Science.gov

Sample records for absorbed heat fluxes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. FLUX-TRAP REACTOR WITH ABSORBER IN THE CENTER

    SciTech Connect

    Ergen, W.K.

    1958-03-01

    An idealized flux-trap reactor is modified by the insertion of absorber. It is shown that, for appreciable absorption, a flux depression results, and the remaining flux is proportional to the diffusion constant D times the center flux in the nonabsorption case. This factor D just cancels the factor 1/D in the expression for this center flux so that the flux in the case with absorber is independent of D. In the case with absorber the advantage of Be and BeO largely disappears. (auth)

  10. 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.

  11. Heat flux limiting sleeves

    DOEpatents

    Harris, William G.

    1985-01-01

    A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

  12. 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.

  13. Energy absorber for sodium-heated heat exchanger

    DOEpatents

    Essebaggers, J.

    1975-12-01

    A heat exchanger is described in which water-carrying tubes are heated by liquid sodium and in which the results of accidental contact between the water and the sodium caused by failure of one or more of the water tubes is minimized. An energy absorbing chamber contains a compressible gas and is connected to the body of flowing sodium by a channel so that, in the event of a sodium-water reaction, products of the reaction will partially fill the energy absorbing chamber to attenuate the rise in pressure within the heat exchanger.

  14. High Flux Heat Exchanger

    DTIC Science & Technology

    1993-01-01

    maximum jet velocity (6.36 m/s), and maximum number of jets (nine). Wadsworth and Mudawar [49] describe the use of a single slotted nozzle to provide...H00503 (ASME), pp. 121-128, 1989. 40 49. D. C. Wadsworth and I. Mudawar , "Cooling of a Multichip Electronic Module by Means of Confined Two-Dimensional...Jets of Dielectric Liquid," HTD-Vol. 111, Heat Transfer in Electrglif, Book No. H00503 (ASME), pp. 79-87, 1989. 50. D.C. Wadsworth and I. Mudawar

  15. Method of absorbance correction in a spectroscopic heating value sensor

    DOEpatents

    Saveliev, Alexei; Jangale, Vilas Vyankatrao; Zelepouga, Sergeui; Pratapas, John

    2013-09-17

    A method and apparatus for absorbance correction in a spectroscopic heating value sensor in which a reference light intensity measurement is made on a non-absorbing reference fluid, a light intensity measurement is made on a sample fluid, and a measured light absorbance of the sample fluid is determined. A corrective light intensity measurement at a non-absorbing wavelength of the sample fluid is made on the sample fluid from which an absorbance correction factor is determined. The absorbance correction factor is then applied to the measured light absorbance of the sample fluid to arrive at a true or accurate absorbance for the sample fluid.

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. Local rectification of heat flux

    NASA Astrophysics Data System (ADS)

    Pons, M.; Cui, Y. Y.; Ruschhaupt, A.; Simón, M. A.; Muga, J. G.

    2017-09-01

    We present a chain-of-atoms model where heat is rectified, with different fluxes 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. Heat flux viscosity in collisional magnetized plasmas

    SciTech Connect

    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

  6. 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.

  7. 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.

  8. Critical heat flux test apparatus

    DOEpatents

    Welsh, Robert E.; Doman, Marvin J.; Wilson, Edward C.

    1992-01-01

    An apparatus for testing, in situ, highly irradiated specimens at high temperature transients is provided. A specimen, which has a thermocouple device attached thereto, is manipulated into test position in a sealed quartz heating tube by a robot. An induction coil around a heating portion of the tube is powered by a radio frequency generator to heat the specimen. Sensors are connected to monitor the temperatures of the specimen and the induction coil. A quench chamber is located below the heating portion to permit rapid cooling of the specimen which is moved into this quench chamber once it is heated to a critical temperature. A vacuum pump is connected to the apparatus to collect any released fission gases which are analyzed at a remote location.

  9. 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

  10. 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

  11. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.; Marsala, Joseph

    1994-11-29

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

  12. 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.

  13. 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.

  14. 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

  15. 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...

  16. 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.

  17. Progress in the measurement of SSME turbine heat flux with plug-type sensors

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.

    1991-01-01

    Data reduction was completed for tests of plug-type heat flux 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 heat flux 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 heat flux measurement facility at Lewis. In this facility, transient and steady state absorbed surface heat flux 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 heat flux measured on the three blades tested in the TBT are presented. High quality heat flux values were measured on all three blades. The experiments demonstrated that reliable and durable gauges can be repeatedly fabricated into the airfoils. The experiment heat flux data are being used for verification of SSME analytical stress, boundary layer, and heat transfer design models. Other experimental results and future plans are also presented.

  18. 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.

  19. 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.

  20. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1996-12-03

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.

  1. Expanding Taylor bubble under constant heat flux

    NASA Astrophysics Data System (ADS)

    Voirand, Antoine; Benselama, Adel M.; Ayel, Vincent; Bertin, Yves

    2016-09-01

    Modelization of non-isothermal bubbles expanding in a capillary, as a contribution to the understanding of the physical phenomena taking place in Pulsating Heat 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 heat flux 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-heating of the vapor phase, although the particular thermal boundary condition used here always ensures an evaporative mass flux at the liquid-vapor interface. Global heat exchange is also investigated, showing a strong decreasing of the PHP performance to convey heat by phase change means for large meniscus velocities.

  2. 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

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

    SciTech Connect

    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.

  4. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, B.A.; Zawacki, T.S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.

  5. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.

  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. Thermoelectric System Absorbing Waste Heat from a Steel Ladle

    NASA Astrophysics Data System (ADS)

    Lu, Baiyi; Meng, Xiangning; Zhu, Miaoyong; Suzuki, Ryosuke O.

    2018-06-01

    China's iron and steel industry has made great progress in energy savings and emission reductions with the application of many waste heat recovery technologies. However, most of the medium and low temperature waste heat and radiant waste heat has not been effectively utilized. This paper proposes a thermoelectric system that generates electricity by absorbing the radiant heat from the surface of steel ladles in a steel plant. The thermoelectric behavior of modules in this system is analyzed by a numerical simulation method. The effects of external resistance and module structure on thermoelectric performance are also discussed in the temperature range of the wall surface of a steel ladle. The results show that the wall temperature has a significant influence on the thermoelectric behavior of the module, so its uniformity and stability should be considered in practical application. The ratio of the optimum external resistance to the internal resistance of the thermoelectric module is in the range of 1.6-2.0, which indicates the importance of external load optimization for a given thermoelectric system. In addition, the output power and the conversion efficiency of the module can be significantly improved by increasing the length of the thermoelectric legs and adopting a double-layer structure. Finally, through the optimization of external resistance and structure, the power output can reach 83-304 W/m2. This system is shown to be a promising approach for energy recovery.

  8. Thermoelectric System Absorbing Waste Heat from a Steel Ladle

    NASA Astrophysics Data System (ADS)

    Lu, Baiyi; Meng, Xiangning; Zhu, Miaoyong; Suzuki, Ryosuke O.

    2018-01-01

    China's iron and steel industry has made great progress in energy savings and emission reductions with the application of many waste heat recovery technologies. However, most of the medium and low temperature waste heat and radiant waste heat has not been effectively utilized. This paper proposes a thermoelectric system that generates electricity by absorbing the radiant heat from the surface of steel ladles in a steel plant. The thermoelectric behavior of modules in this system is analyzed by a numerical simulation method. The effects of external resistance and module structure on thermoelectric performance are also discussed in the temperature range of the wall surface of a steel ladle. The results show that the wall temperature has a significant influence on the thermoelectric behavior of the module, so its uniformity and stability should be considered in practical application. The ratio of the optimum external resistance to the internal resistance of the thermoelectric module is in the range of 1.6-2.0, which indicates the importance of external load optimization for a given thermoelectric system. In addition, the output power and the conversion efficiency of the module can be significantly improved by increasing the length of the thermoelectric legs and adopting a double-layer structure. Finally, through the optimization of external resistance and structure, the power output can reach 83-304 W/m2. This system is shown to be a promising approach for energy recovery.

  9. Critical heat flux in subcooled flow boiling

    NASA Astrophysics Data System (ADS)

    Hall, David Douglas

    The critical heat flux (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 heated 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, heated 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 heat flux. 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 heat required for liquid-vapor conversion as opposed to that for bulk liquid heating. Severe

  10. 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.

  11. 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

  12. Simulating Carbon Flux Dynamics with the Product of PAR Absorbed by Chlorophyll (fAPARchl)

    NASA Astrophysics Data System (ADS)

    Yao, T.; Zhang, Q.

    2016-12-01

    A common way to estimate the gross primary production (GPP) is to use the fraction of photosynthetically radiation (PAR) absorbed by vegetation (FPAR). However, only the PAR absorbed by chlorophyll of the canopy, not the PAR absorbed by the foliage or by the entire canopy, is used for photosynthesis. MODIS fAPARchl product, which refers to the fraction of PAR absorbed by chlorophyll of the canopy, is derived from Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance by using an advanced leaf-canopy-soil-water-snow coupled radiative transfer model PROSAIL4. PROSAIL4 can retrieve surface water cover fraction, snow cover fraction, and physiologically active canopy chemistry components (chlorophyll concentration and water content), fraction of photosynthetically active radiation (PAR) absorbed by a canopy (fAPARcanopy), fraction of PAR absorbed by photosynthetic vegetation (PV) component (mainly chlorophyll) throughout the canopy (fAPARPV, i.e., fAPARchl) and fraction of PAR absorbed by non-photosynthetic vegetation (NPV) component of the canopy (fAPARNPV). We have successfully retrieved these vegetation parameters for selected areas with PROSAIL4 and the MODIS images, or simulated spectrally MODIS-like images. In this study, the product of PAR absorbed by chlorophyll (fAPARchl) has been used to simulate carbon flux over different kinds of vegetation types. The results show that MODIS fAPARchl product has the ability to better characterize phenology than current phenology model in the Community Land Model and it also will likely be able to increase the accuracy of carbon fluxes simulations.

  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. EU Development of High Heat Flux Components

    SciTech Connect

    Linke, J.; Lorenzetto, P.; Majerus, P.

    2005-04-15

    The development of plasma facing components for next step fusion devices in Europe is strongly focused to ITER. Here a wide spectrum of different design options for the divertor target and the first wall have been investigated with tungsten, CFC, and beryllium armor. Electron beam simulation experiments have been used to determine the performance of high heat flux components under ITER specific thermal loads. Beside thermal fatigue loads with power density levels up to 20 MWm{sup -2}, off-normal events are a serious concern for the lifetime of plasma facing components. These phenomena are expected to occur on a time scalemore » of a few milliseconds (plasma disruptions) or several hundred milliseconds (vertical displacement events) and have been identified as a major source for the production of neutron activated metallic or tritium enriched carbon dust which is of serious importance from a safety point of view.The irradiation induced material degradation is another critical concern for future D-T-burning fusion devices. In ITER the integrated neutron fluence to the first wall and the divertor armour will remain in the order of 1 dpa and 0.7 dpa, respectively. This value is low compared to future commercial fusion reactors; nevertheless, a nonnegligible degradation of the materials has been detected, both for mechanical and thermal properties, in particular for the thermal conductivity of carbon based materials. Beside the degradation of individual material properties, the high heat flux performance of actively cooled plasma facing components has been investigated under ITER specific thermal and neutron loads.« less

  16. Flower garden trees' ability to absorb solar radiation heat for local heat reduction

    NASA Astrophysics Data System (ADS)

    Maulana, Muhammad Ilham; Syuhada, Ahmad; Hamdani

    2017-06-01

    Banda Aceh as an urban area tends to have a high air temperature than its rural surroundings. A simple way to cool Banda Aceh city is by planting urban vegetation such as home gardens or parks. In addition to aesthetics, urban vegetation plays an important role as a reducer of air pollution, oxygen producer, and reducer of the heat of the environment. To create an ideal combination of plants, knowledge about the ability of plants to absorb solar radiation heat is necessary. In this study, some types of flowers commonly grown by communities around the house, such as Michelia Champaka, Saraca Asoka, Oliander, Adenium, Codiaeum Variegatum, Jas Minum Sambac, Pisonia Alba, Variegata, Apium Graveolens, Elephantopus Scaber, Randia, Cordylin.Sp, Hibiscus Rosasinensis, Agave, Lili, Amarilis, and Sesamum Indicum, were examined. The expected benefit of this research is to provide information for people, especially in Banda Aceh, on the ability of each plant relationship in absorbing heat for thermal comfort in residential environments. The flower plant which absorbs most of the sun's heat energy is Hibiscus Rosasinensis (kembang sepatu) 6.2 Joule, Elephantopus Scaber.L (tapak leman) 4.l Joule. On the other hand, the lowest heat absorption is Oliander (sakura) 0.9 Joule.

  17. Recent High Heat Flux Tests on W-Rod-Armored Mockups

    SciTech Connect

    NYGREN,RICHARD E.; YOUCHISON,DENNIS L.; MCDONALD,JIMMIE M.

    2000-07-18

    In the authors initial high heat flux 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 heat fluxes, they reduced the heated 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 heat 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 heat flux on this mockup were too high. In the tests in EB 1200 of a second mockup, PW-4, absorbed heat fluxes 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

  18. Reduction of intensity variations on the absorbers of ideal flux concentrators

    NASA Technical Reports Server (NTRS)

    Greenman, P.

    1980-01-01

    Large nonuniformities occur in the instantaneous distribution of flux on the absorber of an ideal light concentrator when it is illuminated by a point source such as the sun. These nonuniformities may be reduced by texturing the reflecting surface with small distortions. Such distortions will also be effective if used in the primary reflector of a two-stage concentrator. Data on a model compound parabolic concentrator are presented. The suitability of such concentrators for use by spacecraft is mentioned.

  19. Gravitational Collapse with Heat Flux and Gravitational Waves

    NASA Astrophysics Data System (ADS)

    Ahmad, Zahid; Ahmed, Qazi Zahoor; Awan, Abdul Sami

    2013-10-01

    In this paper, we investigated the cylindrical gravitational collapse with heat flux 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 heat flux on gravitational collapse are investigated and matched with the results obtained by Herrera and Santos (Class. Quantum Gravity 22:2407, 2005).

  20. 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.

  1. Development of heat flux sensors for turbine airfoils

    NASA Astrophysics Data System (ADS)

    Atkinson, William H.; Cyr, Marcia A.; Strange, Richard R.

    1985-10-01

    The objectives of this program are to develop heat flux sensors suitable for installation in hot section airfoils of advanced aircraft turbine engines and to experimentally verify the operation of these heat flux 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 heat 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 heat flux measurements produced by these sensors. The results of the cylinder in cross flow tests are given.

  2. Development of heat flux sensors for turbine airfoils

    NASA Technical Reports Server (NTRS)

    Atkinson, William H.; Cyr, Marcia A.; Strange, Richard R.

    1985-01-01

    The objectives of this program are to develop heat flux sensors suitable for installation in hot section airfoils of advanced aircraft turbine engines and to experimentally verify the operation of these heat flux 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 heat 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 heat flux measurements produced by these sensors. The results of the cylinder in cross flow tests are given.

  3. 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

  4. 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.

  5. A concentrated solar cavity absorber with direct heat transfer through recirculating metallic particles

    SciTech Connect

    Sarker, M. R. I., E-mail: islamrabiul@yahoo.com; Saha, Manabendra, E-mail: manabendra.saha@adelaide.edu.au, E-mail: manab04me@gmail.com; Beg, R. A.

    A recirculating flow solar particle cavity absorber (receiver) is modeled to investigate the flow behavior and heat transfer characteristics of a novel developing concept. It features a continuous recirculating flow of non-reacting metallic particles (black silicon carbide) with air which are used as a thermal enhancement medium. The aim of the present study is to numerically investigate the thermal behavior and flow characteristics of the proposed concept. The proposed solar particle receiver is modeled using two phase discrete particle model (DPM), RNG k-flow model and discrete ordinate (DO) radiation model. Numerical analysis is carried out considering a solar receiver withmore » only air and the mixture of non-reacting particles and air as a heat transfer as well as heat carrying medium. The parametric investigation is conducted considering the incident solar flux on the receiver aperture and changing air flow rate and recirculation rate inside the receiver. A stand-alone feature of the recirculating flow solar particle receiver concept is that the particles are directly exposed to concentrated solar radiation monotonously through recirculating flow inside the receiver and results in efficient irradiation absorption and convective heat transfer to air that help to achieve high temperature air and consequently increase in thermal efficiency. This paper presents, results from the developed concept and highlights its flow behavior and potential to enhance the heat transfer from metallic particles to air by maximizing heat carrying capacity of the heat transfer medium. The imposed milestones for the present system will be helpful to understand the radiation absorption mechanism of the particles in a recirculating flow based receiver, the thermal transport between the particles, the air and the cavity, and the fluid dynamics of the air and particle in the cavity.« less

  6. Supercritical convection, critical heat flux, and coking characteristics of propane

    NASA Technical Reports Server (NTRS)

    Rousar, D. C.; Gross, R. S.; Boyd, W. C.

    1984-01-01

    The heat transfer characteristics of propane at subcritical and supercritical pressure were experimentally evaluated using electrically heated Monel K-500 tubes. A design correlation for supercritical heat 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 heat flux measured at subcritical pressure was correlated with the product of velocity and subcooling. Long duration tests at fixed heat flux conditions were conducted to evaluate coking on the coolant side tube wall and coking rates comparable to RP-1 were observed.

  7. 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

  8. A method of exploration of the atmosphere of Titan. [hot air balloon heated by solar radiation or planetary thermal flux

    NASA Technical Reports Server (NTRS)

    Blamont, J.

    1978-01-01

    A hot-air balloon, with the air heated by natural sources, is described. Buoyancy is accomplished by either solar heating or by utilizing the IR thermal flux of the planet to heat 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.

  9. 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 index of refraction can considerably influence the temperature distribution and radiative heat flow in semitransparent materials such as some ceramics. For external radiant heating, the refractive index influences the amount of energy transmitted into the interior of the material. Emission within a material depends on the square of its refractive index, and hence this emission can be many times that for a biackbody radiating into a vacuum. Since radiation exiting through an interface into a vacuum cannot exceed that of a blackbody, there is extensive reflection at the internal surface of an interface, mostly by total internal reflection. This redistributes energy within the layer and tends to make its temperature distribution more uniform. The purpose of the present analysis is to show 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 very simply from the results for an index of refraction of unity. For the situation studied here, the layer is subjected to external radiative heating incident on each of its surfaces. The material emits, absorbs, and isotropically scatters radiation. For simplicity the index of refraction is unity in the medium surrounding the layer. The surfaces of the layer are assumed diffuse. This is probably a reasonable approximation for a ceramic layer that has not been polished. When transmitted radiation or radiation emitted from the interior reaches the inner surface of an interface, the radiation is diffused and some of it thereby placed into angular directions for which there is total internal reflection. This provides a trapping effect for retaining energy within the layer and tends to equalize its temperature distribution. An analysis of temperature distributions in absorbing-emitting layers, including index of refraction effects, was developed by Gardon (1958) to predict cooling and heat treating of glass plates

  10. Ultrahigh Flux Thin Film Boiling Heat Transfer Through Nanoporous Membranes.

    PubMed

    Wang, Qingyang; Chen, Renkun

    2018-05-09

    Phase change heat transfer is fundamentally important for thermal energy conversion and management, such as in electronics with power density over 1 kW/cm 2 . The critical heat flux (CHF) of phase change heat transfer, either evaporation or boiling, is limited by vapor flux from the liquid-vapor interface, known as the upper limit of heat flux. 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 heat flux 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 heat transfer. Our work provides a new nanostructuring approach to achieve ultrahigh heat flux in phase change heat transfer and will benefit both theoretical understanding and application in thermal management of high power devices of boiling heat transfer.

  11. 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.

  12. 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.

  13. 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).

  14. 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.

  15. Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1996-11-05

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.

  16. Study on coal char ignition by radiant heat flux.

    NASA Astrophysics Data System (ADS)

    Korotkikh, A. G.; Slyusarskiy, K. V.

    2017-11-01

    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 heat flux 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 heat flux region and lower in low heat flux region. The kinetic constants for overall oxidation reaction were determined using analytic solution of simplified one-dimensional heat transfer equation with radiant heat transfer boundary condition. The activation energy for lignite char was found to be less than it is for bituminous coal char by approximately 20 %.

  17. Explosive Boiling at Very Low Heat Fluxes: A Microgravity Phenomenon

    NASA Technical Reports Server (NTRS)

    Hasan, M. M.; Lin, C. S.; Knoll, R. H.; Bentz, M. D.

    1993-01-01

    The paper presents experimental observations of explosive boiling from a large (relative to bubble sizes) flat heating surface at very low heat fluxes in microgravity. The explosive boiling is characterized as either a rapid growth of vapor mass over the entire heating surface due to the flashing of superheated liquid or a violent boiling spread following the appearance of single bubbles on the heating 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 heat fluxes (0.2 to 1.2 kW/sq m). For a heat flux of 1.0 kW/sq m a wall superheat of 17.9 degrees C was attained in ten minutes of heating. This was followed by an explosive boiling accompanied with a pressure spike and a violent bulk liquid motion. However, at this heat flux the vapor blanketing the heating surface could not be sustained. Stable nucleate boiling continued following the explosive boiling.

  18. Calibrator tests of heat flux gauges mounted in SSME blades

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.

    1989-01-01

    Measurements of heat flux to space shuttle main engine (SSME) turbine blade surfaces are being made in the Lewis heat flux calibration facility. Surface heat flux 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 heat 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 heat flux. It is suggested that it is important to measure heat flux near the hub on the suction surface and at the throat on SSME blades rotating in engines because stress and heat transfer coefficients are high in this region.

  19. Plant temperatures and heat flux in a Sonoran Desert ecosystem.

    PubMed

    Gibbs, Joan G; Patten, D T

    1970-09-01

    In the extreme desert environment the potential energy load is high, consequently high temperatures might be a limiting factor for plant survival. Field measurements of plant temperatures in a Sonoran Desert ecosystem were made using fine thermocouples. Temperatures of six desert species were measured: Opuntia engelmannii, Opuntia bigelovii, Opuntia acanthocarpa, Echinocereus engelmannii, Larrea tridentata and Franseria deltoidea. Daily temperature profiles were used to compare the different responses of cacti and shrubs to the desert heat load and also to compare spring and summer responses. Leaf temperature of shrubs was at or near air temperature during both the mild, spring season and the hotter dry season. The cacti, on the other hand, absorbed and stored heat, thus temperatures were often above air temperature. The energy absorbed is determined largely by plant orientation and surface area exposed to the sun. Actual energy absorbed by the plants was estimated from energy diagrams.The flat stem pads of Opuntia engelmannii plants are oriented to receive maximum sunlight without long periods of continuous heating. Opuntia bigelovii spines reflect and absorb much of the environmental energy load, thereby protecting the thick, succulent stems from overheating. The smaller stems of Opuntia acanthocarpa dissipate heat more effectively by their large surface area exposed to convective air currents. Leaves on desert shrubs remain nearer to air temperature than do succulent stems of cacti, because their very large surface to volume ratio allows them to dissipate much heat by convection.

  20. Charring rate of wood exposed to a constant heat flux

    Treesearch

    R. H. White; H. C. Tran

    1996-01-01

    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 heat release calorimeters using exposures of constant heat flux levels has broadened the...

  1. SYNCHROTRON HEATING BY A FAST RADIO BURST IN A SELF-ABSORBED SYNCHROTRON NEBULA AND ITS OBSERVATIONAL SIGNATURE

    SciTech Connect

    Yang, Yuan-Pei; Dai, Zi-Gao; Zhang, Bing, E-mail: zhang@physics.unlv.edu

    Fast radio bursts (FRBs) are mysterious transient sources. If extragalactic, as suggested by their relative large dispersion measures, their brightness temperatures must be extremely high. Some FRB models (e.g., young pulsar model, magnetar giant flare model, or supra-massive neutron star collapse model) suggest that they may be associated with a synchrotron nebula. Here we study a synchrotron-heating process by an FRB in a self-absorbed synchrotron nebula. If the FRB frequency is below the synchrotron self-absorption frequency of the nebula, electrons in the nebula would absorb FRB photons, leading to a harder electron spectrum and enhanced self-absorbed synchrotron emission. In themore » meantime, the FRB flux is absorbed by the nebula electrons. We calculate the spectra of FRB-heated synchrotron nebulae, and show that the nebula spectra would show a significant hump in several decades near the self-absorption frequency. Identifying such a spectral feature would reveal an embedded FRB in a synchrotron nebula.« less

  2. Large heat flux in electrocaloric multilayer capacitors

    NASA Astrophysics Data System (ADS)

    Faye, Romain; Strozyk, Hervé; Dkhil, Brahim; Defay, Emmanuel

    2017-11-01

    Multi layer capacitors (MLCs) are considered the most promising refrigerant elements for the design and development of electrocaloric cooling devices. Recently, the heat transfer of these MLCs has been considered. However, the heat exchange with the surrounding environment has been poorly addressed. In this work, we measure by infrared thermography the temperature change versus time in four different heat exchange configurations. Depending on the configurations, Newtonian and non-Newtonian regimes with their corresponding Biot number are determined, providing useful thermal characteristics. Indeed, in the case of large area thermal pad contacts, heat transfer coefficients up to 3400 W · m-2 · K-1 were obtained, showing that the standard (non-optimised) MLCs already reach the needs for designing efficient prototypes. We also determined the ideal Brayton cooling power in case of thick wires contact that varied between 3.4 mW and 9.8 mW for operating frequencies varying from 0.25 Hz to 1 Hz. While only heat conduction was considered here, our work provides some design rules for improving heat exchanges in future devices.

  3. Improving Global Net Surface Heat Flux with Ocean Reanalysis

    NASA Astrophysics Data System (ADS)

    Carton, J.; Chepurin, G. A.; Chen, L.; Grodsky, S.

    2017-12-01

    This project addresses the current level of uncertainty in surface heat flux estimates. Time mean surface heat flux 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 fluxes 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 heat flux errors/corrections are obtained. In a second set of experiments the heat fluxes are corrected and the ocean reanalysis experiments are repeated. This second round of experiments shows that the time mean error in the corrected fluxes 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 heat flux 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 fluxes 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 flux error from model error.

  4. QUANTIFICATION OF HEAT FLUX FROM A REACTING THERMITE SPRAY

    SciTech Connect

    Eric Nixon; Michelle Pantoya

    2009-07-01

    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 heat flux from a thermite spray is the objective of this study. Quick response sensors such as thin film heat flux 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 heat conduction code to calculate heat flux values. The details of this device are discussed and illustrated. Temperature and heat flux measurements of various thermite spray conditions are reported. Results indicate that this newly developed energetic material heat flux sensor provides quantitative data with good repeatability.« less

  5. 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.

  6. 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.

  7. A diagnostic for quantifying heat flux from a thermite spray

    SciTech Connect

    E. P. Nixon; M. L. Pantoya; D. J. Prentice

    2010-02-01

    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 heat flux from a thermite spray is the objective of this study. Quick response sensors such as thin film heat flux 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 heat conduction code to calculate heat flux values. The details of this device are discussed and illustrated. Temperature and heat flux measurements of various thermite sprays are reported. Results indicate that this newly designed heat flux sensor provides quantitative data with good repeatability suitable for characterizing energetic material combustion.« less

  8. Turbine blade and vane heat flux sensor development, phase 1

    NASA Astrophysics Data System (ADS)

    Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

    1984-08-01

    Heat flux sensors available for installation in the hot section airfoils of advanced aircraft gas turbine engines were developed. Two heat flux 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 heat flux 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 heat 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.

  9. Turbine blade and vane heat flux sensor development, phase 1

    NASA Technical Reports Server (NTRS)

    Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

    1984-01-01

    Heat flux sensors available for installation in the hot section airfoils of advanced aircraft gas turbine engines were developed. Two heat flux 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 heat flux 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 heat 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.

  10. Turbine blade and vane heat flux sensor development, phase 2

    NASA Technical Reports Server (NTRS)

    Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

    1985-01-01

    The development of heat flux sensors for gas turbine blades and vanes and the demonstration of heat transfer measurement methods are reported. The performance of the heat flux sensors was evaluated in a cylinder in cross flow experiment and compared with two other heat flux 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.

  11. Reducing heat loss from the energy absorber of a solar collector

    DOEpatents

    Chao, Bei Tse; Rabl, Ari

    1976-01-01

    A device is provided for reducing convective heat loss in a cylindrical radiant energy collector. It includes a curved reflective wall in the shape of the arc of a circle positioned on the opposite side of the exit aperture from the reflective side walls of the collector. Radiant energy exiting the exit aperture is directed by the curved wall onto an energy absorber such that the portion of the absorber upon which the energy is directed faces downward to reduce convective heat loss from the absorber.

  12. Progress in extrapolating divertor heat fluxes towards large fusion devices

    NASA Astrophysics Data System (ADS)

    Sieglin, B.; Faitsch, M.; Eich, T.; Herrmann, A.; Suttrop, W.; Collaborators, JET; the MST1 Team; the ASDEX Upgrade Team

    2017-12-01

    Heat 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 heat load mitigation techniques, e.g. sweeping, impurity seeding, but do not generally require it. For large fusion devices however, heat load mitigation will be essential. This paper presents the current progress of the extrapolation of steady state and transient heat loads towards large fusion devices. For transient heat 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 heat load compared to previous scalings. In the presence of magnetic perturbation, the axisymmetry is broken and a 2D heat flux pattern is induced on the divertor target, leading to local increase of the heat flux 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 heat flux disappears.

  13. 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.

  14. 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

  15. Mass, heat and freshwater fluxes in the South Indian Ocean

    NASA Technical Reports Server (NTRS)

    Fu, Lee-Lueng

    1986-01-01

    Six hydrographic sections were used to examine the circulation and property fluxes 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 flux is balanced by the southward Ekman mass flux at the surface, whereas at 32 deg S the northward interior mass flux is balanced by the southward mass flux of the Agulhas Current. There is a weak, southward mass flux 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 flux of water from the Pacific Ocean to the Indian Ocean at a rate of 6.6 x 10 to the 9th kg/s. Heat flux calculations indicate that the Indian Ocean is exporting heat 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).

  16. Urban heat fluxes in the subsurface of Cologne, Germany

    NASA Astrophysics Data System (ADS)

    Zhu, K.; Bayer, P.; Blum, P.

    2012-04-01

    Urbanization during the last hundred years has led to both environmental and thermal impacts on the subsurface. The urban heat 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 heat 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 heat fluxes in Cologne, Germany, and to improve our understanding of the dynamics of subsurface energy fluxes in UHIs. Ideally, our findings will contribute to strategic and more sustainable geothermal use in cities. For a quantitative analysis of the energy fluxes within the subsurface and across the atmospheric boundary, two and three-dimensional coupled numerical flow and heat transport models were developed. The simulation results indicate that during the past hundred years, an average vertical urban heat flux 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 heat transport and temperature development is comprehensively discussed.

  17. [Characteristics of CO2 flux before and in the heating period at urban complex underlying surface area].

    PubMed

    Jia, Qing-yu; Zhou, Guang-sheng; Wang, Yu; Liu, Xiao-mei

    2010-04-01

    Urban areas were significant contributors to global carbon dioxide emissions. The eddy covariance (EC) was used to measure carbon dioxide (CO2) concentration and flux data at urban area in Shenyang. This research analyzed the characteristics of atmospheric CO2 concentration and flux in October 2008 to November 2008 period before and in the heating 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 heating. The result of CO2 flux showed that urban atmospheric CO2 was net emissions, vegetation photosynthesis absorbed CO2 of traffic, the CO2 flux peak appeared at 17:15-18:15 in the heating period, CO2 emission increased 29.37 g x (m2 x d)(-1) in the heating period than that before the heating period; there was corresponding relationship between CO2 flux and the time when temperature peak and sensible heating flux (Hc) turn positive. The results also indicated that atmospheric CO2 concentration and its flux were affected seriously by both wind direction and carbon sources.

  18. Analysis of edge stability for models of heat flux width

    DOE PAGES

    Makowski, Michael A.; Lasnier, Charles J.; Leonard, Anthony W.; ...

    2017-05-12

    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 heat flux 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 heat flux 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 heat flux 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

  19. Remote high-temperature insulatorless heat-flux gauge

    DOEpatents

    Noel, B.W.

    1993-12-28

    A remote optical heat-flux 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 heat flux 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 heat-flux measurements can be made by scanning the light across the surface of the gauge. 3 figures.

  20. Remote high-temperature insulatorless heat-flux gauge

    DOEpatents

    Noel, Bruce W.

    1993-01-01

    A remote optical heat-flux 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 heat flux 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 heat-flux measurements can be made by scanning the light across the surface of the gauge.

  1. 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.

  2. Distributed Sensible Heat Flux Measurements for Wireless Sensor Networks

    NASA Astrophysics Data System (ADS)

    Huwald, H.; Brauchli, T.; Lehning, M.; Higgins, C. W.

    2015-12-01

    The sensible heat flux component of the surface energy balance is typically computed using eddy covariance or two point profile measurements while alternative approaches such as the flux variance method based on convective scaling has been much less explored and applied. Flux 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 heat flux 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 flux 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 heat flux measurements.

  3. Infrared Camera Diagnostic for Heat Flux Measurements on NSTX

    SciTech Connect

    D. Mastrovito; R. Maingi; H.W. Kugel

    2003-03-25

    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 heat flux is derived with a classic one-dimensional conduction model. Preliminary results of heat flux scaling are reported.

  4. Nanoporous membrane device for ultra high heat flux thermal management

    NASA Astrophysics Data System (ADS)

    Hanks, Daniel F.; Lu, Zhengmao; Sircar, Jay; Salamon, Todd R.; Antao, Dion S.; Bagnall, Kevin R.; Barabadi, Banafsheh; Wang, Evelyn N.

    2018-02-01

    High power density electronics are severely limited by current thermal management solutions which are unable to dissipate the necessary heat flux while maintaining safe junction temperatures for reliable operation. We designed, fabricated, and experimentally characterized a microfluidic device for ultra-high heat flux 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 heat 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 heat fluxes 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 heated substrate to ambient vapor. This heat flux, 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 heat 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 flux thermal management strategy over large areas for high-performance electronics.

  5. Heat flux instrumentation for Hyflite thermal protection system

    NASA Technical Reports Server (NTRS)

    Diller, T. E.

    1994-01-01

    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 Heat Flux 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 heat treatment of the sputtered pads. Sample Heat Flux 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 Heat Flux Microsensors in a shock tube facility at Virginia Tech. The response of the heat flux sensor was measured to be faster than 10 micro-s.

  6. Boiling Heat-Transfer Processes and Their Application in the Cooling of High Heat Flux Devices

    DTIC Science & Technology

    1993-06-01

    1991, pp. 395-397. 385. Galloway, J. E. and Mudawar , 1. "Critical Heat Flux Enhancement by Means of Liquid Subcooling and Centrifugal Force Induced...Flow Boiling Heat Transfer for a Spirally Fluted Tube." Heat Tran~ler Engineering, Vol. 13, No.1, 1992, pp. 42-52. 390. Willingham, T. C. and Mudawar

  7. Turbulent heat flux measurements in a transitional boundary layer

    NASA Technical Reports Server (NTRS)

    Sohn, K. H.; Zaman, K. B. M. Q.; Reshotko, E.

    1992-01-01

    During an experimental investigation of the transitional boundary layer over a heated flat plate, an unexpected result was encountered for the turbulent heat flux (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 heat 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 heat flux 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.

  8. Miniature high temperature plug-type heat flux gauges

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.

    1992-01-01

    The objective is to describe continuing efforts to develop methods for measuring surface heat flux, gauge active surface temperature, and heat transfer coefficient quantities. The methodology involves inventing a procedure for fabricating improved plug-type heat flux gauges and also for formulating inverse heat 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.

  9. 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.

  10. Heat-Flux Sensor For Hot Engine Cylinders

    NASA Technical Reports Server (NTRS)

    Kim, Walter S.; Barrows, Richard F.; Smith, Floyd A.; Koch, John

    1989-01-01

    Heat-flux 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-heat-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.

  11. Contagious Coronal Heating from Recurring Emergence of Magnetic Flux

    NASA Astrophysics Data System (ADS)

    Moore, R. L.; Falconer, D. A.; Sterling, A. C.

    2002-01-01

    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 heating in and around the old bipole in response to new magnetic flux emergence within the old bipole. The observations show: 1. In each active region, new flux 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 heating, and enhanced coronal heating 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 flux emergence. 4. There are episodes of enhanced coronal heating 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 flux 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 heating. We Also Note That The Reason For The recurrence of flux emergence in old active regions may be that active-region flux 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.

  12. Contagious Coronal Heating from Recurring Emergence of Magnetic Flux

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Falconer, David; Sterling, Alphonse; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    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 heating in and around the old bipole in response to new magnetic flux emerge= within the old bipole. The observations show: 1. In each active region, new flux 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 heating, and enhanced coronal heating 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 flux emergence. 4. There are episodes of enhanced coronal heating 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 flux 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 heating. We also note that the reason for the recurrence of flux emergence in old active regions may be that active region flux 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.

  13. Horizon-absorbed energy flux in circularized, nonspinning black-hole binaries, and its effective-one-body representation

    NASA Astrophysics Data System (ADS)

    Nagar, Alessandro; Akcay, Sarp

    2012-02-01

    We propose, within the effective-one-body approach, a new, resummed analytical representation of the gravitational-wave energy flux absorbed by a system of two circularized (nonspinning) black holes. This expression is such that it is well-behaved in the strong-field, fast-motion regime, notably up to the effective-one-body-defined last unstable orbit. Building conceptually upon the procedure adopted to resum the multipolar asymptotic energy flux, we introduce a multiplicative decomposition of the multipolar absorbed flux made by three factors: (i) the leading-order contribution, (ii) an “effective source” and (iii) a new residual amplitude correction (ρ˜ℓmH)2ℓ. In the test-mass limit, we use a frequency-domain perturbative approach to accurately compute numerically the horizon-absorbed fluxes along a sequence of stable and unstable circular orbits, and we extract from them the functions ρ˜ℓmH. These quantities are then fitted via rational functions. The resulting analytically represented test-mass knowledge is then suitably hybridized with lower-order analytical information that is valid for any mass ratio. This yields a resummed representation of the absorbed flux for a generic, circularized, nonspinning black-hole binary. Our result adds new information to the state-of-the-art calculation of the absorbed flux at fractional 5 post-Newtonian order [S. Taylor and E. Poisson, Phys. Rev. D 78, 084016 (2008)], which is recovered in the weak-field limit approximation by construction.

  14. Electric control of the heat flux through electrophononic effects

    NASA Astrophysics Data System (ADS)

    Seijas-Bellido, Juan Antonio; Aramberri, Hugo; Íñiguez, Jorge; Rurali, Riccardo

    2018-05-01

    We demonstrate a fully electric control of the heat flux, which can be continuously modulated by an externally applied electric field in PbTiO3, a prototypical ferroelectric perovskite, revealing the mechanisms by which experimentally accessible fields can be used to tune the thermal conductivity by as much as 50% at room temperature.

  15. 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.

  16. 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.

  17. On the use of flux limiters in the discrete ordinates method for 3D radiation calculations in absorbing and scattering media

    NASA Astrophysics Data System (ADS)

    Godoy, William F.; DesJardin, Paul E.

    2010-05-01

    The application of flux limiters to the discrete ordinates method (DOM), SN, for radiative transfer calculations is discussed and analyzed for 3D enclosures for cases in which the intensities are strongly coupled to each other such as: radiative 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 flux 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 heat flux, irradiation and emission. A variety of flux 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 flux limiters to more practical cases. The overall balance of convergence, accuracy, speed and stability using flux limiters is shown to be superior compared to step schemes for any test case.

  18. 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.

  19. Measurement of a surface heat flux and temperature

    NASA Astrophysics Data System (ADS)

    Davis, R. M.; Antoine, G. J.; Diller, T. E.; Wicks, A. L.

    1994-04-01

    The Heat Flux 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 heat flux 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 heat fluxes. 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 Heat Flux Microsensor is directly proportional to the heat flux. Therefore, it can easily be used in both steady and transient flows, and it measures both the steady and unsteady components of the surface heat flux. A version of the Heat Flux 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

  20. Measurement of a surface heat flux and temperature

    NASA Technical Reports Server (NTRS)

    Davis, R. M.; Antoine, G. J.; Diller, T. E.; Wicks, A. L.

    1994-01-01

    The Heat Flux 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 heat flux 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 heat fluxes. 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 Heat Flux Microsensor is directly proportional to the heat flux. Therefore, it can easily be used in both steady and transient flows, and it measures both the steady and unsteady components of the surface heat flux. A version of the Heat Flux 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

  1. Viscous relaxation of Ganymede's impact craters: Constraints on heat flux

    NASA Astrophysics Data System (ADS)

    Bland, Michael T.; Singer, Kelsi N.; McKinnon, William B.; Schenk, Paul M.

    2017-11-01

    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 heat 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 heat flux within the dark terrain when relaxation occurred. We show that the degree of viscous relaxation observed cannot be achieved through radiogenic heating alone, even if all of the relaxed craters are ancient and experienced the high radiogenic fluxes present early in the satellite's history. For craters with diameter ≥ 10 km, heat fluxes of 40-50 mW m-2 can reproduce the observed crater depths, but only if the fluxes are sustained for ∼1 Gyr. These craters can also be explained by shorter-lived "heat 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 heat fluxes 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 heat fluxes derived here and those inferred from other tectonic features suggests that a single event caused both Ganymede's tectonic deformation and

  2. Viscous relaxation of Ganymede's impact craters: Constraints on heat flux

    USGS Publications Warehouse

    Bland, Michael T.; Singer, Kelsi N.; McKinnon, William B.; Schenk, Paul M.

    2017-01-01

    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 heat 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 heat flux within the dark terrain when relaxation occurred. We show that the degree of viscous relaxation observed cannot be achieved through radiogenic heating alone, even if all of the relaxed craters are ancient and experienced the high radiogenic fluxes present early in the satellite’s history. For craters with diameter ≥ 10 km, heat fluxes of 40–50 mW m-2−2"> can reproduce the observed crater depths, but only if the fluxes are sustained for ∼1 Gyr. These craters can also be explained by shorter-lived “heat 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 heat fluxes 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 heat fluxes derived here and those inferred from other tectonic features suggests that a single event

  3. Gyrokinetic projection of the divertor heat-flux width from present tokamaks to ITER

    DOE PAGES

    Chang, Choong Seock; Ku, Seung -Hoe; Loarte, Alberto; ...

    2017-07-11

    Here, the XGC1 edge gyrokinetic code is used to study the width of the heat-flux to divertor plates in attached plasma condition. The flux-driven simulation is performed until an approximate power balance is achieved between the heat-flux across the steep pedestal pressure gradient and the heat-flux on the divertor plates.

  4. 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

  5. Performance of thermal barrier coatings in high heat flux environments

    NASA Technical Reports Server (NTRS)

    Miller, R. A.; Berndt, C. C.

    1984-01-01

    Thermal barrier coatings were exposed to the high temperature and high heat flux produced by a 30 kW plasma torch. Analysis of the specimen heating 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 heating 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 heat treated in argon also did not surface spall. Heat treatment in air led to spalling in as early as 2 cycle from heating 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 heat flux conditions of this study.

  6. 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.

  7. 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.

  8. Heat-Flux Measurements from Collective Thomson-Scattering Spectra

    NASA Astrophysics Data System (ADS)

    Henchen, R. J.; Hu, S. X.; Katz, J.; Froula, D. H.; Rozmus, W.

    2015-11-01

    Collective Thomson scattering was used to measure heat flux 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 flux 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 flux 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 flux qSH = - κ∇Te and are in good agreement with the values of the heat flux 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.

  9. Heat flux and quantum correlations in dissipative cascaded systems

    NASA Astrophysics Data System (ADS)

    Lorenzo, Salvatore; Farace, Alessandro; Ciccarello, Francesco; Palma, G. Massimo; Giovannetti, Vittorio

    2015-02-01

    We study the dynamics of heat flux 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 heat 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 heat-flux 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 heat flux.

  10. Turbulent transport regimes and the SOL heat flux width

    NASA Astrophysics Data System (ADS)

    Myra, J. R.; D'Ippolito, D. A.; Russell, D. A.

    2014-10-01

    Understanding the responsible mechanisms and resulting scaling of the scrape-off layer (SOL) heat flux 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 heat flux 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 heat transport regime. Recent SOLT turbulence code results are employed to understand the roles of these considerations and to develop analytical scalings. We find a heat flux 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.

  11. Scaling Relationships for ELM Diverter Heat Flux on DIII D

    NASA Astrophysics Data System (ADS)

    Peters, E. A.; Makowski, M. A.; Leonard, A. W.

    2015-11-01

    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 heat fluxes 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 heat flux 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 heat transmission coefficient ? on the in/out asymmetry of the calculated ELM heat fluxes. 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).

  12. 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.

  13. 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.

  14. Stability Effects on Heat and Moisture Fluxes at Sea

    NASA Astrophysics Data System (ADS)

    Oost, W. A.; Jacobs, C. M. J.; van Oort, C.

    During the 1996 ASGAMAGE experiment we measured windspeed, air temperature Ta, watertemperature Ts, humidity and the momentum,heat and moisture fluxes 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 heat 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 heat into sensible heat through condensation ofwater vapour just above the water surface. An attemptto re-analyse the data in terms of density fluxes,combining the effects of heat and moisture, still gavenegative transfer coefficients for group C.

  15. Method of fission heat flux determination from experimental data

    DOEpatents

    Paxton, Frank A.

    1999-01-01

    A method is provided for determining the fission heat flux 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 heat flux for the thermocouple test specimens and prime specimen can be calculated.

  16. High Heat Flux Surface Coke Deposition and Removal Assessment

    DTIC Science & Technology

    2015-01-01

    Technical Paper 3. DATES COVERED (From - To) January 2015- May 2015 4. TITLE AND SUBTITLE High Heat Flux Surface Coke Deposition and Removal Assessment... coke ) form. Coke has a much lower thermal conductivity than copper - thicknesses of only a few millionths of an inch can cause liner temperatures to...increase to dangerous levels. Moreover, reusing launch vehicles and main engines increases the likelihood that unsafe levels of coke will be

  17. Development of advanced high-temperature heat flux sensors

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    Various configurations of high temperature, heat flux sensors were studied to determine their suitability for use in experimental combustor liners of advanced aircraft gas turbine engines. It was determined that embedded thermocouple sensors, laminated sensors, and Gardon gauge sensors, were the most viable candidates. Sensors of all three types were fabricated, calibrated, and endurance tested. All three types of sensors met the fabricability survivability, and accuracy requirements established for their application.

  18. A comparison of critical heat flux in tubes and bilaterally heated annuli

    SciTech Connect

    Doerffer, S.; Groeneveld, D.C.; Cheng, S.C.

    1995-09-01

    This paper examines the critical heat flux (CHF) behaviour for annular flow in bilaterally heated annuli and compares it to that in tubes and unilaterally heated annuli. It was found that the differences in CHF between bilaterally and unilaterally heated annuli or tubes strongly depend on pressure and quality. the CHF in bilaterally heated 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 flux 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 heat flux ratio, wasmore » also examined. The prediction of CHF for bilaterally heated 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 heated 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 heated surface.« less

  19. Effect of heat flux on differential rotation in turbulent convection.

    PubMed

    Kleeorin, Nathan; Rogachevskii, Igor

    2006-04-01

    We studied the effect of the turbulent heat flux 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 heat flux. 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 heat flux 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.

  20. 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.

  1. Local Heat Flux Measurements with Single Element Coaxial Injectors

    NASA Technical Reports Server (NTRS)

    Jones, Gregg; Protz, Christopher; Bullard, Brad; Hulka, James

    2006-01-01

    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 heat transfer in liquid propellant rocket engine combustion devices. The ultimate objective was to predict and hence reduce the local peak heat flux 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 heat fluxes were measured in a 1-inch internal diameter heat sink combustion chamber using Medtherm coaxial thermocouples and Gardon heat flux 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.

  2. Determination of ocean surface heat fluxes by a variational method

    NASA Astrophysics Data System (ADS)

    Roquet, H.; Planton, S.; Gaspar, P.

    1993-06-01

    A new technique of determination of the "nonsolar" heat flux (sum of the latent, sensible, and net infrared fluxes) at the ocean surface is proposed. It applies when oceanic advection remains weak and thus relies on a one-dimensional modeling approach. It is based on a variational data assimilation scheme using the adjoint equation formalism. This allows to take advantage of all observed data with their error estimates. Results from experiments performed with station Papa (Gulf of Alaska) and Long-Term Upper Ocean Study (LOTUS, Sargasso Sea) data sets are discussed. The temperature profiles assimilation allows the one-dimensional model to reproduce correctly the temperature evolution at the surface and under the oceanic mixed layer at the two sites. The retrieved fluxes are compared to the fluxes calculated through classical empirical formulae. The diurnal dependence of the fluxes at the LOTUS site is particularly investigated. The results are also compared with those obtained using a simpler technique based on an iterative shooting method and allowing the assimilation of the only sea surface temperature. This second comparison reveals that the variability of the retrieved fluxes is damped when temperature in the inner ocean are assimilated. This is the case for the diurnal cycle at the LOTUS mooring. When the available current data at this site are assimilated, the diurnal variability of the retrieved fluxes is further decreased. This points out a model discrepancy in the representation of mixing processes associated to internal wave activity. The remaining part of the diurnal cycle is significant and could be due to a direct effect of air-sea temperature difference.

  3. Reynolds stress and heat flux in spherical shell convection

    NASA Astrophysics Data System (ADS)

    Käpylä, P. J.; Mantere, M. J.; Guerrero, G.; Brandenburg, A.; Chatterjee, P.

    2011-07-01

    Context. Turbulent fluxes of angular momentum and enthalpy or heat 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 heat 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 fluxes are directed inward and equatorward, respectively. In the rapid rotation regime the radial flux changes sign in accordance with earlier numerical results, but in contradiction with theory. The latitudinal flux 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

  4. Modern perspectives on measuring and interpreting seafloor heat flux

    USGS Publications Warehouse

    Harris, Reid N.; Fisher, A.; Ruppel, C.; Martinez, F.

    2008-01-01

    There has been a resurgence of interest in marine heat flow in the past 10–15 years, coinciding with fundamental achievements in understanding the Earth's thermal state and quantifying the dynamics and impacts of material and energy fluxes within and between the lithosphere and hydrosphere. At the same time, technical capabilities have dwindled to the point that no U.S. academic institution currently operates a seagoing heat flow capacity.In September 2007, a workshop was convened in Salt Lake City with sponsorship from the U.S. National Science Foundation (NSF) and participation by scientists and engineers from North America, Europe, and Asia. The primary goals of the workshop were to (1) assess high-priority scientific and technical needs and (2) to evaluate options for developing and maintaining essential capabilities in marine heat flow for the U.S. scientific community.

  5. Critical heat flux maxima during boiling crisis on textured surfaces

    PubMed Central

    Dhillon, Navdeep Singh; Buongiorno, Jacopo; Varanasi, Kripa K.

    2015-01-01

    Enhancing the critical heat flux (CHF) of industrial boilers by surface texturing can lead to substantial energy savings and global reduction in greenhouse gas emissions, but fundamentally this phenomenon is not well understood. Prior studies on boiling crisis indicate that CHF monotonically increases with increasing texture density. Here we report on the existence of maxima in CHF enhancement at intermediate texture density using measurements on parametrically designed plain and nano-textured micropillar surfaces. Using high-speed optical and infrared imaging, we study the dynamics of dry spot heating and rewetting phenomena and reveal that the dry spot heating timescale is of the same order as that of the gravity and liquid imbibition-induced dry spot rewetting timescale. Based on these insights, we develop a coupled thermal-hydraulic model that relates CHF enhancement to rewetting of a hot dry spot on the boiling surface, thereby revealing the mechanism governing the hitherto unknown CHF enhancement maxima. PMID:26346098

  6. Temperature and heat flux scaling laws for isoviscous, infinite Prandtl number mixed heating convection.

    NASA Astrophysics Data System (ADS)

    Vilella, Kenny; Deschamps, Frederic

    2018-04-01

    Thermal evolution of terrestrial planets is controlled by heat transfer through their silicate mantles. A suitable framework for modelling this heat transport is a system including bottom heating (from the core) and internal heating, e.g., generated by secular cooling or by the decay of radioactive isotopes. The mechanism of heat 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 heating. For moderate internal heating rates, the system is composed of active hot upwellings and cold downwellings. For large internal heating rates, the bottom heat flux 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 heat flux and the temperature jump across both the top and bottom thermal boundary layer (TBL) to the Rayleigh number and the dimensionless internal heating 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 heating rates than that of systems with no or moderate internal heating. The differences between moderate and large internal heating 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 heating 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

  7. Temperature and heat flux scaling laws for isoviscous, infinite Prandtl number mixed heating convection

    NASA Astrophysics Data System (ADS)

    Vilella, Kenny; Deschamps, Frédéric

    2018-07-01

    Thermal evolution of terrestrial planets is controlled by heat transfer through their silicate mantles. A suitable framework for modelling this heat transport is a system including bottom heating (from the core) and internal heating, for example, generated by secular cooling or by the decay of radioactive isotopes. The mechanism of heat 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 heating. For moderate internal heating rates, the system is composed of active hot upwellings and cold downwellings. For large internal heating rates, the bottom heat flux 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 heat flux and the temperature jump across both the top and the bottom thermal boundary layer (TBL) to the Rayleigh number and the dimensionless internal heating 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 heating rates than that of systems with no or moderate internal heating. The differences between moderate and large internal heating 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 heating 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

  8. Simulating the effect of high column density absorbers on the one-dimensional Lyman α forest flux power spectrum

    NASA Astrophysics Data System (ADS)

    Rogers, Keir K.; Bird, Simeon; Peiris, Hiranya V.; Pontzen, Andrew; Font-Ribera, Andreu; Leistedt, Boris

    2018-03-01

    We measure the effect of high column density absorbing systems of neutral hydrogen (H I) on the one-dimensional (1D) Lyman α forest flux power spectrum using cosmological hydrodynamical simulations from the Illustris project. High column density absorbers (which we define to be those with H I column densities N(H I) > 1.6 × 10^{17} atoms cm^{-2}) cause broadened absorption lines with characteristic damping wings. These damping wings bias the 1D Lyman α forest flux power spectrum by causing absorption in quasar spectra away from the location of the absorber itself. We investigate the effect of high column density absorbers on the Lyman α forest using hydrodynamical simulations for the first time. We provide templates as a function of column density and redshift, allowing the flexibility to accurately model residual contamination, i.e. if an analysis selectively clips out the largest damping wings. This flexibility will improve cosmological parameter estimation, for example, allowing more accurate measurement of the shape of the power spectrum, with implications for cosmological models containing massive neutrinos or a running of the spectral index. We provide fitting functions to reproduce these results so that they can be incorporated straightforwardly into a data analysis pipeline.

  9. 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.

  10. 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 .

  11. Methods for absorbing neutrons

    DOEpatents

    Guillen, Donna P [Idaho Falls, ID; Longhurst, Glen R [Idaho Falls, ID; Porter, Douglas L [Idaho Falls, ID; Parry, James R [Idaho Falls, ID

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  12. 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.

  13. 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.

  14. Temporal-spatial variation of DOC concentration, UV absorbance and the flux estimation in the Lower Dagu River, China

    NASA Astrophysics Data System (ADS)

    Xi, Min; Kong, Fanlong; Li, Yue; Kong, Fanting

    2017-12-01

    Dissolved organic carbon (DOC) is an important component for both carbon cycle and energy balance. The concentration, UV absorbance, and export flux of DOC in the natural environment dominate many important transport processes. To better understand the temporal and spatial variation of DOC, 7 sites along the Lower Dagu River were chosen to conduct a comprehensive measurement from March 2013 to February 2014. Specifically, water samples were collected from the Lower Dagu River between the 26th and 29th of every month during the experimental period. The DOC concentration (CDOC) and UV absorbance were analyzed using a total organic carbon analyzer and the ultraviolet-visible absorption spectrum, and the DOC export flux was estimated with a simple empirical model. The results showed that the CDOC of the Lower Dagu River varied from 1.32 to 12.56 mg/L, consistent with global rivers. The CDOC and UV absorbance showed significant spatial variation in the Dagu River during the experiential period because of the upstream natural processes and human activities in the watershed. The spatial variation is mainly due to dam or reservoir constructions, riverside ecological environment changes, and non-point source or wastewater discharge. The seasonal variation of CDOC was mainly related to the source of water DOC, river runoff, and temperature, and the UV absorbance and humification degree of DOC had no obvious differences among months ( P<0.05). UV absorbance was applied to test the CDOC in Lower Dagu River using wave lengths of 254 and 280 nm. The results revealed that the annual DOC export flux varied from 1.6 to 3.76 × 105 g C/km2/yr in a complete hydrological year, significantly lower than the global average. It is worth mentioning that the DOC export flux was mainly concentrated in summer (˜90% of all-year flux in July and August), since the runoff in the Dagu River took place frequently in summer. These observations implied environment change could bring the temporal

  15. Modeling of a heat sink and high heat flux vapor chamber

    NASA Astrophysics Data System (ADS)

    Vadnjal, Aleksander

    An increasing demand for a higher heat flux removal capability within a smaller volume for high power electronics led us to focus on a novel cold plate design. A high heat flux evaporator and micro channel heat 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 heat 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 heat transfer coefficients. The calculation show good agreement with the experimental data. For the heat transfer coefficient closure, a proper average for both fluid and solid is investigated. Different types of heating are also investigated in order to determine how it influences the heat transfer coefficient. A higher heat fluxes in small area condensers led us to the micro channels in contrast to the classical heat fin design. A micro channel can have various shapes to enhance heat transfer, but the shape that will lead to a higher heat flux 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 heat transfer mechanisms; (1) porous media

  16. Investigation of saturated critical heat flux in a single, uniformly heated microchannel

    SciTech Connect

    Wojtan, Leszek; Revellin, Remi; Thome, John R.

    2006-08-15

    A series of tests have been performed to determine the saturated critical heat flux (CHF) in 0.5 and 0.8mm internal diameter microchannel tubes as a function of refrigerant mass velocity, heated length, saturation temperature and inlet liquid subcooling. The tested refrigerants were R-134a and R-245fa and the heated length of microchannel was varied between 20 and 70mm. The results show a strong dependence of CHF on mass velocity, heated 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 heat flux for the forced convective boiling in uniformly heated vertical tubes, Int. J. Heat and Mass Transfer 27 (9) (1984) 1641-1648] and the multichannel correlation of W. Qu and I. Mudawar [Measurement and correlation of critical heat flux in two-phase microchannel heat sinks, Int. J. Heat 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

  17. Coronal Heating and the Magnetic Flux Content of the Network

    NASA Technical Reports Server (NTRS)

    Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    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 flux, and (4) produces only about 5% of the total coronal emission in quiet regions. The heating 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 radiation from the large-scale corona increases roughly as the cube root of the magnetic flux content of the underlying magnetic network. In contrast, the coronal radiation from an active region increases roughly linearly with the magnetic flux 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 heating in quiet regions has a large non-magnetic component, or, if the heating is predominantly produced via the magnetic field, the mechanism is significantly different than in active

  18. Investigation of Instabilities and Heat Transfer Phenomena in Supercritical Fuels at High Heat Flux and Temperatures

    NASA Technical Reports Server (NTRS)

    Linne, Diane L.; Meyer, Michael L.; Braun, Donald C.; Keller, Dennis J.

    2000-01-01

    A series of heated tube experiments was performed to investigate fluid instabilities that occur during heating of supercritical fluids. In these tests, JP-7 flowed vertically through small diameter tubes at supercritical pressures. Test section heated length, diameter, mass flow rate, inlet temperature, and heat flux were varied in an effort to determine the range of conditions that trigger the instabilities. Heat flux 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 heat flux 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.

  19. USE OF PELTIER COOLERS AS SOIL HEAT FLUX TRANSDUCERS.

    USGS Publications Warehouse

    Weaver, H.L.; Campbell, G.S.

    1985-01-01

    Peltier coolers were modified and calibrated to serve as soil heat flux transducers. The modification was to fill their interiors with epoxy. The average calibration constant on 21 units was 13. 6 plus or minus 0. 8 kW m** minus **2 V** minus **1 at 20 degree C. This sensitivity is about eight times that of the two thermopile transducers with which comparisons were made. The thermal conductivity of the Peltier cooler transducers was 0. 4 W m** minus **1 degree C** minus **1, which is comparable to that of dry soil.

  20. Hyperbolic heat conduction, effective temperature, and third law for nonequilibrium systems with heat flux

    NASA Astrophysics Data System (ADS)

    Sobolev, S. L.

    2018-02-01

    Some analogies between different nonequilibrium heat 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 heat carrier velocity, these models lead to the hyperbolic heat 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 heat carriers moving in opposite directions, acts as a criterion for thermalization and is a nonlinear function of the kinetic temperature and heat flux. It is shown that, under highly nonequilibrium conditions when the heat flux tends to its maximum possible value, the effective temperature, heat 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 heat conduction in a monatomic gas and a strong shockwave have been analyzed.

  1. Transectional heat transfer in thermoregulating bigeye tuna (Thunnus obesus) - a 2D heat flux model.

    PubMed

    Boye, Jess; Musyl, Michael; Brill, Richard; Malte, Hans

    2009-11-01

    We developed a 2D heat flux model to elucidate routes and rates of heat 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 heat 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 heat exchanger efficiencies from the steady-state model to predict the distribution of temperature and heat fluxes 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 heat-producing and heat-conserving properties of the white muscle. The best correspondence between model output and observed data was obtained when the countercurrent heat exchangers in the blood flow pathways to the red and white muscle retained 99% and 96% (respectively) of the heat 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 heating and cooling rates. This study shows that the differential cooling and heating rates could be fully accounted for by a mechanism where blood flow to the swimming muscles is either exclusively through the heat 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.

  2. Using Gravity Inversion to Estimate Antarctic Geothermal Heat Flux

    NASA Astrophysics Data System (ADS)

    Vaughan, Alan P. M.; Kusznir, Nick J.; Ferraccioli, Fausto; Leat, Phil T.; Jordan, Tom A. R. M.; Purucker, Michael E.; (Sasha) Golynsky, A. V.; Rogozhina, Irina

    2014-05-01

    New modelling studies for Greenland have recently underlined the importance of GHF for long-term ice sheet behaviour (Petrunin et al. 2013). Revised determinations of top basement heat-flow for Antarctica and adjacent rifted continental margins using gravity inversion mapping of crustal thickness and continental lithosphere thinning (Chappell & Kusznir 2008), using BedMap2 data have provided improved estimates of geothermal heat flux (GHF) in Antarctica where it is very poorly known. Continental lithosphere thinning and post-breakup residual thicknesses of continental crust determined from gravity inversion have been used to predict the preservation of continental crustal radiogenic heat productivity and the transient lithosphere heat-flow contribution within thermally equilibrating rifted continental and oceanic lithosphere. The sensitivity of present-day Antarctic top basement heat-flow to initial continental radiogenic heat productivity, continental rift and margin breakup age has been examined. Recognition of the East Antarctic Rift System (EARS), a major Permian to Cretaceous age rift system that appears to extend from the continental margin at the Lambert Rift to the South Pole region, a distance of 2500 km (Ferraccioli et al. 2011) and is comparable in scale to the well-studied East African rift system, highlights that crustal variability in interior Antarctica is much greater than previously assumed. GHF is also important to understand proposed ice accretion at the base of the EAIS in the GSM and its links to sub-ice hydrology (Bell et al. 2011). References Bell, R.E., Ferraccioli, F., Creyts, T.T., Braaten, D., Corr, H., Das, I., Damaske, D., Frearson, N., Jordan, T., Rose, K., Studinger, M. & Wolovick, M. 2011. Widespread persistent thickening of the East Antarctic Ice Sheet by freezing from the base. Science, 331 (6024), 1592-1595. Chappell, A.R. & Kusznir, N.J. 2008. Three-dimensional gravity inversion for Moho depth at rifted continental margins

  3. 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

  4. Diamond thin film temperature and heat-flux sensors

    NASA Technical Reports Server (NTRS)

    Aslam, M.; Yang, G. S.; Masood, A.; Fredricks, R.

    1995-01-01

    Diamond film temperature and heat-flux sensors are developed using a technology compatible with silicon integrated circuit processing. The technology involves diamond nucleation, patterning, doping, and metallization. Multi-sensor test chips were designed and fabricated to study the thermistor behavior. The minimum feature size (device width) for 1st and 2nd generation chips are 160 and 5 micron, respectively. The p-type diamond thermistors on the 1st generation test chip show temperature and response time ranges of 80-1270 K and 0.29-25 microseconds, respectively. An array of diamond thermistors, acting as heat flux sensors, was successfully fabricated on an oxidized Si rod with a diameter of 1 cm. Some problems were encountered in the patterning of the Pt/Ti ohmic contacts on the rod, due mainly to the surface roughness of the diamond film. The use of thermistors with a minimum width of 5 micron (to improve the spatial resolution of measurement) resulted in lithographic problems related to surface roughness of diamond films. We improved the mean surface roughness from 124 nm to 30 nm by using an ultra high nucleation density of 10(exp 11)/sq cm. To deposit thermistors with such small dimensions on a curved surface, a new 3-D diamond patterning technique is currently under development. This involves writing a diamond seed pattern directly on the curved surface by a computer-controlled nozzle.

  5. Development and Testing of a Refractory Millimeter-Wave Absorbent Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Lambot, Thomas; Myrabo, Leik; Murakami, David; Parkin, Kevin

    2014-01-01

    Central to the Millimeter-Wave Thermal Launch System (MTLS) is the millimeter-wave absorbent heat exchanger. We have developed metallic and ceramic variants, with the key challenge being the millimeter-wave absorbent coatings for each. The ceramic heat exchanger came to fruition first, demonstrating for the first time 1800 K peak surface temperatures under illumination by a 110 GHz Gaussian beam. Absorption efficiencies of up to 80 are calculated for mullite heat exchanger tubes and up to 50 are calculated for alumina tubes. These are compared with estimates based on stratified layer and finite element analyses. The problem of how to connect the 1800 K end of the ceramic tubes to a graphite outlet manifold and nozzle is solved by press fitting, or by threading the ends of the ceramic tubes and screwing them into place. The problem of how to connect the ceramic tubes to a metallic or nylon inlet pipe is solved by using soft compliant PTFE and PVC tubes that accommodate thermal deformations of the ceramic tubes during startup and operation. We show the resulting heat exchangers in static tests using argon and helium as propellants.

  6. A modified force-restore approach to modeling snow-surface heat fluxes

    Treesearch

    Charles H. Luce; David G. Tarboton

    2001-01-01

    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 heat fluxes and the conductive flux into the snowpack. While the dependency of atmospheric fluxes on surface temperature is reasonably well understood and parameterized, conduction of heat from...

  7. Generating a heated fluid using an electromagnetic radiation-absorbing complex

    SciTech Connect

    Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

    A vessel including a concentrator configured to concentrate electromagnetic (EM) radiation received from an EM radiation source and a complex configured to absorb EM radiation to generate heat. The vessel is configured to receive a cool fluid from the cool fluid source, concentrate the EM radiation using the concentrator, apply the EM radiation to the complex, and transform, using the heat generated by the complex, the cool fluid to the heated fluid. The complex is at least one of consisting of copper nanoparticles, copper oxide nanoparticles, nanoshells, nanorods, carbon moieties, encapsulated nanoshells, encapsulated nanoparticles, and branched nanostructures. Further, the EMmore » radiation is at least one of EM radiation in an ultraviolet region of an electromagnetic spectrum, in a visible region of the electromagnetic spectrum, and in an infrared region of the electromagnetic spectrum.« less

  8. Estimating Antarctic Geothermal Heat Flux using Gravity Inversion

    NASA Astrophysics Data System (ADS)

    Vaughan, Alan P. M.; Kusznir, Nick J.; Ferraccioli, Fausto; Leat, Phil T.; Jordan, Tom A. R. M.; Purucker, Michael E.; Golynsky, A. V.; Sasha Rogozhina, Irina

    2013-04-01

    Geothermal heat flux (GHF) in Antarctica is very poorly known. We have determined (Vaughan et al. 2012) top basement heat-flow for Antarctica and adjacent rifted continental margins using gravity inversion mapping of crustal thickness and continental lithosphere thinning (Chappell & Kusznir 2008). Continental lithosphere thinning and post-breakup residual thicknesses of continental crust determined from gravity inversion have been used to predict the preservation of continental crustal radiogenic heat productivity and the transient lithosphere heat-flow contribution within thermally equilibrating rifted continental and oceanic lithosphere. The sensitivity of present-day Antarctic top basement heat-flow to initial continental radiogenic heat productivity, continental rift and margin breakup age has been examined. Knowing GHF distribution for East Antarctica and the Gamburtsev Subglacial Mountains (GSM) region in particular is critical because: 1) The GSM likely acted as key nucleation point for the East Antarctic Ice Sheet (EAIS); 2) the region may contain the oldest ice of the EAIS - a prime target for future ice core drilling; 3) GHF is important to understand proposed ice accretion at the base of the EAIS in the GSM and its links to sub-ice hydrology (Bell et al. 2011). An integrated multi-dataset-based GHF model for East Antarctica is planned that will resolve the wide range of estimates previously published using single datasets. The new map and existing GHF distribution estimates available for Antarctica will be evaluated using direct ice temperature measurements obtained from deep ice cores, estimates of GHF derived from subglacial lakes, and a thermodynamic ice-sheet model of the Antarctic Ice Sheet driven by past climate reconstructions and each of analysed heat flow maps, as has recently been done for the Greenland region (Rogozhina et al. 2012). References Bell, R.E., Ferraccioli, F., Creyts, T.T., Braaten, D., Corr, H., Das, I., Damaske, D., Frearson, N

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

    SciTech Connect

    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

  10. Development of advanced high-temperature heat flux sensors. Phase 2: Verification testing

    NASA Technical Reports Server (NTRS)

    Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

    1985-01-01

    A two-phase program is conducted to develop heat flux sensors capable of making heat flux measurements throughout the hot section of gas turbine engines. In Phase 1, three types of heat flux 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 heat flux sensors then tested in a high pressure combustor rig. Radiometer probes are also used to measure the radiant heat loads to more fully characterize the combustor environment. Test results show the heat flux sensors to be in good agreement with radiometer probes and the predicted data trends. In general, heat flux sensors have strong potential for use in combustor development programs.

  11. The Influence of Heat Flux Boundary Heterogeneity on Heat Transport in Earth's Core

    NASA Astrophysics Data System (ADS)

    Davies, C. J.; Mound, J. E.

    2017-12-01

    Rotating convection in planetary systems can be subjected to large lateral variations in heat flux 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 heat flux 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 flux-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 heat flux conditions are applied at the outer boundary.

  12. Control and design heat flux bending in thermal devices with transformation optics.

    PubMed

    Xu, Guoqiang; Zhang, Haochun; Jin, Yan; Li, Sen; Li, Yao

    2017-04-17

    We propose a fundamental latent function of control heat transfer and heat flux density vectors at random positions on thermal materials by applying transformation optics. The expressions for heat flux 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 heat flux bending exists corresponding to the temperature gradients of the 3D domain. The heat flux path can be controlled in random space based on the geometrical azimuths, radial positions, and thermal conductivity ratios of the selected materials.

  13. 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.

  14. A Comparison of Latent Heat Fluxes over Global Oceans for Four Flux Products

    NASA Technical Reports Server (NTRS)

    Chou, Shu-Hsien; Nelkin, Eric; Ardizzone, Joe; Atlas, Robert M.

    2003-01-01

    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 heat fluxes (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 Fluxes) over global Oceans during 1992-93 are compared with those of HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes 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 heat flux

  15. The surface latent heat flux anomalies related to major earthquake

    NASA Astrophysics Data System (ADS)

    Jing, Feng; Shen, Xuhui; Kang, Chunli; Xiong, Pan; Hong, Shunying

    2011-12-01

    SLHF (Surface Latent Heat Flux) is an atmospheric parameter, which can describe the heat released by phase changes and dependent on meteorological parameters such as surface temperature, relative humidity, wind speed etc. There is a sharp difference between the ocean surface and the land surface. Recently, many studies related to the SLHF anomalies prior to earthquakes have been developed. It has been shown that the energy exchange enhanced between coastal surface and atmosphere prior to earthquakes can increase the rate of the water-heat exchange, which will lead to an obviously increases in SLHF. In this paper, two earthquakes in 2010 (Haiti earthquake and southwest of Sumatra in Indonesia earthquake) have been analyzed using SLHF data by STD (standard deviation) threshold method. It is shows that the SLHF anomaly may occur in interpolate earthquakes or intraplate earthquakes and coastal earthquakes or island earthquakes. And the SLHF anomalies usually appear 5-6 days prior to an earthquake, then disappear quickly after the event. The process of anomaly evolution to a certain extent reflects a dynamic energy change process about earthquake preparation, that is, weak-strong-weak-disappeared.

  16. Comparison of Turbulent Heat-Transfer Results for Uniform Wall Heat Flux and Uniform Wall Temperature

    NASA Technical Reports Server (NTRS)

    Siegel, R.; Sparrow, E. M.

    1960-01-01

    The purpose of this note is to examine in a more precise way how the Nusselt numbers for turbulent heat 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 heat flux (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 heat flux, 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 heat flux. 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.

  17. Coronal Heating and the Magnetic Flux Content of the Network

    NASA Technical Reports Server (NTRS)

    Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    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 flux, and (4) produces only about 5% of the total coronal emission in quiet regions. The heating 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 radiation from the large-scale corona increases roughly as the cube root of the magnetic flux content of the underlying magnetic network. In contrast, Fisher et A (1998, ApJ, 508, 985-998) found that the coronal radiation from an active region increases roughly linearly with the magnetic flux 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 heating in quiet regions has a large non-magnetic component, or, if the heating

  18. 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.

  19. 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://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> </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://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://hdl.handle.net/2060/20160009728','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160009728"><span>Hybrid <span class="hlt">Heat</span> Pipes for Lunar and Martian Surface and High <span class="hlt">Heat</span> <span class="hlt">Flux</span> Space Applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ababneh, Mohammed T.; Tarau, Calin; Anderson, William G.; Farmer, Jeffery T.; Alvarez-Hernandez, Angel R.</p> <p>2016-01-01</p> <p>Novel hybrid wick <span class="hlt">heat</span> pipes are developed to operate against gravity on planetary surfaces, operate in space carrying power over long distances and act as thermosyphons on the planetary surface for Lunar and Martian landers and rovers. These hybrid <span class="hlt">heat</span> pipes will be capable of operating at the higher <span class="hlt">heat</span> <span class="hlt">flux</span> requirements expected in NASA's future spacecraft and on the next generation of polar rovers and equatorial landers. In addition, the sintered evaporator wicks mitigate the start-up problems in vertical gravity aided <span class="hlt">heat</span> pipes because of large number of nucleation sites in wicks which will allow easy boiling initiation. ACT, NASA Marshall Space Flight Center, and NASA Johnson Space Center, are working together on the Advanced Passive Thermal experiment (APTx) to test and validate the operation of a hybrid wick VCHP with warm reservoir and HiK"TM" plates in microgravity environment on the ISS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1414121-critical-role-electron-heat-flux-bohm-criterion','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1414121-critical-role-electron-heat-flux-bohm-criterion"><span>Critical role of electron <span class="hlt">heat</span> <span class="hlt">flux</span> on Bohm criterion</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Tang, Xianzhu; Guo, Zehua</p> <p>2016-12-05</p> <p>Bohm criterion, originally derived for an isothermal-electron and cold-ion plasma, is often used as a rule of thumb for more general plasmas. Here, we establish a more precise determination of the Bohm criterion that are quantitatively useful for understanding and modeling collisional plasmas that still have collisional mean-free-path much greater than plasma Debye length. Specifically, it is shown that electron <span class="hlt">heat</span> <span class="hlt">flux</span>, rather than the isothermal electron assumption, is what sets the Bohm speed to bemore » $$\\sqrt{k_B(T_e||+3T_i||)/m_i}$$ with T e,i∥ the electron and ion parallel temperature at the sheath entrance and m i the ion mass.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920007788','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920007788"><span><span class="hlt">Heat</span> <span class="hlt">flux</span> sensor research and development: The cool film calorimeter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Abtahi, A.; Dean, P.</p> <p>1990-01-01</p> <p>The goal was to meet the measurement requirement of the NASP program for a gauge capable of measuring <span class="hlt">heat</span> <span class="hlt">flux</span> into a 'typical' structure in a 'typical' hypersonic flight environment. A device is conceptually described that has fast response times and is small enough to fit in leading edge or cowl lip structures. The device relies heavily on thin film technology. The main conclusion is the description of the limitations of thin film technology both in the art of fabrication and in the assumption that thin films have the same material properties as the original bulk material. Three gauges were designed and fabricated. Thin film deposition processes were evaluated. The effect of different thin film materials on the performance and fabrication of the gauge was studied. The gauges were tested in an arcjet facility. Survivability and accuracy were determined under various hostile environment conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhPl...23l0701T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhPl...23l0701T"><span>Critical role of electron <span class="hlt">heat</span> <span class="hlt">flux</span> on Bohm criterion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, Xian-Zhu; Guo, Zehua</p> <p>2016-12-01</p> <p>Bohm criterion, originally derived for an isothermal-electron and cold-ion plasma, is often used as a rule of thumb for more general plasmas. Here, we establish a more precise determination of the Bohm criterion that are quantitatively useful for understanding and modeling collisional plasmas that still have collisional mean-free-path much greater than plasma Debye length. Specifically, it is shown that electron <span class="hlt">heat</span> <span class="hlt">flux</span>, rather than the isothermal electron assumption, is what sets the Bohm speed to be √{ k B ( T e ∥ + 3 T i ∥ ) / m i } with T e , i ∥ the electron and ion parallel temperature at the sheath entrance and mi the ion mass.</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 radiation (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/2018ResPh...8..365M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ResPh...8..365M"><span>Viscous dissipation and Joule <span class="hlt">heating</span> effects in MHD 3D flow with <span class="hlt">heat</span> and mass <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>Muhammad, Taseer; Hayat, Tasawar; Shehzad, Sabir Ali; Alsaedi, Ahmed</p> <p>2018-03-01</p> <p>The present research explores the three-dimensional stretched flow of viscous fluid in the presence of prescribed <span class="hlt">heat</span> (PHF) and concentration (PCF) <span class="hlt">fluxes</span>. Mathematical formulation is developed in the presence of chemical reaction, viscous dissipation and Joule <span class="hlt">heating</span> effects. Fluid is electrically conducting in the presence of an applied magnetic field. Appropriate transformations yield the nonlinear ordinary differential systems. The resulting nonlinear system has been solved. Graphs are plotted to examine the impacts of physical parameters on the temperature and concentration distributions. Skin friction coefficients and local Nusselt and Sherwood numbers are computed and analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PlST...16..278C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PlST...16..278C"><span>Behavior of Brazed W/Cu Mockup Under High <span class="hlt">Heat</span> <span class="hlt">Flux</span> Loads</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Lei; Lian, Youyun; Liu, Xiang</p> <p>2014-03-01</p> <p>In order to transfer the <span class="hlt">heat</span> from the armor to the coolant, tungsten has to be connected with a copper <span class="hlt">heat</span> sink. The joint technology is the most critical issue for manufacturing plasma facing components. Consequently, the reliability of the joints should be verified by a great number of high-<span class="hlt">heat-flux</span> (HHF) tests to simulate the real load conditions. W/Cu brazed joint technology with sliver free filler metal CuMnNi has been developed at Southwestern Institute of Physics (SWIP). Screening and thermal fatigue tests of one small-scale flat tile W/CuCrZr mockup were performed on a 60 kW electron-beam Material testing scenario (EMS-60) constructed recently at SWIP. The module successfully survived screening test with the <span class="hlt">absorbed</span> power density (Pabs) of 2 MW/m2 to 10 MW/m2 and the following 1000 cycles at Pabs of 7.2 MW/m2 without hot spots and overheating zones during the whole test campaign. Metallurgy and SEM observations did not find any cracks at both sides and the interface, indicating a good bonding of W and CuCrZr alloy. In addition, finite element simulations by ANSYS 12.0 under experimental load conditions were performed and compared with experimental results.</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/2018HMT...tmp..135O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT...tmp..135O"><span>Experimental investigation of the <span class="hlt">heat</span> and mass transfer in a tube bundle <span class="hlt">absorber</span> of an absorption chiller</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olbricht, Michael; Luke, Andrea</p> <p>2018-05-01</p> <p>The design of the <span class="hlt">absorber</span> of absorption chillers is still subject to great uncertainty since the coupled processes of <span class="hlt">heat</span> and mass transfer as well as the influence of systemic interactions on the absorption process are not fully understood. Unfortunately, only a few investigations on the transport phenomena in the <span class="hlt">absorber</span> during operation in an absorption chiller are reported in the literature. Therefore, experimental investigations on the <span class="hlt">heat</span> and mass transfer during falling film absorption of steam in aqueous LiBr-solution are carried out in an <span class="hlt">absorber</span> installed in an absorption chiller in this work. An improvement of <span class="hlt">heat</span> and mass transfer due to the increase in convective effects are observed as the Ref number increases. Furthermore, an improvement of the <span class="hlt">heat</span> transfer in the <span class="hlt">absorber</span> with increasing coolant temperature can be identified in the systemic context. This is explained by a corresponding reduction in the average viscosity of the solution in the <span class="hlt">absorber</span>. A comparison with experimental data from literature obtained from so-called <span class="hlt">absorber</span>-generator test rigs shows a good consistency. Thus, it has been shown that the findings obtained on these simplified experimental setups can be transferred to the <span class="hlt">absorber</span> in an absorption chiller. However, a comparison with correlations from the literature reveals a strong deviation between experimental and calculated results. Hence, further research activities on the development of better correlations are required in future.</p> </li> <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('http://adsabs.harvard.edu/abs/1992ThApC..46...53B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992ThApC..46...53B"><span>Tests of a robust eddy correlation system for sensible <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>Blanford, J. H.; Gay, L. W.</p> <p>1992-03-01</p> <p>Sensible <span class="hlt">heat</span> <span class="hlt">flux</span> 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. <span class="hlt">Flux</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span> measurements can be combined with net radiation and soil <span class="hlt">heat</span> <span class="hlt">flux</span> measurements to estimate latent <span class="hlt">heat</span> as a residual in the surface energy balance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/868695','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/868695"><span>Quantitative method for measuring <span class="hlt">heat</span> <span class="hlt">flux</span> emitted from a cryogenic object</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Duncan, Robert V.</p> <p>1993-01-01</p> <p>The present invention is a quantitative method for measuring the total <span class="hlt">heat</span> <span class="hlt">flux</span>, and of deriving the total power dissipation, of a <span class="hlt">heat-fluxing</span> object which includes the steps of placing an electrical noise-emitting <span class="hlt">heat-fluxing</span> 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 <span class="hlt">heat-fluxing</span> object or a temperature-dependent resistive thin film in intimate contact with the <span class="hlt">heat-fluxing</span> 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 <span class="hlt">heat-fluxing</span> object, and the temperature of the liquid helium bath when the electrical noise emitted by the <span class="hlt">heat-fluxing</span> object becomes greatly reduced, is determined. The total <span class="hlt">heat</span> <span class="hlt">flux</span> from the <span class="hlt">heat-fluxing</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6278578','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6278578"><span>Quantitative method for measuring <span class="hlt">heat</span> <span class="hlt">flux</span> emitted from a cryogenic object</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Duncan, R.V.</p> <p>1993-03-16</p> <p>The present invention is a quantitative method for measuring the total <span class="hlt">heat</span> <span class="hlt">flux</span>, and of deriving the total power dissipation, of a <span class="hlt">heat-fluxing</span> object which includes the steps of placing an electrical noise-emitting <span class="hlt">heat-fluxing</span> 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 <span class="hlt">heat-fluxing</span> object or a temperature-dependent resistive thin film in intimate contact with the <span class="hlt">heat-fluxing</span> 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 <span class="hlt">heat-fluxing</span> object, and the temperature of the liquid helium bath when the electrical noise emitted by the <span class="hlt">heat-fluxing</span> object becomes greatly reduced, is determined. The total <span class="hlt">heat</span> <span class="hlt">flux</span> from the <span class="hlt">heat-fluxing</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ZaMP...69...71B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ZaMP...69...71B"><span>Systems with a constant <span class="hlt">heat</span> <span class="hlt">flux</span> with applications to radiative <span class="hlt">heat</span> transport across nanoscale gaps and layers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Budaev, Bair V.; Bogy, David B.</p> <p>2018-06-01</p> <p>We extend the statistical analysis of equilibrium systems to systems with a constant <span class="hlt">heat</span> <span class="hlt">flux</span>. This extension leads to natural generalizations of Maxwell-Boltzmann's and Planck's equilibrium energy distributions to energy distributions of systems with a net <span class="hlt">heat</span> <span class="hlt">flux</span>. This development provides a long needed foundation for addressing problems of nanoscale <span class="hlt">heat</span> transport by a systematic method based on a few fundamental principles. As an example, we consider the computation of the radiative <span class="hlt">heat</span> <span class="hlt">flux</span> between narrowly spaced half-spaces maintained at different temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JQSRT.103..545L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JQSRT.103..545L"><span>Least-squares collocation meshless approach for radiative <span class="hlt">heat</span> transfer in <span class="hlt">absorbing</span> 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>Liu, L. H.; Tan, J. Y.</p> <p>2007-02-01</p> <p>A least-squares collocation meshless method is employed for solving the radiative <span class="hlt">heat</span> transfer in <span class="hlt">absorbing</span>, emitting and scattering media. The least-squares collocation meshless method for radiative transfer is based on the discrete ordinates equation. A moving least-squares approximation is applied to construct the trial functions. Except for the collocation points which are used to construct the trial functions, a number of auxiliary points are also adopted to form the total residuals of the problem. The least-squares technique is used to obtain the solution of the problem by minimizing the summation of residuals of all collocation and auxiliary points. Three numerical examples are studied to illustrate the performance of this new solution method. The numerical results are compared with the other benchmark approximate solutions. By comparison, the results show that the least-squares collocation meshless method is efficient, accurate and stable, and can be used for solving the radiative <span class="hlt">heat</span> transfer in <span class="hlt">absorbing</span>, emitting and scattering media.</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 radiative 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 radiative losses. The majority of the radiative 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 radiative 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://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://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> </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('http://hdl.handle.net/2060/19900018410','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900018410"><span>Apparatus for measuring high-<span class="hlt">flux</span> <span class="hlt">heat</span> transfer in radiatively <span class="hlt">heated</span> compact exchangers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Olson, Douglas A.</p> <p>1989-01-01</p> <p>An apparatus is described which can deliver uniform <span class="hlt">heat</span> <span class="hlt">flux</span> densities of up to 80 W/sq cm over an area 7.8 cm x 15.2 cm for use in measuring the <span class="hlt">heat</span> transfer and pressure drop in thin (6 mm or less), compact <span class="hlt">heat</span> 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).</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('https://eric.ed.gov/?q=Heat+AND+transfer&id=EJ844005','ERIC'); return false;" href="https://eric.ed.gov/?q=Heat+AND+transfer&id=EJ844005"><span>The Role of the Velocity Gradient in Laminar Convective <span class="hlt">Heat</span> Transfer through a Tube with a Uniform Wall <span class="hlt">Heat</span> <span class="hlt">Flux</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wang, Liang-Bi; Zhang, Qiang; Li, Xiao-Xia</p> <p>2009-01-01</p> <p>This paper aims to contribute to a better understanding of convective <span class="hlt">heat</span> transfer. For this purpose, the reason why thermal diffusivity should be placed before the Laplacian operator of the <span class="hlt">heat</span> <span class="hlt">flux</span>, and the role of the velocity gradient in convective <span class="hlt">heat</span> transfer are analysed. The background to these analyses is that, when the energy…</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://hdl.handle.net/2060/19870006083','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870006083"><span>Comparison of measured and modeled radiation, <span class="hlt">heat</span> and water vapor <span class="hlt">fluxes</span>: FIFE pilot study</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.; Hubbard, Kenneth G.; Verma, Shashi B.; Starks, Patrick; Norman, John M.; Walter-Shea, Elizabeth</p> <p>1987-01-01</p> <p>The feasibility of using radio frequency receivers to collect data from automated weather stations to model <span class="hlt">fluxes</span> of latent <span class="hlt">heat</span>, sensible <span class="hlt">heat</span>, and radiation using routine weather data collected by automated weather stations was tested and the estimated <span class="hlt">fluxes</span> were compared with <span class="hlt">fluxes</span> measured over wheat. The model Cupid was used to model the <span class="hlt">fluxes</span>. 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> is just beginning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27294929','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27294929"><span>Dispersion of <span class="hlt">Heat</span> <span class="hlt">Flux</span> Sensors Manufactured in Silicon Technology.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ziouche, Katir; Lejeune, Pascale; Bougrioua, Zahia; Leclercq, Didier</p> <p>2016-06-09</p> <p>In this paper, we focus on the dispersion performances related to the manufacturing process of <span class="hlt">heat</span> <span class="hlt">flux</span> sensors realized in CMOS (Complementary metal oxide semi-conductor) compatible 3-in technology. In particular, we have studied the performance dispersion of our sensors and linked these to the physical characteristics of dispersion of the materials used. This information is mandatory to ensure low-cost manufacturing and especially to reduce production rejects during the fabrication process. The results obtained show that the measured sensitivity of the sensors is in the range 3.15 to 6.56 μV/(W/m²), associated with measured resistances ranging from 485 to 675 kΩ. The dispersions correspond to a Gaussian-type distribution with more than 90% determined around average sensitivity S e ¯ = 4.5 µV/(W/m²) and electrical resistance R ¯ = 573.5 kΩ within the interval between the average and, more or less, twice the relative standard deviation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030025342','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030025342"><span>Time and Space Resolved <span class="hlt">Heat</span> Transfer Measurements Under Nucleate Bubbles with Constant <span class="hlt">Heat</span> <span class="hlt">Flux</span> Boundary Conditions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Myers, Jerry G.; Hussey, Sam W.; Yee, Glenda F.; Kim, Jungho</p> <p>2003-01-01</p> <p>Investigations into single bubble pool boiling phenomena are often complicated by the difficulties in obtaining time and space resolved information in the bubble region. This usually occurs because the heaters and diagnostics used to measure <span class="hlt">heat</span> transfer data are often on the order of, or larger than, the bubble characteristic length or region of influence. This has contributed to the development of many different and sometimes contradictory models of pool boiling phenomena and dominant <span class="hlt">heat</span> transfer mechanisms. Recent investigations by Yaddanapyddi and Kim and Demiray and Kim have obtained time and space resolved <span class="hlt">heat</span> transfer information at the bubble/heater interface under constant temperature conditions using a novel micro-heater array (10x10 array, each heater 100 microns on a side) that is semi-transparent and doubles as a measurement sensor. By using active feedback to maintain a state of constant temperature at the heater surface, they showed that the area of influence of bubbles generated in FC-72 was much smaller than predicted by standard models and that micro-conduction/micro-convection due to re-wetting dominated <span class="hlt">heat</span> transfer effects. This study seeks to expand on the previous work by making time and space resolved measurements under bubbles nucleating on a micro-heater array operated under constant <span class="hlt">heat</span> <span class="hlt">flux</span> conditions. In the planned investigation, wall temperature measurements made under a single bubble nucleation site will be synchronized with high-speed video to allow analysis of the bubble energy removal from the wall.</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://adsabs.harvard.edu/abs/2013APJAS..49..443P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APJAS..49..443P"><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, Sang-Jong; Choi, Tae-Jin; Kim, Seong-Joong</p> <p>2013-08-01</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 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 <span class="hlt">heat</span> <span class="hlt">flux</span> is about -11 Wm-2, latent <span class="hlt">heat</span> <span class="hlt">flux</span> 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, <span class="hlt">heat</span> and moisture are 5.15 × 10-3, 1.19 × 10-3, and 1.87 × 10-3, respectively. The observed exchange coefficients of <span class="hlt">heat</span> shows clear diurnal variations while those of momentum and moisture do not show diurnal variation. The parameterized exchange coefficients of <span class="hlt">heat</span> and moisture produces <span class="hlt">heat</span> <span class="hlt">fluxes</span> which compare well with the observed diurnal variations of <span class="hlt">heat</span> <span class="hlt">fluxes</span>.</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://adsabs.harvard.edu/abs/2017NIMPA.841....1S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NIMPA.841....1S"><span>Investigation of vacuum properties of CuCrZr alloy for high-<span class="hlt">heat</span>-load <span class="hlt">absorber</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shueh, C.; Chan, C. K.; Chang, C. C.; Sheng, I. C.</p> <p>2017-01-01</p> <p>The Taiwan Photon Source (TPS) uses high-<span class="hlt">heat</span>-load (HHL) <span class="hlt">absorbers</span> to protect downstream ultrahigh-vacuum chambers from overheating. In this work, we propose to use the CuCrZr alloy (ASTM C18150) for the HHL <span class="hlt">absorber</span> body and the ConFlat® flanges. We use the throughput method to measure the thermal outgassing rate and a helium leak detector to verify the vacuum seal between the CuCrZr alloy and stainless-steel flanges. The measured outgassing rate of the CuCrZr alloy was 5.8×10-10 Pa m/s after 72 h of pumping and decreased to 2.0 × 10-10 Pa m/s after 100 h of pumping. The leak rate through the vacuum seal between a CuCrZr flange and a stainless-steel flange was less than 1 × 10-10 Pa m3/s even after mounting and unmounting the flanges ten times and baking them at 250 °C. These results indicate that CuCrZr alloy is suitable for integrating HHL components with ConFlat® CuCrZr flanges for the absorption of the synchrotron radiation generated by the TPS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhyB..538...95H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyB..538...95H"><span>Nonlinear radiative <span class="hlt">heat</span> <span class="hlt">flux</span> and <span class="hlt">heat</span> source/sink on entropy generation minimization rate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hayat, T.; Khan, M. Waleed Ahmed; Khan, M. Ijaz; Alsaedi, A.</p> <p>2018-06-01</p> <p>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 <span class="hlt">heat</span> <span class="hlt">flux</span>. Velocity and temperature gradients are discussed through graphs. Meaningful results are concluded in the final remarks.</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/scitech">SciTech Connect</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('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://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://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> </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('http://adsabs.harvard.edu/abs/2017AIPC.1865h0005P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1865h0005P"><span>Critical <span class="hlt">heat</span> <span class="hlt">flux</span> phenomena depending on pre-pressurization in transient <span class="hlt">heat</span> input</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Jongdoc; Fukuda, Katsuya; Liu, Qiusheng</p> <p>2017-07-01</p> <p>The critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) levels that occurred due to exponential <span class="hlt">heat</span> inputs for varying periods to a 1.0-mm diameter horizontal cylinder immersed in various liquids were measured to develop an extended database on the effect of various pressures and subcoolings by photographic study. Two main mechanisms of CHF were found. One mechanism is due to the time lag of the hydrodynamic instability (HI) which starts at steady-state CHF upon fully developed nucleate boiling, and the other mechanism is due to the explosive process of heterogeneous spontaneous nucleation (HSN) which occurs at a certain HSN superheat in originally flooded cavities on the cylinder surface. The incipience of boiling processes was completely different depending on pre-pressurization. Also, the dependence of pre-pressure in transient CHFs changed due to the wettability of boiling liquids. The objective of this work is to clarify the transient CHF phenomena due to HI or HSN by photographic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26800333','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26800333"><span>Tissue responses to fractional transient <span class="hlt">heating</span> with sinusoidal <span class="hlt">heat</span> <span class="hlt">flux</span> condition on skin surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ezzat, Magdy A; El-Bary, Alaa A; Al-Sowayan, Noorah S</p> <p>2016-10-01</p> <p>A fractional model of Bioheat equation for describing quantitatively the thermal responses of skin tissue under sinusoidal <span class="hlt">heat</span> <span class="hlt">flux</span> conditions on skin surface is given. Laplace transform technique is used to obtain the solution in a closed form. The resulting formulation is applied to one-dimensional application to investigate the temperature distribution in skin with instantaneous surface <span class="hlt">heating</span> for different cases. According to the numerical results and its graphs, conclusion about the fractional bioheat transfer equation has been constructed. Sensitivity analysis is performed to explore the thermal effects of various control parameters on tissue temperature. The comparisons are made with the results obtained in the case of the absence of time-fractional order. © 2016 Japanese Society of Animal Science. © 2016 Japanese Society of Animal Science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/6361303','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/6361303"><span>Countercurrent flow limited (CCFL) <span class="hlt">heat</span> <span class="hlt">flux</span> in the high <span class="hlt">flux</span> isotope reactor (HFIR) fuel element</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ruggles, A.E.</p> <p>1990-10-12</p> <p>The countercurrent flow (CCF) performance in the fuel element region of the HFIR is examined experimentally and theoretically. The fuel element consists of two concentric annuli filled with aluminum clad fuel plates of 1.27 mm thickness separated by 1.27 mm flow channels. The plates are curved as they go radially outward to accomplish constant flow channel width and constant metal-to-coolant ratio. A full-scale HFIR fuel element mock-up is studied in an adiabatic air-water CCF experiment. A review of CCF models for narrow channels is presented along with the treatment of CCFs in system of parallel channels. The experimental results aremore » related to the existing models and a mechanistic model for the annular'' CCF in a narrow channel is developed that captures the data trends well. The results of the experiment are used to calculate the CCFL <span class="hlt">heat</span> <span class="hlt">flux</span> of the HFIR fuel assembly. It was determined that the HFIR fuel assembly can reject 0.62 Mw of thermal power in the CCFL situation. 31 refs., 17 figs.« less</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/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('http://adsabs.harvard.edu/abs/2017RPFSU..25..123H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RPFSU..25..123H"><span>The Effect of the <span class="hlt">Heat</span> <span class="hlt">Flux</span> on the Self-Ignition of Oriented Strand Board</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirle, Siegfried; Balog, Karol</p> <p>2017-06-01</p> <p>This article deals with the initiation phase of flaming and smouldering burning of oriented strand board. The influence of <span class="hlt">heat</span> <span class="hlt">flux</span> on thermal degradation of OSB boards, time to ignition, <span class="hlt">heat</span> release rate and mass loss rate using thermal analysis and vertical electrical radiation panel methods were studied. Significant information on the influence of the <span class="hlt">heat</span> <span class="hlt">flux</span> density and the thickness of the material on time to ignition was obtained.</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/2017JMetR..31..363C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMetR..31..363C"><span>Effects of optimized root water uptake parameterization schemes on water and <span class="hlt">heat</span> <span class="hlt">flux</span> simulation in a maize agroecosystem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cai, Fu; Ming, Huiqing; Mi, Na; Xie, Yanbing; Zhang, Yushu; Li, Rongping</p> <p>2017-04-01</p> <p>As root water uptake (RWU) is an important link in the water and <span class="hlt">heat</span> exchange between plants and ambient air, improving its parameterization is key to enhancing the performance of land surface model simulations. Although different types of RWU functions have been adopted in land surface models, there is no evidence as to which scheme most applicable to maize farmland ecosystems. Based on the 2007-09 data collected at the farmland ecosystem field station in Jinzhou, the RWU function in the Common Land Model (CoLM) was optimized with scheme options in light of factors determining whether roots <span class="hlt">absorb</span> water from a certain soil layer ( W x ) and whether the baseline cumulative root efficiency required for maximum plant transpiration ( W c ) is reached. The sensibility of the parameters of the optimization scheme was investigated, and then the effects of the optimized RWU function on water and <span class="hlt">heat</span> <span class="hlt">flux</span> simulation were evaluated. The results indicate that the model simulation was not sensitive to W x but was significantly impacted by W c . With the original model, soil humidity was somewhat underestimated for precipitation-free days; soil temperature was simulated with obvious interannual and seasonal differences and remarkable underestimations for the maize late-growth stage; and sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> were overestimated and underestimated, respectively, for years with relatively less precipitation, and both were simulated with high accuracy for years with relatively more precipitation. The optimized RWU process resulted in a significant improvement of CoLM's performance in simulating soil humidity, temperature, sensible <span class="hlt">heat</span>, and latent <span class="hlt">heat</span>, for dry years. In conclusion, the optimized RWU scheme available for the CoLM model is applicable to the simulation of water and <span class="hlt">heat</span> <span class="hlt">flux</span> for maize farmland ecosystems in arid areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.9946S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.9946S"><span><span class="hlt">Heat</span> <span class="hlt">Fluxes</span> and Evaporation Measurements by Multi-Function <span class="hlt">Heat</span> Pulse Probe: a Laboratory Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sharma, V.; Ciocca, F.; Hopmans, J. W.; Kamai, T.; Lunati, I.; Parlange, M. B.</p> <p>2012-04-01</p> <p>Multi Functional <span class="hlt">Heat</span> Pulse Probes (MFHPP) are multi-needles probes developed in the last years able to measure temperature, thermal properties such as thermal diffusivity and volumetric <span class="hlt">heat</span> capacity, from which soil moisture is directly retrieved, and electric conductivity (through a Wenner array). They allow the simultaneous measurement of coupled <span class="hlt">heat</span>, water and solute transport in porous media, then. The use of only one instrument to estimate different quantities in the same volume and almost at the same time significantly reduces the need to interpolate different measurement types in space and time, increasing the ability to study the interdependencies characterizing the coupled transports, especially of water and <span class="hlt">heat</span>, and water and solute. A three steps laboratory experiment is realized at EPFL to investigate the effectiveness and reliability of the MFHPP responses in a loamy soil from Conthey, Switzerland. In the first step specific calibration curves of volumetric <span class="hlt">heat</span> capacity and thermal conductivity as function of known volumetric water content are obtained placing the MFHPP in small samplers filled with the soil homogeneously packed at different saturation degrees. The results are compared with literature values. In the second stage the ability of the MFHPP to measure <span class="hlt">heat</span> <span class="hlt">fluxes</span> is tested within a homemade thermally insulated calibration box and results are matched with those by two self-calibrating Heatflux plates (from Huxseflux), placed in the same box. In the last step the MFHPP are used to estimate the cumulative subsurface evaporation inside a small column (30 centimeters height per 8 centimeters inner diameter), placed on a scale, filled with the same loamy soil (homogeneously packed and then saturated) and equipped with a vertical array of four MFHPP inserted close to the surface. The subsurface evaporation is calculated from the difference between the net sensible <span class="hlt">heat</span> and the net <span class="hlt">heat</span> storage in the volume scanned by the probes, and the</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('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=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('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://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/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://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('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/2060/20130000651','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('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('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> </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://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('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('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('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/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://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/scitech">SciTech Connect</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/2013EPJWC..4501127C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EPJWC..4501127C"><span>Experimental investigations of the performance of a solar air collector with latent <span class="hlt">heat</span> thermal storage integrated with the solar <span class="hlt">absorber</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Charvat, P.; Pech, O.; Hejcik, J.</p> <p>2013-04-01</p> <p>The paper deals with experimental investigations of the performance of a solar air collector with latent <span class="hlt">heat</span> thermal storage integrated with the solarabsorber. The main purpose of <span class="hlt">heat</span> storage in solar thermal systems is to store <span class="hlt">heat</span> when the supply of solar <span class="hlt">heat</span> exceeds demand and release it when otherwise. A number of <span class="hlt">heat</span> storage materials can be used for this purpose; the phase change materials among them. Short-term latent <span class="hlt">heat</span> thermal storage integrated with the solar <span class="hlt">absorber</span> can stabilize the air temperature at the outlet of the collector on cloudy days when solar radiation intensity incident on a solar collector fluctuates significantly. Two experimental front-and-back pass solar air collectors of the same dimensions have been built for the experimental investigations. One collector had a "conventional" solar <span class="hlt">absorber</span> made of a metal sheet while the solar <span class="hlt">absorber</span> of the other collector consisted of containers filled with organic phase change material. The experimental collectors were positioned side by side during the investigations to ensure the same operating conditions (incident solar radiation, outdoor temperature).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16390562','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16390562"><span>Partial liquid ventilation: effects of closed breathing systems, <span class="hlt">heat</span>-and-moisture-exchangers and sodalime <span class="hlt">absorbers</span> on perfluorocarbon evaporation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wilms, C T; Schober, P; Kalb, R; Loer, S A</p> <p>2006-01-01</p> <p>During partial liquid ventilation perfluorocarbons are instilled into the airways from where they subsequently evaporate via the bronchial system. This process is influenced by multiple factors, such as the vapour pressure of the perfluorocarbons, the instilled volume, intrapulmonary perfluorocarbon distribution, postural positioning and ventilatory settings. In our study we compared the effects of open and closed breathing systems, a <span class="hlt">heat</span>-and-moisture-exchanger and a sodalime <span class="hlt">absorber</span> on perfluorocarbon evaporation during partial liquid ventilation. Isolated rat lungs were suspended from a force transducer. After intratracheal perfluorocarbon instillation (10 mL kg(-1)) the lungs were either ventilated with an open breathing system (n = 6), a closed breathing system (n = 6), an open breathing system with an integrated <span class="hlt">heat</span>-and-moisture-exchanger (n = 6), an open breathing system with an integrated sodalime <span class="hlt">absorber</span> (n = 6), or a closed breathing system with an integrated <span class="hlt">heat</span>-and-moisture-exchanger and a sodalime <span class="hlt">absorber</span> (n = 6). Evaporative perfluorocarbon elimination was determined gravimetrically. When compared to the elimination half-life in an open breathing system (1.2 +/- 0.07 h), elimination half-life was longer with a closed system (6.4 +/- 0.9 h, P 0.05) when compared to a closed system. Evaporative perfluorocarbon loss can be reduced effectively with closed breathing systems, followed by the use of sodalime <span class="hlt">absorbers</span> and <span class="hlt">heat</span>-and-moisture-exchangers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......121B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......121B"><span>Thermal barrier coatings (TBC's) for high <span class="hlt">heat</span> <span class="hlt">flux</span> thrust chambers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bradley, Christopher M.</p> <p></p> <p>-section components has become critical, but at the same time the service conditions have put our best alloy systems to their limits. As a result, implementation of cooling holes and thermal barrier coatings are new advances in hot-section technologies now looked at for modifications to reach higher temperature applications. Current thermal barrier coatings used in today's turbine applications is known as 8%yttria-stabilized zirconia (YSZ) and there are no coatings for current thrust chambers. Current research is looking at the applicability of 8%yttria-stabilized hafnia (YSH) for turbine applications and the implementation of 8%YSZ onto thrust chambers. This study intends to determine if the use of thermal barrier coatings are applicable for high <span class="hlt">heat</span> <span class="hlt">flux</span> thrust chambers using industrial YSZ will be advantageous for improvements in efficiency, thrust and longer service life by allowing the thrust chambers to be used more than once.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930057675&hterms=self+regulatory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dself%2Bregulatory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930057675&hterms=self+regulatory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dself%2Bregulatory"><span><span class="hlt">Flux</span>-tube divergence, coronal <span class="hlt">heating</span>, and the solar wind</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Y.-M.</p> <p>1993-01-01</p> <p>Using model calculations based on a self-consistent treatment of the coronal energy balance, we show how the magnetic <span class="hlt">flux</span>-tube divergence rate controls the coronal temperature and the properties of the solar wind. For a fixed input of mechanical and Alfven-wave energy at the coronal base, we find that as the divergence rate increases, the maximum coronal temperature decreases but the mass <span class="hlt">flux</span> leaving the sun gradually increases. As a result, the asymptotic wind speed decreases with increasing expansion factor near the sun, in agreement with empirical studies. As noted earlier by Withbroe, the calculated mass <span class="hlt">flux</span> at the sun is remarkably insensitive to parameter variations; when combined with magnetohydrodynamic considerations, this self-regulatory property of the model explains the observed constancy of the mass <span class="hlt">flux</span> at earth.</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('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('http://hdl.handle.net/2060/19890001997','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890001997"><span>Comparison of measured and modeled radiation, <span class="hlt">heat</span> and water vapor <span class="hlt">fluxes</span>: FIFE pilot study</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.; Verma, Shashi B.; Hubbard, Kenneth G.; Starks, Patrick; Hays, Cynthia; Norman, John M.; Waltershea, Elizabeth</p> <p>1988-01-01</p> <p>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 <span class="hlt">fluxes</span> of latent <span class="hlt">heat</span>, sensible <span class="hlt">heat</span>, and radiation over wheat. The model Cupid was used to calculate these <span class="hlt">fluxes</span> which were compared with <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> and sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> from the prairie vegetation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AIPC..899..580K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AIPC..899..580K"><span>The Thermal Conductivity Measurements of Solid Samples by <span class="hlt">Heat</span> <span class="hlt">Flux</span> Differantial Scanning Calorimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kök, M.; Aydoǧdu, Y.</p> <p>2007-04-01</p> <p>The thermal conductivity of polyvinylchloride (PVC), polysytrene (PS) and polypropylene (PP) were measured by <span class="hlt">heat</span> <span class="hlt">flux</span> DSC. Our results are in good agreement with the results observed by different methods.</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('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('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/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/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> </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('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('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/scitech">SciTech Connect</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/2016AGUFMGC34B..06G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC34B..06G"><span>Capabilities of VOS-based <span class="hlt">fluxes</span> for estimating ocean <span class="hlt">heat</span> budget and its variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gulev, S.; Belyaev, K.</p> <p>2016-12-01</p> <p>We consider here the perspective of using VOS observations by merchant ships available form the ICOADS data for estimating ocean surface <span class="hlt">heat</span> budget at different time scale. To this purpose we compute surface turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> as well as short- and long-wave radiative <span class="hlt">fluxes</span> from the ICOADS reports for the last several decades in the North Atlantic mid latitudes. Turbulent <span class="hlt">fluxes</span> were derived using COARE-3 algorithm and for computation of radiative <span class="hlt">fluxes</span> new algorithms accounting for cloud types were used. Sampling uncertainties in the VOS-based <span class="hlt">fluxes</span> were estimated by sub-sampling of the recomputed reanalysis (ERA-Interim) <span class="hlt">fluxes</span> according to the VOS sampling scheme. For the turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> we suggest an approach to minimize sampling uncertainties. The approach is based on the integration of the turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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 <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> transport are available from the ocean cross-sections. Over the last 35 years turbulent <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> 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.</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('http://adsabs.harvard.edu/abs/2017AIPC.1850o0002F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1850o0002F"><span><span class="hlt">Heat</span> transfer experiments with a central receiver tube subjected to unsteady and non-uniform <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>Fernández-Torrijos, María; Marugán-Cruz, Carolina; Sobrino, Celia; Santana, Domingo</p> <p>2017-06-01</p> <p>In this work, a molten salt test loop to study the <span class="hlt">heat</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span>, 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 <span class="hlt">heat</span> <span class="hlt">flux</span>. The main advantage of using an induction heater is the control of <span class="hlt">heating</span> in different areas of the tube. In order to measure the effects of a non-homogenous and unsteady <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span> and water velocity to study their effects on the <span class="hlt">heat</span> transfer process.</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/scitech">SciTech Connect</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('http://www.ars.usda.gov/research/publications/publication/?seqNo115=309452','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=309452"><span>Changes in <span class="hlt">fluxes</span> of <span class="hlt">heat</span>, H2O, CO2 caused by a large wind farm</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>The Crop Wind Energy Experiment (CWEX) provides a platform to investigate the effect of wind turbines and large wind farms on surface <span class="hlt">fluxes</span> of momentum, <span class="hlt">heat</span>, moisture and carbon dioxide (CO2). In 2010 and 2011, eddy covariance <span class="hlt">flux</span> stations were installed between two lines of turbines at the south...</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('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('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('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('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('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('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('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://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/scitech">SciTech Connect</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/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.ncbi.nlm.nih.gov/pubmed/23775374','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23775374"><span>Relationship between core temperature, skin temperature, and <span class="hlt">heat</span> <span class="hlt">flux</span> during exercise in <span class="hlt">heat</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Xiaojiang; Karis, Anthony J; Buller, Mark J; Santee, William R</p> <p>2013-09-01</p> <p>This paper investigates the relationship between core temperature (T c), skin temperature (T s) and <span class="hlt">heat</span> <span class="hlt">flux</span> (HF) during exercise in hot conditions. Nine test volunteers, wearing an Army Combat Uniform and body armor, participated in three sessions at 25 °C/50 % relative humidity (RH); 35 °C/70 % RH; and 42 °C/20 % RH. Each session consisted of two 1-h treadmill walks at ~350 W and ~540 W intensity. T s and HF from six sites on the forehead, sternum, pectoralis, left rib cage, left scapula, and left thigh, and T c (i.e., core temperature pill used as a suppository) were measured. Multiple linear regressions were conducted to derive algorithms that estimate T c from T s and HF at each site. A simple model was developed to simulate influences of thermal conductivity and thickness of the local body tissues on the relationship between T c, T s, and HF. Coefficient of determination (R (2)) ranged from 0.30 to 0.88, varying with locations and conditions. Good sites for T c measurement at surface were the sternum, and a combination of the sternum, scapula, and rib sites. The combination of T s and HF measured at the sternum explained ~75 % or more of variance in observed T c in hot environments. The forehead was found unsuitable for exercise in <span class="hlt">heat</span> due to sweating and evaporative <span class="hlt">heat</span> loss. The derived algorithms are likely applicable only for the same ensemble or ensembles with similar thermal and vapor resistances. Algorithms for T c measurement are location-specific and their accuracy is dependent, to a large degree, on sensor placement.</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/2060/19720018905','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> </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://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/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 <span class="hlt">absorbs</span> infrared (IR) radiation and re-emits the radiation back to the ocean's surface which is subsequently <span class="hlt">absorbed</span> resulting in a rise in the ocean <span class="hlt">heat</span> content. However, the incoming longwave radiation, LWin, is <span class="hlt">absorbed</span> 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 radiation 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 radiation, 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 radiation, wind-driven shear and possibilities of TSL disruption. The results show independence between the turbulent <span class="hlt">fluxes</span> and radiative <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 <span class="hlt">absorbing</span> 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('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('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/2060/19730022520','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('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://eric.ed.gov/?q=hydrate&id=EJ936775','ERIC'); return false;" href="https://eric.ed.gov/?q=hydrate&id=EJ936775"><span>Waters of Hydration of Cupric Hydrates: A Comparison between <span class="hlt">Heating</span> and <span class="hlt">Absorbance</span> Methods</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Barlag, Rebecca; Nyasulu, Frazier</p> <p>2011-01-01</p> <p>The empirical formulas of four cupric hydrates are determined by measuring the <span class="hlt">absorbance</span> in aqueous solution. The Beer-Lambert Law is verified by constructing a calibration curve of <span class="hlt">absorbance</span> versus known Cu[superscript 2+](aq) concentration. A solution of the unknown hydrate is prepared by using 0.2-0.3 g of hydrate, and water is added such…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760006922','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760006922"><span>Quasi-exospheric <span class="hlt">heat</span> <span class="hlt">flux</span> of solar-wind electrons</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Eviatar, A.; Schultz, M.</p> <p>1975-01-01</p> <p>Density, bulk-velocity, and <span class="hlt">heat</span>-flow moments are calculated for truncated Maxwellian distributions representing the cool and hot populations of solar-wind electrons, as realized at the base of a hypothetical exosphere. The electrostatic potential is thus calculated by requiring charge quasi-neutrality and the absence of electrical current. Plasma-kinetic coupling of the cool-electron and proton bulk velocities leads to an increase in the electrostatic potential and a decrease in the <span class="hlt">heat</span>-flow moment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B11D0379L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B11D0379L"><span>A Semi-parametric Multivariate Gap-filling Model for Eddy Covariance Latent <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>Li, M.; Chen, Y.</p> <p>2010-12-01</p> <p>Quantitative descriptions of latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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 <span class="hlt">fluxes</span> over time scales ranging from hours to years. However, unfavorable micrometeorological conditions, instrument failures, and applicable measurement limitations may cause inevitable <span class="hlt">flux</span> gaps in time series data. Development and application of suitable gap-filling techniques are crucial to estimate long term <span class="hlt">fluxes</span>. In this study, a semi-parametric multivariate gap-filling model was developed to fill latent <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">flux</span> gaps as the weighted sum latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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</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://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('http://adsabs.harvard.edu/abs/2017EPJC...77..251S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJC...77..251S"><span>Dynamics of charged bulk viscous collapsing cylindrical source 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>Shah, S. M.; Abbas, G.</p> <p>2017-04-01</p> <p>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 <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span>, we have formulated the <span class="hlt">heat</span> transport equations in the context of Müller-Israel-Stewart theory by assuming that thermodynamics viscous/<span class="hlt">heat</span> 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 <span class="hlt">heat</span> transport equation; the consequences of the resulting coupled <span class="hlt">heat</span> equation have been analyzed in detail.</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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990008950','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990008950"><span>Remote <span class="hlt">Heat</span> <span class="hlt">Flux</span> Using a Self Calibration Multiwavelength Pyrometer and a Transparent Material</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ng, Daniel</p> <p>1998-01-01</p> <p>A self calibrating multiwavelength pyrometer was used to conduct remote <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">heat</span> transfer coefficients h, and h2 of its surfaces are determined experimentally. An analysis of the <span class="hlt">heat</span> <span class="hlt">flux</span> measurement is presented.</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/scitech">SciTech Connect</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> <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://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/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('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> <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> </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://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://adsabs.harvard.edu/abs/2017AIPC.1859b0091S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1859b0091S"><span>Hall effects on MHD flow of <span class="hlt">heat</span> generating/<span class="hlt">absorbing</span> fluid through porous medium in a rotating parallel plate channel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swarnalathamma, B. V.; Krishna, M. Veera</p> <p>2017-07-01</p> <p>We studied <span class="hlt">heat</span> transfer on MHD convective flow of viscous electrically conducting <span class="hlt">heat</span> generating/<span class="hlt">absorbing</span> fluid through porous medium in a rotating channel under uniform transverse magnetic field normal to the channel and taking Hall current. The flow is governed by the Brinkman's model. The diagnostic solutions for the velocity and temperature are obtained by perturbation technique and computationally discussed with respect to flow parameters through the graphs. The skin friction and Nusselt number are also evaluated and computationally discussed with reference to pertinent parameters in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...49.1531H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...49.1531H"><span>Revisiting the global surface energy budgets with maximum-entropy-production model of 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>Huang, Shih-Yu; Deng, Yi; Wang, Jingfeng</p> <p>2017-09-01</p> <p>The maximum-entropy-production (MEP) model of surface <span class="hlt">heat</span> <span class="hlt">fluxes</span>, based on contemporary non-equilibrium thermodynamics, information theory, and atmospheric turbulence theory, is used to re-estimate the global surface <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The MEP model predicted surface <span class="hlt">fluxes</span> 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 <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span> is higher than previously reported. The MEP model also produces the first global map of ocean surface <span class="hlt">heat</span> <span class="hlt">flux</span> that is not available from existing global reanalysis products.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JQSRT..96..439T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JQSRT..96..439T"><span>Numerical <span class="hlt">heat</span> transfer study in a scattering, <span class="hlt">absorbing</span> and emitting semi-transparent porous medium in a cylindrical enclosure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Timoumi, M.; Chérif, B.; Sifaoui, M. S.</p> <p>2005-12-01</p> <p>In this paper, <span class="hlt">heat</span> transfer problem through a semi-transparent porous medium in a cylindrical enclosure is investigated. The governing equations for this problem and the boundary conditions are non-linear differential equations depending on the dimensionless radial coordinate, Planck number N, scattering albedo ω, walls emissivity and thermal conductivity ratio kr. The set of differential equations are solved by a numerical technique taken from the IMSL MATH/LIBRARY. Various results are obtained for the dimensionless temperature profiles in the solid and fluid phases and the radiative <span class="hlt">heat</span> <span class="hlt">flux</span>. The effects of some radiative properties of the medium on the <span class="hlt">heat</span> transfer rate are examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1734b0009G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1734b0009G"><span>Two new methods used to simulate the circumferential solar <span class="hlt">flux</span> density concentrated on the <span class="hlt">absorber</span> of a parabolic trough solar collector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, Minghuan; Wang, Zhifeng; Sun, Feihu</p> <p>2016-05-01</p> <p>The optical efficiencies of a solar trough concentrator are important to the whole thermal performance of the solar collector, and the outer surface of the tube <span class="hlt">absorber</span> is a key interface of energy <span class="hlt">flux</span>. So it is necessary to simulate and analyze the concentrated solar <span class="hlt">flux</span> density distributions on the tube <span class="hlt">absorber</span> of a parabolic trough solar collector for various sun beam incident angles, with main optical errors considered. Since the solar trough concentrators are linear focusing, it is much of interest to investigate the solar <span class="hlt">flux</span> density distribution on the cross-section profile of the tube <span class="hlt">absorber</span>, rather than the <span class="hlt">flux</span> density distribution along the focal line direction. Although a few integral approaches based on the "solar cone" concept were developed to compute the concentrated <span class="hlt">flux</span> density for some simple trough concentrator geometries, all those integral approaches needed special integration routines, meanwhile, the optical parameters and geometrical properties of collectors also couldn't be changed conveniently. Flexible Monte Carlo ray trace (MCRT) methods are widely used to simulate the more accurate concentrated <span class="hlt">flux</span> density distribution for compound parabolic solar trough concentrators, while generally they are quite time consuming. In this paper, we first mainly introduce a new backward ray tracing (BRT) method combined with the lumped effective solar cone, to simulate the cross-section <span class="hlt">flux</span> density on the region of interest of the tube <span class="hlt">absorber</span>. For BRT, bundles of rays are launched at <span class="hlt">absorber</span>-surface points of interest, directly go through the glass cover of the <span class="hlt">absorber</span>, strike on the uniformly sampled mirror segment centers in the close-related surface region of the parabolic reflector, and then direct to the effective solar cone around the incident sun beam direction after the virtual backward reflection. All the optical errors are convoluted into the effective solar cone. The brightness distribution of the effective solar cone is supposed</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://www.dtic.mil/docs/citations/AD1001866','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1001866"><span>Thermal Infrared Signatures and <span class="hlt">Heat</span> <span class="hlt">Fluxes</span> of Sea Foam</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-01-13</p> <p>4 air flow 0.5 m 0.5 m MWIR LWIR FTIR Pitot tube and Temperature air diffuser 1 m EO foam IR H20 vapor analyzer <span class="hlt">Heat</span>...verify this, we measured velocity profiles with a pitot tube over 5 water and foam surfaces spanning our range of tested wind speeds. The profiles (not</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('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('https://ntrs.nasa.gov/search.jsp?R=20020022517&hterms=balance+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dbalance%2Bsheet','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020022517&hterms=balance+sheet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dbalance%2Bsheet"><span>Electron <span class="hlt">Heat</span> <span class="hlt">Flux</span> in Pressure Balance Structures at Ulysses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yamauchi, Yohei; Suess, Steven T.; Sakurai, Takashi; Whitaker, Ann F. (Technical Monitor)</p> <p>2001-01-01</p> <p>Pressure balance structures (PBSs) are a common feature in the high-latitude solar wind near solar minimum. Rom previous studies, PBSs are believed to be remnants of coronal plumes and be related to network activity such as magnetic reconnection in the photosphere. We investigated the magnetic structures of the PBSs, applying a minimum variance analysis to Ulysses/Magnetometer data. At 2001 AGU Spring meeting, we reported that PBSs have structures like current sheets or plasmoids, and suggested that they are associated with network activity at the base of polar plumes. In this paper, we have analyzed high-energy electron data at Ulysses/SWOOPS to see whether bi-directional electron flow exists and confirm the conclusions more precisely. As a result, although most events show a typical <span class="hlt">flux</span> directed away from the Sun, we have obtained evidence that some PBSs show bi-directional electron <span class="hlt">flux</span> and others show an isotropic distribution of electron pitch angles. The evidence shows that plasmoids are flowing away from the Sun, changing their flow direction dynamically in a way not caused by Alfven waves. From this, we have concluded that PBSs are generated due to network activity at the base of polar plumes and their magnetic structures axe current sheets or plasmoids.</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('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/2017JGRC..122.4068S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.4068S"><span>Air-sea <span class="hlt">heat</span> <span class="hlt">flux</span> climatologies in the Mediterranean Sea: Surface energy balance and its consistency with ocean <span class="hlt">heat</span> storage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Song, Xiangzhou; Yu, Lisan</p> <p>2017-05-01</p> <p>This study provides an analysis of the Mediterranean Sea surface energy budget using nine surface <span class="hlt">heat</span> <span class="hlt">flux</span> climatologies. The ensemble mean estimation shows that the net downward shortwave radiation (192 ± 19 W m-2) is balanced by latent <span class="hlt">heat</span> <span class="hlt">flux</span> (-98 ± 10 W m-2), followed by net longwave radiation (-78 ± 13 W m-2) and sensible <span class="hlt">heat</span> <span class="hlt">flux</span> (-13 ± 4 W m-2). The resulting net <span class="hlt">heat</span> 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 <span class="hlt">heat</span> budget equation by using historic hydrological observations to determine the <span class="hlt">heat</span> content changes and advective <span class="hlt">heat</span> <span class="hlt">flux</span>. 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994JNuM..212.1141T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994JNuM..212.1141T"><span>High <span class="hlt">heat</span> <span class="hlt">flux</span> composites for plasma-facing materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ting, J.-M.; Lake, M. L.</p> <p>1994-09-01</p> <p>Vapor grown carbon fiber (VGCF) has been shown to have the highest thermal conductivity of all carbon fiber currently available. This property holds potential of increasing the thickness and longevity of fusion reactor plasma-facing materials. The use of VGCF as a reinforcement in carbon/carbon composites has been explored, as well as methods of joining these plasma-facing materials to copper alloy <span class="hlt">heat</span> pipes. In extensive study of VGCF/carbon matrix composites, the influence of fiber volume fraction, density, densification method, and <span class="hlt">heat</span> treatment on composite properties were investigated. Joining of VGCF/carbon composites to copper and beryllium to copper using a novel alloying method was studied. The joint interface was examined by RBS analysis and thermal conductance.</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/scitech">SciTech Connect</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://adsabs.harvard.edu/abs/2017AGUFM.A53G2359A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A53G2359A"><span>Multi Seasonal and Diurnal Characterization of Sensible <span class="hlt">Heat</span> <span class="hlt">Flux</span> in an Arid Land Environment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Al-Mashharawi, S.; Aragon, B.; McCabe, M.</p> <p>2017-12-01</p> <p>In sparsely vegetated arid and semi-arid regions, the available energy is transformed primarily into sensible <span class="hlt">heat</span>, with little to no energy partitioned into latent <span class="hlt">heat</span>. 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 <span class="hlt">heat</span> <span class="hlt">flux</span> and the net radiation to soil <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">flux</span> estimation, to derive and monitor soil <span class="hlt">heat</span> <span class="hlt">flux</span> dynamics, estimate the <span class="hlt">heat</span> 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.</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> <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('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> </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('https://www.osti.gov/servlets/purl/111415','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/111415"><span>A formal approach for the prediction of the critical <span class="hlt">heat</span> <span class="hlt">flux</span> in subcooled water</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lombardi, C.</p> <p>1995-09-01</p> <p>The critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) in subcooled water at high mass <span class="hlt">fluxes</span> are not yet satisfactory correlated. For this scope a formal approach is here followed, which is based on an extension of the parameters and the correlation used for the dryout prediction for medium high quality mixtures. The obtained correlation, in spite of its simplicity and its explicit form, yields satisfactory predictions, also when applied to more conventional CHF data at low-medium mass <span class="hlt">fluxes</span> and high pressures. Further improvements are possible, if a more complete data bank will be available. The main and general open item is the definitionmore » of a criterion, depending only on independent parameters, such as mass <span class="hlt">flux</span>, pressure, inlet subcooling and geometry, to predict whether the <span class="hlt">heat</span> transfer crisis will result as a DNB or a dryout phenomenon.« less</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://hdl.handle.net/2060/19970000386','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970000386"><span>The Development of Novel, High-<span class="hlt">Flux</span>, <span class="hlt">Heat</span> Transfer Cells for Thermal Control in Microgravity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, Marc K.; Glezer, Ari</p> <p>1996-01-01</p> <p>In order to meet the future needs of thermal management and control in space applications such as the Space Lab, new <span class="hlt">heat</span>-transfer technology capable of much larger <span class="hlt">heat</span> <span class="hlt">fluxes</span> must be developed. To this end, we describe complementary numerical and experimental investigations into the fundamental fluid mechanics and <span class="hlt">heat</span>-transfer processes involved in a radically new, self contained, <span class="hlt">heat</span> transfer cell for microgravity applications. In contrast to conventional <span class="hlt">heat</span> pipes, the <span class="hlt">heat</span> transfer in this cell is based on a forced droplet evaporation process using a fine spray. The spray is produced by a novel fluidic technology recently developed at Georgia Tech. This technology is based on a vibration induced droplet atomization process. In this technique, a liquid droplet is placed on a flexible membrane and is vibrated normal to itself. When the proper drop size is attained, the droplet resonates with the surface motion of the membrane and almost immediately bursts into a shower of very fine secondary droplets. The small droplets travel to the opposite end of the cell where they impact a <span class="hlt">heated</span> surface and are evaporated. The vapor returns to the cold end of the cell and condenses to form the large droplets that are fragmented to form the spray. Preliminary estimates show that a <span class="hlt">heat</span> transfer cell based on this technology would have a <span class="hlt">heat-flux</span> capacity that is an order of magnitude higher than those of current <span class="hlt">heat</span> pipes designs used in microgravity applications.</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3468294','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3468294"><span><span class="hlt">Heat</span> localization for targeted tumor treatment with nanoscale near-infrared radiation <span class="hlt">absorbers</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>Xie, Bin; Singh, Ravi; Torti, F. M.; Keblinski, Pawel; Torti, Suzy</p> <p>2012-01-01</p> <p>Focusing <span class="hlt">heat</span> delivery while minimizing collateral damage to normal tissues is essential for successful nanoparticle-mediated laser-induced thermal cancer therapy. We present thermal maps obtained via magnetic resonance imaging (MRI) characterizing laser <span class="hlt">heating</span> of a phantom tissue containing a multiwalled carbon nanotube inclusion. The data demonstrate that <span class="hlt">heating</span> continuously over tens of seconds leads to poor localization (~ 0.5 cm) of the elevated temperature region. By contrast, for the same energy input, <span class="hlt">heat</span> localization can be reduced to the millimeter rather than centimeter range by increasing the laser power and shortening the pulse duration. The experimental data can be well understood within a simple diffusive <span class="hlt">heat</span> conduction model. Analysis of the model indicates that to achieve 1 mm or better resolution, <span class="hlt">heating</span> pulses of ~ 2s or less need to be used with appropriately higher <span class="hlt">heating</span> power. Modeling these data using a diffusive <span class="hlt">heat</span> conduction analysis predicts parameters for optimal targeted delivery of <span class="hlt">heat</span> for ablative therapy. PMID:22948207</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1046432','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1046432"><span>Sensible <span class="hlt">Heat</span> <span class="hlt">Flux</span> Related to Variations in Atmospheric Turbulence Kinetic Energy on a Sandy Beach</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2017-06-01</p> <p><span class="hlt">FLUX</span> RELATED TO VARIATIONS IN ATMOSPHERIC TURBULENCE KINETIC ENERGY ON A SANDY BEACH by Jessica S. Koscinski June 2017 Thesis Advisor...KINETIC ENERGY ON A SANDY BEACH 5. FUNDING NUMBERS 6. AUTHOR(S) Jessica S. Koscinski 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval...Sensible <span class="hlt">heat</span> <span class="hlt">flux</span>, turbulence kinetic energy , surf zone 15. NUMBER OF PAGES 57 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT</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('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('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/2018PhyB..537...98M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhyB..537...98M"><span>Nonlinear radiated MHD flow of nanoliquids due to a rotating disk with irregular <span class="hlt">heat</span> source and <span class="hlt">heat</span> <span class="hlt">flux</span> condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mahanthesh, B.; Gireesha, B. J.; Shehzad, S. A.; Rauf, A.; Kumar, P. B. Sampath</p> <p>2018-05-01</p> <p>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 <span class="hlt">heat</span> source and nonlinear radiative terms are accounted in the law of energy. We used the <span class="hlt">heat</span> <span class="hlt">flux</span> condition instead of constant surface temperature condition. <span class="hlt">Heat</span> <span class="hlt">flux</span> 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.</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> <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 radiation 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('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://adsabs.harvard.edu/abs/2017PhFl...29h2001A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhFl...29h2001A"><span>Free convection flow of some fractional nanofluids over a moving vertical plate with uniform <span class="hlt">heat</span> <span class="hlt">flux</span> and <span class="hlt">heat</span> source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Azhar, Waqas Ali; Vieru, Dumitru; Fetecau, Constantin</p> <p>2017-08-01</p> <p>Free convection flow of some water based fractional nanofluids over a moving infinite vertical plate with uniform <span class="hlt">heat</span> <span class="hlt">flux</span> and <span class="hlt">heat</span> source is analytically and graphically studied. Exact solutions for dimensionless temperature and velocity fields, Nusselt numbers, and skin friction coefficients are established in integral form in terms of modified Bessel functions of the first kind. These solutions satisfy all imposed initial and boundary conditions and reduce to the similar solutions for ordinary nanofluids when the fractional parameters tend to one. Furthermore, they reduce to the known solutions from the literature when the plate is fixed and the <span class="hlt">heat</span> source is absent. The influence of fractional parameters on <span class="hlt">heat</span> transfer and fluid motion is graphically underlined and discussed. The enhancement of <span class="hlt">heat</span> transfer in such flows is higher for fractional nanofluids in comparison with ordinary nanofluids. Moreover, the use of fractional models allows us to choose the fractional parameters in order to get a very good agreement between experimental and theoretical results.</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://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('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://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://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('http://adsabs.harvard.edu/abs/2013AGUFMSA51B2083V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA51B2083V"><span>Estimation of the <span class="hlt">heat</span>/Na <span class="hlt">flux</span> using lidar data recorded at ALO, Cerro Pachon, Chile</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vargas, F.; Gardner, C. S.; Liu, A. Z.; Swenson, G. R.</p> <p>2013-12-01</p> <p>In this poster, lidar nigh-time data are used to estimate the vertical <span class="hlt">fluxes</span> of <span class="hlt">heat</span> and Na at the mesopause region due to dissipating gravity waves presenting periods from 5 min to 8 h, and vertical wavelengths > 2 km. About 60 hours of good quality data were recorded near the equinox during two observation campaigns held in Mar, 2012 and Apr, 2013 at the Andes Lidar Observatory (30.3S,70.7W). These first measurements of the <span class="hlt">heat</span>/Na <span class="hlt">flux</span> in the southern hemisphere will be discussed and compared with those from the northern hemisphere stations obtained at the Starfire Optical Range, NM, and Maui, HW.</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('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('https://www.osti.gov/biblio/1084433-remote-measurement-heat-flux-from-power-plant-cooling-lakes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1084433-remote-measurement-heat-flux-from-power-plant-cooling-lakes"><span>Remote Measurement of <span class="hlt">Heat</span> <span class="hlt">Flux</span> from Power Plant Cooling Lakes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Garrett, Alfred J.; Kurzeja, Robert J.; Villa-Aleman, Eliel</p> <p>2013-06-01</p> <p>Laboratory experiments have demonstrated a correlation between the rate of <span class="hlt">heat</span> loss q" from an experimental fluid to the air above and the standard deviation σ of the thermal variability in images of the fluid surface. These experimental results imply that q" can be derived directly from thermal imagery by computing σ. This paper analyses thermal imagery collected over two power plant cooling lakes to determine if the same relationship exists. Turbulent boundary layer theory predicts a linear relationship between q" and σ when both forced (wind driven) and free (buoyancy driven) convection are present. Datasets derived from ground- andmore » helicopter-based imagery collections had correlation coefficients between σ and q" of 0.45 and 0.76, respectively. Values of q" computed from a function of σ and friction velocity u* derived from turbulent boundary layer theory had higher correlations with measured values of q" (0.84 and 0.89). Finally, this research may be applicable to the problem of calculating losses of <span class="hlt">heat</span> from the ocean to the atmosphere during high-latitude cold-air outbreaks because it does not require the information typically needed to compute sensible, evaporative, and thermal radiation energy losses to the atmosphere.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JNuM..499..225D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JNuM..499..225D"><span>High <span class="hlt">heat</span> <span class="hlt">flux</span> performance of W-Eurofer brazed joints</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Prado, J.; Sánchez, M.; Wirtz, M.; Pintsuk, G.; Du, J.; Linke, J.; Ureña, A.</p> <p>2018-02-01</p> <p>The qualification process of the materials and components for the next generation of fusion reactors makes it necessary to expose them to similar service conditions as expected during the service life of the reactor. In the present work, W-Eurofer brazed joints (tungsten block: 8 × 8 × 4 mm; steel block: 8 × 8 × 4 mm; joined to an actively cooled copper <span class="hlt">heat</span> sink) were exposed to steady state <span class="hlt">heat</span> loads to study the effect of the thermal fatigue on their microstructure and mechanical integrity. Three different W surface temperatures were tested (400, 500 and 600 °C) varying the number of applied cycles (100 and 1000). The results allowed identifying a braze temperature of 359 °C as threshold condition under which the brazed joints could be used without deterioration. The increase of the surface temperature deteriorated the mechanical integrity of the joints in comparison to those analyzed after the brazing process and accordingly reduced the refrigeration capabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995JThSc...4..151C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995JThSc...4..151C"><span>High <span class="hlt">heat</span> <span class="hlt">flux</span> burnout 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>Celata, G. P.; Cumo, M.; Mariani, A.</p> <p>1995-09-01</p> <p>The paper reports the results of an experimental research carried out at the <span class="hlt">Heat</span> Transfer Division of the Energy Department, C.R. Casaccia, on the thermal hydraulic characterization of subcooled flow boiling CHF under typical conditions of thermonuclear fusion reactors, i.e. high liquid velocity and subcooling. The experiment was carried out exploring the following parameters: channel diameter (from 2.5 to 8.0 mm), <span class="hlt">heated</span> length (10 and 15 cm), liquid velocity (from 2 to 40 m/s), exit pressure (from atmospheric to 5.0 MPa), inlet temperature (from 30 to 80 °C), channel orientation (vertical and horizontal). A maximum CHF value of 60.6 MW/m2 has been obtained under the following conditions: T in=30°, p=2.5 MPa, u=40 m/s, D=2.5 mm (smooth channel) Turbulence promoters (helically coiled wires) have been employed to further enhance the CHF attainable with subcooled flow boiling. Helically coiled wires allow an increase of 50% of the maximum CHF obtained with smooth channels.</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('http://adsabs.harvard.edu/abs/1981mgfm.rept.....M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981mgfm.rept.....M"><span>Development of selective solar <span class="hlt">absorbers</span> on the basis of aluminum roll-bond <span class="hlt">heat</span> exchangers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moeller, M.</p> <p>1981-11-01</p> <p>A deposition technique comparable to two-stage anodizing and especially suited for solar <span class="hlt">absorber</span> panels, using roll-bond Al 99.5 and AlMnZr alloys as a substrate, was developed. The coating is of the nickel structure filter type and provides average solar absorptivity values of 94% and thermal emission values of 14%. The setup of a production plant capable of coating surfaces up to 2 sq m is described as well as the development of corrosion resistent hermetically sealed collectors. By means of an appropriate surface treatment the same corrosion resistance was achieved for <span class="hlt">absorbers</span> mounted in ventilated collectors.</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/scitech">SciTech Connect</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> <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('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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ResPh...6..139M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ResPh...6..139M"><span>Effect of radiator position and mass <span class="hlt">flux</span> on the dryer room <span class="hlt">heat</span> transfer rate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mirmanto, M.; Sulistyowati, E. D.; Okariawan, I. D. K.</p> <p></p> <p>A room radiator as usually used in cold countries, is actually able to be used as a <span class="hlt">heat</span> 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 <span class="hlt">flux</span> on <span class="hlt">heat</span> transfer rate were performed. This study is to determine the best position of the radiator and the optimum mass <span class="hlt">flux</span>. 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 <span class="hlt">heated</span> water flowing inside the radiator and air circulating naturally inside the prototype room. The nominal mass <span class="hlt">fluxes</span> 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 <span class="hlt">flux</span> on the forced and free convection <span class="hlt">heat</span> transfer rate is insignificant but the radiator position strongly affects the <span class="hlt">heat</span> transfer rate for both forced and free convection.</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('https://www.ncbi.nlm.nih.gov/pubmed/25353740','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25353740"><span>Nonadiabatic effect on the quantum <span class="hlt">heat</span> <span class="hlt">flux</span> control.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Uchiyama, Chikako</p> <p>2014-05-01</p> <p>We provide a general formula of quantum transfer that includes the nonadiabatic effect under periodic environmental modulation by using full counting statistics in Hilbert-Schmidt space. Applying the formula to an anharmonic junction model that interacts with two bosonic environments within the Markovian approximation, we find that the quantum transfer is divided into the adiabatic (dynamical and geometrical phases) and nonadiabatic contributions. This extension shows the dependence of quantum transfer on the initial condition of the anharmonic junction just before the modulation, as well as the characteristic environmental parameters such as interaction strength and cut-off frequency of spectral density. We show that the nonadiabatic contribution represents the reminiscent effect of past modulation including the transition from the initial condition of the anharmonic junction to a steady state determined by the very beginning of the modulation. This enables us to tune the frequency range of modulation, whereby we can obtain the quantum <span class="hlt">flux</span> corresponding to the geometrical phase by setting the initial condition of the anharmonic junction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AcAau.136..312P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AcAau.136..312P"><span>Modeling of aerodynamic <span class="hlt">heat</span> <span class="hlt">flux</span> and thermoelastic behavior of nose caps of hypersonic vehicles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Persova, Marina G.; Soloveichik, Yury G.; Belov, Vasiliy K.; Kiselev, Dmitry S.; Vagin, Denis V.; Domnikov, Petr A.; Patrushev, Ilya I.; Kurskiy, Denis N.</p> <p>2017-07-01</p> <p>In this paper, the problem of numerical modeling of thermoelastic behavior of nose caps of hypersonic vehicles at different angles of attack is considered. 3D finite element modeling is performed by solving the coupled <span class="hlt">heat</span> and elastic problems taking into account thermal and mechanical properties variations with temperature. A special method for calculating the aerodynamic <span class="hlt">heat</span> <span class="hlt">flux</span> entering the nose cap from its surface is proposed. This method is characterized by very low computational costs and allows calculating the aerodynamic <span class="hlt">heat</span> <span class="hlt">flux</span> at different values of the Mach number and angles of attack which may vary during the aerodynamic <span class="hlt">heating</span>. The numerical results obtained by the proposed approach are compared with the numerical results and experimental data obtained by other authors. The developed approach has been used for studying the impact of the angle of attack on the thermoelastic behavior of nose caps main components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880009508','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880009508"><span>Prototype thin-film thermocouple/<span class="hlt">heat-flux</span> sensor for a ceramic-insulated diesel engine</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.</p> <p>1988-01-01</p> <p>A platinum versus platinum-13 percent rhodium thin-film thermocouple/<span class="hlt">heat-flux</span> sensor was devised and tested in the harsh, high-temperature environment of a ceramic-insulated, low-<span class="hlt">heat</span>-rejection diesel engine. The sensor probe assembly was developed to provide experimental validation of <span class="hlt">heat</span> transfer and thermal analysis methodologies applicable to the insulated diesel engine concept. The thin-film thermocouple configuration was chosen to approximate an uninterrupted chamber surface and provide a 1-D <span class="hlt">heat-flux</span> path through the probe body. The engine test was conducted by Purdue University for Integral Technologies, Inc., under a DOE-funded contract managed by NASA Lewis Research Center. The thin-film sensor performed reliably during 6 to 10 hr of repeated engine runs at indicated mean surface temperatures up to 950 K. However, the sensor suffered partial loss of adhesion in the thin-film thermocouple junction area following maximum cyclic temperature excursions to greater than 1150 K.</p> </li> <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/2018MPLB...3250078D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MPLB...3250078D"><span>Effect of boundary <span class="hlt">heat</span> <span class="hlt">flux</span> on columnar formation in binary alloys: A phase-field study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Du, Lifei; Zhang, Peng; Yang, Shaomei; Chen, Jie; Du, Huiling</p> <p>2018-02-01</p> <p>A non-isothermal phase-field model was employed to simulate the columnar formation during rapid solidification in binary Ni-Cu alloy. <span class="hlt">Heat</span> <span class="hlt">flux</span> at different boundaries was applied to investigate the temperature gradient effect on the morphology, concentration and temperature distributions during directional solidifications. With the <span class="hlt">heat</span> <span class="hlt">flux</span> input/extraction from boundaries, coupling with latent <span class="hlt">heat</span> release and initial temperature gradient, temperature distributions are significantly changed, leading to solute diffusion changes during the phase-transition. Thus, irregular columnar structures are formed during the directional solidification, and the concentration distribution in solid columnar arms could also be changed due to the different growing speeds and temperature distributions at the solid-liquid interfaces. Therefore, applying specific <span class="hlt">heat</span> conditions at the solidifying boundaries could be an efficient way to control the microstructure during solidifications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29679059','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29679059"><span><span class="hlt">Flux</span>-tunable <span class="hlt">heat</span> sink for quantum electric circuits.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Partanen, M; Tan, K Y; Masuda, S; Govenius, J; Lake, R E; Jenei, M; Grönberg, L; Hassel, J; Simbierowicz, S; Vesterinen, V; Tuorila, J; Ala-Nissila, T; Möttönen, M</p> <p>2018-04-20</p> <p>Superconducting microwave circuits show great potential for practical quantum technological applications such as quantum information processing. However, fast and on-demand initialization of the quantum degrees of freedom in these devices remains a challenge. Here, we experimentally implement a tunable <span class="hlt">heat</span> sink that is potentially suitable for the initialization of superconducting qubits. Our device consists of two coupled resonators. The first resonator has a high quality factor and a fixed frequency whereas the second resonator is designed to have a low quality factor and a tunable resonance frequency. We engineer the low quality factor using an on-chip resistor and the frequency tunability using a superconducting quantum interference device. When the two resonators are in resonance, the photons in the high-quality resonator can be efficiently dissipated. We show that the corresponding loaded quality factor can be tuned from above 10 5 down to a few thousand at 10 GHz in good quantitative agreement with our theoretical model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.P43D2905H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.P43D2905H"><span>The <span class="hlt">Heat</span> <span class="hlt">Flux</span> through the Ice Shell on Europa, Constraints from Measurements in Terrestrial Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hruba, J.; Kletetschka, G.</p> <p>2017-12-01</p> <p><span class="hlt">Heat</span> 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, <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">heat</span> ocean sources available to the rock-ocean interface at the ocean's bottom due to tidal dissipation and potential radioactive sources. The <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">heat</span> the water below. Due to temperature gradient, there is a <span class="hlt">heat</span> <span class="hlt">flux</span> from the water to the ice (Qwi), which may reduce ice growth at the bottom. Details and variables that constrain the <span class="hlt">heat</span> <span class="hlt">flux</span> 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, <span class="hlt">Heat</span> 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, <span class="hlt">Heat</span> 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</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('http://hdl.handle.net/2060/19790020559','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790020559"><span>Solar sustained plasma/<span class="hlt">absorber</span> conceptual design</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rodgers, R. J.; Krascella, N. L.; Kendall, J. S.</p> <p>1979-01-01</p> <p>A space power system concept was evaluated which uses concentrated solar energy to <span class="hlt">heat</span> a working fluid to temperatures as high as 4000 K. The high temperature working fluid could be used for efficient electric power production in advanced thermal or magnetohydrodynamic conversion cycles. Energy <span class="hlt">absorber</span> configurations utilizing particles or cesium vapor <span class="hlt">absorber</span> material were investigaed. Results of detailed radiant <span class="hlt">heat</span> transfer calculations indicated approximately 86 percent of the incident solar energy could be <span class="hlt">absorbed</span> within a 12-cm-dia flowing stream of gas borne carbon particles. Calculated total energy absorption in the cesium vapor seeded <span class="hlt">absorber</span> configuration ranged from 34 percent to 64 percent of the incident solar energy. Solar <span class="hlt">flux</span> concentration ratios of between approximately 3000 and 10,000 will be required to sustain <span class="hlt">absorber</span> temperatures in the range from 3000 K to 4000 K.</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=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=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://adsabs.harvard.edu/abs/2003EAEJA.....5126S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....5126S"><span>Evaluation of parameterization for turbulent <span class="hlt">fluxes</span> of momentum and <span class="hlt">heat</span> in stably stratified surface layers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sodemann, H.; Foken, Th.</p> <p>2003-04-01</p> <p>General Circulation Models calculate the energy exchange between surface and atmosphere by means of parameterisations for turbulent <span class="hlt">fluxes</span> of momentum and <span class="hlt">heat</span> in the surface layer. However, currently implemented parameterisations after Louis (1979) create large discrepancies between predictions and observational data, especially in stably stratified surface layers. This work evaluates a new surface layer parameterisation proposed by Zilitinkevich et al. (2002), which was specifically developed to improve energy <span class="hlt">flux</span> predictions in stable stratification. The evaluation comprises a detailed study of important surface layer characteristics, a sensitivity study of the parameterisation, and a direct comparison to observational data from Antarctica and predictions by the Louis (1979) parameterisation. The stability structure of the stable surface layer was found to be very complex, and strongly influenced <span class="hlt">fluxes</span> in the surface layer. The sensitivity study revealed that the new parameterisation depends strongly on the ratio between roughness length and roughness temperature, which were both observed to be very variable parameters. The comparison between predictions and measurements showed good agreement for momentum <span class="hlt">fluxes</span>, but large discrepancies for <span class="hlt">heat</span> <span class="hlt">fluxes</span>. A stability dependent evaluation of selected data showed better agreement for the new parameterisation of Zilitinkevich et al. (2002) than for the Louis (1979) scheme. Nevertheless, this comparison underlines the need for more detailed and physically sound concepts for parameterisations of <span class="hlt">heat</span> <span class="hlt">fluxes</span> in stably stratified surface layers. Zilitinkevich, S. S., V. Perov and J. C. King (2002). "Near-surface turbulent <span class="hlt">fluxes</span> in stable stratification: Calculation techniques for use in General Circulation Models." Q. J. R. Meteorol. Soc. 128(583): 1571--1587. Louis, J. F. (1979). "A Parametric Model of Vertical Eddy <span class="hlt">Fluxes</span> in the Atmosphere." Bound.-Layer Meteor. 17(2): 187--202.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1437164-amoc-sensitivity-surface-buoyancy-fluxes-stronger-ocean-meridional-heat-transport-weaker-volume-transport','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1437164-amoc-sensitivity-surface-buoyancy-fluxes-stronger-ocean-meridional-heat-transport-weaker-volume-transport"><span>AMOC sensitivity to surface buoyancy <span class="hlt">fluxes</span>: Stronger ocean meridional <span class="hlt">heat</span> transport with a weaker volume transport?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Sevellec, Florian; Fedorov, Alexey V.</p> <p>2016-01-04</p> <p>Oceanic northward <span class="hlt">heat</span> transport is commonly assumed to be positively correlated with the Atlantic meridional overturning circulation (AMOC). For example, in numerical "water-hosing" experiments, imposing anomalous freshwater <span class="hlt">fluxes</span> in the northern Atlantic leads to a slow-down of the AMOC and the corresponding reduction of oceanic northward <span class="hlt">heat</span> transport. Here, we study the sensitivity of the ocean <span class="hlt">heat</span> and volume transports to surface <span class="hlt">heat</span> and freshwater <span class="hlt">fluxes</span> using a generalized stability analysis. For the sensitivity to surface freshwater <span class="hlt">fluxes</span>, we find that, while the direct relationship between the AMOC volume and <span class="hlt">heat</span> transports holds on shorter time scales, it can reversemore » on timescales longer than 500 years or so. That is, depending on the model surface boundary conditions, reduction in the AMOC volume transport can potentially lead to a stronger <span class="hlt">heat</span> transport on long timescales, resulting from the gradual increase in ocean thermal stratification. Finally, we discuss the implications of these results for the problem of steady state (statistical equilibrium) in ocean and climate GCM as well as paleoclimate problems including millennial climate variability.« less</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/scitech">SciTech Connect</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('http://adsabs.harvard.edu/abs/2016ClDy...47.1497S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ClDy...47.1497S"><span>AMOC sensitivity to surface buoyancy <span class="hlt">fluxes</span>: Stronger ocean meridional <span class="hlt">heat</span> transport with a weaker volume transport?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sévellec, Florian; Fedorov, Alexey V.</p> <p>2016-09-01</p> <p>Oceanic northward <span class="hlt">heat</span> transport is commonly assumed to be positively correlated with the Atlantic meridional overturning circulation (AMOC). For example, in numerical "water-hosing" experiments, imposing anomalous freshwater <span class="hlt">fluxes</span> in the northern Atlantic leads to a slow-down of the AMOC and the corresponding reduction of oceanic northward <span class="hlt">heat</span> transport. Here, we study the sensitivity of the ocean <span class="hlt">heat</span> and volume transports to surface <span class="hlt">heat</span> and freshwater <span class="hlt">fluxes</span> using a generalized stability analysis. For the sensitivity to surface freshwater <span class="hlt">fluxes</span>, we find that, while the direct relationship between the AMOC volume and <span class="hlt">heat</span> transports holds on shorter time scales, it can reverse on timescales longer than 500 years or so. That is, depending on the model surface boundary conditions, reduction in the AMOC volume transport can potentially lead to a stronger <span class="hlt">heat</span> transport on long timescales, resulting from the gradual increase in ocean thermal stratification. We discuss the implications of these results for the problem of steady state (statistical equilibrium) in ocean and climate GCM as well as paleoclimate problems including millennial climate variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1437164','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1437164"><span>AMOC sensitivity to surface buoyancy <span class="hlt">fluxes</span>: Stronger ocean meridional <span class="hlt">heat</span> transport with a weaker volume transport?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sevellec, Florian; Fedorov, Alexey V.</p> <p></p> <p>Oceanic northward <span class="hlt">heat</span> transport is commonly assumed to be positively correlated with the Atlantic meridional overturning circulation (AMOC). For example, in numerical "water-hosing" experiments, imposing anomalous freshwater <span class="hlt">fluxes</span> in the northern Atlantic leads to a slow-down of the AMOC and the corresponding reduction of oceanic northward <span class="hlt">heat</span> transport. Here, we study the sensitivity of the ocean <span class="hlt">heat</span> and volume transports to surface <span class="hlt">heat</span> and freshwater <span class="hlt">fluxes</span> using a generalized stability analysis. For the sensitivity to surface freshwater <span class="hlt">fluxes</span>, we find that, while the direct relationship between the AMOC volume and <span class="hlt">heat</span> transports holds on shorter time scales, it can reversemore » on timescales longer than 500 years or so. That is, depending on the model surface boundary conditions, reduction in the AMOC volume transport can potentially lead to a stronger <span class="hlt">heat</span> transport on long timescales, resulting from the gradual increase in ocean thermal stratification. Finally, we discuss the implications of these results for the problem of steady state (statistical equilibrium) in ocean and climate GCM as well as paleoclimate problems including millennial climate variability.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910009750','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910009750"><span>Development of a laser-induced <span class="hlt">heat</span> <span class="hlt">flux</span> technique for measurement of convective <span class="hlt">heat</span> transfer coefficients in a supersonic flowfield</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Porro, A. Robert; Keith, Theo G., Jr.; Hingst, Warren R.; Chriss, Randall M.; Seablom, Kirk D.</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 <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 load 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 experimental results agreed reasonably well with theoretical predictions of convective <span class="hlt">heat</span> transfer of flat plate laminar boundary layers. The results indicate that this non-intrusive optical measurement technique has the potential to obtain high quality surface convective <span class="hlt">heat</span> transfer measurements in high speed flowfields.</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/2060/19910011011','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/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://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/scitech">SciTech Connect</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('https://eric.ed.gov/?q=equations+AND+differential+AND+applied+AND+Engineering&id=EJ1085692','ERIC'); return false;" href="https://eric.ed.gov/?q=equations+AND+differential+AND+applied+AND+Engineering&id=EJ1085692"><span>A Methodology to Determine Self-Similarity, Illustrated by Example: Transient <span class="hlt">Heat</span> Transfer with Constant <span class="hlt">Flux</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Monroe, Charles; Newman, John</p> <p>2005-01-01</p> <p>This simple example demonstrates the physical significance of similarity solutions and the utility of dimensional and asymptotic analysis of partial differential equations. A procedure to determine the existence of similarity solutions is proposed and subsequently applied to transient constant-<span class="hlt">flux</span> <span class="hlt">heat</span> transfer. Short-time expressions follow from…</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('http://www.ars.usda.gov/research/publications/publication/?seqNo115=309893','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=309893"><span>Temperature regimes and turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> across a heterogeneous canopy in an Alaskan boreal forest</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>We evaluate local differences in thermal regimes and turbulent <span class="hlt">heat</span> <span class="hlt">fluxes</span> across the heterogeneous canopy of a black spruce boreal forest on discontinuous permafrost in interior Alaska. The data was taken during an intensive observing period in the summer of 2013 from two micrometeorological tower...</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/2017AMT....10.2253T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AMT....10.2253T"><span>Use of a <span class="hlt">heated</span> graphite scrubber as a means of reducing interferences in UV-<span class="hlt">absorbance</span> measurements of atmospheric ozone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turnipseed, Andrew A.; Andersen, Peter C.; Williford, Craig J.; Ennis, Christine A.; Birks, John W.</p> <p>2017-06-01</p> <p>A new solid-phase scrubber for use in conventional ozone (O3) photometers was investigated as a means of reducing interferences from other UV-<span class="hlt">absorbing</span> species and water vapor. It was found that when <span class="hlt">heated</span> to 100-130 °C, a tubular graphite scrubber efficiently removed up to 500 ppb ozone and ozone monitors using the <span class="hlt">heated</span> graphite scrubber were found to be less susceptible to interferences from water vapor, mercury vapor, and aromatic volatile organic compounds (VOCs) compared to conventional metal oxide scrubbers. Ambient measurements from a graphite scrubber-equipped photometer and a co-located Federal equivalent method (FEM) ozone analyzer showed excellent agreement over 38 days of measurements and indicated no loss in the scrubber's ability to remove ozone when operated at 130 °C. The use of a <span class="hlt">heated</span> graphite scrubber was found to reduce the interference from mercury vapor to ≤ 3 % of that obtained using a packed-bed Hopcalite scrubber. For a series of substituted aromatic compounds (ranging in volatility and absorption cross section at 253.7 nm), the graphite scrubber was observed to consistently exhibit reduced levels of interference, typically by factors of 2.5 to 20 less than with Hopcalite. Conventional solid-phase scrubbers also exhibited complex VOC adsorption and desorption characteristics that were dependent upon the relative humidity (RH), volatility of the VOC, and the available surface area of the scrubber. This complex behavior involving humidity is avoided by use of a <span class="hlt">heated</span> graphite scrubber. These results suggest that <span class="hlt">heated</span> graphite scrubbers could be substituted in most ozone photometers as a means of reducing interferences from other UV-<span class="hlt">absorbing</span> species found in the atmosphere. This could be particularly important in ozone monitoring for compliance with the United States (U.S.) Clean Air Act or for use in VOC-rich environments such as in smog chambers and monitoring indoor air quality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.C23C1233B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.C23C1233B"><span>Partitioning of sublimation and evaporation from Lake Bonney using water vapor isotope and latent <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>Bellagamba, A. W.; Berkelhammer, M. B.; Winslow, L.; Peter, D.; Myers, K. F.</p> <p>2017-12-01</p> <p>The landscapes of the McMurdo Dry Valleys in Antarctica are characterized by a series of frozen lakes. Although the conditions in this region are severe, the lakes share common characteristics with lakes at glacial termini elsewhere. Geochemical and geomorphological evidence suggest these lakes have experienced large historical changes indicative of changes water balances. While part of these shifts in lake volume arise from changes in glacial inflow, they likely also reflect changes in the latent <span class="hlt">heat</span> <span class="hlt">flux</span> from the lake surfaces. Here we present a joint analysis of the stable isotopic ratio of surface ice/water and the water vapor <span class="hlt">flux</span> over Dry Valley frozen lakes to ascertain the processes controlling water losses from the lake surfaces. We compare the isotopic ratio of the latent <span class="hlt">heat</span> <span class="hlt">flux</span> with the surface water isotopes to derive a fractionation factor associated with latent <span class="hlt">flux</span>. This data is then used to provide insight into how much of the water vapor <span class="hlt">flux</span> is sublimated versus evaporated, as well as how the sublimation and evaporative components of the <span class="hlt">flux</span> change with synoptic weather. We used a Picarro L2130-I isotopic water analyzer to measure humidity and the isotopic ratio of water vapor at three heights over Lake Bonney in Taylor Valley, Antarctica and used the <span class="hlt">flux</span>-gradient approach to convert the isotopic ratio of the vapor to an "isoflux". An on-site meteorological station recorded temperature, relative humidity and wind direction/intensity at two different heights above the lake and an infrared radiometer recorded lake skin temperature. These data were used to calculate the sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The fractionation factor was close to 0, which indicates that sublimation was the primary component of the <span class="hlt">flux</span> although evaporation became increasingly prominent following a katabatic wind event. The results suggest this technique could be an effective tool to study the sensitivity of latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> to weather here and in other similar</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70019534','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70019534"><span>A Three Component Model 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://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Chehbouni, A.; Nichols, W.D.; Njoku, E.G.; Qi, J.; Kerr, Y.H.; Cabot, F.</p> <p>1997-01-01</p> <p>It is now recognized that accurate partitioning of available energy into sensible and latent <span class="hlt">heat</span> <span class="hlt">flux</span> is crucial to understanding 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. The objective of this paper is to present a three-component model to estimate sensible <span class="hlt">heat</span> <span class="hlt">flux</span> over heterogeneous surfaces. The surface was represented with two adjacent compartments. The first compartment is made up of two components, shrubs and shaded soil; the second compartment consists of bare, unshaded soil. Data collected at two different sites in Nevada 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> </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/1986DoSSR.286..579A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986DoSSR.286..579A"><span>Radiant <span class="hlt">heat</span> <span class="hlt">fluxes</span> in supersonic flow of an inviscid gas past three-dimensional bodies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Apshtein, E. Z.; Vartanian, N. V.; Sakharov, V. I.; Tirskii, G. A.</p> <p></p> <p>Supersonic flow of an inviscid non-<span class="hlt">heat</span>-conducting gas past three-dimensional bodies of various shapes (spheres, ellipsoids, hyperboloids, paraboloids, and power-law bodies of revolution) in the earth atmosphere is investigated numerically in the velocity range 10-18 km/s for heights of 40-80 km and densities of the incoming flow ranging from 0.003 to 0.00017 kg/cu m. It is shown that, at a constant flight velocity, the ratio of the radiant <span class="hlt">heat</span> <span class="hlt">flux</span> to the <span class="hlt">flux</span> at the critical point is largely determined by the angle of the shock wave and is practically independent of the body dimensions and flight height. The results are used to develop a simplified method for determining radiant <span class="hlt">fluxes</span> toward the nose section of three-dimensional bodies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017WRR....5310858L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017WRR....5310858L"><span>Mapping Surface <span class="hlt">Heat</span> <span class="hlt">Fluxes</span> by Assimilating SMAP Soil Moisture and GOES Land Surface Temperature Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Yang; Steele-Dunne, Susan C.; Farhadi, Leila; van de Giesen, Nick</p> <p>2017-12-01</p> <p>Surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> play a crucial role in the surface energy and water balance. In situ measurements are costly and difficult, and large-scale <span class="hlt">flux</span> mapping is hindered by surface heterogeneity. Previous studies have demonstrated that surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> can be estimated by assimilating land surface temperature (LST) and soil moisture to determine two key parameters: a neutral bulk <span class="hlt">heat</span> transfer coefficient (CHN) and an evaporative fraction (EF). Here a methodology is proposed to estimate surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> by assimilating Soil Moisture Active Passive (SMAP) soil moisture data and Geostationary Operational Environmental Satellite (GOES) LST data into a dual-source (DS) model using a hybrid particle assimilation strategy. SMAP soil moisture data are assimilated using a particle filter (PF), and GOES LST data are assimilated using an adaptive particle batch smoother (APBS) to account for the large gap in the spatial and temporal resolution. The methodology is implemented in an area in the U.S. Southern Great Plains. Assessment against in situ observations suggests that soil moisture and LST estimates are in better agreement with observations after assimilation. The RMSD for 30 min (daytime) <span class="hlt">flux</span> estimates is reduced by 6.3% (8.7%) and 31.6% (37%) for H and LE on average. Comparison against a LST-only and a soil moisture-only assimilation case suggests that despite the coarse resolution, assimilating SMAP soil moisture data is not only beneficial but also crucial for successful and robust <span class="hlt">flux</span> estimation, particularly when the uncertainties in the model estimates are large.</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('http://adsabs.harvard.edu/abs/2017MMTB...48.1951Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MMTB...48.1951Y"><span>Controlling Radiative <span class="hlt">Heat</span> Transfer Across the Mold <span class="hlt">Flux</span> Layer by the Scattering Effect of the Borosilicate Mold <span class="hlt">Flux</span> System with Metallic Iron</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yoon, Dae-Woo; Cho, Jung-Wook; Kim, Seon-Hyo</p> <p>2017-08-01</p> <p>The present study proposes a countermeasure for regulating total <span class="hlt">heat</span> <span class="hlt">flux</span> through the mold <span class="hlt">flux</span> layer by designed mold <span class="hlt">flux</span> with additive metallic iron particles. The <span class="hlt">heat</span> <span class="hlt">flux</span> through the B2O3-CaO-SiO2-Na2O-CaF2-Fe system was investigated using the infrared emitter technique to evaluate total <span class="hlt">flux</span> density across the mold <span class="hlt">flux</span> 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 <span class="hlt">flux</span>. It was confirmed that the crystalline layer of studied mold <span class="hlt">fluxes</span> does not have a meaningful effect on the total <span class="hlt">heat</span> <span class="hlt">flux</span> density due to the similar structure and fraction of the crystalline phase. The extinction coefficient was measured for glassy mold <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span> through the mold <span class="hlt">flux</span> film during the casting process.</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('http://adsabs.harvard.edu/abs/2014APS..DPPGI1003A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPGI1003A"><span>Broadening of the divertor <span class="hlt">heat</span> <span class="hlt">flux</span> footprint with increasing number of ELM filaments in NSTX</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahn, Joon-Wook</p> <p>2014-10-01</p> <p>We report on the broadening (narrowing) of the ELM <span class="hlt">heat</span> <span class="hlt">flux</span> footprint with increasing (decreasing) number of filamentary striations from in-depth thermography measurements in NSTX. Edge localized modes (ELMs) represent a challenge to future fusion devices, due to the high <span class="hlt">heat</span> <span class="hlt">fluxes</span> on plasma facing surfaces. One ameliorating factor has been that the divertor <span class="hlt">heat</span> <span class="hlt">flux</span> characteristic profile width (λq) has been observed to broaden with the size of ELM, as compared with the inter-ELM λq, which keeps the peak <span class="hlt">heat</span> <span class="hlt">flux</span> (qpeak) from increasing. In contrast, λq has been observed to narrow during ELMs under certain conditions in NSTX, for both naturally occurring and 3-D fields triggered ELMs. Fast thermographic measurements and detailed analysis demonstrate that the ELM λq increases with the number of observed filamentary striations, i . e . , profile narrowing (broadening) occurs when the number of striations is smaller (larger) than 3-4. With profile narrowing, qpeak at ELM peak times is inversely related (proportional) to λq (the ELM size), exacerbating the <span class="hlt">heat</span> <span class="hlt">flux</span> problem. Edge stability analysis shows that NSTX ELMs almost always lie on the current-driven kink/peeling mode side with low toroidal mode number (n = 1--5), consistent with the typical numbers of striations in NSTX (0-8) in comparison 10--15 striations are normally observed in intermediate-n peeling-ballooning ELMs, e.g., from JET. The NSTX characteristics may translate directly to ITER, which is also projected to lie on the low-n kink/peeling stability boundary. This work was supported by the U.S. DOE, Contract DE-AC05-00OR22725 (ORNL) and DE-AC02-09CH11466 (PPPL).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010521','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010521"><span>Sabots, Obturator and Gas-In-Launch Tube Techniques for <span class="hlt">Heat</span> <span class="hlt">Flux</span> Models in Ballistic Ranges</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bogdanoff, David W.; Wilder, Michael C.</p> <p>2013-01-01</p> <p>For thermal protection system (<span class="hlt">heat</span> shield) design for space vehicle entry into earth and other planetary atmospheres, it is essential to know the augmentation of the <span class="hlt">heat</span> <span class="hlt">flux</span> due to vehicle surface roughness. At the NASA Ames Hypervelocity Free Flight Aerodynamic Facility (HFFAF) ballistic range, a campaign of <span class="hlt">heat</span> <span class="hlt">flux</span> studies on rough models, using infrared camera techniques, has been initiated. Several phenomena can interfere with obtaining good <span class="hlt">heat</span> <span class="hlt">flux</span> data when using this measuring technique. These include leakage of the hot drive gas in the gun barrel through joints in the sabot (model carrier) to create spurious thermal imprints on the model forebody, deposition of sabot material on the model forebody, thereby changing the thermal properties of the model surface and unknown in-barrel <span class="hlt">heating</span> of the model. This report presents developments in launch techniques to greatly reduce or eliminate these problems. The techniques include the use of obturator cups behind the launch package, enclosed versus open front sabot designs and the use of hydrogen gas in the launch tube. Attention also had to be paid to the problem of the obturator drafting behind the model and impacting the model. Of the techniques presented, the obturator cups and hydrogen in the launch tube were successful when properly implemented</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060048167','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060048167"><span>Local <span class="hlt">Heat</span> <span class="hlt">Flux</span> Measurements with Single and Small Multi-element Coaxial Element-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 NASA's Vision for Space Exploration mission, 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 with regeneratively cooled chamber walls, as well as in small thrust chambers with few elements in the injector. In this program, single and three-element injectors were hot-fire tested with liquid oxygen and 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, Injector configurations were tested with both shear coaxial elements and swirl coaxial elements. Both a straight and a scarfed single element swirl injector were tested. This paper includes general descriptions of the experimental hardware, instrumentation, and results of the hot-fire testing for three coaxial shear and swirl elements. Detailed geometry and test results the for shear coax elements has already been published. Detailed test result for the remaining 6 swirl coax element for the will be published in a future JANNAF presentation to provide well-defined data sets for development and model validation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100002217','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100002217"><span><span class="hlt">Heat</span> <span class="hlt">Flux</span> and Wall Temperature Estimates for the NASA Langley HIFiRE Direct Connect Rig</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cuda, Vincent, Jr.; Hass, Neal E.</p> <p>2010-01-01</p> <p>An objective of the Hypersonic International Flight Research Experimentation (HIFiRE) Program Flight 2 is to provide validation data for high enthalpy scramjet prediction tools through a single flight test and accompanying ground tests of the HIFiRE Direct Connect Rig (HDCR) tested in the NASA LaRC Arc <span class="hlt">Heated</span> Scramjet Test Facility (AHSTF). The HDCR is a full-scale, copper <span class="hlt">heat</span> sink structure designed to simulate the isolator entrance conditions and isolator, pilot, and combustor section of the HIFiRE flight test experiment flowpath and is fully instrumented to assess combustion performance over a range of operating conditions simulating flight from Mach 5.5 to 8.5 and for various fueling schemes. As part of the instrumentation package, temperature and <span class="hlt">heat</span> <span class="hlt">flux</span> sensors were provided along the flowpath surface and also imbedded in the structure. The purpose of this paper is to demonstrate that the surface <span class="hlt">heat</span> <span class="hlt">flux</span> and wall temperature of the Zirconia coated copper wall can be obtained with a water-cooled <span class="hlt">heat</span> <span class="hlt">flux</span> gage and a sub-surface temperature measurement. An algorithm was developed which used these two measurements to reconstruct the surface conditions along the flowpath. Determinations of the surface conditions of the Zirconia coating were conducted for a variety of conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29749202','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29749202"><span>[Characteristics of water and <span class="hlt">heat</span> <span class="hlt">fluxes</span> and its footprint climatology on farmland in low hilly region of red soil].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Yang; Jing, Yuan Shu; Qin, Ben Ben</p> <p>2017-01-01</p> <p>The analysis of the characteristics and footprint climatology of farmland water and <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> at different temporal scales and the corresponding source area distribution of <span class="hlt">flux</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> were greater in August than in September, while the net radiation <span class="hlt">flux</span> was more distributed to latent <span class="hlt">heat</span> exchange. The proportion of net radiation to latent <span class="hlt">heat</span> <span class="hlt">flux</span> decreased in September compared to August, but the sensible <span class="hlt">heat</span> <span class="hlt">flux</span> was vice versa. With combined effects of weather conditions (particularly wind), stability, and surface condition, the source areas of <span class="hlt">flux</span> 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.</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/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/2060/20160007102','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160007102"><span>Estimation of Surface Temperature and <span class="hlt">Heat</span> <span class="hlt">Flux</span> by Inverse <span class="hlt">Heat</span> Transfer Methods Using Internal Temperatures Measured While Radiantly <span class="hlt">Heating</span> a Carbon/Carbon Specimen up to 1920 F</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pizzo, Michelle; Daryabeigi, Kamran; Glass, David</p> <p>2015-01-01</p> <p>The ability to solve the <span class="hlt">heat</span> conduction equation is needed when designing materials to be used on vehicles exposed to extremely high temperatures; e.g. vehicles used for atmospheric entry or hypersonic flight. When using test and flight data, computational methods such as finite difference schemes may be used to solve for both the direct <span class="hlt">heat</span> conduction problem, i.e., solving between internal temperature measurements, and the inverse <span class="hlt">heat</span> conduction problem, i.e., using the direct solution to march forward in space to the surface of the material to estimate both surface temperature and <span class="hlt">heat</span> <span class="hlt">flux</span>. The completed research first discusses the methods used in developing a computational code to solve both the direct and inverse <span class="hlt">heat</span> transfer problems using one dimensional, centered, implicit finite volume schemes and one dimensional, centered, explicit space marching techniques. The developed code assumed the boundary conditions to be specified time varying temperatures and also considered temperature dependent thermal properties. The completed research then discusses the results of analyzing temperature data measured while radiantly <span class="hlt">heating</span> a carbon/carbon specimen up to 1920 F. The temperature was measured using thermocouple (TC) plugs (small carbon/carbon material specimens) with four embedded TC plugs inserted into the larger carbon/carbon specimen. The purpose of analyzing the test data was to estimate the surface <span class="hlt">heat</span> <span class="hlt">flux</span> and temperature values from the internal temperature measurements using direct and inverse <span class="hlt">heat</span> transfer methods, thus aiding in the thermal and structural design and analysis of high temperature vehicles.</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/2012IJAEO..17...76S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012IJAEO..17...76S"><span>A revised surface resistance parameterisation for estimating latent <span class="hlt">heat</span> <span class="hlt">flux</span> from remotely sensed data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Song, Yi; Wang, Jiemin; Yang, Kun; Ma, Mingguo; Li, Xin; Zhang, Zhihui; Wang, Xufeng</p> <p>2012-07-01</p> <p>Estimating evapotranspiration (ET) is required for many environmental studies. Remote sensing provides the ability to spatially map latent <span class="hlt">heat</span> <span class="hlt">flux</span>. Many studies have developed approaches to derive spatially distributed surface energy <span class="hlt">fluxes</span> from various satellite sensors with the help of field observations. In this study, remote-sensing-based λE mapping was conducted using a Landsat Thematic Mapper (TM) image and an Enhanced Thematic Mapper Plus (ETM+) image. The remotely sensed data and field observations employed in this study were obtained from Watershed Allied Telemetry Experimental Research (WATER). A biophysics-based surface resistance model was revised to account for water stress and temperature constraints. The precision of the results was validated using 'ground truth' data obtained by eddy covariance (EC) system. Scale effects play an important role, especially for parameter optimisation and validation of the latent <span class="hlt">heat</span> <span class="hlt">flux</span> (λE). After considering the footprint of EC, the λE derived from the remote sensing data was comparable to the EC measured value during the satellite's passage. The results showed that the revised surface resistance parameterisation scheme was useful for estimating the latent <span class="hlt">heat</span> <span class="hlt">flux</span> over cropland in arid regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPT10081S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPT10081S"><span>Particle and <span class="hlt">heat</span> <span class="hlt">flux</span> estimates in Proto-MPEX in Helicon Mode with IR imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Showers, M. A.; Biewer, T. M.; Caughman, J. B. O.; Donovan, D. C.; Goulding, R. H.; Rapp, J.</p> <p>2016-10-01</p> <p>The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) at Oak Ridge National Laboratory (ORNL) is a linear plasma device developing the plasma source concept for the Material Plasma Exposure eXperiment (MPEX), which will address plasma material interaction (PMI) science for future fusion reactors. To better understand how and where energy is being lost from the Proto-MPEX plasma during ``helicon mode'' operations, particle and <span class="hlt">heat</span> <span class="hlt">fluxes</span> are quantified at multiple locations along the machine length. Relevant diagnostics include infrared (IR) cameras, four double Langmuir probes (LPs), and in-vessel thermocouples (TCs). The IR cameras provide temperature measurements of Proto-MPEX's plasma-facing dump and target plates, located on either end of the machine. The change in surface temperature is measured over the duration of the plasma shot to determine the <span class="hlt">heat</span> <span class="hlt">flux</span> hitting the plates. The IR cameras additionally provide 2-D thermal load distribution images of these plates, highlighting Proto-MPEX plasma behaviors, such as hot spots. The LPs and TCs provide additional plasma measurements required to determine particle and <span class="hlt">heat</span> <span class="hlt">fluxes</span>. Quantifying axial variations in <span class="hlt">fluxes</span> will help identify machine operating parameters that will improve Proto-MPEX's performance, increasing its PMI research capabilities. This work was supported by the U.S. D.O.E. contract DE-AC05-00OR22725.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030063051','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030063051"><span>Momentum and <span class="hlt">Heat</span> <span class="hlt">Flux</span> Measurements in the Exhaust of VASIMR using Helium Propellant</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chavers, D. Gregory; Chang-Diaz, Franklin R.; Irvine, Claude; Squire, Jared P.</p> <p>2003-01-01</p> <p>Interplanetary travel requires propulsion systems that can provide high specific impulse (Isp), while also having sufficient thrust to rapidly accelerate large payloads. One such propulsion system is the Variable Specific Impulse Magneto-plasma Rocket (VASIMR), which creates, <span class="hlt">heats</span>, and ejects plasma to provide variable thrust and Isp, designed to optimally meet the mission requirements. The fraction of the total energy invested in creating the plasma, as compared to the plasma's total kinetic energy, is an important factor in determining the overall system efficiency. In VASIMR, this 'frozen flow loss' is appreciable when at high thrust, but negligible at high Isp. The loss applies to other electric thrusters as well. If some of this energy could be recovered through recombination processes, and reinjected as neutral kinetic energy, the efficiency of VASIMR, in its low Isp/high thrust mode may be improved. An experiment is being conducted to investigate the possibility of recovering some of the energy used to create the plasma by studying the flow characteristics of the charged and neutral particles in the exhaust of the thruster. This paper will cover the measurements of momentum <span class="hlt">flux</span> and <span class="hlt">heat</span> <span class="hlt">flux</span> in the exhaust of the VASIMR test facility using helium as the propellant where the <span class="hlt">heat</span> <span class="hlt">flux</span> is comprised of both kinetic and plasma recombination energy. The <span class="hlt">flux</span> measurements also assist in diagnosing and verifying the plasma conditions in the existing experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JApMe..42..227B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JApMe..42..227B"><span>Evaluation of Latent <span class="hlt">Heat</span> <span class="hlt">Flux</span> Fields from Satellites and Models during SEMAPHORE.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bourras, Denis; Liu, W. Timothy; Eymard, Laurence; Tang, Wenqing</p> <p>2003-02-01</p> <p>Latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> were derived from satellite observations in the region of Structure des Echanges Mer-Atmosphère, Propriétés des Hétérogénéités Océaniques: Recherche Expérimentale (SEMAPHORE), which was conducted near the Azores islands in the North Atlantic Ocean in autumn of 1993. The satellite <span class="hlt">fluxes</span> were compared with output fields of two atmospheric circulation models and in situ measurements. The rms error of the instantaneous satellite <span class="hlt">fluxes</span> is between 35 and 40 W m-2 and the bias is 60-85 W m-2. The large bias is mainly attributed to a bias in satellite-derived atmospheric humidity and is related to the particular shape of the vertical humidity profiles during SEMAPHORE. The bias in humidity implies that the range of estimated <span class="hlt">fluxes</span> is smaller than the range of ship <span class="hlt">fluxes</span>, by 34%-38%. The rms errors for <span class="hlt">fluxes</span> from models are 30-35 W m-2, and the biases are smaller than the biases in satellite <span class="hlt">fluxes</span> (14-18 W m-2). Two case studies suggest that the satellites detect horizontal gradients of wind speed and specific humidity if the magnitude of the gradients exceeds a detection threshold, which is 1.27 g kg-1 (100 km)-1 for specific humidity and between 0.35 and 0.82 m s-1 (30 km)-1 for wind speed. In contrast, the accuracy of the spatial gradients of bulk variables from models always varies as a function of the location and number of assimilated observations. A comparison between monthly <span class="hlt">fluxes</span> from satellites and models reveals that satellite-derived <span class="hlt">flux</span> anomaly fields are consistent with reanalyzed fields, whereas operational model products lack part of the mesoscale structures present in the satellite fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090007599','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090007599"><span>Multi-Dimensional, Inviscid <span class="hlt">Flux</span> Reconstruction for Simulation of Hypersonic <span class="hlt">Heating</span> on Tetrahedral Grids</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gnoffo, Peter A.</p> <p>2009-01-01</p> <p>The quality of simulated hypersonic stagnation region <span class="hlt">heating</span> on tetrahedral meshes is investigated by using a three-dimensional, upwind reconstruction algorithm for the inviscid <span class="hlt">flux</span> vector. Two test problems are investigated: hypersonic flow over a three-dimensional cylinder with special attention to the uniformity of the solution in the spanwise direction and hypersonic flow over a three-dimensional sphere. The tetrahedral cells used in the simulation are derived from a structured grid where cell faces are bisected across the diagonal resulting in a consistent pattern of diagonals running in a biased direction across the otherwise symmetric domain. This grid is known to accentuate problems in both shock capturing and stagnation region <span class="hlt">heating</span> encountered with conventional, quasi-one-dimensional inviscid <span class="hlt">flux</span> reconstruction algorithms. Therefore the test problem provides a sensitive test for algorithmic effects on <span class="hlt">heating</span>. This investigation is believed to be unique in its focus on three-dimensional, rotated upwind schemes for the simulation of hypersonic <span class="hlt">heating</span> on tetrahedral grids. This study attempts to fill the void left by the inability of conventional (quasi-one-dimensional) approaches to accurately simulate <span class="hlt">heating</span> in a tetrahedral grid system. Results show significant improvement in spanwise uniformity of <span class="hlt">heating</span> with some penalty of ringing at the captured shock. Issues with accuracy near the peak shear location are identified and require further study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080020459','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080020459"><span>Analysis of the Effects of Vitiates on Surface <span class="hlt">Heat</span> <span class="hlt">Flux</span> in Ground Tests of Hypersonic Vehicles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cuda, Vincent; Gaffney, Richard L</p> <p>2008-01-01</p> <p>To achieve the high enthalpy conditions associated with hypersonic flight, many ground test facilities burn fuel in the air upstream of the test chamber. Unfortunately, the products of combustion contaminate the test gas and alter gas properties and the <span class="hlt">heat</span> <span class="hlt">fluxes</span> associated with aerodynamic <span class="hlt">heating</span>. The difference in the <span class="hlt">heating</span> rates between clean air and a vitiated test medium needs to be understood so that the thermal management system for hypersonic vehicles can be properly designed. This is particularly important for advanced hypersonic vehicle concepts powered by air-breathing propulsion systems that couple cooling requirements, fuel flow rates, and combustor performance by flowing fuel through sub-surface cooling passages to cool engine components and preheat the fuel prior to combustion. An analytical investigation was performed comparing clean air to a gas vitiated with methane/oxygen combustion products to determine if variations in gas properties contributed to changes in predicted <span class="hlt">heat</span> <span class="hlt">flux</span>. This investigation started with simple relationships, evolved into writing an engineering-level code, and ended with running a series of CFD cases. It was noted that it is not possible to simultaneously match all of the gas properties between clean and vitiated test gases. A study was then conducted selecting various combinations of freestream properties for a vitiated test gas that matched clean air values to determine which combination of parameters affected the computed <span class="hlt">heat</span> transfer the least. The best combination of properties to match was the free-stream total sensible enthalpy, dynamic pressure, and either the velocity or Mach number. This combination yielded only a 2% difference in <span class="hlt">heating</span>. Other combinations showed departures of up to 10% in the <span class="hlt">heat</span> <span class="hlt">flux</span> estimate.</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://www.osti.gov/biblio/22525314-time-dependent-turbulent-heating-open-flux-tubes-chromosphere-corona-solar-wind','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22525314-time-dependent-turbulent-heating-open-flux-tubes-chromosphere-corona-solar-wind"><span>TIME-DEPENDENT TURBULENT <span class="hlt">HEATING</span> OF OPEN <span class="hlt">FLUX</span> TUBES IN THE CHROMOSPHERE, CORONA, AND SOLAR WIND</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Woolsey, L. N.; Cranmer, S. R., E-mail: lwoolsey@cfa.harvard.edu</p> <p></p> <p>We investigate several key questions of plasma <span class="hlt">heating</span> in open-field regions of the corona that connect to the solar wind. We present results for a model of Alfvén-wave-driven turbulence for three typical open magnetic field structures: a polar coronal hole, an open <span class="hlt">flux</span> tube neighboring an equatorial streamer, and an open <span class="hlt">flux</span> tube near a strong-field active region. We compare time-steady, one-dimensional turbulent <span class="hlt">heating</span> models against fully time-dependent three-dimensional reduced-magnetohydrodynamic modeling of BRAID. We find that the time-steady results agree well with time-averaged results from BRAID. The time dependence allows us to investigate the variability of the magnetic fluctuations andmore » of the <span class="hlt">heating</span> in the corona. The high-frequency tail of the power spectrum of fluctuations forms a power law whose exponent varies with height, and we discuss the possible physical explanation for this behavior. The variability in the <span class="hlt">heating</span> rate is bursty and nanoflare-like in nature, and we analyze the amount of energy lost via dissipative <span class="hlt">heating</span> in transient events throughout the simulation. The average energy in these events is 10{sup 21.91} erg, within the “picoflare” range, and many events reach classical “nanoflare” energies. We also estimated the multithermal distribution of temperatures that would result from the <span class="hlt">heating</span>-rate variability, and found good agreement with observed widths of coronal differential emission measure distributions. The results of the modeling presented in this paper provide compelling evidence that turbulent <span class="hlt">heating</span> in the solar atmosphere by Alfvén waves accelerates the solar wind in open <span class="hlt">flux</span> tubes.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3291C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3291C"><span>Progress in remote sensing of global land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> and evaporations with a turbulent <span class="hlt">heat</span> exchange parameterization method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Xuelong; Su, Bob</p> <p>2017-04-01</p> <p>Remote sensing has provided us an opportunity to observe Earth land surface with a much higher resolution than any of GCM simulation. Due to scarcity of information for land surface physical parameters, up-to-date GCMs still have large uncertainties in the coupled land surface process modeling. One critical issue is a large amount of parameters used in their land surface models. Thus remote sensing of land surface spectral information can be used to provide information on these parameters or assimilated to decrease the model uncertainties. Satellite imager could observe the Earth land surface with optical, thermal and microwave bands. Some basic Earth land surface status (land surface temperature, canopy height, canopy leaf area index, soil moisture etc.) has been produced with remote sensing technique, which already help scientists understanding Earth land and atmosphere interaction more precisely. However, there are some challenges when applying remote sensing variables to calculate global land-air <span class="hlt">heat</span> and water exchange <span class="hlt">fluxes</span>. Firstly, a global turbulent exchange parameterization scheme needs to be developed and verified, especially for global momentum and <span class="hlt">heat</span> roughness length calculation with remote sensing information. Secondly, a compromise needs to be innovated to overcome the spatial-temporal gaps in remote sensing variables to make the remote sensing based land surface <span class="hlt">fluxes</span> applicable for GCM model verification or comparison. A <span class="hlt">flux</span> network data library (more 200 <span class="hlt">flux</span> towers) was collected to verify the designed method. Important progress in remote sensing of global land <span class="hlt">flux</span> and evaporation will be presented and its benefits for GCM models will also be discussed. Some in-situ studies on the Tibetan Plateau and problems of land surface process simulation will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA549369','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA549369"><span>Physics-Based Modeling and Measurement of High-<span class="hlt">Flux</span> Condensation <span class="hlt">Heat</span> Transfer</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-09-01</p> <p>TRANSFER (Contract No. N000140811139) by Prof. Issam Mudawar Sung-Min Kim Joseph Kim Boiling and Two-Phase Flow Laboratory School of...Final 01-10-2008 to 30-09-2011 Physics-Based Modeling and Measurement of High-<span class="hlt">Flux</span> Condensation <span class="hlt">Heat</span> Transfer NA N00014-08-1-1139 NA NA NA NA Mudawar ...respectively. phase change, condensation, electronics cooling, micro-channel, high-<span class="hlt">flux</span> U U U UU 107 Mudawar , Issam 765-494-5705 Reset PHYSICS-BASED</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/2016APS..DPPN10136L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPN10136L"><span>Momentum transport and non-local transport in <span class="hlt">heat-flux</span>-driven magnetic reconnection in HEDP</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Chang; Fox, Will; Bhattacharjee, Amitava</p> <p>2016-10-01</p> <p>Strong magnetic fields are readily generated in high-energy-density plasmas and can affect the <span class="hlt">heat</span> confinement properties of the plasma. Magnetic reconnection can in turn be important as an inverse process, which destroys or reconfigures the magnetic field. Recent theory has demonstrated a novel physics regime for reconnection in high-energy-density plasmas where the magnetic field is advected into the reconnection layer by plasma <span class="hlt">heat</span> <span class="hlt">flux</span> via the Nernst effect. In this work we elucidate the physics of the electron dissipation layer in this <span class="hlt">heat-flux</span>-driven regime. Through fully kinetic simulation and a new generalized Ohm's law, we show that momentum transport due to the <span class="hlt">heat-flux</span>-viscosity effect provides the dissipation mechanism to allow magnetic field line reconnection. Scaling analysis and simulations show that the characteristic width of the current sheet in this regime is several electron mean-free-paths. These results additionally show a coupling between non-local transport and momentum transport, which in turn affects the dynamics of the magnetic field. This work was supported by the U.S. Department of Energy under Contract No. DE-SC0008655.</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://hdl.handle.net/2060/20120016444','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016444"><span>Fabrication and Testing of a Thin-Film <span class="hlt">Heat</span> <span class="hlt">Flux</span> Sensor for a Stirling Convertor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Scott D.; Fralick, Gustave; Wrbanek, John; Sayir, Ali</p> <p>2009-01-01</p> <p>The NASA Glenn Research Center (GRC) has been testing high efficiency free-piston Stirling convertors for potential use in radioisotope power systems since 1999. Stirling convertors are being operated for many years to demonstrate a radioisotope power system capable of providing reliable power for potential multi-year missions. Techniques used to monitor the convertors for change in performance include measurements of temperature, pressure, energy addition, and energy rejection. Micro-porous bulk insulation is used in the Stirling convertor test set up to minimize the loss of thermal energy from the electric <span class="hlt">heat</span> source to the environment. The insulation is characterized before extended operation, enabling correlation of the net thermal energy addition to the convertor. Aging microporous bulk insulation changes insulation efficiency, introducing errors in the correlation for net thermal energy addition. A thin-mm <span class="hlt">heat</span> <span class="hlt">flux</span> sensor was designed and fabricated to directly measure the net thermal energy addition to the Stirling convertor. The fabrication techniques include slip casting and using Physical Vapor Deposition (PVD). One micron thick noble metal thermocouples measure temperature on the surface of an Alumina ceramic disc and <span class="hlt">heat</span> <span class="hlt">flux</span> is calculated. Fabrication, integration, and test results of a thin film <span class="hlt">heat</span> <span class="hlt">flux</span> sensor are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100005642','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100005642"><span>Fabrication and Testing of a Thin-Film <span class="hlt">Heat</span> <span class="hlt">Flux</span> Sensor for a Stirling Convertor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Scott D.; Fralick, Gus c.; Wrbanek, John D.; Sayir, Ali</p> <p>2010-01-01</p> <p>The NASA Glenn Research Center (GRC) has been testing high-efficiency free-piston Stirling convertors for potential use in radioisotope power systems since 1999. Stirling convertors are being operated for many years to demonstrate a radioisotope power system capable of providing reliable power for potential multiyear missions. Techniques used to monitor the convertors for change in performance include measurements of temperature, pressure, energy addition, and energy rejection. Micro-porous bulk insulation is used in the Stirling convertor test setup to minimize the loss of thermal energy from the electric <span class="hlt">heat</span> source to the environment. The insulation is characterized before extended operation, enabling correlation of the net thermal energy addition to the convertor. Aging micro-porous bulk insulation changes insulation efficiency, introducing errors in the correlation for net thermal energy addition. A thin-film <span class="hlt">heat</span> <span class="hlt">flux</span> sensor was designed and fabricated to directly measure the net thermal energy addition to the Stirling convertor. The fabrication techniques include slipcasting and using Physical Vapor Deposition (PVD). One-micron-thick noble metal thermocouples measure temperature on the surface of an alumina ceramic disk and <span class="hlt">heat</span> <span class="hlt">flux</span> is calculated. Fabrication, integration, and test results of a thin-film <span class="hlt">heat</span> <span class="hlt">flux</span> sensor are presented.</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/scitech">SciTech Connect</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/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('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('http://adsabs.harvard.edu/abs/1994PhDT........43L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994PhDT........43L"><span>Effect of Particle Size Distribution on Wall <span class="hlt">Heat</span> <span class="hlt">Flux</span> in Pulverized-Coal Furnaces and Boilers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Jun</p> <p></p> <p>A mathematical model of combustion and <span class="hlt">heat</span> 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, <span class="hlt">heat</span> 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 <span class="hlt">heat</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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 <span class="hlt">flux</span>. 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 <span class="hlt">flux</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span> is significant. But there is only a small effect on gas temperature and fuel fraction burned; it is speculated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5456908','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5456908"><span>Numerical Study of Laminar Flow and Convective <span class="hlt">Heat</span> Transfer Utilizing Nanofluids in Equilateral Triangular Ducts with Constant <span class="hlt">Heat</span> <span class="hlt">Flux</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>Ting, Hsien-Hung; Hou, Shuhn-Shyurng</p> <p>2016-01-01</p> <p>This study numerically investigates <span class="hlt">heat</span> transfer augmentation using water-based Al2O3 and CuO nanofluids flowing in a triangular cross-sectional duct under constant <span class="hlt">heat</span> <span class="hlt">flux</span> in laminar flow conditions. The Al2O3/water nanofluids with different volume fractions (0.1%, 0.5%, 1%, 1.5%, and 2%) and CuO/water nanofluids with various volume fractions (0.05%, 0.16%, 0.36%, 0.5%, and 0.8%) are employed, and Reynolds numbers in the range of 700 to 1900 in a laminar flow are considered. The <span class="hlt">heat</span> transfer rate becomes more remarkable when employing nanofluids. As compared with pure water, at a Peclet number of 7000, a 35% enhancement in the convective <span class="hlt">heat</span> transfer coefficient, is obtained for an Al2O3/water nanofluid with 2% particle volume fraction; at the same Peclet number, a 41% enhancement in the convective <span class="hlt">heat</span> transfer coefficient is achieved for a CuO/water nanofluid with 0.8% particle volume concentration. <span class="hlt">Heat</span> transfer enhancement increases with increases in particle volume concentration and Peclet number. Moreover, the numerical results are found to be in good agreement with published experimental data. PMID:28773698</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('http://adsabs.harvard.edu/abs/2007APS..DPPBI1005S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007APS..DPPBI1005S"><span>Divertor <span class="hlt">Heat</span> <span class="hlt">Flux</span> Reduction and Detachment in the National Spherical Torus eXperiment.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Soukhanovskii, Vsevolod</p> <p>2007-11-01</p> <p>Steady-state handling of the <span class="hlt">heat</span> <span class="hlt">flux</span> 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-<span class="hlt">heated</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span>, 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 <span class="hlt">flux</span> expansion in the divertor region. Up to 60 % reduction in divertor peak <span class="hlt">heat</span> <span class="hlt">flux</span> was achieved at similar levels of scrape-off layer power by varying plasma shaping and thereby increasing the outer strike point (OSP) poloidal <span class="hlt">flux</span> expansion from 4-6 to 18-22. In recent experiments conducted in highly-shaped 1.0-1.2 MA 6 MW NBI <span class="hlt">heated</span> H-mode plasmas with divertor D2 injection at rates up to 10^22 s-1, a PDD regime with OSP peak <span class="hlt">heat</span> <span class="hlt">flux</span> 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</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('https://www.osti.gov/biblio/22611415-mhd-effects-heat-transfer-ucm-fluid-along-joule-heating-thermal-radiation-using-cattaneo-christov-heat-flux-model','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22611415-mhd-effects-heat-transfer-ucm-fluid-along-joule-heating-thermal-radiation-using-cattaneo-christov-heat-flux-model"><span>MHD effects and <span class="hlt">heat</span> transfer for the UCM fluid along with Joule <span class="hlt">heating</span> and thermal radiation using Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shah, S., E-mail: sajidshah313@yahoo.com; Hussain, S.; Sagheer, M.</p> <p>2016-08-15</p> <p>Present study examines the numerical analysis of MHD flow of Maxwell fluid with thermal radiation and Joule <span class="hlt">heating</span> by considering the recently developed Cattaneo-Christov <span class="hlt">heat</span> <span class="hlt">flux</span> model which explains the time relaxation characteristics for the <span class="hlt">heat</span> <span class="hlt">flux</span>. 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013hea..book..165F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013hea..book..165F"><span>Sound <span class="hlt">Absorbers</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fuchs, H. V.; Möser, M.</p> <p></p> <p>Sound absorption indicates the transformation of sound energy into <span class="hlt">heat</span>. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing <span class="hlt">absorbing</span> components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound <span class="hlt">absorbers</span> also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25145698','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25145698"><span>Influence of stem temperature changes on <span class="hlt">heat</span> pulse sap <span class="hlt">flux</span> density measurements.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vandegehuchte, Maurits W; Burgess, Stephen S O; Downey, Alec; Steppe, Kathy</p> <p>2015-04-01</p> <p>While natural spatial temperature gradients between measurement needles have been thoroughly investigated for continuous <span class="hlt">heat</span>-based sap flow methods, little attention has been given to how natural changes in stem temperature impact <span class="hlt">heat</span> pulse-based methods through temporal rather than spatial effects. By modelling the theoretical equation for both an ideal instantaneous pulse and a step pulse and applying a finite element model which included actual needle dimensions and wound effects, the influence of a varying stem temperature on <span class="hlt">heat</span> pulse-based methods was investigated. It was shown that the <span class="hlt">heat</span> ratio (HR) method was influenced, while for the compensation <span class="hlt">heat</span> pulse and Tmax methods changes in stem temperatures of up to 0.002 °C s(-1) did not lead to significantly different results. For the HR method, rising stem temperatures during measurements led to lower <span class="hlt">heat</span> pulse velocity values, while decreasing stem temperatures led to both higher and lower <span class="hlt">heat</span> pulse velocities, and to imaginary results for high flows. These errors of up to 40% can easily be prevented by including a temperature correction in the data analysis procedure, calculating the slope of the natural temperature change based on the measured temperatures before application of the <span class="hlt">heat</span> pulse. Results of a greenhouse and outdoor experiment on Pinus pinea L. show the influence of this correction on low and average sap <span class="hlt">flux</span> densities. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983tehs.nasa...45A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983tehs.nasa...45A"><span>Development of <span class="hlt">heat</span> <span class="hlt">flux</span> sensors for turbine airfoils and combustor liners</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.</p> <p>1983-10-01</p> <p>The design of durable turbine airfoils that use a minimum amount of cooling air requires knowledge of the <span class="hlt">heat</span> loads on the airfoils during engine operation. Measurement of these <span class="hlt">heat</span> loads will permit the verification or modification of the analytical models used in the design process and will improve the ability to predict and confirm the thermal performance of turbine airfoil designs. <span class="hlt">Heat</span> <span class="hlt">flux</span> sensors for turbine blades and vanes must be compatible with the cast nickel-base and cobalt-base materials used in their fabrication and will need to operate in a hostile environment with regard to temperature, pressure and thermal cycling. There is also a need to miniaturize the sensors to obtain measurements without perturbing the <span class="hlt">heat</span> flows that are to be measured.</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://adsabs.harvard.edu/abs/2009PhST..138a4059H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhST..138a4059H"><span>Experiences with tungsten coatings in high <span class="hlt">heat</span> <span class="hlt">flux</span> tests and under plasma load in ASDEX Upgrade</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herrmann, A.; Greuner, H.; Fuchs, J. C.; de Marné, P.; Neu, R.; ASDEX Upgrade Team</p> <p>2009-12-01</p> <p>ASDEX Upgrade was operated with about 6400 s plasma discharge during the scientific program in 2007/2008 exploring tungsten as a first wall material in tokamaks. In the first phase, the <span class="hlt">heating</span> power was restricted to 10 MW. It was increased to 15 MW in the second phase. During this operational period, a delamination of the 200 μm W-VPS coating happened at 2 out of 128 tiles of the outer divertor and an unscheduled opening was required. In the third phase, ASDEX Upgrade was operated with partly predamaged tiles and up to 15 MW <span class="hlt">heating</span> power. The target load was actively controlled by N2-seeding. This paper presents the screening test of target tiles in the high <span class="hlt">heat</span> <span class="hlt">flux</span> test facility GLADIS, experiences with operation and detected damages of the outer divertor as well as the <span class="hlt">heat</span> load to the outer divertor and the reasons for the toroidal asymmetry of the divertor load.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050217477','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050217477"><span>Flow-Boiling Critical <span class="hlt">Heat</span> <span class="hlt">Flux</span> Experiments Performed in Reduced Gravity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hasan, Mohammad M.; Mudawar, Issam</p> <p>2005-01-01</p> <p>Poor understanding of flow boiling in microgravity has recently emerged as a key obstacle to the development of many types of power generation and advanced life support systems intended for space exploration. The critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) is perhaps the most important thermal design parameter for boiling systems involving both heatflux-controlled devices and intense <span class="hlt">heat</span> removal. Exceeding the CHF limit can lead to permanent damage, including physical burnout of the <span class="hlt">heat</span>-dissipating device. The importance of the CHF limit creates an urgent need to develop predictive design tools to ensure both the safe and reliable operation of a two-phase thermal management system under the reduced-gravity (like that on the Moon and Mars) and microgravity environments of space. At present, very limited information is available on flow-boiling <span class="hlt">heat</span> transfer and the CHF under these conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1218.1546B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1218.1546B"><span>Experimental Study of a Nitrogen Natural Circulation Loop at Low <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>Baudouy, B.</p> <p>2010-04-01</p> <p>A natural convection circulation loop in liquid nitrogen, i.e. an open thermosiphon flow configuration, has been investigated experimentally near atmospheric pressure. The experiments were conducted on a 2 m high loop with a copper tube of 10 mm inner diameter uniformly <span class="hlt">heated</span> over a length of 0.95 m. Evolution of the total mass flow rate of the loop and the pressure difference along the tube are described. We also report the boiling curves where single phase and two-phase flows are identified with increasing <span class="hlt">heat</span> <span class="hlt">flux</span>. We focus our <span class="hlt">heat</span> transfer analysis on the single phase regime where mixed convection is encountered. A <span class="hlt">heat</span> transfer coefficient correlation is proposed. We also examine the boiling incipience as a function of the tube height.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AcAau.138..168H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AcAau.138..168H"><span>Drag and <span class="hlt">heat</span> <span class="hlt">flux</span> reduction mechanism of blunted cone with aerodisks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Wei; Li, Lang-quan; Yan, Li; Zhang, Tian-tian</p> <p>2017-09-01</p> <p>The major challenge among a number of design requirements for hypersonic vehicles is the reduction of drag and aerodynamic <span class="hlt">heating</span>. Of all these techniques of drag and <span class="hlt">heat</span> <span class="hlt">flux</span> reduction, application of forward facing aerospike conceived in 1950s is an effective and simpler technique to reduce the drag as well as the <span class="hlt">heat</span> transfer rate for blunt nosed bodies at hypersonic Mach numbers. In this paper, the flow fields around a blunt cone with and without aerodisk flying at hypersonic Mach numbers are computed numerically, and the numerical simulations are conducted by specifying the freestream velocity, static pressure and static temperatures at the inlet of the computational domain with a three-dimensional, steady, Reynolds-averaged Navier-Stokes equation. An aerodisk is attached to the tip of the rod to reduce the drag and <span class="hlt">heat</span> <span class="hlt">flux</span> further. The influences of the length of rod and the diameter of aerodisk on the drag and <span class="hlt">heat</span> <span class="hlt">flux</span> reduction mechanism are analyzed comprehensively, and eight configurations are taken into consideration in the current study. The obtained results show that for all aerodisks, the reduction in drag of the blunt body is proportional to the extent of the recirculation dead air region. For long rods, the aerodisk is found not that beneficial in reducing the drag, and an aerodisk is more effective than an aerospike. The spike produces a region of recirculation separated flow that shields the blunt-nosed body from the incoming flow, and the recirculation region is formed around the root of the spike up to the reattachment point of the flow at the shoulder of the blunt body. The dynamic pressure in the recirculation area is highly reduced and thus leads to the decrease in drag and <span class="hlt">heat</span> load on the surface of the blunt body. Because of the reattachment of the shear layer on the shoulder of the blunt body, the pressure near that point becomes large.</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-radiative 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://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3231132','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3231132"><span>Design and Characterization of a High Resolution Microfluidic <span class="hlt">Heat</span> <span class="hlt">Flux</span> Sensor with Thermal Modulation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nam, Sung-Ki; Kim, Jung-Kyun; Cho, Sung-Cheon; Lee, Sun-Kyu</p> <p>2010-01-01</p> <p>A complementary metal-oxide semiconductor-compatible process was used in the design and fabrication of a suspended membrane microfluidic <span class="hlt">heat</span> <span class="hlt">flux</span> sensor with a thermopile for the purpose of measuring the <span class="hlt">heat</span> flow rate. The combination of a thirty-junction gold and nickel thermoelectric sensor with an ultralow noise preamplifier, a low pass filter, and a lock-in amplifier can yield a resolution 20 nW with a sensitivity of 461 V/W. The thermal modulation method is used to eliminate low-frequency noise from the sensor output, and various amounts of fluidic <span class="hlt">heat</span> were applied to the sensor to investigate its suitability for microfluidic applications. For sensor design and analysis of signal output, a method of modeling and simulating electro-thermal behavior in a microfluidic <span class="hlt">heat</span> <span class="hlt">flux</span> sensor with an integrated electronic circuit is presented and validated. The electro-thermal domain model was constructed by using system dynamics, particularly the bond graph. The electro-thermal domain system model in which the thermal and the electrical domains are coupled expresses the <span class="hlt">heat</span> generation of samples and converts thermal input to electrical output. The proposed electro-thermal domain system model is in good agreement with the measured output voltage response in both the transient and the steady state. PMID:22163568</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21233731-simplified-model-determining-local-heat-flux-boundary-conditions-slagging-wall','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21233731-simplified-model-determining-local-heat-flux-boundary-conditions-slagging-wall"><span>Simplified model for determining local <span class="hlt">heat</span> <span class="hlt">flux</span> boundary conditions for slagging wall</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bingzhi Li; Anders Brink; Mikko Hupa</p> <p>2009-07-15</p> <p>In this work, two models for calculating <span class="hlt">heat</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">heat</span> balance in the model is investigated. It is found that simplification of the <span class="hlt">heat</span> balance can be applied when the radiation <span class="hlt">heat</span> <span class="hlt">flux</span> is dominant in the balance. 9 refs., 7 figs., 10 tabs.« less</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/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=19930036989&hterms=coulomb&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcoulomb','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930036989&hterms=coulomb&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcoulomb"><span><span class="hlt">Heat</span> <span class="hlt">flux</span> dropouts in the solar wind and Coulomb scattering effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fitzenreiter, R. J.; Ogilvie, K. W.</p> <p>1992-01-01</p> <p>Data on solar wind electrons at the ISEE 3 spacecraft located 0.01 AU upstream from the earth (McComas et al., 1989) showed periods of time when the <span class="hlt">flux</span> of antisunward suprathermal electrons would decrease suddenly, leading to <span class="hlt">heat</span> <span class="hlt">flux</span> dropouts (HFDs). This paper examines data from ISEE 1 at the 1.5 x 10 exp 6 km downstream location to determine whether HFDs identified at ISEE 3 by McComas et al. can be detected at this location and whether the ISEE 1 observations can provide information to one or the other possible interpretations of HFDs: that HFDs are due to enhanced Coulomb scattering, or to disconnection from the sun of the magnetic <span class="hlt">flux</span> tube. The results of the examination identified the presence of HFD events in the ISEE 1 data, and the findings indicate that Coulomb scattering plays a substantial role in at least some HFD events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1408602-heat-deposition-analysis-high-flux-isotope-reactors-heu-leu-core-models','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1408602-heat-deposition-analysis-high-flux-isotope-reactors-heu-leu-core-models"><span><span class="hlt">Heat</span> deposition analysis for the High <span class="hlt">Flux</span> Isotope Reactor’s HEU and LEU core models</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Davidson, Eva E.; Betzler, Benjamin R.; Chandler, David; ...</p> <p>2017-08-01</p> <p>The High <span class="hlt">Flux</span> Isotope Reactor at Oak Ridge National Laboratory is an 85 MW th pressurized light-water-cooled and -moderated <span class="hlt">flux</span>-trap type research reactor. The reactor is used to conduct numerous experiments, advancing various scientific and engineering disciplines. As part of an ongoing program sponsored by the US Department of Energy National Nuclear Security Administration Office of Material Management and Minimization, studies are being performed to assess the feasibility of converting the reactor’s highly enriched uranium fuel to low-enriched uranium fuel. To support this conversion project, reference models with representative experiment target loading and explicit fuel plate representation were developed andmore » benchmarked for both fuels to (1) allow for consistent comparison between designs for both fuel types and (2) assess the potential impact of low-enriched uranium conversion. These high-fidelity models were used to conduct <span class="hlt">heat</span> deposition analyses at the beginning and end of the reactor cycle and are presented herein. This article (1) discusses the High <span class="hlt">Flux</span> Isotope Reactor models developed to facilitate detailed <span class="hlt">heat</span> deposition analyses of the reactor’s highly enriched and low-enriched uranium cores, (2) examines the computational approach for performing <span class="hlt">heat</span> deposition analysis, which includes a discussion on the methodology for calculating the amount of energy released per fission, <span class="hlt">heating</span> rates, power and volumetric <span class="hlt">heating</span> rates, and (3) provides results calculated throughout various regions of the highly enriched and low-enriched uranium core at the beginning and end of the reactor cycle. These are the first detailed high-fidelity <span class="hlt">heat</span> deposition analyses for the High <span class="hlt">Flux</span> Isotope Reactor’s highly enriched and low-enriched core models with explicit fuel plate representation. Lastly, these analyses are used to compare <span class="hlt">heat</span> distributions obtained for both fuel designs at the beginning and end of the reactor cycle, and they are essential</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP11C1564F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP11C1564F"><span>Reconstructing <span class="hlt">Heat</span> <span class="hlt">Fluxes</span> Over Lake Erie During the Lake Effect Snow Event of November 2014</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fitzpatrick, L.; Fujisaki-Manome, A.; Gronewold, A.; Anderson, E. J.; Spence, C.; Chen, J.; Shao, C.; Posselt, D. J.; Wright, D. M.; Lofgren, B. M.; Schwab, D. J.</p> <p>2017-12-01</p> <p>The extreme North American winter storm of November 2014 triggered a record lake effect snowfall (LES) event in southwest New York. This study examined the evaporation from Lake Erie during the record lake effect snowfall event, November 17th-20th, 2014, by reconstructing <span class="hlt">heat</span> <span class="hlt">fluxes</span> and evaporation rates over Lake Erie using the unstructured grid, Finite-Volume Community Ocean Model (FVCOM). Nine different model runs were conducted using combinations of three different <span class="hlt">flux</span> algorithms: the Met <span class="hlt">Flux</span> Algorithm (COARE), a method routinely used at NOAA's Great Lakes Environmental Research Laboratory (SOLAR), and the Los Alamos Sea Ice Model (CICE); and three different meteorological forcings: the Climate Forecast System version 2 Operational Analysis (CFSv2), Interpolated observations (Interp), and the High Resolution Rapid Refresh (HRRR). A few non-FVCOM model outputs were also included in the evaporation analysis from an atmospheric reanalysis (CFSv2) and the large lake thermodynamic model (LLTM). Model-simulated water temperature and meteorological forcing data (wind direction and air temperature) were validated with buoy data at three locations in Lake Erie. The simulated sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> were validated with the eddy covariance measurements at two offshore sites; Long Point Lighthouse in north central Lake Erie and Toledo water crib intake in western Lake Erie. The evaluation showed a significant increase in <span class="hlt">heat</span> <span class="hlt">fluxes</span> over three days, with the peak on the 18th of November. Snow water equivalent data from the National Snow Analyses at the National Operational Hydrologic Remote Sensing Center showed a spike in water content on the 20th of November, two days after the peak <span class="hlt">heat</span> <span class="hlt">fluxes</span>. The ensemble runs presented a variation in spatial pattern of evaporation, lake-wide average evaporation, and resulting cooling of the lake. Overall, the evaporation tended to be larger in deep water than shallow water near the shore. The lake-wide average evaporations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990064338&hterms=Clustering&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DClustering','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990064338&hterms=Clustering&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DClustering"><span>Large-Scale Coronal <span class="hlt">Heating</span>, Clustering of Coronal Bright Points, and Concentration 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>Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.</p> <p>1998-01-01</p> <p>By combining quiet-region Fe XII coronal images from SOHO/EIT with magnetograms from NSO/Kitt Peak and from SOHO/MDI, we show that on scales larger than a supergranule the population of network coronal bright points and the magnetic <span class="hlt">flux</span> content of the network are both markedly greater under the bright half of the quiet corona than under the dim half. These results (1) support the view that the <span class="hlt">heating</span> of the entire corona in quiet regions and coronal holes is driven by fine-scale magnetic activity (microflares, explosive events, spicules) seated low in the magnetic network, and (2) suggest that this large-scale modulation of the magnetic <span class="hlt">flux</span> and coronal <span class="hlt">heating</span> is a signature of giant convection cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97t5414O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97t5414O"><span>Circular <span class="hlt">heat</span> and momentum <span class="hlt">flux</span> radiated by magneto-optical nanoparticles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ott, A.; Ben-Abdallah, P.; Biehs, S.-A.</p> <p>2018-05-01</p> <p>In the present article we investigate the <span class="hlt">heat</span> and momentum <span class="hlt">fluxes</span> radiated by a hot magneto-optical nanoparticle in its surroundings under the action of an external magnetic field. We show that the <span class="hlt">flux</span> 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 <span class="hlt">heat</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhST..167a4072H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhST..167a4072H"><span>Progress on performance assessment of ITER enhanced <span class="hlt">heat</span> <span class="hlt">flux</span> first wall technology after neutron irradiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirai, T.; Bao, L.; Barabash, V.; Chappuis, Ph; Eaton, R.; Escourbiac, F.; Giqcuel, S.; Merola, M.; Mitteau, R.; Raffray, R.; Linke, J.; Loewenhoff, Th; Pintsuk, G.; Wirtz, M.; Boomstra, D.; Magielsen, A.; Chen, J.; Wang, P.; Gervash, A.; Safronov, V.</p> <p>2016-02-01</p> <p>ITER first wall (FW) panels are irradiated by energetic neutrons during the nuclear phase. Thus, an irradiation and high <span class="hlt">heat</span> <span class="hlt">flux</span> testing programme is undertaken by the ITER organization in order to evaluate the effects of neutron irradiation on the performance of enhanced <span class="hlt">heat</span> <span class="hlt">flux</span> (EHF) FW components. The test campaign includes neutron irradiation (up to 0.6-0.8 dpa at 200 °C-250 °C) of mock-ups that are representative of the final EHF FW panel design, followed by thermal fatigue tests (up to 4.7 MW m-2). Mock-ups were manufactured by the same manufacturing process as proposed for the series production. After a pre-irradiation thermal screening, eight mock-ups will be selected for the irradiation campaigns. This paper reports the preparatory work of HHF tests and neutron irradiation, assessment results as well as a brief description of mock-up manufacturing and inspection routes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhDT.......186G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhDT.......186G"><span>Closed-form solution of temperature and <span class="hlt">heat</span> <span class="hlt">flux</span> in embedded cooling channels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Griggs, Steven Craig</p> <p>1997-11-01</p> <p>An analytical method is discussed for predicting temperature in a layered composite material with embedded cooling channels. The cooling channels are embedded in the material to maintain its temperature at acceptable levels. Problems of this type are encountered in the aerospace industry and include high-temperature or high-<span class="hlt">heat-flux</span> protection for advanced composite-material skins of high-speed air vehicles; thermal boundary-layer flow control on supersonic transports; or infrared signature suppression on military vehicles. A Green's function solution of the diffusion equation is used to simultaneously predict the global and localized effects of temperature in the material and in the embedded cooling channels. The integral method is used to solve the energy equation with fluid flow to find the solution of temperature and <span class="hlt">heat</span> <span class="hlt">flux</span> in the cooling fluid and material simultaneously. This method of calculation preserves the three-dimensional nature of this problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PlST...20g4006B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PlST...20g4006B"><span>Double-null divertor configuration discharge and disruptive <span class="hlt">heat</span> <span class="hlt">flux</span> simulation using TSC on EAST</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bo, SHI; Jinhong, YANG; Cheng, YANG; Desheng, CHENG; Hui, WANG; Hui, ZHANG; Haifei, DENG; Junli, QI; Xianzu, GONG; Weihua, WANG</p> <p>2018-07-01</p> <p>The tokamak simulation code (TSC) is employed to simulate the complete evolution of a disruptive discharge in the experimental advanced superconducting tokamak. The multiplication factor of the anomalous transport coefficient was adjusted to model the major disruptive discharge with double-null divertor configuration based on shot 61 916. The real-time feed-back control system for the plasma displacement was employed. Modeling results of the evolution of the poloidal field coil currents, the plasma current, the major radius, the plasma configuration all show agreement with experimental measurements. Results from the simulation show that during disruption, <span class="hlt">heat</span> <span class="hlt">flux</span> about 8 MW m‑2 flows to the upper divertor target plate and about 6 MW m‑2 flows to the lower divertor target plate. Computations predict that different amounts of <span class="hlt">heat</span> <span class="hlt">fluxes</span> on the divertor target plate could result by adjusting the multiplication factor of the anomalous transport coefficient. This shows that TSC has high flexibility and predictability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750034251&hterms=stress+good&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstress%2Bgood','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750034251&hterms=stress+good&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstress%2Bgood"><span>The measurement of shear stress and total <span class="hlt">heat</span> <span class="hlt">flux</span> in a nonadiabatic turbulent 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>Mikulla, V.; Horstman, C. C.</p> <p>1975-01-01</p> <p>Turbulent shear stress and direct turbulent total <span class="hlt">heat-flux</span> measurements have been made across a nonadiabatic, zero pressure gradient, hypersonic boundary layer by using specially designed hot-wire probes free of strain-gauging and wire oscillation. <span class="hlt">Heat-flux</span> measurements were in reasonably good agreement with values obtained by integrating the energy equation using measured profiles of velocity and temperature. The shear-stress values deduced from the measurements, by assuming zero correlation of velocity and pressure fluctuations, were lower than the values obtained by integrating the momentum equation. Statistical properties of the cross-correlations are similar to corresponding incompressible measurements at approximately the same momentum-thickness Reynolds number.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRD..12011957A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRD..12011957A"><span>Recent trends (2003-2013) of land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> on the southern side of the central Himalayas, Nepal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amatya, Pukar Man; Ma, Yaoming; Han, Cunbo; Wang, Binbin; Devkota, Lochan Prasad</p> <p>2015-12-01</p> <p>Novice efforts have been made in order to study the regional distribution of land surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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 <span class="hlt">flux</span> is increasing as a result of decreasing precipitation (drier environment). The sensible <span class="hlt">heat</span> <span class="hlt">flux</span> did not change much except for the northwestern High Himalaya and High Mountains. In northwestern High Himalaya sensible <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span> 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 <span class="hlt">heat</span> <span class="hlt">flux</span> can be attributed to increase in net radiation <span class="hlt">flux</span> under persistent forest cover and irrigation land used for agriculture.</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 radiation 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 radiation). 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> </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://hdl.handle.net/2060/20030022688','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030022688"><span>Development of Advanced Thermal and Environmental Barrier Coatings Using a High-<span class="hlt">Heat-Flux</span> Testing Approach</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhu, Dongming; Miller, Robert A.</p> <p>2003-01-01</p> <p>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-<span class="hlt">heat-flux</span> 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 <span class="hlt">heat-flux</span> techniques. The external radiation resistance of the coating is assessed based on the measured specimen temperature response under a laser- <span class="hlt">heated</span> intense radiation-<span class="hlt">flux</span> 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 <span class="hlt">heat-flux</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ApPhL..97h1502D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ApPhL..97h1502D"><span>Production of high transient <span class="hlt">heat</span> and particle <span class="hlt">fluxes</span> in a linear plasma device</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Temmerman, G.; Zielinski, J. J.; van der Meiden, H.; Melissen, W.; Rapp, J.</p> <p>2010-08-01</p> <p>We report on the generation of high transient <span class="hlt">heat</span> and particle <span class="hlt">fluxes</span> in a linear plasma device by pulsed operation of the plasma source. A capacitor bank is discharged into the source to transiently increase the discharge current up to 1.7 kA, allowing peak densities and temperature of 70×1020 m-3 and 6 eV corresponding to a surface power density of about 400 MW m-2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MAP...tmp...17X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MAP...tmp...17X"><span>Comparison of surface sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> over the Tibetan Plateau from reanalysis and observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, Jin; Yu, Ye; Li, Jiang-lin; Ge, Jun; Liu, Chuan</p> <p>2018-02-01</p> <p>Surface sensible and latent <span class="hlt">heat</span> <span class="hlt">fluxes</span> (SH and LE) over the Tibetan Plateau (TP) have been under research since 1950s, especially for recent several years, by mainly using observation, reanalysis, and satellite data. However, the spatiotemporal changes are not consistent among different studies. This paper focuses on the spatiotemporal variation of SH and LE over the TP from 1981 to 2013 using reanalysis data sets (ERA-Interim, JRA-55, and MERRA) and observations. Results show that the spatiotemporal changes from the three reanalysis data sets are significantly different and the probable causes are discussed. Averaged for the whole TP, both SH and LE from MERRA are obviously higher than the other two reanalysis data sets. ERA-Interim shows a significant downward trend for SH and JRA-55 shows a significant increase of LE during the 33 years with other data sets having no obvious changes. By comparing the <span class="hlt">heat</span> <span class="hlt">fluxes</span> and some climate factors from the reanalysis with observations, it is found that the differences of <span class="hlt">heat</span> <span class="hlt">fluxes</span> among the three reanalysis data sets are closely related to their differences in meteorological conditions as well as the different parameterizations for surface transfer coefficients. In general, the <span class="hlt">heat</span> <span class="hlt">fluxes</span> from the three reanalysis have a better representation in the western TP than that in the eastern TP under inter-annual scale. While in terms of monthly variation, ERA-Interim may have better applicability in the eastern TP with dense vegetation conditions, while SH of JRA-55 and LE of MERRA are probably more representative for the middle and western TP with poor vegetation conditions.</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 radiation 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('http://adsabs.harvard.edu/abs/2018IJT....39...14V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018IJT....39...14V"><span>Measurement of the Nonlinearity of <span class="hlt">Heat-Flux</span> Sensors Employing a CO_2 laser</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van der Ham, E. W. M.; Beer, C. M.; Ballico, M. J.</p> <p>2018-01-01</p> <p><span class="hlt">Heat-flux</span> sensors are widely used in industry to test building products and designs for resistance to bushfire, to test the flammability of textiles and in numerous applications such as concentrated solar collectors. In Australia, such detectors are currently calibrated by the National Measurement Institute Australia (NMIA) at low <span class="hlt">flux</span> levels of 20 W \\cdot m^{-2}. Estimates of the uncertainty arising from nonlinearity at industrial levels (e.g. 50 kW \\cdot m^{-2} for bushfire testing) rely on literature information. NMIA has developed a facility to characterize the linearity response of these <span class="hlt">heat-flux</span> sensors up to 110 kW \\cdot m^{-2} using a low-power CO_2 laser and a chopped quartz tungsten-halogen lamp. The facility was validated by comparison with the conventional <span class="hlt">flux</span>-addition method, and used to characterize several Schmidt-Boelter-type sensors. A significant nonlinear response was found, ranging from (3.2 ± 0.9)% at 40 kW \\cdot m^{-2} to more than 8 % at 100 kW \\cdot m^{-2}. Additional measurements confirm that this is not attributable to convection effects, but due to the temperature dependence of the sensor's responsivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyB..503...64M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyB..503...64M"><span><span class="hlt">Heat</span> <span class="hlt">flux</span> measurements of Tb3M series (M=Co, Rh and Ru): Specific <span class="hlt">heat</span> and magnetocaloric properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Monteiro, J. C. B.; Lombardi, G. A.; dos Reis, R. D.; Freitas, H. E.; Cardoso, L. P.; Mansanares, A. M.; Gandra, F. G.</p> <p>2016-12-01</p> <p>We report on the magnetic properties and magnetocaloric effect (MCE) for the Tb3M series, with M=Co, Rh and Ru, obtained using a <span class="hlt">heat</span> <span class="hlt">flux</span> technique. The specific <span class="hlt">heat</span> of Tb3Co and Tb3Rh are very similar, with a first order type transition occurring around 6 K below the magnetic ordering temperature without any corresponding feature on the magnetization. The slightly enhanced electronic specific <span class="hlt">heat</span>, the Debye temperature around 150 K and the presence of the magnetic specific <span class="hlt">heat</span> well above the ordering temperature are also characteristic of many other compounds of the R3M family (R=Rare Earth). The specific <span class="hlt">heat</span> for Tb3Ru, however, presents two peaks at 37 K and 74 K. The magnetization shows that below the first peak the system presents an antiferromagnetic behavior and is paramagnetic above 74 K. We obtained a magnetocaloric effect for M=Co and Rh, -∆S=12 J/kg K, but for Tb3Ru it is less than 3 J/kg K (μ0∆H=5 T). We believe that the experimental results show that the MCE is directly related with the process of hybridization of the (R)5d-(M)d electrons that occurs in the R3M materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3089965','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3089965"><span>In situ methods for measuring thermal properties and <span class="hlt">heat</span> <span class="hlt">flux</span> on planetary bodies</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kömle, Norbert I.; Hütter, Erika S.; Macher, Wolfgang; Kaufmann, Erika; Kargl, Günter; Knollenberg, Jörg; Grott, Matthias; Spohn, Tilman; Wawrzaszek, Roman; Banaszkiewicz, Marek; Seweryn, Karoly; Hagermann, Axel</p> <p>2011-01-01</p> <p>The thermo-mechanical properties of planetary surface and subsurface layers control to a high extent in which way a body interacts with its environment, in particular how it responds to solar irradiation and how it interacts with a potentially existing atmosphere. Furthermore, if the natural temperature profile over a certain depth can be measured in situ, this gives important information about the <span class="hlt">heat</span> <span class="hlt">flux</span> from the interior and thus about the thermal evolution of the body. Therefore, in most of the recent and planned planetary lander missions experiment packages for determining thermo-mechanical properties are part of the payload. Examples are the experiment MUPUS on Rosetta's comet lander Philae, the TECP instrument aboard NASA's Mars polar lander Phoenix, and the mole-type instrument HP3 currently developed for use on upcoming lunar and Mars missions. In this review we describe several methods applied for measuring thermal conductivity and <span class="hlt">heat</span> <span class="hlt">flux</span> and discuss the particular difficulties faced when these properties have to be measured in a low pressure and low temperature environment. We point out the abilities and disadvantages of the different instruments and outline the evaluation procedures necessary to extract reliable thermal conductivity and <span class="hlt">heat</span> <span class="hlt">flux</span> data from in situ measurements. PMID:21760643</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21760643','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21760643"><span>In situ methods for measuring thermal properties and <span class="hlt">heat</span> <span class="hlt">flux</span> on planetary bodies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kömle, Norbert I; Hütter, Erika S; Macher, Wolfgang; Kaufmann, Erika; Kargl, Günter; Knollenberg, Jörg; Grott, Matthias; Spohn, Tilman; Wawrzaszek, Roman; Banaszkiewicz, Marek; Seweryn, Karoly; Hagermann, Axel</p> <p>2011-06-01</p> <p>The thermo-mechanical properties of planetary surface and subsurface layers control to a high extent in which way a body interacts with its environment, in particular how it responds to solar irradiation and how it interacts with a potentially existing atmosphere. Furthermore, if the natural temperature profile over a certain depth can be measured in situ, this gives important information about the <span class="hlt">heat</span> <span class="hlt">flux</span> from the interior and thus about the thermal evolution of the body. Therefore, in most of the recent and planned planetary lander missions experiment packages for determining thermo-mechanical properties are part of the payload. Examples are the experiment MUPUS on Rosetta's comet lander Philae, the TECP instrument aboard NASA's Mars polar lander Phoenix, and the mole-type instrument HP(3) currently developed for use on upcoming lunar and Mars missions. In this review we describe several methods applied for measuring thermal conductivity and <span class="hlt">heat</span> <span class="hlt">flux</span> and discuss the particular difficulties faced when these properties have to be measured in a low pressure and low temperature environment. We point out the abilities and disadvantages of the different instruments and outline the evaluation procedures necessary to extract reliable thermal conductivity and <span class="hlt">heat</span> <span class="hlt">flux</span> data from in situ measurements.</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/scitech">SciTech Connect</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/2060/20050210107','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050210107"><span>Spray Cooling Trajectory Angle Impact Upon <span class="hlt">Heat</span> <span class="hlt">Flux</span> Using a Straight Finned Enhanced Surface</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Silk, Eric A.; Kim, Jungho; Kiger, Ken</p> <p>2005-01-01</p> <p>Experiments were conducted to study the effects of spray trajectory angles upon <span class="hlt">heat</span> <span class="hlt">flux</span> for flat and enhanced surface spray cooling. The surface enhancement consisted of straight fins machined on the top surface of a copper heater block. Spray cooling curves were obtained with the straight fin surface aligned both parallel (axial) and perpendicular (transverse) to the spray axis. Measurements were also obtained on a flat surface heater block for comparison purposes. Each copper block had a cross-sectional area of 2.0 sq cm. A 2x2 nozzle array was used with PF-5060 as the working fluid. Thermal performance data was obtained under nominally degassed (chamber pressure of 41.4 kPa) conditions. Results show that the maximum CHF in all cases was attained for a trajectory angle of 30' from the surface normal. Furthermore, trajectory angles applied to straight finned surfaces can have a critical <span class="hlt">heat</span> <span class="hlt">flux</span> (CHF) enhancement as much as 75% (<span class="hlt">heat</span> <span class="hlt">flux</span> value of 140 W/sq cm) relative to the vertical spray orientation for the analogous flat surface case under nominally degassed conditions.</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('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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5784416','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5784416"><span>Hindcasting the Madden‐Julian Oscillation With a New Parameterization of Surface <span class="hlt">Heat</span> <span class="hlt">Fluxes</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>Wang, Jingfeng; Lin, Wenshi</p> <p>2017-01-01</p> <p>Abstract The recently developed maximum entropy production (MEP) model, an alternative parameterization of surface <span class="hlt">heat</span> <span class="hlt">fluxes</span>, is incorporated into the Weather Research and Forecasting (WRF) model. A pair of WRF cloud‐resolving experiments (5 km grids) using the bulk transfer model (WRF default) and the MEP model of surface <span class="hlt">heat</span> <span class="hlt">fluxes</span> are performed to hindcast the October Madden‐Julian oscillation (MJO) event observed during the 2011 Dynamics of the MJO (DYNAMO) field campaign. The simulated surface latent and sensible <span class="hlt">heat</span> <span class="hlt">fluxes</span> in the MEP and bulk transfer model runs are in general consistent with in situ observations from two research vessels. Compared to the bulk transfer model, the convection envelope is strengthened in the MEP run and shows a more coherent propagation over the Maritime Continent. The simulated precipitable water in the MEP run is in closer agreement with the observations. Precipitation in the MEP run is enhanced during the active phase of the MJO with significantly reduced regional dry and wet biases. Large‐scale ocean evaporation is stronger in the MEP run leading to stronger boundary layer moistening to the east of the convection center, which facilitates the eastward propagation of the MJO. PMID:29399269</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/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 radiation, 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/2060/19880001849','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/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('http://adsabs.harvard.edu/abs/2018JPhD...51z4001B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhD...51z4001B"><span>MHD <span class="hlt">heat</span> <span class="hlt">flux</span> mitigation in hypersonic flow around a blunt body with ablating surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bityurin, V. A.; Bocharov, A. N.</p> <p>2018-07-01</p> <p>One of the possible applications of magnetohydrodynamic flow control is considered. Namely, the surface <span class="hlt">heat</span> <span class="hlt">flux</span> mitigation by means of magnetohydrodynamic (MHD) interaction in hypersonic flow around a blunt body. The 2D computational model realizes a coupled solution of chemically non-equilibrium ionized airflow in magnetic field. <span class="hlt">Heat</span>- and mass-transfer due to the ablation of materials from the body surface is taken into account. Two cases of free-stream flow conditions are considered: moderate free-stream velocity (7500 m s‑1) case and high free-stream velocity (11 000 m s‑1) case. It is shown that the first flow case results in moderate ionization in the shock layer, while the second flow case results in high ionization. In the first case, the Hall effect is significant, and effective electrical conductivity in the shock layer is rather low. In the second case, the Hall effect reduces, and effective conductivity is high. Even if the Hall effect is strong, as in the first case, intensive MHD deceleration of the flow behind the shock is provided due to the presence of insulating boundaries, the bow shock front and non-conductive wall of the blunt body. In the second case, high effective conductivity provides a high intensity of MHD flow deceleration. In both cases, a strong effect of MHD interaction on the flow structure is observed. As a consequence, a noticeable reduction of the surface <span class="hlt">heat</span> <span class="hlt">flux</span> is revealed for reasonable values of magnetic induction. The new treatment of mechanism for the surface <span class="hlt">heat</span> <span class="hlt">flux</span> reduction is proposed, which is different from commonly used one assuming that MHD interaction increases the bow shock stand-off distance, and, consequently results in a decrease of the mean temperature drop across the shock layer. The new effect of ‘saturation of <span class="hlt">heat</span> flux’ is discussed.</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/2060/20050174677','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050174677"><span>A Prototype <span class="hlt">Flux</span>-Plate <span class="hlt">Heat</span>-Flow Sensor for Venus Surface <span class="hlt">Heat</span>-Flow Determinations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morgan, Paul; Reyes, Celso; Smrekar, Suzanne E.</p> <p>2005-01-01</p> <p>Venus is the most Earth-like planet in the Solar System in terms of size, and the densities of the two planets are almost identical when selfcompression of the two planets is taken into account. Venus is the closest planet to Earth, and the simplest interpretation of their similar densities is that their bulk compositions are almost identical. Models of the thermal evolution of Venus predict interior temperatures very similar to those indicated for the regions of Earth subject to solid-state convection, but even global analyses of the coarse Pioneer Venus elevation data suggest Venus does not lose <span class="hlt">heat</span> by the same primary <span class="hlt">heat</span> loss mechanism as Earth, i.e., seafloor spreading. The comparative paucity of impact craters on Venus has been interpreted as evidence for relatively recent resurfacing of the planet associated with widespread volcanic and tectonic activity. The difference in the gross tectonic styles of Venus and Earth, and the origins of some of the enigmatic volcano-tectonic features on Venus, such as the coronae, appear to be intrinsically related to Venus <span class="hlt">heat</span> loss mechanism(s). An important parameter in understanding Venus geological evolution, therefore, is its present surface <span class="hlt">heat</span> flow. Before the complications of survival in the hostile Venus surface environment were tackled, a prototype fluxplate <span class="hlt">heat</span>-flow sensor was built and tested for use under synthetic stable terrestrial surface conditions. The design parameters for this prototype were that it should operate on a conforming (sand) surface, with a small, self-contained power and recording system, capable of operating without servicing for at least several days. The precision and accuracy of the system should be < 5 mW/sq m. Additional information is included in the original extended abstract.</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('https://www.ncbi.nlm.nih.gov/pubmed/29474062','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29474062"><span><span class="hlt">Heating</span> Rate of Light <span class="hlt">Absorbing</span> Aerosols: Time-Resolved Measurements, the Role of Clouds, and Source Identification.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ferrero, Luca; Močnik, Griša; Cogliati, Sergio; Gregorič, Asta; Colombo, Roberto; Bolzacchini, Ezio</p> <p>2018-03-20</p> <p>Light <span class="hlt">absorbing</span> aerosols (LAA) <span class="hlt">absorb</span> sunlight and <span class="hlt">heat</span> the atmosphere. This work presents a novel methodology to experimentally quantify the <span class="hlt">heating</span> rate (HR) induced by LAA into an atmospheric layer. Multiwavelength aerosol absorption measurements were coupled with spectral measurements of the direct, diffuse and surface reflected radiation to obtain highly time-resolved measurements of HR apportioned in the context of LAA species (black carbon, BC; brown carbon, BrC; dust), sources (fossil fuel, FF; biomass burning, BB), and as a function of cloudiness. One year of continuous and time-resolved measurements (5 min) of HR were performed in the Po Valley. We experimentally determined (1) the seasonal behavior of HR (winter 1.83 ± 0.02 K day -1 ; summer 1.04 ± 0.01 K day -1 ); (2) the daily cycle of HR (asymmetric, with higher values in the morning than in the afternoon); (3) the HR in different sky conditions (from 1.75 ± 0.03 K day -1 in clear sky to 0.43 ± 0.01 K day -1 in complete overcast); (4) the apportionment to different sources: HR FF (0.74 ± 0.01 K day -1 ) and HR BB (0.46 ± 0.01 K day -1 ); and (4) the HR of BrC (HR BrC : 0.15 ± 0.01 K day -1 , 12.5 ± 0.6% of the total) and that of BC (HR BC : 1.05 ± 0.02 K day -1 ; 87.5 ± 0.6% of the total).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.1791W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.1791W"><span>Modelling storm development and the impact when introducing waves, sea spray and <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>Wu, Lichuan; Rutgersson, Anna; Sahlée, Erik</p> <p>2015-04-01</p> <p>In high wind speed conditions, sea spray generated due to intensity breaking waves have big influence on the wind stress and <span class="hlt">heat</span> <span class="hlt">fluxes</span>. Measurements show that drag coefficient will decrease in high wind speed. Sea spray generation function (SSGF), an important term of wind stress parameterization in high wind speed, usually treated as a function of wind speed/friction velocity. In this study, we introduce a wave state depended SSGG and wave age depended Charnock number into a high wind speed wind stress parameterization (Kudryavtsev et al., 2011; 2012). The proposed wind stress parameterization and sea spray <span class="hlt">heat</span> <span class="hlt">fluxes</span> parameterization from Andreas et al., (2014) were applied to an atmosphere-wave coupled model to test on four storm cases. Compared with measurements from the FINO1 platform in the North Sea, the new wind stress parameterization can reduce the forecast errors of wind in high wind speed range, but not in low wind speed. Only sea spray impacted on wind stress, it will intensify the storms (minimum sea level pressure and maximum wind speed) and lower the air temperature (increase the errors). Only the sea spray impacted on the <span class="hlt">heat</span> <span class="hlt">fluxes</span>, it can improve the model performance on storm tracks and the air temperature, but not change much in the storm intensity. If both of sea spray impacted on the wind stress and <span class="hlt">heat</span> <span class="hlt">fluxes</span> are taken into account, it has the best performance in all the experiment for minimum sea level pressure and maximum wind speed and air temperature. Andreas, E. L., Mahrt, L., and Vickers, D. (2014). An improved bulk air-sea surface <span class="hlt">flux</span> algorithm, including spray-mediated transfer. Quarterly Journal of the Royal Meteorological Society. Kudryavtsev, V. and Makin, V. (2011). Impact of ocean spray on the dynamics of the marine atmospheric boundary layer. Boundary-layer meteorology, 140(3):383-410. Kudryavtsev, V., Makin, V., and S, Z. (2012). On the sea-surface drag and <span class="hlt">heat</span>/mass transfer at strong winds. Technical report, Royal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1435724-inversion-geothermal-heat-flux-thermomechanically-coupled-nonlinear-stokes-ice-sheet-model','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1435724-inversion-geothermal-heat-flux-thermomechanically-coupled-nonlinear-stokes-ice-sheet-model"><span>Inversion of geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> in a thermomechanically coupled nonlinear Stokes ice sheet model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Zhu, Hongyu; Petra, Noemi; Stadler, Georg; ...</p> <p>2016-07-13</p> <p>We address the inverse problem of inferring the basal geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> from surface velocity observations using a steady-state thermomechanically coupled nonlinear Stokes ice flow model. This is a challenging inverse problem since the map from basal <span class="hlt">heat</span> <span class="hlt">flux</span> to surface velocity observables is indirect: the <span class="hlt">heat</span> <span class="hlt">flux</span> is a boundary condition for the thermal advection–diffusion equation, which couples to the nonlinear Stokes ice flow equations; together they determine the surface ice flow velocity. This multiphysics inverse problem is formulated as a nonlinear least-squares optimization problem with a cost functional that includes the data misfit between surface velocity observations andmore » model predictions. A Tikhonov regularization term is added to render the problem well posed. We derive adjoint-based gradient and Hessian expressions for the resulting partial differential equation (PDE)-constrained optimization problem and propose an inexact Newton method for its solution. As a consequence of the Petrov–Galerkin discretization of the energy equation, we show that discretization and differentiation do not commute; that is, the order in which we discretize the cost functional and differentiate it affects the correctness of the gradient. Using two- and three-dimensional model problems, we study the prospects for and limitations of the inference of the geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> field from surface velocity observations. The results show that the reconstruction improves as the noise level in the observations decreases and that short-wavelength variations in the geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> are difficult to recover. We analyze the ill-posedness of the inverse problem as a function of the number of observations by examining the spectrum of the Hessian of the cost functional. Motivated by the popularity of operator-split or staggered solvers for forward multiphysics problems – i.e., those that drop two-way coupling terms to yield a one-way coupled forward Jacobian </p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016TCry...10.1477Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016TCry...10.1477Z"><span>Inversion of geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> in a thermomechanically coupled nonlinear Stokes ice sheet model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Hongyu; Petra, Noemi; Stadler, Georg; Isaac, Tobin; Hughes, Thomas J. R.; Ghattas, Omar</p> <p>2016-07-01</p> <p>We address the inverse problem of inferring the basal geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> from surface velocity observations using a steady-state thermomechanically coupled nonlinear Stokes ice flow model. This is a challenging inverse problem since the map from basal <span class="hlt">heat</span> <span class="hlt">flux</span> to surface velocity observables is indirect: the <span class="hlt">heat</span> <span class="hlt">flux</span> is a boundary condition for the thermal advection-diffusion equation, which couples to the nonlinear Stokes ice flow equations; together they determine the surface ice flow velocity. This multiphysics inverse problem is formulated as a nonlinear least-squares optimization problem with a cost functional that includes the data misfit between surface velocity observations and model predictions. A Tikhonov regularization term is added to render the problem well posed. We derive adjoint-based gradient and Hessian expressions for the resulting partial differential equation (PDE)-constrained optimization problem and propose an inexact Newton method for its solution. As a consequence of the Petrov-Galerkin discretization of the energy equation, we show that discretization and differentiation do not commute; that is, the order in which we discretize the cost functional and differentiate it affects the correctness of the gradient. Using two- and three-dimensional model problems, we study the prospects for and limitations of the inference of the geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> field from surface velocity observations. The results show that the reconstruction improves as the noise level in the observations decreases and that short-wavelength variations in the geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> are difficult to recover. We analyze the ill-posedness of the inverse problem as a function of the number of observations by examining the spectrum of the Hessian of the cost functional. Motivated by the popularity of operator-split or staggered solvers for forward multiphysics problems - i.e., those that drop two-way coupling terms to yield a one-way coupled forward Jacobian - we study the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1435724','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1435724"><span>Inversion of geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> in a thermomechanically coupled nonlinear Stokes ice sheet model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhu, Hongyu; Petra, Noemi; Stadler, Georg</p> <p></p> <p>We address the inverse problem of inferring the basal geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> from surface velocity observations using a steady-state thermomechanically coupled nonlinear Stokes ice flow model. This is a challenging inverse problem since the map from basal <span class="hlt">heat</span> <span class="hlt">flux</span> to surface velocity observables is indirect: the <span class="hlt">heat</span> <span class="hlt">flux</span> is a boundary condition for the thermal advection–diffusion equation, which couples to the nonlinear Stokes ice flow equations; together they determine the surface ice flow velocity. This multiphysics inverse problem is formulated as a nonlinear least-squares optimization problem with a cost functional that includes the data misfit between surface velocity observations andmore » model predictions. A Tikhonov regularization term is added to render the problem well posed. We derive adjoint-based gradient and Hessian expressions for the resulting partial differential equation (PDE)-constrained optimization problem and propose an inexact Newton method for its solution. As a consequence of the Petrov–Galerkin discretization of the energy equation, we show that discretization and differentiation do not commute; that is, the order in which we discretize the cost functional and differentiate it affects the correctness of the gradient. Using two- and three-dimensional model problems, we study the prospects for and limitations of the inference of the geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> field from surface velocity observations. The results show that the reconstruction improves as the noise level in the observations decreases and that short-wavelength variations in the geothermal <span class="hlt">heat</span> <span class="hlt">flux</span> are difficult to recover. We analyze the ill-posedness of the inverse problem as a function of the number of observations by examining the spectrum of the Hessian of the cost functional. Motivated by the popularity of operator-split or staggered solvers for forward multiphysics problems – i.e., those that drop two-way coupling terms to yield a one-way coupled forward Jacobian </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://www.dtic.mil/docs/citations/ADA584968','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA584968"><span>A Review of Boiling <span class="hlt">Heat</span> Transfer Processes at High <span class="hlt">Heat</span> <span class="hlt">Flux</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1991-04-01</p> <p>Hydrogen on Burnout for Water Flowing Vertically Upward in Round Tubes at 2000 psia," WAPD - TH-318, April 1957. 100. Doroschuck, V. E. and Lantsman, F. P...34Forced-Convection <span class="hlt">Heat</span> Transfer Burnout Studies for Water in Rectangular Channels and Round Tubes at Pressures above 500 psia," USAEC Rept. WAPD ...Volumes in Subcooled Boiling Systems, ASME Paper 58-HT-19, 1958. 264 . Core, T. C. and Sato, K., "Determination of Burnout Limits of Polyphenyl Coolants</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('http://adsabs.harvard.edu/abs/2017InJPh.tmp..314H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017InJPh.tmp..314H"><span>Convective <span class="hlt">heat</span> transfer for a gaseous slip flow in micropipe and parallel-plate microchannel with uniform wall <span class="hlt">heat</span> <span class="hlt">flux</span>: effect of axial <span class="hlt">heat</span> conduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haddout, Y.; Essaghir, E.; Oubarra, A.; Lahjomri, J.</p> <p>2017-12-01</p> <p>Thermally developing laminar slip flow through a micropipe and a parallel plate microchannel, with axial <span class="hlt">heat</span> conduction and uniform wall <span class="hlt">heat</span> <span class="hlt">flux</span>, is studied analytically by using a powerful method of self-adjoint formalism. This method results from a decomposition of the elliptic energy equation into a system of two first-order partial differential equations. The advantage of this method over other methods, resides in the fact that the decomposition procedure leads to a selfadjoint problem although the initial problem is apparently not a self-adjoint one. The solution is an extension of prior studies and considers a first order slip model boundary conditions at the fluid-wall interface. The analytical expressions for the developing temperature and local Nusselt number in the thermal entrance region are obtained in the general case. Therefore, the solution obtained could be extended easily to any hydrodynamically developed flow and arbitrary <span class="hlt">heat</span> <span class="hlt">flux</span> distribution. The analytical results obtained are compared for select simplified cases with available numerical calculations and they both agree. The results show that the <span class="hlt">heat</span> transfer characteristics of flow in the thermal entrance region are strongly influenced by the axial <span class="hlt">heat</span> conduction and rarefaction effects which are respectively characterized by Péclet and Knudsen numbers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018InJPh..92..741H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018InJPh..92..741H"><span>Convective <span class="hlt">heat</span> transfer for a gaseous slip flow in micropipe and parallel-plate microchannel with uniform wall <span class="hlt">heat</span> <span class="hlt">flux</span>: effect of axial <span class="hlt">heat</span> conduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haddout, Y.; Essaghir, E.; Oubarra, A.; Lahjomri, J.</p> <p>2018-06-01</p> <p>Thermally developing laminar slip flow through a micropipe and a parallel plate microchannel, with axial <span class="hlt">heat</span> conduction and uniform wall <span class="hlt">heat</span> <span class="hlt">flux</span>, is studied analytically by using a powerful method of self-adjoint formalism. This method results from a decomposition of the elliptic energy equation into a system of two first-order partial differential equations. The advantage of this method over other methods, resides in the fact that the decomposition procedure leads to a selfadjoint problem although the initial problem is apparently not a self-adjoint one. The solution is an extension of prior studies and considers a first order slip model boundary conditions at the fluid-wall interface. The analytical expressions for the developing temperature and local Nusselt number in the thermal entrance region are obtained in the general case. Therefore, the solution obtained could be extended easily to any hydrodynamically developed flow and arbitrary <span class="hlt">heat</span> <span class="hlt">flux</span> distribution. The analytical results obtained are compared for select simplified cases with available numerical calculations and they both agree. The results show that the <span class="hlt">heat</span> transfer characteristics of flow in the thermal entrance region are strongly influenced by the axial <span class="hlt">heat</span> conduction and rarefaction effects which are respectively characterized by Péclet and Knudsen numbers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21021096-impact-different-correlations-tracev4-predicted-critical-heat-flux','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21021096-impact-different-correlations-tracev4-predicted-critical-heat-flux"><span>Impact of Different Correlations on TRACEv4.160 Predicted Critical <span class="hlt">Heat</span> <span class="hlt">Flux</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jasiulevicius, A.; Macian-Juan, R.</p> <p>2006-07-01</p> <p>This paper presents an independent assessment of the Critical <span class="hlt">Heat</span> <span class="hlt">Flux</span> (CHF) models implemented in TRACEv4.160 with data from the experiments carried out at the Royal Institute of Technology (RIT) in Stockholm, Sweden, with single vertical uniformly <span class="hlt">heated</span> 7.0 m long tubes. In previous CHF assessment studies with TRACE, it was noted that, although the overall code predictions in long single tubes with inner diameters of 1.0 to 2.49 cm agreed rather well with the results of experiments (with r.m.s. error being 25.6%), several regions of pressure and coolant mass <span class="hlt">flux</span> could be identified, in which the code strongly under-predictsmore » or over-predicts the CHF. In order to evaluate the possibility of improving the code performance, some of the most widely used and assessed CHF correlations were additionally implemented in TRACEv4.160, namely Bowring, Levitan - Lantsman, and Tong-W3. The results obtained for the CHF predictions in single tubes with uniform axial <span class="hlt">heat</span> <span class="hlt">flux</span> by using these correlations, were compared to the results produced with the standard TRACE correlations (Biasi and CISE-GE), and with the experimental data from RIT, which covered a broad range of pressures (3-20 MPa) and coolant mass <span class="hlt">fluxes</span> (500-3000 kg/m{sup 2}s). Several hundreds of experimental points were calculated to cover the parameter range mentioned above for the evaluation of the newly implemented correlations in the TRACEv4.160 code. (author)« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcAau.129...95W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcAau.129...95W"><span>Experimental investigation on drag and <span class="hlt">heat</span> <span class="hlt">flux</span> reduction in supersonic/hypersonic flows: A survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Zhen-guo; Sun, Xi-wan; Huang, Wei; Li, Shi-bin; Yan, Li</p> <p>2016-12-01</p> <p>The drag and <span class="hlt">heat</span> reduction problem of hypersonic vehicles has always attracted the attention worldwide, and the experimental test approach is the basis of theoretical analysis and numerical simulation. In the current study, research progress of experimental investigations on drag and <span class="hlt">heat</span> reduction are summarized by several kinds of mechanism, namely the forward-facing cavity, the opposing jet, the aerospike, the energy deposition and their combinational configurations, and the combinational configurations include the combinational opposing jet and forward-facing cavity concept and the combinational opposing jet and aerospike concept. The geometric models and flow conditions are emphasized, especially for the basic principle for the drag and <span class="hlt">heat</span> <span class="hlt">flux</span> reduction of each device. The measurement results of aerodynamic and aerothermodynamic are compared and analyzed as well, which can be a reference for assessing the accuracy of numerical results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850048606&hterms=moisture+condensation&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmoisture%2Bcondensation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850048606&hterms=moisture+condensation&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmoisture%2Bcondensation"><span>Generalization of the quasi-geostrophic Eliassen-Palm <span class="hlt">flux</span> to include eddy forcing of condensation <span class="hlt">heating</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stone, P. H.; Salustri, G.</p> <p>1984-01-01</p> <p>A modified Eulerian form of the Eliassen-Palm <span class="hlt">flux</span> which includes the effect of eddy forcing on condensation <span class="hlt">heating</span> is defined. With the two-dimensional vector <span class="hlt">flux</span> in the meridional plane which is a function of the zonal mean eddy <span class="hlt">fluxes</span> replaced by the modified <span class="hlt">flux</span>, both the Eliassen-Palm theorem and a modified but more general form of the nonacceleration theorem for quasi-geostrophic motion still hold. Calculations of the divergence of the modified <span class="hlt">flux</span> and of the eddy forcing of the moisture field are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24465388','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24465388"><span>MHD boundary layer slip flow and <span class="hlt">heat</span> transfer of ferrofluid along a stretching cylinder with prescribed <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>Qasim, Muhammad; Khan, Zafar Hayat; Khan, Waqar Ahmad; Ali Shah, Inayat</p> <p>2014-01-01</p> <p>This study investigates the magnetohydrodynamic (MHD) flow of ferrofluid along a stretching cylinder. The velocity slip and prescribed surface <span class="hlt">heat</span> <span class="hlt">flux</span> boundary conditions are employed on the cylinder surface. Water as conventional base fluid containing nanoparticles of magnetite (Fe3O4) is used. Comparison between magnetic (Fe3O4) and non-magnetic (Al2O3) nanoparticles is also made. The governing non-linear partial differential equations are reduced to non-linear ordinary differential equations and then solved numerically using shooting method. Present results are compared with the available data in the limiting cases. The present results are found to be in an excellent agreement. It is observed that with an increase in the magnetic field strength, the percent difference in the <span class="hlt">heat</span> transfer rate of magnetic nanoparticles with Al2O3 decreases. Surface shear stress and the <span class="hlt">heat</span> transfer rate at the surface increase as the curvature parameter increases, i.e curvature helps to enhance the <span class="hlt">heat</span> transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JNuM..491...94P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JNuM..491...94P"><span>Experimental design and analysis for irradiation of SiC/SiC composite tubes under a prototypic high <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>Petrie, Christian M.; Koyanagi, Takaaki; McDuffee, Joel L.; Deck, Christian P.; Katoh, Yutai; Terrani, Kurt A.</p> <p>2017-08-01</p> <p>The purpose of this work is to design an irradiation vehicle for testing silicon carbide (SiC) fiber-reinforced SiC matrix composite cladding materials under conditions representative of a light water reactor in order to validate thermo-mechanical models of stress states in these materials due to irradiation swelling and differential thermal expansion. The design allows for a constant tube outer surface temperature in the range of 300-350 °C under a representative high <span class="hlt">heat</span> <span class="hlt">flux</span> (∼0.66 MW/m2) during one cycle of irradiation in an un-instrumented ;rabbit; capsule in the High <span class="hlt">Flux</span> Isotope Reactor. An engineered aluminum foil was developed to <span class="hlt">absorb</span> the expansion of the cladding tubes, due to irradiation swelling, without changing the thermal resistance of the gap between the cladding and irradiation capsule. Finite-element analyses of the capsule were performed, and the models used to calculate thermal contact resistance were validated by out-of-pile testing and post-irradiation examination of the foils and passive SiC thermometry. Six irradiated cladding tubes (both monoliths and composites) were irradiated and subsequently disassembled in a hot cell. The calculated temperatures of passive SiC thermometry inside the capsules showed good agreement with temperatures measured post-irradiation, with two calculated temperatures falling within 10 °C of experimental measurements. The success of this design could lead to new opportunities for irradiation applications with materials that suffer from irradiation swelling, creep, or other dimensional changes that can affect the specimen temperature during irradiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1356893-experimental-design-analysis-irradiation-sic-sic-composite-tubes-under-prototypic-high-heat-flux','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1356893-experimental-design-analysis-irradiation-sic-sic-composite-tubes-under-prototypic-high-heat-flux"><span>Experimental design and analysis for irradiation of SiC/SiC composite tubes under a prototypic high <span class="hlt">heat</span> <span class="hlt">flux</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Petrie, Christian M.; Koyanagi, Takaaki; McDuffee, Joel L.</p> <p></p> <p>The purpose of this work is to design an irradiation vehicle for testing silicon carbide (SiC) fiber-reinforced SiC matrix composite cladding materials under conditions representative of a light water reactor in order to validate thermo-mechanical models of stress states in these materials due to irradiation swelling and differential thermal expansion. The design allows for a constant tube outer surface temperature in the range of 300–350 °C under a representative high <span class="hlt">heat</span> <span class="hlt">flux</span> (~0.66 MW/m 2) during one cycle of irradiation in an un-instrumented “rabbit” capsule in the High <span class="hlt">Flux</span> Isotope Reactor. An engineered aluminum foil was developed to <span class="hlt">absorb</span> themore » expansion of the cladding tubes, due to irradiation swelling, without changing the thermal resistance of the gap between the cladding and irradiation capsule. Finite-element analyses of the capsule were performed, and the models used to calculate thermal contact resistance were validated by out-of-pile testing and post-irradiation examination of the foils and passive SiC thermometry. Six irradiated cladding tubes (both monoliths and composites) were irradiated and subsequently disassembled in a hot cell. The calculated temperatures of passive SiC thermometry inside the capsules showed good agreement with temperatures measured post-irradiation, with two calculated temperatures falling within 10 °C of experimental measurements. Furthermore, the success of this design could lead to new opportunities for irradiation applications with materials that suffer from irradiation swelling, creep, or other dimensional changes that can affect the specimen temperature during irradiation.« less</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('http://adsabs.harvard.edu/abs/2015EGUGA..1710493D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1710493D"><span>Comparing convective <span class="hlt">heat</span> <span class="hlt">fluxes</span> derived from thermodynamics to a radiative-convective model and GCMs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dhara, Chirag; Renner, Maik; Kleidon, Axel</p> <p>2015-04-01</p> <p>The convective transport of <span class="hlt">heat</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> as the result of a <span class="hlt">heat</span> engine. We combine the well-known Carnot limit of this <span class="hlt">heat</span> engine with the energy balances of the surface-atmosphere system that describe how the temperature difference is affected by convective <span class="hlt">heat</span> 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 <span class="hlt">heat</span> <span class="hlt">fluxes</span> 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.</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, radiative, 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