2) the same panel reworked to eliminate the VCHP feature and referred to as the feasibility fluid header panel, and (3) an optimized flight-weight fluid header panel termed the 'prototype.' A description of freeze-thaw thermal vacuum tests conducted on the feasibility VCHP was included. In addition, the results of ambient tests made on the feasibility fluid header are presented, including a comparison with analytical results. A thermal model of a fluid header <span class="hlt">heat</span> pipe <span class="hlt">radiator</span> was constructed and a computer program written. The program was used to make a comparison of the VCHP and fluid-header concepts for both single and multiple panel applications. The computer program was also employed for a parametric study, including optimum feeder <span class="hlt">heat</span> pipe spacing, of the prototype fluid header.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040034110','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040034110"><span>A Comparison of Latent <span class="hlt">Heat</span> <span class="hlt">Fluxes</span> over Global Oceans for Four <span class="hlt">Flux</span> Products</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chou, Shu-Hsien; Nelkin, Eric; Ardizzone, Joe; Atlas, Robert M.</p> <p>2003-01-01</p> <p>To improve our understanding of global energy and water cycle variability, and to improve model simulations of climate variations, it is vital to have accurate latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> (LHF) over global oceans. Monthly LHF, 10-m wind speed (U10m), 10-m specific humidity (Q10h), and sea-air humidity difference (Qs-Q10m) of GSSTF2 (version 2 Goddard Satellite-based Surface Turbulent <span class="hlt">Fluxes</span>) over global Oceans during 1992-93 are compared with those of HOAPS (Hamburg Ocean Atmosphere Parameters and <span class="hlt">Fluxes</span> from Satellite Data), NCEP (NCEP/NCAR reanalysis). The mean differences, standard deviations of differences, and temporal correlation of these monthly variables over global Oceans during 1992-93 between GSSTF2 and each of the three datasets are analyzed. The large-scale patterns of the 2yr-mean fields for these variables are similar among these four datasets, but significant quantitative differences are found. The temporal correlation is higher in the northern extratropics than in the south for all variables, with the contrast being especially large for da Silva as a result of more missing ship data in the south. The da Silva has extremely low temporal correlation and large differences with GSSTF2 for all variables in the southern extratropics, indicating that da Silva hardly produces a realistic variability in these variables. The NCEP has extremely low temporal correlation (0.27) and large spatial variations of differences with GSSTF2 for Qs-Q10m in the tropics, which causes the low correlation for LHF. Over the tropics, the HOAPS LHF is significantly smaller than GSSTF2 by approx. 31% (37 W/sq m), whereas the other two datasets are comparable to GSSTF2. This is because the HOAPS has systematically smaller LHF than GSSTF2 in space, while the other two datasets have very large spatial variations of large positive and negative LHF differences with GSSTF2 to cancel and to produce smaller regional-mean differences. Our analyses suggest that the GSSTF2 latent <span class="hlt">heat</span> <span class="hlt">flux</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018RScI...89f3502X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018RScI...89f3502X"><span>Application of the space-resolving <span class="hlt">flux</span> detector for <span class="hlt">radiation</span> measurements from an octahedral-aperture spherical hohlraum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, Xufei; Du, Huabing; Chen, Jinwen; Liu, Shenye; Li, Zhichao; Yang, Dong; Huang, Yunbao; Ren, Kuan; Hou, Lifei; Li, Sanwei; Guo, Liang; Jiang, Xiaohua; Huo, Wenyi; Chen, Yaohua; Ren, Guoli; Lan, Ke; Wang, Feng; Jiang, Shaoen; Ding, Yongkun</p> <p>2018-06-01</p> <p>Space-resolving <span class="hlt">flux</span> detection is an important technique for the diagnostic of the <span class="hlt">radiation</span> field within the hohlraum in inertial confinement fusion, especially for the <span class="hlt">radiation</span> field diagnostic in the novel spherical hohlraum with octahedral six laser entrance holes (LEHs), where localized measurements are necessary for the discrimination of the <span class="hlt">radiation</span> <span class="hlt">flux</span> from different LEHs. A novel space-resolving <span class="hlt">flux</span> detector (SRFD) is developed at the SG-III laser facility for the <span class="hlt">radiation</span> <span class="hlt">flux</span> measurement in the first campaign of the octahedral spherical hohlraum energetics experiment. The principle and configuration of the SRFD system is introduced. The <span class="hlt">radiation</span> <span class="hlt">flux</span> from the wall of a gas-filled octahedral spherical hohlraum is measured for the first time by placing the SRFD system at the equatorial position of the SG-III laser facility, aiming at the hohlraum wall through one of the six LEHs. The absolute <span class="hlt">radiation</span> <span class="hlt">flux</span> from the re-emission area on the hohlraum wall is measured, and good consistency is found between the experimental data and the calculated data from a three-dimensional view factor analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060033621&hterms=neural+networks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dneural%2Bnetworks','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060033621&hterms=neural+networks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dneural%2Bnetworks"><span>A neural network to retrieve the mesoscale instantaneous latent <span class="hlt">heat</span> <span class="hlt">flux</span> over oceans from SSM/I observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bourras, D.; Eymard, L.; Liu, W. T.</p> <p>2000-01-01</p> <p>The turbulent latent and sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> are necessary to study <span class="hlt">heat</span> budget of the upper ocean or initialize ocean general circulation models. In order to retrieve the latent <span class="hlt">heat</span> <span class="hlt">flux</span> from satellite observations authors mostly use a bulk approximation of the <span class="hlt">flux</span> whose parameters are derived from different instrument. In this paper, an approach based on artificial neural networks is proposed and compared to the bulk method on a global data set and 3 local data sets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JHyd..411..331S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JHyd..411..331S"><span>Controls on sensible <span class="hlt">heat</span> and latent energy <span class="hlt">fluxes</span> from a short-hydroperiod Florida Everglades marsh</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schedlbauer, Jessica L.; Oberbauer, Steven F.; Starr, Gregory; Jimenez, Kristine L.</p> <p>2011-12-01</p> <p>SummaryLittle is known of energy balance in low latitude wetlands where there is a year-round growing season and a climate best defined by wet and dry seasons. The Florida Everglades is a highly managed and extensive subtropical wetland that exerts a substantial influence on the hydrology and climate of the south Florida region. However, the effects of seasonality and active water management on energy balance in the Everglades ecosystem are poorly understood. An eddy covariance and micrometeorological tower was established in a short-hydroperiod Everglades marsh to examine the dominant environmental controls on sensible <span class="hlt">heat</span> ( H) and latent energy ( LE) <span class="hlt">fluxes</span>, as well as the effects of seasonality on these parameters. Seasonality differentially affected H and LE <span class="hlt">fluxes</span> in this marsh, such that H was principally dominant in the dry season and LE was strongly dominant in the wet season. The Bowen ratio was high for much of the dry season (1.5-2.4), but relatively low (<0.7) in the wet season. Net <span class="hlt">radiation</span> strongly influenced H and LE <span class="hlt">fluxes</span> across nearly all seasons and years ( Radj2=0.48-0.79). However, the 2009 dry season LE data were not consistent with this relationship ( Radj2=0.08) because of low seasonal variation in LE following a prolonged end to the previous wet season. In addition to net <span class="hlt">radiation</span>, H and LE <span class="hlt">fluxes</span> were significantly related to soil volumetric water content (VWC), water depth, air temperature, and occasionally vapor pressure deficit. Given that VWC and water depth were determined in part by water management decisions, it is clear that human actions have the ability to influence the mode of energy dissipation from this ecosystem. Impending modifications to water management under the Comprehensive Everglades Restoration Plan may shift the dominant turbulent <span class="hlt">flux</span> from this ecosystem further toward LE, and this change will likely affect local hydrology and climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54..501S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54..501S"><span>Prediction of forced convective <span class="hlt">heat</span> transfer and critical <span class="hlt">heat</span> <span class="hlt">flux</span> for subcooled water flowing in miniature tubes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shibahara, Makoto; Fukuda, Katsuya; Liu, Qiusheng; Hata, Koichi</p> <p>2018-02-01</p> <p>The <span class="hlt">heat</span> transfer characteristics of forced convection for subcooled water in small tubes were clarified using the commercial computational fluid dynamic (CFD) code, PHENICS ver. 2013. The analytical model consists of a platinum tube (the <span class="hlt">heated</span> section) and a stainless tube (the non-<span class="hlt">heated</span> section). Since the platinum tube was <span class="hlt">heated</span> by direct current in the authors' previous experiments, a uniform <span class="hlt">heat</span> <span class="hlt">flux</span> with the exponential function was given as a boundary condition in the numerical simulation. Two inner diameters of the tubes were considered: 1.0 and 2.0 mm. The upward flow velocities ranged from 2 to 16 m/s and the inlet temperature ranged from 298 to 343 K. The numerical results showed that the difference between the surface temperature and the bulk temperature was in good agreement with the experimental data at each <span class="hlt">heat</span> <span class="hlt">flux</span>. The numerical model was extended to the liquid sublayer analysis for the CHF prediction and was evaluated by comparing its results with the experimental data. It was postulated that the CHF occurs when the fluid temperature near the <span class="hlt">heated</span> wall exceeds the saturated temperature, based on Celata et al.'s superheated layer vapor replenishment (SLVR) model. The suggested prediction method was in good agreement with the experimental data and with other CHF data in literature within ±25%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhDT.......141M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhDT.......141M"><span>Aerosol Direct <span class="hlt">Radiative</span> Effects and <span class="hlt">Heating</span> in the New Era of Active Satellite Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matus, Alexander V.</p> <p></p> <p>Atmospheric aerosols impact the global energy budget by scattering and absorbing solar <span class="hlt">radiation</span>. Despite their impacts, aerosols remain a significant source of uncertainty in our ability to predict future climate. Multi-sensor observations from the A-Train satellite constellation provide valuable observational constraints necessary to reduce uncertainties in model simulations of aerosol direct effects. This study will discuss recent efforts to quantify aerosol direct effects globally and regionally using CloudSat's <span class="hlt">radiative</span> <span class="hlt">fluxes</span> and <span class="hlt">heating</span> rates product. Improving upon previous techniques, this approach leverages the capability of CloudSat and CALIPSO to retrieve vertically resolved estimates of cloud and aerosol properties critical for accurately evaluating the <span class="hlt">radiative</span> impacts of aerosols. We estimate the global annual mean aerosol direct effect to be -1.9 +/- 0.6 W/m2, which is in better agreement with previously published estimates from global models than previous satellite-based estimates. Detailed comparisons against a fully coupled simulation of the Community Earth System Model, however, reveal that this agreement on the global annual mean masks large regional discrepancies between modeled and observed estimates of aerosol direct effects related to model biases in cloud cover. A low bias in stratocumulus cloud cover over the southeastern Pacific Ocean, for example, leads to an overestimate of the <span class="hlt">radiative</span> effects of marine aerosols. Stratocumulus clouds over the southeastern Atlantic Ocean can enhance aerosol absorption by 50% allowing aerosol layers to remain self-lofted in an area of subsidence. Aerosol <span class="hlt">heating</span> is found to peak at 0.6 +/- 0.3 K/day an altitude of 4 km in September when biomass burning reaches a maximum. Finally, the contributions of observed aerosols components are evaluated to estimate the direct <span class="hlt">radiative</span> forcing of anthropogenic aerosols. Aerosol forcing is computed using satellite-based <span class="hlt">radiative</span> kernels that describe the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAP...122f3302G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAP...122f3302G"><span>Material impacts and <span class="hlt">heat</span> <span class="hlt">flux</span> characterization of an electrothermal plasma source with an applied magnetic field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gebhart, T. E.; Martinez-Rodriguez, R. A.; Baylor, L. R.; Rapp, J.; Winfrey, A. L.</p> <p>2017-08-01</p> <p>To produce a realistic tokamak-like plasma environment in linear plasma device, a transient source is needed to deliver <span class="hlt">heat</span> and particle <span class="hlt">fluxes</span> similar to those seen in an edge localized mode (ELM). ELMs in future large tokamaks will deliver <span class="hlt">heat</span> <span class="hlt">fluxes</span> of ˜1 GW/m2 to the divertor plasma facing components at a few Hz. An electrothermal plasma source can deliver <span class="hlt">heat</span> <span class="hlt">fluxes</span> of this magnitude. These sources operate in an ablative arc regime which is driven by a DC capacitive discharge. An electrothermal source was configured with two pulse lengths and tested under a solenoidal magnetic field to determine the resulting impact on liner ablation, plasma parameters, and delivered <span class="hlt">heat</span> <span class="hlt">flux</span>. The arc travels through and ablates a boron nitride liner and strikes a tungsten plate. The tungsten target plate is analyzed for surface damage using a scanning electron microscope.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910021158','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910021158"><span>A laser-induced <span class="hlt">heat</span> <span class="hlt">flux</span> technique for convective <span class="hlt">heat</span> transfer measurements in high speed flows</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Porro, A. R.; Keith, T. G., Jr.; Hingst, W. R.</p> <p>1991-01-01</p> <p>A technique is developed to measure the local convective <span class="hlt">heat</span> transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local <span class="hlt">heat</span> <span class="hlt">flux</span> at the model test surface, and an infrared camera system determines the local temperature distribution due to the <span class="hlt">heating</span>. From this temperature distribution and an analysis of the <span class="hlt">heating</span> process, a local convective <span class="hlt">heat</span> transfer coefficient is determined. The technique was used to measure the local surface convective <span class="hlt">heat</span> transfer coefficient distribution on a flat plate at nominal Mach numbers of 2.5, 3.0, 3.5, and 4.0. The flat plate boundary layer initially was laminar and became transitional in the measurement region. The experimentally determined convective <span class="hlt">heat</span> transfer coefficients were generally higher than the theoretical predictions for flat plate laminar boundary layers. However, the results indicate that this nonintrusive optical measurement technique has the potential to measure surface convective <span class="hlt">heat</span> transfer coefficients in high speed flow fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920071694&hterms=transfer+techniques&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dtransfer%2Btechniques','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920071694&hterms=transfer+techniques&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dtransfer%2Btechniques"><span>A laser-induced <span class="hlt">heat</span> <span class="hlt">flux</span> technique for convective <span class="hlt">heat</span> transfer measurements in high speed flows</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Porro, A. R.; Keith, T. G., Jr.; Hingst, W. R.</p> <p>1991-01-01</p> <p>A technique is developed to measure the local convective <span class="hlt">heat</span> transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local <span class="hlt">heat</span> <span class="hlt">flux</span> at the model test surface, and an infrared camera system determines the local temperature distribution due to the <span class="hlt">heating</span>. From this temperature distribution and an analysis of the <span class="hlt">heating</span> process, a local convective <span class="hlt">heat</span> transfer coefficient is determined. The technique was used to measure the local surface convective <span class="hlt">heat</span> transfer coefficient distribution on a flat plate at nominal Mach numbers of 2.5, 3.0, 3.5, and 4.0. The flat plate boundary layer initially was laminar and became transitional in the measurement region. The experimentally determined convective <span class="hlt">heat</span> transfer coefficients were generally higher than the theoretical predictions for flat plate laminar boundary layers. However, the results indicate that this nonintrusive optical measurement technique has the potential to measure surface convective <span class="hlt">heat</span> transfer coefficients in high-speed flowfields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A41A0026S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A41A0026S"><span>Advances in the Surface Renewal <span class="hlt">Flux</span> Measurement Method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shapland, T. M.; McElrone, A.; Paw U, K. T.; Snyder, R. L.</p> <p>2011-12-01</p> <p>The measurement of ecosystem-scale energy and mass <span class="hlt">fluxes</span> between the planetary surface and the atmosphere is crucial for understanding geophysical processes. Surface renewal is a <span class="hlt">flux</span> measurement technique based on analyzing the turbulent coherent structures that interact with the surface. It is a less expensive technique because it does not require fast-response velocity measurements, but only a fast-response scalar measurement. It is therefore also a useful tool for the study of the global cycling of trace gases. Currently, surface renewal requires calibration against another <span class="hlt">flux</span> measurement technique, such as eddy covariance, to account for the linear bias of its measurements. We present two advances in the surface renewal theory and methodology that bring the technique closer to becoming a fully independent <span class="hlt">flux</span> measurement method. The first advance develops the theory of turbulent coherent structure transport associated with the different scales of coherent structures. A novel method was developed for identifying the scalar change rate within structures at different scales. Our results suggest that for canopies less than one meter in height, the second smallest coherent structure scale dominates the energy and mass <span class="hlt">flux</span> process. Using the method for resolving the scalar exchange rate of the second smallest coherent structure scale, calibration is unnecessary for surface renewal measurements over short canopies. This study forms the foundation for analysis over more complex surfaces. The second advance is a sensor frequency response correction for measuring the sensible <span class="hlt">heat</span> <span class="hlt">flux</span> via surface renewal. Inexpensive fine-wire thermocouples are frequently used to record high frequency temperature data in the surface renewal technique. The sensible <span class="hlt">heat</span> <span class="hlt">flux</span> is used in conjunction with net <span class="hlt">radiation</span> and ground <span class="hlt">heat</span> <span class="hlt">flux</span> measurements to determine the latent <span class="hlt">heat</span> <span class="hlt">flux</span> as the energy balance residual. The robust thermocouples commonly used in field experiments</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MS%26E..353a2001E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MS%26E..353a2001E"><span><span class="hlt">Heat</span> performance resulting from combined effects of <span class="hlt">radiation</span> and mixed convection in a rectangular cavity ventilated by injection or suction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ezzaraa, K.; Bahlaoui, A.; Arroub, I.; Raji, A.; Hasnaoui, M.; Naïmi, M.</p> <p>2018-05-01</p> <p>In this work, we investigated numerically <span class="hlt">heat</span> transfer by mixed convection coupled to thermal <span class="hlt">radiation</span> in a vented rectangular enclosure uniformly <span class="hlt">heated</span> from below with a constant <span class="hlt">heat</span> <span class="hlt">flux</span>. The fresh fluid is admitted into the cavity by injection or suction, by means of two openings located on the lower part of both right and left vertical sides. Another opening is placed on the middle of the top wall to ensure the ventilation. Air, a <span class="hlt">radiatively</span> transparent medium, is considered to be the cooling fluid. The inner surfaces, in contact with the fluid, are assumed to be gray, diffuse emitters and reflectors of <span class="hlt">radiation</span> with identical emissivities. The effects of some pertinent parameters such as the Reynolds number, 300 ≤ Re ≤ 5000, and the emissivity of the walls, 0 ≤ ɛ ≤ 0.85, on flow and temperature patterns as well as on the <span class="hlt">heat</span> transfer rate within the enclosure are presented for the two ventilation modes (injection and suction). The results indicate that the flow and thermal structures are affected by the thermal <span class="hlt">radiation</span> for the two modes of imposed flow. However, the suction mode is found to be more favorable to the <span class="hlt">heat</span> transfer in comparison with the injection one.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20540843','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20540843"><span>Analytical study of the <span class="hlt">heat</span> loss attenuation by clothing on thermal manikins under <span class="hlt">radiative</span> <span class="hlt">heat</span> loads.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Den Hartog, Emiel A; Havenith, George</p> <p>2010-01-01</p> <p>For wearers of protective clothing in <span class="hlt">radiation</span> environments there are no quantitative guidelines available for the effect of a <span class="hlt">radiative</span> <span class="hlt">heat</span> load on <span class="hlt">heat</span> exchange. Under the European Union funded project ThermProtect an analytical effort was defined to address the issue of <span class="hlt">radiative</span> <span class="hlt">heat</span> load while wearing protective clothing. As within the ThermProtect project much information has become available from thermal manikin experiments in thermal <span class="hlt">radiation</span> environments, these sets of experimental data are used to verify the analytical approach. The analytical approach provided a good prediction of the <span class="hlt">heat</span> loss in the manikin experiments, 95% of the variance was explained by the model. The model has not yet been validated at high <span class="hlt">radiative</span> <span class="hlt">heat</span> loads and neglects some physical properties of the <span class="hlt">radiation</span> emissivity. Still, the analytical approach provides a pragmatic approach and may be useful for practical implementation in protective clothing standards for moderate thermal <span class="hlt">radiation</span> environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC13C0652T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC13C0652T"><span>Southern Ocean air-sea <span class="hlt">heat</span> <span class="hlt">flux</span>, SST spatial anomalies, and implications for multi-decadal upper ocean <span class="hlt">heat</span> content trends.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tamsitt, V. M.; Talley, L. D.; Mazloff, M. R.</p> <p>2014-12-01</p> <p>The Southern Ocean displays a zonal dipole (wavenumber one) pattern in sea surface temperature (SST), with a cool zonal anomaly in the Atlantic and Indian sectors and a warm zonal anomaly in the Pacific sector, associated with the large northward excursion of the Malvinas and southeastward flow of the Antarctic Circumpolar Current (ACC). To the north of the cool Indian sector is the warm, narrow Agulhas Return Current (ARC). Air-sea <span class="hlt">heat</span> <span class="hlt">flux</span> is largely the inverse of this SST pattern, with ocean <span class="hlt">heat</span> gain in the Atlantic/Indian, cooling in the southeastward-flowing ARC, and cooling in the Pacific, based on adjusted <span class="hlt">fluxes</span> from the Southern Ocean State Estimate (SOSE), a ⅙° eddy permitting model constrained to all available in situ data. This <span class="hlt">heat</span> <span class="hlt">flux</span> pattern is dominated by turbulent <span class="hlt">heat</span> loss from the ocean (latent and sensible), proportional to perturbations in the difference between SST and surface air temperature, which are maintained by ocean advection. Locally in the Indian sector, intense <span class="hlt">heat</span> loss along the ARC is contrasted by ocean <span class="hlt">heat</span> gain of 0.11 PW south of the ARC. The IPCC AR5 50 year depth-averaged 0-700 m temperature trend shows surprising similarities in its spatial pattern, with upper ocean warming in the ARC contrasted by cooling to the south. Using diagnosed <span class="hlt">heat</span> budget terms from the most recent (June 2014) 6-year run of the SOSE we find that surface cooling in the ARC is balanced by <span class="hlt">heating</span> from south-eastward advection by the current whereas <span class="hlt">heat</span> gain in the ACC is balanced by cooling due to northward Ekman transport driven by strong westerly winds. These results suggest that spatial patterns in multi-decadal upper ocean temperature trends depend on regional variations in upper ocean dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930022671','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930022671"><span>Hypersonic engine component experiments in high <span class="hlt">heat</span> <span class="hlt">flux</span>, supersonic flow environment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gladden, Herbert J.; Melis, Matthew E.</p> <p>1993-01-01</p> <p>A major concern in advancing the state-of-the-art technologies for hypersonic vehicles is the development of an aeropropulsion system capable of withstanding the sustained high thermal loads expected during hypersonic flight. Even though progress has been made in the computational understanding of fluid dynamics and the physics/chemistry of high speed flight, there is also a need for experimental facilities capable of providing a high <span class="hlt">heat</span> <span class="hlt">flux</span> environment for testing component concepts and verifying/calibrating these analyses. A hydrogen/oxygen rocket engine <span class="hlt">heat</span> source was developed at the NASA Lewis Research Center as one element in a series of facilities at national laboratories designed to fulfill this need. This 'Hot Gas Facility' is capable of providing <span class="hlt">heat</span> <span class="hlt">fluxes</span> up to 450 w/sq cm on flat surfaces and up to 5,000 w/sq cm at the leading edge stagnation point of a strut in a supersonic flow stream. Gas temperatures up to 3050 K can also be attained. Two recent experimental programs conducted in this facility are discussed. The objective of the first experiment is to evaluate the erosion and oxidation characteristics of a coating on a cowl leading edge (or strut leading edge) in a supersonic, high <span class="hlt">heat</span> <span class="hlt">flux</span> environment. Macrophotographic data from a coated leading edge model show progressive degradation over several thermal cycles at aerothermal conditions representative of high Mach number flight. The objective of the second experiment is to assess the capability of cooling a porous surface exposed to a high temperature, high velocity flow environment and to provide a <span class="hlt">heat</span> transfer data base for a design procedure. Experimental results from transpiration cooled surfaces in a supersonic flow environment are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820011907','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820011907"><span>Estimating ocean-air <span class="hlt">heat</span> <span class="hlt">fluxes</span> during cold air outbreaks by satellite</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chou, S. H.; Atlas, D.</p> <p>1981-01-01</p> <p>Nomograms of mean column <span class="hlt">heating</span> due to surface sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> were developed. Mean sensible <span class="hlt">heating</span> of the cloud free region is related to the cloud free path (CFP, the distance from the shore to the first cloud formation) and the difference between land air and sea surface temperatures, theta sub 1 and theta sub 0, respectively. Mean latent <span class="hlt">heating</span> is related to the CFP and the difference between land air and sea surface humidities q sub 1 and q sub 0 respectively. Results are also applicable to any path within the cloud free region. Corresponding <span class="hlt">heat</span> <span class="hlt">fluxes</span> may be obtained by multiplying the mean <span class="hlt">heating</span> by the mean wind speed in the boundary layer. The sensible <span class="hlt">heating</span> estimated by the present method is found to be in good agreement with that computed from the bulk transfer formula. The sensitivity of the solutions to the variations in the initial coastal soundings and large scale subsidence is also investigated. The results are not sensitive to divergence but are affected by the initial lapse rate of potential temperature; the greater the stability, the smaller the <span class="hlt">heating</span>, other things being equal. Unless one knows the lapse rate at the shore, this requires another independent measurement. For this purpose the downwind slope of the square of the boundary layer height is used, the mean value of which is also directly proportional to the mean sensible <span class="hlt">heating</span>. The height of the boundary layer should be measurable by future spaceborn lidar systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JCoPh.229.3189G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JCoPh.229.3189G"><span>On the use of <span class="hlt">flux</span> limiters in the discrete ordinates method for 3D <span class="hlt">radiation</span> calculations in absorbing and scattering media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Godoy, William F.; DesJardin, Paul E.</p> <p>2010-05-01</p> <p>The application of <span class="hlt">flux</span> limiters to the discrete ordinates method (DOM), SN, for <span class="hlt">radiative</span> transfer calculations is discussed and analyzed for 3D enclosures for cases in which the intensities are strongly coupled to each other such as: <span class="hlt">radiative</span> equilibrium and scattering media. A Newton-Krylov iterative method (GMRES) solves the final systems of linear equations along with a domain decomposition strategy for parallel computation using message passing libraries in a distributed memory system. Ray effects due to angular discretization and errors due to domain decomposition are minimized until small variations are introduced by these effects in order to focus on the influence of <span class="hlt">flux</span> limiters on errors due to spatial discretization, known as numerical diffusion, smearing or false scattering. Results are presented for the DOM-integrated quantities such as <span class="hlt">heat</span> <span class="hlt">flux</span>, irradiation and emission. A variety of <span class="hlt">flux</span> limiters are compared to "exact" solutions available in the literature, such as the integral solution of the RTE for pure absorbing-emitting media and isotropic scattering cases and a Monte Carlo solution for a forward scattering case. Additionally, a non-homogeneous 3D enclosure is included to extend the use of <span class="hlt">flux</span> limiters to more practical cases. The overall balance of convergence, accuracy, speed and stability using <span class="hlt">flux</span> limiters is shown to be superior compared to step schemes for any test case.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4174507','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4174507"><span>Nonlinear <span class="hlt">Radiation</span> <span class="hlt">Heat</span> Transfer Effects in the Natural Convective Boundary Layer Flow of Nanofluid Past a Vertical Plate: A Numerical Study</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mustafa, Meraj; Mushtaq, Ammar; Hayat, Tasawar; Ahmad, Bashir</p> <p>2014-01-01</p> <p>The problem of natural convective boundary layer flow of nanofluid past a vertical plate is discussed in the presence of nonlinear <span class="hlt">radiative</span> <span class="hlt">heat</span> <span class="hlt">flux</span>. The effects of magnetic field, Joule <span class="hlt">heating</span> and viscous dissipation are also taken into consideration. The governing partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations via similarity transformations and then solved numerically using the Runge–Kutta fourth-fifth order method with shooting technique. The results reveal an existence of point of inflection for the temperature distribution for sufficiently large wall to ambient temperature ratio. Temperature and thermal boundary layer thickness increase as Brownian motion and thermophoretic effects intensify. Moreover temperature increases and <span class="hlt">heat</span> transfer from the plate decreases with an increase in the <span class="hlt">radiation</span> parameter. PMID:25251242</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16318867','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16318867"><span>Interannual variability of surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> in the Adriatic Sea in the period 1998-2001 and comparison with observations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chiggiato, Jacopo; Zavatarelli, Marco; Castellari, Sergio; Deserti, Marco</p> <p>2005-12-15</p> <p>Surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> of the Adriatic Sea are estimated for the period 1998-2001 through bulk formulae with the goal to assess the uncertainties related to their estimations and to describe their interannual variability. In addition a comparison to observations is conducted. We computed the components of the sea surface <span class="hlt">heat</span> budget by using two different operational meteorological data sets as inputs: the ECMWF operational analysis and the regional limited area model LAMBO operational forecast. Both results are consistent with previous long-term climatology and short-term analyses present in the literature. In both cases we obtained that the Adriatic Sea loses 26 W/m2 on average, that is consistent with the assessments found in the literature. Then we conducted a comparison with observations of the <span class="hlt">radiative</span> components of the <span class="hlt">heat</span> budget collected on offshore platforms and one coastal station. In the case of shortwave <span class="hlt">radiation</span>, results show a little overestimation on the annual basis. Values obtained in this case are 172 W/m2 when using ECMWF data and 169 W/m2 when using LAMBO data. The use of either Schiano's or Gilman's and Garrett's corrections help to get even closer values. More difficult is to assess the comparison in the case of longwave <span class="hlt">radiation</span>, with relative errors of an order of 10-20%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150023475','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150023475"><span>The Impact of Trends in the Large Scale Atmospheric Circulation on Mediterranean Surface Turbulent <span class="hlt">Heat</span> <span class="hlt">Fluxes</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Romanski, Joy; Hameed, Sultan</p> <p>2015-01-01</p> <p>Interannual variations of latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> (LHF) and sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> (SHF) over the Mediterranean for the boreal winter season (DJF) show positive trends during 1958-2011. Comparison of correlations between the <span class="hlt">heat</span> <span class="hlt">fluxes</span> and the intensity and location of the Azores High (AH), and the NAO and East Atlantic-West Russia (EAWR) teleconnections, along with analysis of composites of surface temperature, humidity and wind fields for different teleconnection states, demonstrates that variations of the AH are found to explain the <span class="hlt">heat</span> <span class="hlt">flux</span> changes more successfully than the NAO and the EAWR. Trends in sea level pressure and longitude of the Azores High during DJF show a strengthening, and an eastward shift. DJF Azores High pressure and longitude are shown to co-vary such that variability of the Azores High occurs along an axis defined by lower pressure and westward location at one extreme, and higher pressure and eastward location at the other extreme. The shift of the Azores High from predominance of the low/west state to the high/east state induces trends in Mediterranean Sea surface winds, temperature and moisture. These, combined with sea surface warming trends, produce trends in wintertime Mediterranean Sea sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1367091-heat-flux-modeling-using-ion-drift-effects-diii-mode-plasmas-resonant-magnetic-perturbations','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1367091-heat-flux-modeling-using-ion-drift-effects-diii-mode-plasmas-resonant-magnetic-perturbations"><span><span class="hlt">Heat</span> <span class="hlt">flux</span> modeling using ion drift effects in DIII-D H-mode plasmas with resonant magnetic perturbations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Wingen, Andreas; Schmitz, Oliver; Evans, Todd E.; ...</p> <p>2014-01-01</p> <p>The <span class="hlt">heat</span> <span class="hlt">flux</span> patterns measured in low-collisionality DIII-D H-mode plasmas strongly deviate from simultaneously measured CII emission patterns, used as indicator of particle <span class="hlt">flux</span>, during applied resonant magnetic perturbations. While the CII emission clearly shows typical striations, which are similar to magnetic footprint patterns obtained from vacuum field line tracing, the <span class="hlt">heat</span> <span class="hlt">flux</span> is usually dominated by one large peak at the strike point position. The vacuum approximation, which only considers applied magnetic fields and neglects plasma response and plasma effects, cannot explain the shape of the observed <span class="hlt">heat</span> <span class="hlt">flux</span> pattern. One possible explanation is the effect of particle drifts.more » This is included in the field line equations and the results are discussed with reference to the measurement. Electrons and ions show di fferent drift motions at thermal energy levels in a guiding center approximation. While electrons hardly deviate from the field lines, ions can drift several centimetres away from field line <span class="hlt">flux</span> surfaces. A model is presented in which an ion <span class="hlt">heat</span> <span class="hlt">flux</span>, based on the ion drift motion from various kinetic energies as they contribute to a thermal Maxwellian distribution, is calculated. The simulated <span class="hlt">heat</span> <span class="hlt">flux</span> is directly compared to measurements with a varying edge safety factor q95. This analysis provides evidence for the dominate e ect of high-energy ions in carrying <span class="hlt">heat</span> from the plasma inside the separatrix to the target. High-energy ions are deposited close to the unperturbed strike line while low-energy ions can travel into the striated magnetic topology.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JNuM..329..687L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JNuM..329..687L"><span>High <span class="hlt">heat</span> <span class="hlt">flux</span> properties of pure tungsten and plasma sprayed tungsten coatings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, X.; Tamura, S.; Tokunaga, K.; Yoshida, N.; Noda, N.; Yang, L.; Xu, Z.</p> <p>2004-08-01</p> <p>High <span class="hlt">heat</span> <span class="hlt">flux</span> properties of pure tungsten and plasma sprayed tungsten coatings on carbon substrates have been studied by annealing and cyclic <span class="hlt">heat</span> loading. The recrystallization temperature and an activation energy QR=126 kJ/mol for grain growth of tungsten coating by vacuum plasma spray (VPS) were estimated, and the microstructural changes of multi-layer tungsten and rhenium interface pre-deposited by physical vapor deposition (PVD) with anneal temperature were investigated. Cyclic load tests indicated that pure tungsten and VPS-tungsten coating could withstand 1000 cycles at 33-35 MW/m 2 <span class="hlt">heat</span> <span class="hlt">flux</span> and 3 s pulse duration, and inert gas plasma spray (IPS)-tungsten coating showed local cracks by 300 cycles but did not induce failure by further cycles. However, the failure of pure tungsten and VPS-tungsten coating by fatigue cracking was observed under higher <span class="hlt">heat</span> load (55-60 MW/m 2) for 420 and 230 cycles, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..DPPTP9070P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..DPPTP9070P"><span>Kinetic studies of divertor <span class="hlt">heat</span> <span class="hlt">fluxes</span> in Alcator C-Mod</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pankin, A. Y.; Bateman, G.; Kritz, A. H.; Rafiq, T.; Park, G. Y.; Chang, C. S.; Brunner, D.; Hughes, J. W.; Labombard, B.; Terry, J.</p> <p>2010-11-01</p> <p>The kinetic XGC0 code [C.S. Chang et al, Phys. Plasmas 11 (2004) 2649] is used to model the H- mode pedestal and SOL regions in Alcator C-Mod discharges. The self-consistent simulations in this study include kinetic neoclassical physics and anomalous transport models along with the ExB flow shear effects. The <span class="hlt">heat</span> <span class="hlt">fluxes</span> on the divertor plates are computed and the <span class="hlt">fluxes</span> to the outer plate are compared with experimental observations. The dynamics of the radial electric field near the separatrix and in the SOL region are computed with the XGC0 code, and the effect of the anomalous transport on the <span class="hlt">heat</span> <span class="hlt">fluxes</span> in the SOL region is investigated. In particular, the particle and thermal diffusivities obtained in the analysis mode are compared with predictions from the theory-based anomalous transport models such as MMM95 [G. Bateman et al, Phys. Plasmas 5 (1998) 1793] and DRIBM [T. Rafiq et al, to appear in Phys. Plasmas (2010)]. It is found that there is a notable pinch effect in the inner separatrix region. Possible physical mechanisms for the particle and thermal pinches are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1376436-material-impacts-heat-flux-characterization-electrothermal-plasma-source-applied-magnetic-field','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1376436-material-impacts-heat-flux-characterization-electrothermal-plasma-source-applied-magnetic-field"><span>Material impacts and <span class="hlt">heat</span> <span class="hlt">flux</span> characterization of an electrothermal plasma source with an applied magnetic field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Gebhart, T. E.; Martinez-Rodriguez, R. A.; Baylor, L. R.; ...</p> <p>2017-08-11</p> <p>To produce a realistic tokamak-like plasma environment in linear plasma device, a transient source is needed to deliver <span class="hlt">heat</span> and particle <span class="hlt">fluxes</span> similar to those seen in an edge localized mode (ELM). ELMs in future large tokamaks will deliver <span class="hlt">heat</span> <span class="hlt">fluxes</span> of ~1 GW/m 2 to the divertor plasma facing components at a few Hz. An electrothermal plasma source can deliver <span class="hlt">heat</span> <span class="hlt">fluxes</span> of this magnitude. These sources operate in an ablative arc regime which is driven by a DC capacitive discharge. An electrothermal source was configured in this paper with two pulse lengths and tested under a solenoidal magneticmore » field to determine the resulting impact on liner ablation, plasma parameters, and delivered <span class="hlt">heat</span> <span class="hlt">flux</span>. The arc travels through and ablates a boron nitride liner and strikes a tungsten plate. Finally, the tungsten target plate is analyzed for surface damage using a scanning electron microscope.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1376436-material-impacts-heat-flux-characterization-electrothermal-plasma-source-applied-magnetic-field','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1376436-material-impacts-heat-flux-characterization-electrothermal-plasma-source-applied-magnetic-field"><span>Material impacts and <span class="hlt">heat</span> <span class="hlt">flux</span> characterization of an electrothermal plasma source with an applied magnetic field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gebhart, T. E.; Martinez-Rodriguez, R. A.; Baylor, L. R.</p> <p></p> <p>To produce a realistic tokamak-like plasma environment in linear plasma device, a transient source is needed to deliver <span class="hlt">heat</span> and particle <span class="hlt">fluxes</span> similar to those seen in an edge localized mode (ELM). ELMs in future large tokamaks will deliver <span class="hlt">heat</span> <span class="hlt">fluxes</span> of ~1 GW/m 2 to the divertor plasma facing components at a few Hz. An electrothermal plasma source can deliver <span class="hlt">heat</span> <span class="hlt">fluxes</span> of this magnitude. These sources operate in an ablative arc regime which is driven by a DC capacitive discharge. An electrothermal source was configured in this paper with two pulse lengths and tested under a solenoidal magneticmore » field to determine the resulting impact on liner ablation, plasma parameters, and delivered <span class="hlt">heat</span> <span class="hlt">flux</span>. The arc travels through and ablates a boron nitride liner and strikes a tungsten plate. Finally, the tungsten target plate is analyzed for surface damage using a scanning electron microscope.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999GPC....20...33G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999GPC....20...33G"><span>Surface <span class="hlt">radiation</span> <span class="hlt">fluxes</span> in transient climate simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garratt, J. R.; O'Brien, D. M.; Dix, M. R.; Murphy, J. M.; Stephens, G. L.; Wild, M.</p> <p>1999-01-01</p> <p>Transient CO 2 experiments from five coupled climate models, in which the CO 2 concentration increases at rates of 0.6-1.1% per annum for periods of 75-200 years, are used to document the responses of surface <span class="hlt">radiation</span> <span class="hlt">fluxes</span>, and associated atmospheric properties, to the CO 2 increase. In all five models, the responses of global surface temperature and column water vapour are non-linear and fairly tightly constrained. Thus, global warming lies between 1.9 and 2.7 K at doubled, and between 3.1 and 4.1 K at tripled, CO 2, whilst column water vapour increases by between 3.5 and 4.5 mm at doubled, and between 7 and 8 mm at tripled, CO 2. Global cloud fraction tends to decrease by 1-2% out to tripled CO 2, mainly the result of decreases in low cloud. Global increases in column water, and differences in these increases between models, are mainly determined by the warming of the tropical oceans relative to the middle and high latitudes; these links are emphasised in the zonal profiles of warming and column water vapour increase, with strong water vapour maxima in the tropics. In all models the all-sky shortwave <span class="hlt">flux</span> to the surface S↓ (global, annual average) changes by less than 5 W m -2 out to tripled CO 2, in some cases being essentially invariant in time. In contrast, the longwave <span class="hlt">flux</span> to the surface L↓ increases significantly, by 25 W m -2 typically at tripled CO 2. The variations of S↓ and L↓ (clear-sky and all-sky <span class="hlt">fluxes</span>) with increase in CO 2 concentration are generally non-linear, reflecting the effects of ocean thermal inertia, but as functions of global warming are close to linear in all five models. This is best illustrated for the clear-sky downwelling <span class="hlt">fluxes</span>, and the net <span class="hlt">radiation</span>. Regionally, as illustrated in zonal profiles and global distributions, greatest changes in both S↓ and L↓ are the result primarily of local maxima in warming and column water vapour increases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ResPh...8..341H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ResPh...8..341H"><span>Effect of Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> on Jeffrey fluid flow with variable thermal conductivity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hayat, Tasawar; Javed, Mehwish; Imtiaz, Maria; Alsaedi, Ahmed</p> <p>2018-03-01</p> <p>This paper presents the study of Jeffrey fluid flow by a rotating disk with variable thickness. Energy equation is constructed by using Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> model with variable thermal conductivity. A system of equations governing the model is obtained by applying boundary layer approximation. Resulting nonlinear partial differential system is transformed to ordinary differential system. Homotopy concept leads to the convergent solutions development. Graphical analysis for velocities and temperature is made to examine the influence of different involved parameters. Thermal relaxation time parameter signifies that temperature for Fourier's <span class="hlt">heat</span> law is more than Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span>. A constitutional analysis is made for skin friction coefficient and <span class="hlt">heat</span> transfer rate. Effects of Prandtl number on temperature distribution and <span class="hlt">heat</span> transfer rate are scrutinized. It is observed that larger Reynolds number gives illustrious temperature distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080046190&hterms=heat+exchanger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dheat%2Bexchanger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080046190&hterms=heat+exchanger&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dheat%2Bexchanger"><span>Phase Change Material <span class="hlt">Heat</span> Exchanger Life Test</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lillibridge, Sean; Stephan, Ryan; Lee, Steve; He, Hung</p> <p>2008-01-01</p> <p>Low Lunar Orbit (LLO) poses unique thermal challenges for the orbiting space craft, particularly regarding the performance of the <span class="hlt">radiators</span>. The emitted infrared (IR) <span class="hlt">heat</span> <span class="hlt">flux</span> from the lunar surface varies drastically from the light side to the dark side of the moon. Due to the extremely high incident IR <span class="hlt">flux</span>, especially at low beta angles, a <span class="hlt">radiator</span> is oftentimes unable to reject the vehicle <span class="hlt">heat</span> load throughout the entire lunar orbit. One solution to this problem is to implement Phase Change Material (PCM) <span class="hlt">Heat</span> Exchangers. PCM <span class="hlt">Heat</span> Exchangers act as a "thermal capacitor," storing thermal energy when the <span class="hlt">radiator</span> is unable to reject the required <span class="hlt">heat</span> load. The stored energy is then removed from the PCM <span class="hlt">heat</span> exchanger when the environment is more benign. Because they do not use an expendable resource, such as the feed water used by sublimators and evaporators, PCM <span class="hlt">Heat</span> Exchangers are ideal for long duration Low Lunar Orbit missions. The Advanced Thermal Control project at JSC is completing a PCM <span class="hlt">heat</span> exchanger life test to determine whether further technology development is warranted. The life test is being conducted on four nPentadecane, carbon filament <span class="hlt">heat</span> exchangers. Fluid loop performance, repeatability, and measurement of performance degradation over 2500 melt-freeze cycles will be performed and reported in the current document.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1020790-model-heat-transfer-sapwood-implications-sap-flux-density-measurements-using-thermal-dissipation-probes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1020790-model-heat-transfer-sapwood-implications-sap-flux-density-measurements-using-thermal-dissipation-probes"><span>A model of <span class="hlt">heat</span> transfer in sapwood and implications for sap <span class="hlt">flux</span> density measurements using thermal dissipation probes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wullschleger, Stan D; Childs, Kenneth W; King, Anthony Wayne</p> <p>2011-01-01</p> <p>A variety of thermal approaches are used to estimate sap <span class="hlt">flux</span> density in stems of woody plants. Models have proven valuable tools for interpreting the behavior of <span class="hlt">heat</span> pulse, <span class="hlt">heat</span> balance, and <span class="hlt">heat</span> field deformation techniques, but have seldom been used to describe <span class="hlt">heat</span> transfer dynamics for the <span class="hlt">heat</span> dissipation method. Therefore, to better understand the behavior of <span class="hlt">heat</span> dissipation probes, a model was developed that takes into account the thermal properties of wood, the physical dimensions and thermal characteristics of the probes, and the conductive and convective <span class="hlt">heat</span> transfer that occurs due to water flow in the sapwood. Probesmore » were simulated as aluminum tubes 20 mm in length and 2 mm in diameter, whereas sapwood, heartwood, and bark each had a density and water fraction that determined their thermal properties. Base simulations assumed a constant sap <span class="hlt">flux</span> density with sapwood depth and no wounding or physical disruption of xylem beyond the 2 mm diameter hole drilled for probe installation. Simulations across a range of sap <span class="hlt">flux</span> densities showed that the dimensionless quantity k defined as ( Tm T)/ T where Tm is the temperature differential ( T) between the <span class="hlt">heated</span> and unheated probe under zero flow conditions was dependent on the thermal conductivity of the sapwood. The relationship between sap <span class="hlt">flux</span> density and k was also sensitive to radial gradients in sap <span class="hlt">flux</span> density and to xylem disruption near the probe. Monte Carlo analysis in which 1000 simulations were conducted while simultaneously varying thermal conductivity and wound diameter revealed that sap <span class="hlt">flux</span> density and k showed considerable departure from the original calibration equation used with this technique. The departure was greatest for abrupt patterns of radial variation typical of ring-porous species. Depending on the specific combination of thermal conductivity and wound diameter, use of the original calibration equation resulted in an 81% under- to 48% over-estimation of sap <span class="hlt">flux</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/content/what-are-down-and-net-fluxes','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/content/what-are-down-and-net-fluxes"><span>What are Up, Down and Net <span class="hlt">Fluxes</span>?</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2014-12-08</p> <p>... Given the vertical layered structure of Earth atmosphere above underlying surfaces, the vertical variability of these <span class="hlt">fluxes</span> ... for the net energy loss or gain within any two such layers. This concept is important in defining the <span class="hlt">radiative</span> <span class="hlt">heating</span> or cooling ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=267929','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=267929"><span>Energy <span class="hlt">fluxes</span> estimation in a juniper tree area of the Donana biological reserve through TSEB method and Landsat-5TM imagery</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Energy <span class="hlt">fluxes</span> computing (actual evapotranspiration, net <span class="hlt">radiation</span>, sensible <span class="hlt">heat</span> and soil <span class="hlt">heat</span> <span class="hlt">flux</span>) are essential to improve the knowledge of the hydrological cycle, especially in natural vegetation covers. In this paper we present the first results of the energy <span class="hlt">fluxes</span> modeling by means of the TSE...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930037556&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DMagnetic%2BFlux','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930037556&hterms=Magnetic+Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DMagnetic%2BFlux"><span>Siphon flows in isolated magnetic <span class="hlt">flux</span> tubes. V - <span class="hlt">Radiative</span> flows with variable ionization</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Montesinos, Benjamin; Thomas, John H.</p> <p>1993-01-01</p> <p>Steady siphon flows in arched isolated magnetic <span class="hlt">flux</span> tubes in the solar atmosphere are calculated here including <span class="hlt">radiative</span> transfer between the <span class="hlt">flux</span> tube and its surrounding and variable ionization of the flowing gas. It is shown that the behavior of a siphon flow is strongly determined by the degree of <span class="hlt">radiative</span> coupling between the <span class="hlt">flux</span> tube and its surroundings in the superadiabatic layer just below the solar surface. Critical siphon flows with adiabatic tube shocks in the downstream leg are calculated, illustrating the <span class="hlt">radiative</span> relaxation of the temperature jump downstream of the shock. For flows in arched <span class="hlt">flux</span> tubes reaching up to the temperature minimum, where the opacity is low, the gas inside the <span class="hlt">flux</span> tube is much cooler than the surrounding atmosphere at the top of the arch. It is suggested that gas cooled by siphon flows contribute to the cool component of the solar atmosphere at the height of the temperature minimum implied by observations of the infrared CO bands at 4.6 and 2.3 microns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29358631','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29358631"><span>High geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> in close proximity to the Northeast Greenland Ice Stream.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rysgaard, Søren; Bendtsen, Jørgen; Mortensen, John; Sejr, Mikael K</p> <p>2018-01-22</p> <p>The Greenland ice sheet (GIS) is losing mass at an increasing rate due to surface melt and flow acceleration in outlet glaciers. Currently, there is a large disagreement between observed and simulated ice flow, which may arise from inaccurate parameterization of basal motion, subglacial hydrology or geothermal <span class="hlt">heat</span> sources. Recently it was suggested that there may be a hidden <span class="hlt">heat</span> source beneath GIS caused by a higher than expected geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> (GHF) from the Earth's interior. Here we present the first direct measurements of GHF from beneath a deep fjord basin in Northeast Greenland. Temperature and salinity time series (2005-2015) in the deep stagnant basin water are used to quantify a GHF of 93 ± 21 mW m -2 which confirm previous indirect estimated values below GIS. A compilation of <span class="hlt">heat</span> <span class="hlt">flux</span> recordings from Greenland show the existence of geothermal <span class="hlt">heat</span> sources beneath GIS and could explain high glacial ice speed areas such as the Northeast Greenland ice stream.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011E%26PSL.306..205Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011E%26PSL.306..205Z"><span><span class="hlt">Heat</span> <span class="hlt">fluxes</span> at the Earth's surface and core-mantle boundary since Pangea formation and their implications for the geomagnetic superchrons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Nan; Zhong, Shijie</p> <p>2011-06-01</p> <p>The Earth's surface and core-mantle boundary (CMB) <span class="hlt">heat</span> <span class="hlt">fluxes</span> are controlled by mantle convection and have important influences on Earth's thermal evolution and geodynamo processes in the core. However, the long-term variations of the surface and CMB <span class="hlt">heat</span> <span class="hlt">fluxes</span> remain poorly understood, particularly in response to the supercontinent Pangea — likely the most significant global tectonic event in the last 500 Ma. In this study, we reconstruct temporal evolution of the surface and CMB <span class="hlt">heat</span> <span class="hlt">fluxes</span> since the Paleozoic by formulating three-dimensional spherical models of mantle convection with plate motion history for the last 450 Ma that includes the assembly and break-up of supercontinent Pangea. Our models reproduce well present-day observations of the surface <span class="hlt">heat</span> <span class="hlt">flux</span> and seafloor age distribution. Our models show that the present-day CMB <span class="hlt">heat</span> <span class="hlt">flux</span> is low below the central Pacific and Africa but high elsewhere due to subducted slabs, particularly when chemically dense piles are present above the CMB. We show that while the surface <span class="hlt">heat</span> <span class="hlt">flux</span> may not change significantly in response to Pangea assembly, it increases by ~ 16% from 200 to 120 Ma ago as a result of Pangea breakup and then decreases for the last 120 Ma to approximately the pre-200 Ma value. As consequences of the assembly and breakup of Pangea, equatorial CMB <span class="hlt">heat</span> <span class="hlt">flux</span> reaches minimum at ~ 270 Ma and again at ~ 100 Ma ago, while global CMB <span class="hlt">heat</span> <span class="hlt">flux</span> is a maximum at ~ 100 Ma ago. These extrema in CMB <span class="hlt">heat</span> <span class="hlt">fluxes</span> coincide with the Kiaman (316-262 Ma) and Cretaceous (118-83 Ma) Superchrons, respectively, and may be responsible for the Superchrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090035866&hterms=spacex&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dspacex','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090035866&hterms=spacex&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dspacex"><span>Validation of PICA Ablation and Thermal-Response Model at Low <span class="hlt">Heat</span> <span class="hlt">Flux</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Milos, Frank S.; Chen, Yih-Kanq</p> <p>2009-01-01</p> <p>Phenolic Impregnated Carbon Ablator (PICA) was the forebody heatshield material on the Stardust sample-return capsule and is also a primary candidate material for the Mars Science Lander (MSL), the Orion Crew Module, and the SpaceX Dragon vehicle. As part of the heatshield qualification for Orion, physical and thermal properties of virgin and charred PICA were measured, and an ablation and thermal response model was developed. We validated the model by comparing it with recession and temperature data from stagnation arcjet tests conducted over a wide range of stagnation <span class="hlt">heat</span> <span class="hlt">flux</span> of 107 to 1102 W/sq cm. The effect of orthotropic thermal conductivity was evident in the thermal response of the arcjet models. In general, model predictions compared well with the data; however, the uncertainty of the recession prediction was greatest for <span class="hlt">heat</span> <span class="hlt">fluxes</span> below 200 W/sq cm. More recent MSL testing focused on the low <span class="hlt">heat</span> <span class="hlt">flux</span> regime of 45 to 250 W/sq cm. The new results confirm the recession uncertainty, especially for pressures below 6 kPa. In this work we focus on improving the model predictions for MSL and Orion tests below 250 W/sq cm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1389513','SCIGOV-DOEDE'); return false;" href="https://www.osti.gov/servlets/purl/1389513"><span>Intercomparison of <span class="hlt">Radiation</span> Codes in Climate Models (ICRCCM) Infrared (Clear-Sky) Line-by Line <span class="hlt">Radiative</span> <span class="hlt">Fluxes</span> (DB1002)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/dataexplorer">DOE Data Explorer</a></p> <p>Arking, A.; Ridgeway, B.; Clough, T.; Iacono, M.; Fomin, B.; Trotsenko, A.; Freidenreich, S.; Schwarzkopf, D.</p> <p>1994-01-01</p> <p>The intercomparison of <span class="hlt">Radiation</span> Codes in Climate Models (ICRCCM) study was launched under the auspices of the World Meteorological Organization and with the support of the U.S. Department of Energy to document differences in results obtained with various <span class="hlt">radiation</span> codes and <span class="hlt">radiation</span> parameterizations in general circulation models (GCMs). ICRCCM produced benchmark, longwave, line-by-line (LBL) <span class="hlt">fluxes</span> that may be compared against each other and against models of lower spectral resolution. During ICRCCM, infrared <span class="hlt">fluxes</span> and cooling rates for several standard model atmospheres with varying concentrations of water vapor, carbon dioxide, and ozone were calculated with LBL methods at resolutions of 0.01 cm-1 or higher. For comparison with other models, values were summed for the IR spectrum and given at intervals of 5 or 10 cm-1. This archive contains <span class="hlt">fluxes</span> for ICRCCM-prescribed clear-sky cases. <span class="hlt">Radiative</span> <span class="hlt">flux</span> and cooling-rate profiles are given for specified atmospheric profiles for temperature, water vapor, and ozone-mixing ratios. The archive contains 328 files, including spectral summaries, formatted data files, and a variety of programs (i.e., C-shell scripts, FORTRAN codes, and IDL programs) to read, reformat, and display data. Collectively, these files require approximately 59 MB of disk space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSA41A4056H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSA41A4056H"><span>Direct measurements of vertical <span class="hlt">heat</span> <span class="hlt">flux</span> and Na <span class="hlt">flux</span> in the mesosphere and lower thermosphere by lidar at Boulder (40°N, 105°W), Colorado</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, W.; Chu, X.; Gardner, C. S.; Barry, I. F.; Smith, J. A.; Fong, W.; Yu, Z.; Chen, C.</p> <p>2014-12-01</p> <p>The vertical transport of <span class="hlt">heat</span> and constituent by gravity waves and tides plays a fundamental role in establishing the thermal and constituent structures of the mesosphere and lower thermosphere (MLT), but has not been thoroughly investigated by observations. In particular, direct measurements of vertical <span class="hlt">heat</span> <span class="hlt">flux</span> and metal constituent <span class="hlt">flux</span> caused by dissipating waves are extremely rare, which demand precise measurements with high spatial and temporal resolutions over a long period. Such requirements are necessary to overcome various uncertainties to reveal the small quantities of the <span class="hlt">heat</span> and constituent <span class="hlt">fluxes</span> induced by dissipating waves. So far such direct observations have only been reported for vertical <span class="hlt">heat</span> and Na <span class="hlt">fluxes</span> using a Na Doppler lidar at Starfire Optical Range (SOR) in Albuquerque, New Mexico. Furthermore, estimate of eddy <span class="hlt">heat</span> and constituent <span class="hlt">fluxes</span> from the turbulent mixing generated by breaking waves is even more challenging due to the even smaller temporal and spatial scales of the eddy. Consequently, the associated coefficients of thermal (kH) and constituent (kzz) diffusion have not been well characterized and remain as large uncertainties in models. We attempt to address these issues with direct measurements by a Na Doppler lidar with exceptional high-resolution measurement capabilities. Since summer 2010, we have been operating a Na Doppler lidar at Boulder, Colorado. The efficiency of the lidar has been greatly improved in summer of 2011 and achieved generally over 1000 counts of Na signal per lidar pulse in winter. In 2013, we made extensive Na lidar observations in 98 nights. These data covering each month of a full year will be used to characterize the seasonal variations of <span class="hlt">heat</span> and Na <span class="hlt">fluxes</span> and to be compared with the pioneering observations at SOR. In November 2013, we further upgraded the lidar with two new frequency shifters and a new data acquisition scheme, which are optimized for estimating eddy <span class="hlt">fluxes</span> and reducing the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100015631','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100015631"><span>Thin Film <span class="hlt">Heat</span> <span class="hlt">Flux</span> Sensor Development for Ceramic Matrix Composite (CMC) Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wrbanek, John D.; Fralick, Gustave C.; Hunter, Gary W.; Zhu, Dongming; Laster, Kimala L.; Gonzalez, Jose M.; Gregory, Otto J.</p> <p>2010-01-01</p> <p>The NASA Glenn Research Center (GRC) has an on-going effort for developing high temperature thin film sensors for advanced turbine engine components. Stable, high temperature thin film ceramic thermocouples have been demonstrated in the lab, and novel methods of fabricating sensors have been developed. To fabricate thin film <span class="hlt">heat</span> <span class="hlt">flux</span> sensors for Ceramic Matrix Composite (CMC) systems, the rough and porous nature of the CMC system posed a significant challenge for patterning the fine features required. The status of the effort to develop thin film <span class="hlt">heat</span> <span class="hlt">flux</span> sensors specifically for use on silicon carbide (SiC) CMC systems with these new technologies is described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6984481-radiation-fluxes-fife-site-final-report-january-july','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6984481-radiation-fluxes-fife-site-final-report-january-july"><span><span class="hlt">Radiation</span> <span class="hlt">fluxes</span> at the FIFE site. Final report, 1 January 1991-31 July 1992</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Walter-Shea, E.A.; Blad, B.L.; Zara, P.</p> <p>1993-01-01</p> <p>The main objective of the International Satellite Land Surface Climatology Project (ISLSCP) has been stated as 'the development of techniques that may be applied to satellite observations of the <span class="hlt">radiation</span> reflected and emitted from the Earth to yield quantitative information concerning land surface climatological conditions'. The major field study, FIFE (the First ISLSCP Field Experiment), was conducted in 1987-89 to accomplish this objective. Four intensive field campaigns (IFC's) were carried out in 1987 and one in 1989. Factors contributing to observed reflected <span class="hlt">radiation</span> from the FIFE site must be understood before the <span class="hlt">radiation</span> observed by satellites can be used tomore » quantify surface processes. Our last report (Walter-Shea et al.) focused on slope effects on incoming and outgoing shortwave <span class="hlt">radiation</span> and net <span class="hlt">radiation</span> from data collected in 1989. We report here on the final analysis of the slope data as well as results from thermal <span class="hlt">radiation</span> studies conducted during the FIFE experiment. The specific areas reported are the following: (1) analysis of slope effects on measured reflectance values and estimates of surface albedo; (2) using remotely-measured surface temperatures as a means of estimating sensible <span class="hlt">heat</span> <span class="hlt">flux</span> from the Konza Prairie; (3) extracting canopy temperatures from remotely-measured composite surface temperatures; (4) modeling the measured composite temperature of partially vegetated surfaces; and (5) estimating gap distribution in partially vegetated surfaces from reflectance measurements.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSM41A2414M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSM41A2414M"><span>Comparison of lighting activity and inner <span class="hlt">radiation</span> belt particle <span class="hlt">fluxes</span> perturbations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martinez Calderon, C.; Bortnik, J.; Li, W.; Spence, H. E.; Rodger, C. J.</p> <p>2016-12-01</p> <p>Lightning discharges are known to inject whistlers into the inner magnetosphere over a wide range of latitudes around their source. When a discharge occurs, it <span class="hlt">radiates</span> electromagnetic energy, some of which propagates in the whistler-mode wave through the ionospheric plasma travelling away from the Earth. Previous studies have discussed the effects of whistler-induced electron precipitation and <span class="hlt">radiation</span> belt losses associated with lightning but there has been little research on the long term effects of these precipitation on the inner <span class="hlt">radiation</span> belts [Rodger et al. (2004), Clilverd et al. (2004)].Here, we use data from the World Wide Lightning Location Network (WWLLN), which has continuously monitored global lightning since 2004, to examine one year of lightning data and locate the L-shells with high lighting activity. We use Van Allen Probes' Energetic Particle, Composition, and Thermal Plasma Suite (ECT) from both satellites (RBSP-A/B) to measure electron <span class="hlt">fluxes</span> in the inner <span class="hlt">radiation</span> belt at the L-shells of interest. We compare these <span class="hlt">fluxes</span> to a globally-integrated count of lightning strikes and investigate the relationship between global lightning occurrence and RBSP electron <span class="hlt">fluxes</span>. We examine several factors, such as different energy ranges, timescales ranging from a few weeks to the entire year and seasonal changes in order to quantify the loss process driven by lightning in the inner <span class="hlt">radiation</span> belts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830016548','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830016548"><span>Long titanium <span class="hlt">heat</span> pipes for high-temperature space <span class="hlt">radiators</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Girrens, S. P.; Ernst, D. M.</p> <p>1982-01-01</p> <p>Titanium <span class="hlt">heat</span> pipes are being developed to provide light weight, reliable <span class="hlt">heat</span> rejection devices as an alternate <span class="hlt">radiator</span> design for the Space Reactor Power System (SP-100). The <span class="hlt">radiator</span> design includes 360 <span class="hlt">heat</span> pipes, each of which is 5.2 m long and dissipates 3 kW of power at 775 K. The <span class="hlt">radiator</span> <span class="hlt">heat</span> pipes use potassium as the working fluid, have two screen arteries for fluid return, a roughened surface distributive wicking system, and a D shaped cross section container configuration. A prototype titanium <span class="hlt">heat</span> pipe, 5.5 m long, was fabricated and tested in space simulating conditions. Results from startup and isothermal operation tests are presented. These results are also compared to theoretical performance predictions that were used to design the <span class="hlt">heat</span> pipe initially.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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