Comparison of gamma densitometry and electrical capacitance measurements applied to hold-up prediction of oil–water flow patterns in horizontal and slightly inclined pipes

NASA Astrophysics Data System (ADS)

Perera, Kshanthi; Kumara, W. A. S.; Hansen, Fredrik; Mylvaganam, Saba; Time, Rune W.

2018-06-01

Measurement techniques are vital for the control and operation of multiphase oil–water flow in pipes. The development of such techniques depends on laboratory experiments involving flow visualization, liquid fraction (‘hold-up’), phase slip and pressure drop measurements. They provide valuable information by revealing the physics, spatial and temporal structures of complex multiphase flow phenomena. This paper presents the hold-up measurement of oil–water flow in pipelines using gamma densitometry and electrical capacitance tomography (ECT) sensors. The experiments were carried out with different pipe inclinations from  ‑5° to  +6° for selected mixture velocities (0.2–1.5 m s‑1), and at selected watercuts (0.05–0.95). Mineral oil (Exxsol D60) and water were used as test fluids. Nine flow patterns were identified including a new pattern called stratified wavy and mixed interface flow. As a third direct method, visual observations and high-speed videos were used for the flow regime and interface identification. ECT and gamma densitometry hold-up measurements show similar trends for changes in pipeline inclinations. Changing the pipe inclination affected the flow mostly at lower mixture velocities and caused a change of flow patterns, allowing the highest change of hold-up. ECT hold-up measurements overpredict the gamma densitometry measurements at higher input water cuts and underpredict at intermediate water cuts. Gamma hold-up results showed good agreement with the literature results, having a maximum deviation of 6%, while it was as high as 22% for ECT in comparison to gamma densitometry. Uncertainty analysis of the measurement techniques was carried out with single-phase oil flow. This shows that the measurement error associated with gamma densitometry is approximately 3.2%, which includes 1.3% statistical error and 2.9% error identified as electromagnetically induced noise in electronics. Thus, gamma densitometry can predict hold-up with a higher accuracy in comparison to ECT when applied to oil–water systems at minimized electromagnetic noise.

Carbonate Mineral Assemblages as Inclusions in Yakutian Diamonds: TEM Verifications

NASA Astrophysics Data System (ADS)

Logvinova, A. M.; Wirth, R.; Sobolev, N. V.; Taylor, L. A.

2014-12-01

Carbonate mineral inclusions are quite rare in diamonds from the upper mantle, but are evidence for a carbonate abundance in the mantle. It is believed that such carbonatitic inclusions originated from high-density fluids (HDFs) that were enclosed in diamond during its growth. Using TEM and EPMA, several kinds of carbonate inclusions have been identified in Yakutian diamonds : aragonite, dolomite, magnesite, Ba-, Sr-, and Fe-rich carbonates. Most of them are represented by multi-phase inclusions of various chemically distinct carbonates, rich in Ca, Mg, and K and associated with minor amounts of silicate, oxide, saline, and volatile phases. Volatiles, leaving some porosity, played a significant role in the diamond growth. A single crystal of aragonite (60μm) is herein reported for the first time. This inclusion is located in the center of a diamond from the Komsomolskaya pipe. Careful CL imaging reveals the total absence of cracks around the aragonite inclusion - i.e., closed system. This inclusion has been identified by X-ray diffraction and microprobe analysis. At temperatures above 1000 0C, aragonite is only stable at high pressures of 5-6 GPa. Inside this aragonite, we observed nanocrystalline inclusions of titanite, Ni-rich sulfide, magnetite, water-bearing Mg-silicate, and fluid bubbles. Dolomite is common in carbonate multi-phase inclusions in diamonds from the Internatsionalnaya, Yubileinaya, and Udachnaya kimberlite pipes. Alluvial diamonds of the northeastern Siberian Platform are divided into two groups based on the composition of HDFs: 1) Mg-rich multi-phase inclusions (60% magnesite + dolomite + Fe-spinel + Ti-silicate + fluid bubbles); and 2) Ca-rich multi-phase inclusions (Ca,Ba-, Ca,Sr-, Ca,Fe-carbonates + Ti-silicate + Ba-apatite + fluid bubbles). High-density fluids also contain K. Volatiles in the fluid bubbles are represented by water, Cl, F, S, CO2, CH4, and heavy hydrocarbons. Origin of the second group of HDFs may be related to the non-silicate carbonatitic melt. We consider the primary hydrous, Сa-rich and Mg-poor carbonate melts as having formed in subducted oceanic crust. Variations of carbonate-inclusion compositions among diamonds indicate the variability in the source media during the formation of diamond and may be the result of metasomatic interaction with host rocks.

Oil-Water Flow Investigations using Planar-Laser Induced Fluorescence and Particle Velocimetry

NASA Astrophysics Data System (ADS)

Ibarra, Roberto; Matar, Omar K.; Markides, Christos N.

2017-11-01

The study of the complex behaviour of immiscible liquid-liquid flow in pipes requires the implementation of advanced measurement techniques in order to extract detailed in situ information. Laser-based diagnostic techniques allow the extraction of high-resolution space- and time resolve phase and velocity information, which aims to improve the fundamental understanding of these flows and to validate closure relations for advanced multiphase flow models. This work shows a novel simultaneous planar-laser induced fluorescence and particle velocimetry in stratified oil-water flows using two laser light sheets at two different wavelengths for fluids with different refractive indices at horizontal and upward pipe inclinations (<5°) in stratified flow conditions (i.e. separated layers). Complex flow structures are extracted from 2-D instantaneous velocity fields, which are strongly dependent on the pipe inclination at low velocities. The analysis of mean wall-normal velocity profiles and velocity fluctuations suggests the presence of single- and counter-rotating vortices in the azimuthal direction, especially in the oil layer, which can be attributed to the influence of the interfacial waves. Funding from BP, and the TMF Consortium is gratefully acknowledged.

Mathematical Simulation of Drying Process of Fibrous Material

NASA Astrophysics Data System (ADS)

Blejchař, Tomáš; Raška, Jiří; Jablonská, Jana

2018-06-01

The article describes mathematical simulation of flowing air through porous zone and water vaporisation from mentioned porous area which actually represents dried fibrous material - cotton towel. Simulation is based on finite volume method. Wet towel is placed in pipe and hot air flow through the towel. Water from towel is evaporated. Simulation of airflow through porous element is described first. Eulerian multiphase model is then used for simulation of water vaporisation from porous medium. Results of simulation are compared with experiment. Ansys Fluent 13.0 was used for calculation.

Theoretical and computational analyses of LNG evaporator

NASA Astrophysics Data System (ADS)

Chidambaram, Palani Kumar; Jo, Yang Myung; Kim, Heuy Dong

2017-04-01

Theoretical and numerical analysis on the fluid flow and heat transfer inside a LNG evaporator is conducted in this work. Methane is used instead of LNG as the operating fluid. This is because; methane constitutes over 80% of natural gas. The analytical calculations are performed using simple mass and energy balance equations. The analytical calculations are made to assess the pressure and temperature variations in the steam tube. Multiphase numerical simulations are performed by solving the governing equations (basic flow equations of continuity, momentum and energy equations) in a portion of the evaporator domain consisting of a single steam pipe. The flow equations are solved along with equations of species transport. Multiphase modeling is incorporated using VOF method. Liquid methane is the primary phase. It vaporizes into the secondary phase gaseous methane. Steam is another secondary phase which flows through the heating coils. Turbulence is modeled by a two equation turbulence model. Both the theoretical and numerical predictions are seen to match well with each other. Further parametric studies are planned based on the current research.

Numerical Simulations of Instabilities in Single-Hole Office Elements

NASA Technical Reports Server (NTRS)

Ahuja, Vineet; Hosangadi, Ashvin; Hitt, Matthew A.; Lineberry, David M.

2013-01-01

An orifice element is commonly used in liquid rocket engine test facilities either as a flow metering device, a damper for acoustic resonance or to provide a large reduction in pressure over a very small distance in the piping system. While the orifice as a device is largely effective in stepping down pressure, it is also susceptible to a wake-vortex type instability that generates pressure fluctuations that propagate downstream and interact with other elements of the test facility resulting in structural vibrations. Furthermore in piping systems an unstable feedback loop can exist between the vortex shedding and acoustic perturbations from upstream components resulting in an amplification of the modes convecting downstream. Such was the case in several tests conducted at NASA as well as in the Ariane 5 strap-on P230 engine in a static firing test where pressure oscillations of 0.5% resulted in 5% thrust oscillations. Exacerbating the situation in cryogenic test facilities, is the possibility of the formation of vapor clouds when the pressure in the wake falls below the vapor pressure leading to a cavitation instability that has a lower frequency than the primary wake-vortex instability. The cavitation instability has the potential for high amplitude fluctuations that can cause catastrophic damage in the facility. In this paper high-fidelity multi-phase numerical simulations of an orifice element are used to characterize the different instabilities, understand the dominant instability mechanisms and identify the tonal content of the instabilities.

Imaging water velocity and volume fraction distributions in water continuous multiphase flows using inductive flow tomography and electrical resistance tomography

NASA Astrophysics Data System (ADS)

Meng, Yiqing; Lucas, Gary P.

2017-05-01

This paper presents the design and implementation of an inductive flow tomography (IFT) system, employing a multi-electrode electromagnetic flow meter (EMFM) and novel reconstruction techniques, for measuring the local water velocity distribution in water continuous single and multiphase flows. A series of experiments were carried out in vertical-upward and upward-inclined single phase water flows and ‘water continuous’ gas-water and oil-gas-water flows in which the velocity profiles ranged from axisymmetric (single phase and vertical-upward multiphase flows) to highly asymmetric (upward-inclined multiphase flows). Using potential difference measurements obtained from the electrode array of the EMFM, local axial velocity distributions of the continuous water phase were reconstructed using two different IFT reconstruction algorithms denoted RT#1, which assumes that the overall water velocity profile comprises the sum of a series of polynomial velocity components, and RT#2, which is similar to RT#1 but which assumes that the zero’th order velocity component may be replaced by an axisymmetric ‘power law’ velocity distribution. During each experiment, measurement of the local water volume fraction distribution was also made using the well-established technique of electrical resistance tomography (ERT). By integrating the product of the local axial water velocity and the local water volume fraction in the cross section an estimate of the water volumetric flow rate was made which was compared with a reference measurement of the water volumetric flow rate. In vertical upward flows RT#2 was found to give rise to water velocity profiles which are consistent with the previous literature although the profiles obtained in the multiphase flows had relatively higher central velocity peaks than was observed for the single phase profiles. This observation was almost certainly a result of the transfer of axial momentum from the less dense dispersed phases to the water, which occurred preferentially at the pipe centre. For upward inclined multiphase flows RT#1 was found to give rise to water velocity profiles which are more consistent with results in the previous literature than was the case for RT#2—which leads to the tentative conclusion that the upward inclined multiphase flows investigated in the present study did not contain significant axisymmetric velocity components.

Multiphase boudinage: a case study of amphibolites in marble in the Naxos migmatite core

NASA Astrophysics Data System (ADS)

Virgo, Simon; von Hagke, Christoph; Urai, Janos L.

2018-02-01

In multiply deformed terrains multiphase boudinage is common, but identification and analysis of these is difficult. Here we present an analysis of multiphase boudinage and fold structures in deformed amphibolite layers in marble from the migmatitic centre of the Naxos metamorphic core complex. Overprinting between multiple boudinage generations is shown in exceptional 3-D outcrop. We identify five generations of boudinage, reflecting the transition from high-strain high-temperature ductile deformation to medium- to low-strain brittle boudins formed during cooling and exhumation. All boudin generations indicate E-W horizontal shortening and variable direction of bedding parallel extension, evolving from subvertical extension in the earliest boudins to subhorizontal N-S extension during exhumation. Two phases of E-W shortening can be inferred, the first associated with lower crustal synmigmatic convergent flow and the second associated with exhumation and N-S extension, possibly related to movement of the North Anatolian Fault.

Heat Pipe Materials Compatibility

NASA Technical Reports Server (NTRS)

Eninger, J. E.; Fleischman, G. L.; Luedke, E. E.

1976-01-01

An experimental program to evaluate noncondensable gas generation in ammonia heat pipes was completed. A total of 37 heat pipes made of aluminum, stainless steel and combinations of these materials were processed by various techniques, operated at different temperatures and tested at low temperature to quantitatively determine gas generation rates. In order of increasing stability are aluminum/stainless combination, all aluminum and all stainless heat pipes. One interesting result is the identification of intentionally introduced water in the ammonia during a reflux step as a means of surface passivation to reduce gas generation in stainless-steel/aluminum heat pipes.

Online recognition of the multiphase flow regime and study of slug flow in pipeline

NASA Astrophysics Data System (ADS)

Liejin, Guo; Bofeng, Bai; Liang, Zhao; Xin, Wang; Hanyang, Gu

2009-02-01

Multiphase flow is the phenomenon existing widely in nature, daily life, as well as petroleum and chemical engineering industrial fields. The interface structure among multiphase and their movement are complicated, which distribute random and heterogeneously in the spatial and temporal scales and have multivalue of the flow structure and state[1]. Flow regime is defined as the macro feature about the multiphase interface structure and its distribution, which is an important feature to describe multiphase flow. The energy and mass transport mechanism differ much for each flow regimes. It is necessary to solve the flow regime recognition to get a clear understanding of the physical phenomena and their mechanism of multiphase flow. And the flow regime is one of the main factors affecting the online measurement accuracy of phase fraction, flow rate and other phase parameters. Therefore, it is of great scientific and technological importance to develop new principles and methods of multiphase flow regime online recognition, and of great industrial background. In this paper, the key reasons that the present method cannot be used to solve the industrial multiphase flow pattern recognition are clarified firstly. Then the prerequisite to realize the online recognition of multiphase flow regime is analyzed, and the recognition rules for partial flow pattern are obtained based on the massive experimental data. The standard templates for every flow regime feature are calculated with self-organization cluster algorithm. The multi-sensor data fusion method is proposed to realize the online recognition of multiphase flow regime with the pressure and differential pressure signals, which overcomes the severe influence of fluid flow velocity and the oil fraction on the recognition. The online recognition method is tested in the practice, which has less than 10 percent measurement error. The method takes advantages of high confidence, good fault tolerance and less requirement of single sensor performance. Among various flow patterns of gas-liquid flow, slug flow occurs frequently in the petroleum, chemical, civil and nuclear industries. In the offshore oil and gas field, the maximum slug length and its statistical distribution are very important for the design of separator and downstream processing facility at steady state operations. However transient conditions may be encountered in the production, such as operational upsets, start-up, shut-down, pigging and blowdown, which are key operational and safety issues related to oil field development. So it is necessary to have an understanding the flow parameters under transient conditions. In this paper, the evolution of slug length along a horizontal pipe in gas-liquid flow is also studied in details and then an experimental study of flowrate transients in slug flow is provided. Also, the special gas-liquid flow phenomena easily encountered in the life span of offshore oil fields, called severe slugging, is studied experimentally and some results are presented.

Flow pattern changes influenced by variation of viscosities of a heterogeneous gas-liquid mixture flow in a vertical channel

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

Keska, Jerry K.; Hincapie, Juan; Jones, Richard

In the steady-state flow of a heterogeneous mixture such as an air-liquid mixture, the velocity and void fraction are space- and time-dependent parameters. These parameters are the most fundamental in the analysis and description of a multiphase flow. The determination of flow patterns in an objective way is extremely critical, since this is directly related to sudden changes in spatial and temporal changes of the random like characteristic of concentration. Flow patterns can be described by concentration signals in time, amplitude, and frequency domains. Despite the vital importance and countless attempts to solve or incorporate the flow pattern phenomena intomore » multiphase models, it has still been a very challenging topic in the scientific community since the 1940's and has not yet reached a satisfactory solution. This paper reports the experimental results of the impact of fluid viscosity on flow patterns for two-phase flow. Two-phase flow was created in laboratory equipment using air and liquid as phase medium. The liquid properties were changed by using variable concentrations of glycerol in water mixture which generated a wide-range of dynamic viscosities ranging from 1 to 1060 MPa s. The in situ spatial concentration vs. liquid viscosity and airflow velocity of two-phase flow in a vertical ID=50.8 mm pipe were measured using two concomitant computer-aided measurement systems. After acquiring data, the in situ special concentration signals were analyzed in time (spatial concentration and RMS of spatial concentration vs. time), amplitude (PDF and CPDF), and frequency (PSD and CPSD) domains that documented broad flow pattern changes caused by the fluid viscosity and air velocity changes. (author)« less

Study of high viscous multiphase phase flow in a horizontal pipe

NASA Astrophysics Data System (ADS)

Baba, Yahaya D.; Aliyu, Aliyu M.; Archibong, Archibong-Eso; Almabrok, Almabrok A.; Igbafe, A. I.

2018-03-01

Heavy oil accounts for a major portion of the world's total oil reserves. Its production and transportation through pipelines is beset with great challenges due to its highly viscous nature. This paper studies the effects of high viscosity on heavy oil two-phase flow characteristics such as pressure gradient, liquid holdup, slug liquid holdup, slug frequency and slug liquid holdup using an advanced instrumentation (i.e. Electrical Capacitance Tomography). Experiments were conducted in a horizontal flow loop with a pipe internal diameter (ID) of 0.0762 m; larger than most reported in the open literature for heavy oil flow. Mineral oil of 1.0-5.0 Pa.s viscosity range and compressed air were used as the liquid and gas phases respectively. Pressure gradient (measured by means differential pressure transducers) and mean liquid holdup was observed to increase as viscosity of oil is increased. Obtained results also revealed that increase in liquid viscosity has significant effects on flow pattern and slug flow features.

CFD simulation of gas and non-Newtonian fluid two-phase flow in anaerobic digesters.

PubMed

Wu, Binxin

2010-07-01

This paper presents an Eulerian multiphase flow model that characterizes gas mixing in anaerobic digesters. In the model development, liquid manure is assumed to be water or a non-Newtonian fluid that is dependent on total solids (TS) concentration. To establish the appropriate models for different TS levels, twelve turbulence models are evaluated by comparing the frictional pressure drops of gas and non-Newtonian fluid two-phase flow in a horizontal pipe obtained from computational fluid dynamics (CFD) with those from a correlation analysis. The commercial CFD software, Fluent12.0, is employed to simulate the multiphase flow in the digesters. The simulation results in a small-sized digester are validated against the experimental data from literature. Comparison of two gas mixing designs in a medium-sized digester demonstrates that mixing intensity is insensitive to the TS in confined gas mixing, whereas there are significant decreases with increases of TS in unconfined gas mixing. Moreover, comparison of three mixing methods indicates that gas mixing is more efficient than mixing by pumped circulation while it is less efficient than mechanical mixing.

Radiation detector system having heat pipe based cooling

DOEpatents

Iwanczyk, Jan S.; Saveliev, Valeri D.; Barkan, Shaul

2006-10-31

A radiation detector system having a heat pipe based cooling. The radiation detector system includes a radiation detector thermally coupled to a thermo electric cooler (TEC). The TEC cools down the radiation detector, whereby heat is generated by the TEC. A heat removal device dissipates the heat generated by the TEC to surrounding environment. A heat pipe has a first end thermally coupled to the TEC to receive the heat generated by the TEC, and a second end thermally coupled to the heat removal device. The heat pipe transfers the heat generated by the TEC from the first end to the second end to be removed by the heat removal device.

Coiled Tube Gas Heaters For Nuclear Gas-Brayton Power Conversion

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

Peterson, Per F.

This project developed an alternative design for heat exchangers for application to heating supercritical carbon dioxide (S-CO 2) or air for power conversion. We have identified an annular coiled tube bundle configuration–where hot sodium enters tubes from multiple vertical inlet manifold pipes, flows in a spiral pattern radially inward and downward, and then exits into an equal number of vertical outlet manifold pipes–as a potentially attractive option. The S-CO 2 gas or air flows radially outward through the tube bundle. Coiled tube gas heaters (CTGHs) are expected to have excellent thermal shock, long-term thermal creep, in-service inspection, and reparability characteristics,more » compared to alternative options. CTGHs have significant commonality with modern nuclear steam generators. Extensive experience exists with the design, manufacture, operation, in-service inspection and maintenance of nuclear steam generators. The U.S. Nuclear Regulatory Commission also has extensive experience with regulatory guidance documented in NUREG 0800. CTGHs leverage this experience and manufacturing capability. The most important difference between steam generators and gas-Brayton cycles such as the S-CO 2 cycle is that the heat exchangers must operate with counter flow with high effectiveness to minimize the pinch-point temperature difference between the hot liquid coolant and the heated gas. S-CO 2-cycle gas heaters also operate at sufficiently elevated temperatures that time dependent creep is important and allowable stresses are relatively low. Designing heat exchangers to operate in this regime requires configurations that minimize stresses and stress concentrations. The cylindrical tubes and cylindrical manifold pipes used in CTGHs are particularly effective geometries. The first major goal of this research project was to develop and experimentally validate a detailed, 3-D multi-phase (gas-solid-liquid) heat transport model for CTGHs, using methods similar to earlier UCB multi-scale models for PCHEs, which will enable optimization of CTGH designs with respect to the number of manifold pipes, S-CO 2 and sodium circulating power, and other design parameters. CTGHs are relatively novel because the tubes loaded in compression as well as the manifold pipes which form the tube sheets. The second major goal of the experimental and modeling effort was to optimize the assembly and heat treatment of the tube-to-tubesheet joints, using a novel tapered joint configuration, and to develop diffusion-bonded joints with high shear strength and creep resistance, as has been done in other applications for tapered plugs. The project would also conduct creep testing of these tubesheet joints in pressurized furnaces under prototypical conditions of stress and temperature, however this was not feasible due to numerous hinderances. Detailed microstructural investigations was conducted on the diffusion bond interface, while the bond strength was evaluated by tensile testing. The mechanical testing quantified the overall strength of the bond and measured the pull out force as well as long term behavior, which complemented the microstructural analysis and gave a complete understanding of the diffusion bond.« less

Discussion on the solar concentrating thermoelectric generation using micro-channel heat pipe array

NASA Astrophysics Data System (ADS)

Li, Guiqiang; Feng, Wei; Jin, Yi; Chen, Xiao; Ji, Jie

2017-11-01

Heat pipe is a high efficient tool in solar energy applications. In this paper, a novel solar concentrating thermoelectric generation using micro-channel heat pipe array (STEG-MCHP) was presented. The flat-plate micro-channel heat pipe array not only has a higher heat transfer performance than the common heat pipe, but also can be placed on the surface of TEG closely, which can further reduce the thermal resistance between the heat pipe and the TEG. A preliminary comparison experiment was also conducted to indicate the advantages of the STEG-MCHP. The optimization based on the model verified by the experiment was demonstrated, and the concentration ratio and selective absorbing coating area were also discussed. In addition, the cost analysis was also performed to compare between the STEG-MCHP and the common solar concentrating TEGs in series. The outcome showed that the solar concentrating thermoelectric generation using micro-channel heat pipe array has the higher electrical efficiency and lower cost, which may provide a suitable way for solar TEG applications.

Locating hot and cold-legs in a nuclear powered steam generation system

DOEpatents

Ekeroth, D.E.; Corletti, M.M.

1993-11-16

A nuclear reactor steam generator includes a reactor vessel for heating water and a steam generator with a pump casing at the lowest point on the steam generator. A cold-leg pipe extends horizontally between the steam generator and the reactor vessel to return water from the steam generator to the reactor vessel. The bottom of the cold-leg pipe is at a first height above the bottom of the reactor vessel. A hot-leg pipe with one end connected to the steam generator and a second end connected to the reactor vessel has a first pipe region extending downwardly from the steam generator to a location between the steam generator and the reactor vessel at which a bottom of the hot-leg pipe is at a second height above the bottom of the reactor vessel. A second region extends from that location in a horizontal direction at the second height to the point at which the hot-leg pipe connects to the reactor vessel. A pump is attached to the casing at a location below the first and second heights and returns water from the steam generator to the reactor vessel over the cold-leg. The first height is greater than the second height and the bottom of the steam generator is at a height above the bottom of the reactor vessel that is greater than the first and second heights. A residual heat recovery pump is below the hot-leg and has an inlet line from the hot-leg that slopes down continuously to the pump inlet. 2 figures.

Locating hot and cold-legs in a nuclear powered steam generation system

DOEpatents

Ekeroth, Douglas E.; Corletti, Michael M.

1993-01-01

A nuclear reactor steam generator includes a reactor vessel for heating water and a steam generator with a pump casing at the lowest point on the steam generator. A cold-leg pipe extends horizontally between the steam generator and the reactor vessel to return water from the steam generator to the reactor vessel. The bottom of the cold-leg pipe is at a first height above the bottom of the reactor vessel. A hot-leg pipe with one end connected to the steam generator and a second end connected to the reactor vessel has a first pipe region extending downwardly from the steam generator to a location between the steam generator and the reactor vessel at which a bottom of the hot-leg pipe is at a second height above the bottom of the reactor vessel. A second region extends from that location in a horizontal direction at the second height to the point at which the hot-leg pipe connects to the reactor vessel. A pump is attached to the casing at a location below the first and second heights and returns water from the steam generator to the reactor vessel over the cold-leg. The first height is greater than the second height and the bottom of the steam generator is at a height above the bottom of the reactor vessel that is greater than the first and second heights. A residual heat recovery pump is below the hot-leg and has an inlet line from the hot-leg that slopes down continuously to the pump inlet.

Light as a key driver of freshwater biofouling surface roughness in an experimental hydrocanal pipe rig.

PubMed

Ravizza, Matilde; Giosio, Dean; Henderson, Alan; Hovenden, Mark; Hudson, Monica; Salleh, Sazlina; Sargison, Jane; Shaw, Jennifer L; Walker, Jessica; Hallegraeff, Gustaaf

2016-07-01

Biofouling in canals and pipelines used for hydroelectric power generation decreases the flow capacity of conduits. A pipeline rig was designed consisting of test sections of varying substrata (PVC, painted steel) and light levels (transparent, frosted, opaque). Stalk-forming diatoms were abundant in both the frosted and transparent PVC pipes but negligible in the painted steel and opaque PVC pipes. Fungi were slightly more abundant in the painted steel pipe but equally present in all the other pipes while bacterial diversity was similar in all pipes. Photosynthetically functional biofouling (mainly diatoms) was able to develop in near darkness. Different biological fouling compositions generated differing friction factors. The highest friction factor was observed in the transparent pipe (densest diatom fouling), the lowest peak friction for the opaque PVC pipe (lowest fouling biomass), and with the painted steel pipe (high fouling biomass, but composed of fungal and bacterial crusts) being intermediate between the opaque and frosted PVC pipes.

Generation of Turbulent Inflow Conditions for Pipe Flow via an Annular Ribbed Turbulator

NASA Astrophysics Data System (ADS)

Moallemi, Nima; Brinkerhoff, Joshua

2016-11-01

The generation of turbulent inflow conditions adds significant computational expense to direct numerical simulations (DNS) of turbulent pipe flows. Typical approaches involve introducing boxes of isotropic turbulence to the velocity field at the inlet of the pipe. In the present study, an alternative method is proposed that incurs a lower computational cost and allows the anisotropy observed in pipe turbulence to be physically captured. The method is based on a periodic DNS of a ribbed turbulator upstream of the inlet boundary of the pipe. The Reynolds number based on the bulk velocity and pipe diameter is 5300 and the blockage ratio (BR) is 0.06 based on the rib height and pipe diameter. The pitch ratio is defined as the ratio of rib streamwise spacing to rib height and is varied between 1.7 and 5.0. The generation of turbulent flow structures downstream of the ribbed turbulator are identified and discussed. Suitability of this method for accurate representation of turbulent inflow conditions is assessed through comparison of the turbulent mean properties, fluctuations, Reynolds stress profiles, and spectra with published pipe flow DNS studies. The DNS results achieve excellent agreement with the numerical and experimental data available in the literature.

Parallelization of Catalytic Packed-Bed Microchannels with Pressure-Drop Microstructures for Gas-Liquid Multiphase Reactions

NASA Astrophysics Data System (ADS)

Murakami, Sunao; Ohtaki, Kenichiro; Matsumoto, Sohei; Inoue, Tomoya

2012-06-01

High-throughput and stable treatments are required to achieve the practical production of chemicals with microreactors. However, the flow maldistribution to the paralleled microchannels has been a critical problem in achieving the productive use of multichannel microreactors for multiphase flow conditions. In this study, we newly designed and fabricated a glass four-channel catalytic packed-bed microreactor for the scale-up of gas-liquid multiphase chemical reactions. We embedded microstructures generating high pressure losses at the upstream side of each packed bed, and experimentally confirmed the efficacy of the microstructures in decreasing the maldistribution of the gas-liquid flow to the parallel microchannels.

The small community solar thermal power experiment. Parabolic dish technology for industrial process heat application

NASA Technical Reports Server (NTRS)

Polzien, R. E.; Rodriguez, D.

1981-01-01

Aspects of incorporating a thermal energy transport system (ETS) into a field of parabolic dish collectors for industrial process heat (IPH) applications were investigated. Specific objectives are to: (1) verify the mathematical optimization of pipe diameters and insulation thicknesses calculated by a computer code; (2) verify the cost model for pipe network costs using conventional pipe network construction; (3) develop a design and the associated production costs for incorporating risers and downcomers on a low cost concentrator (LCC); (4) investigate the cost reduction of using unconventional pipe construction technology. The pipe network design and costs for a particular IPH application, specifically solar thermally enhanced oil recovery (STEOR) are analyzed. The application involves the hybrid operation of a solar powered steam generator in conjunction with a steam generator using fossil fuels to generate STEOR steam for wells. It is concluded that the STEOR application provides a baseline pipe network geometry used for optimization studies of pipe diameter and insulation thickness, and for development of comparative cost data, and operating parameters for the design of riser/downcomer modifications to the low cost concentrator.

Multiphase computer-generated holograms for full-color image generation

NASA Astrophysics Data System (ADS)

Choi, Kyong S.; Choi, Byong S.; Choi, Yoon S.; Kim, Sun I.; Kim, Jong Man; Kim, Nam; Gil, Sang K.

2002-06-01

Multi-phase and binary-phase computer-generated holograms were designed and demonstrated for full-color image generation. Optimize a phase profile of the hologram that achieves each color image, we employed a simulated annealing method. The design binary phase hologram had the diffraction efficiency of 33.23 percent and the reconstruction error of 0.367 X 10-2. And eight phase hologram had the diffraction efficiency of 67.92 percent and the reconstruction error of 0.273 X 10-2. The designed BPH was fabricated by micro photolithographic technique with a minimum pixel width of 5micrometers . And the it was reconstructed using by two Ar-ion lasers and a He-Ne laser. In addition, the color dispersion characteristic of the fabricate grating and scaling problem of the reconstructed image were discussed.

Project Themis: PIV Measurement of Elbow Flow through a Flow Conditioner

DTIC Science & Technology

2011-12-01

validation of the component. CFD simulations, using LH2 , showed that the pipe with a VORTAB generated more vorticity at the exit than the pipe without a...using LH2 , showed that the pipe with a Vortab generated more vorticity at the exit than the pipe without a Vortab. PA#11932 4 Particle Image...number Fluid Vortab location Comment 9,000,000 LH2 9D USET installation 32,000 Air 9D For Validation Additional details • Fluent • k-ε

Unraveling the Geometry Dependence of In-Nozzle Cavitation in High-Pressure Injectors

PubMed Central

Im, Kyoung-Su; Cheong, Seong-Kyun; Powell, Christopher F.; Lai, Ming-chia D.; Wang, Jin

2013-01-01

Cavitation is an intricate multiphase phenomenon that interplays with turbulence in fluid flows. It exhibits clear duality in characteristics, being both destructive and beneficial in our daily lives and industrial processes. Despite the multitude of occurrences of this phenomenon, highly dynamic and multiphase cavitating flows have not been fundamentally well understood in guiding the effort to harness the transient and localized power generated by this process. In a microscale, multiphase flow liquid injection system, we synergistically combined experiments using time-resolved x-radiography and a novel simulation method to reveal the relationship between the injector geometry and the in-nozzle cavitation quantitatively. We demonstrate that a slight alteration of the geometry on the micrometer scale can induce distinct laminar-like or cavitating flows, validating the multiphase computational fluid dynamics simulation. Furthermore, the simulation identifies a critical geometric parameter with which the high-speed flow undergoes an intriguing transition from non-cavitating to cavitating. PMID:23797665

Design and Construction of a Shock Tube Experiment for Multiphase Instability Experiments

NASA Astrophysics Data System (ADS)

Middlebrooks, John; Black, Wolfgang; Avgoustopoulos, Constantine; Allen, Roy; Kathakapa, Raj; Guo, Qiwen; McFarland, Jacob

2016-11-01

Hydrodynamic instabilities are important phenomena that have a wide range of practical applications in engineering and physics. One such instability, the shock driven multiphase instability (SDMI), arises when a shockwave accelerates an interface between two particle-gas mixtures with differing multiphase properties. The SDMI is present in high energy explosives, scramjets, and supernovae. A practical way of studying shock wave driven instabilities is through experimentation in a shock tube laboratory. This poster presentation will cover the design and data acquisition process of the University of Missouri's Fluid Mixing Shock Tube Laboratory. In the shock tube, a pressure generated shockwave is passed through a multiphase interface, creating the SDMI instability. This can be photographed for observation using high speed cameras, lasers, and advance imaging techniques. Important experimental parameters such as internal pressure and temperature, and mass flow rates of gases can be set and recorded by remotely controlled devices. The experimental facility provides the University of Missouri's Fluid Mixing Shock Tube Laboratory with the ability to validate simulated experiments and to conduct further inquiry into the field of shock driven multiphase hydrodynamic instabilities. Advisor.

Heat Pipe-Assisted Thermoelectric Power Generation Technology for Waste Heat Recovery

NASA Astrophysics Data System (ADS)

Jang, Ju-Chan; Chi, Ri-Guang; Rhi, Seok-Ho; Lee, Kye-Bock; Hwang, Hyun-Chang; Lee, Ji-Su; Lee, Wook-Hyun

2015-06-01

Currently, large amounts of thermal energy dissipated from automobiles are emitted through hot exhaust pipes. This has resulted in the need for a new efficient recycling method to recover energy from waste hot exhaust gas. The present experimental study investigated how to improve the power output of a thermoelectric generator (TEG) system assisted by a wickless loop heat pipe (loop thermosyphon) under the limited space of the exhaust gas pipeline. The present study shows a novel loop-type heat pipe-assisted TEG concept to be applied to hybrid vehicles. The operating temperature of a TEG's hot side surface should be as high as possible to maximize the Seebeck effect. The present study shows a novel TEG concept of transferring heat from the source to the sink. This technology can transfer waste heat to any local place with a loop-type heat pipe. The present TEG system with a heat pipe can transfer heat and generate an electromotive force power of around 1.3 V in the case of 170°C hot exhaust gas. Two thermoelectric modules (TEMs) for a conductive block model and four Bi2Te3 TEMs with a heat pipe-assisted model were installed in the condenser section. Heat flows to the condenser section from the evaporator section connected to the exhaust pipe. This novel TEG system with a heat pipe can be placed in any location on an automobile.

Design of a High-Reynolds Number Recirculating Water Tunnel

NASA Astrophysics Data System (ADS)

Daniel, Libin; Elbing, Brian

2014-11-01

An experimental fluid mechanics laboratory focused on turbulent boundary layers, drag reduction techniques, multiphase flows and fluid-structure interactions has recently been established at Oklahoma State University. This laboratory has three primary components; (1) a recirculating water tunnel, (2) a multiphase pipe flow loop, and (3) a multi-scale flow visualization system. The design of the water tunnel is the focus of this talk. The criteria used for the water tunnel design was that it had to produce a momentum-thickness based Reynolds number in excess of 104, negligible flow acceleration due to boundary layer growth, maximize optical access for use of the flow visualization system, and minimize inlet flow non-uniformity. This Reynolds number was targeted to bridge the gap between typical university/commercial water tunnels (103) and the world's largest water tunnel facilities (105) . These objectives were achieved with a 152 mm (6-inch) square test section that is 1 m long and has a maximum flow speed of 10 m/s. The flow non-uniformity was mitigated with the use of a tandem honeycomb configuration, a settling chamber and an 8.5:1 contraction. The design process that produced this final design will be presented along with its current status.

Overpressures in the Uinta Basin, Utah: Analysis using a three-dimensional basin evolution model

NASA Astrophysics Data System (ADS)

McPherson, Brian J. O. L.; Bredehoeft, John D.

2001-04-01

High pore fluid pressures, approaching lithostatic, are observed in the deepest sections of the Uinta basin, Utah. Geologic observations and previous modeling studies suggest that the most likely cause of observed overpressures is hydrocarbon generation. We studied Uinta overpressures by developing and applying a three-dimensional, numerical model of the evolution of the basin. The model was developed from a public domain computer code, with addition of a new mesh generator that builds the basin through time, coupling the structural, thermal, and hydrodynamic evolution. Also included in the model are in situ hydrocarbon generation and multiphase migration. The modeling study affirmed oil generation as an overpressure mechanism, but also elucidated the relative roles of multiphase fluid interaction, oil density and viscosity, and sedimentary compaction. An important result is that overpressures by oil generation create conditions for rock fracturing, and associated fracture permeability may regulate or control the propensity to maintain overpressures.

Study on heat pipe assisted thermoelectric power generation system from exhaust gas

NASA Astrophysics Data System (ADS)

Chi, Ri-Guang; Park, Jong-Chan; Rhi, Seok-Ho; Lee, Kye-Bock

2017-11-01

Currently, most fuel consumed by vehicles is released to the environment as thermal energy through the exhaust pipe. Environmentally friendly vehicle technology needs new methods to increase the recycling efficiency of waste exhaust thermal energy. The present study investigated how to improve the maximum power output of a TEG (Thermoelectric generator) system assisted with a heat pipe. Conventionally, the driving energy efficiency of an internal combustion engine is approximately less than 35%. TEG with Seebeck elements is a new idea for recycling waste exhaust heat energy. The TEG system can efficiently utilize low temperature waste heat, such as industrial waste heat and solar energy. In addition, the heat pipe can transfer heat from the automobile's exhaust gas to a TEG. To improve the efficiency of the thermal power generation system with a heat pipe, effects of various parameters, such as inclination angle, charged amount of the heat pipe, condenser temperature, and size of the TEM (thermoelectric element), were investigated. Experimental studies, CFD simulation, and the theoretical approach to thermoelectric modules were carried out, and the TEG system with heat pipe (15-20% charged, 20°-30° inclined configuration) showed the best performance.

Piping support system for liquid-metal fast-breeder reactor

DOEpatents

Brussalis, Jr., William G.

1984-01-01

A pipe support consisting of a rigid link pivotally attached to a pipe and an anchor, adapted to generate stress or strain in the link and pipe due to pipe thermal movement, which stress or strain can oppose further pipe movement and generally provides pipe support. The pipe support can be used in multiple combinations with other pipe supports to form a support system. This support system is most useful in applications in which the pipe is normally operated at a constant elevated or depressed temperature such that desired stress or strain can be planned in advance of pipe and support installation. The support system is therefore especially useful in steam stations and in refrigeration equipment.

Thermoelectric Power Generation System for Future Hybrid Vehicles Using Hot Exhaust Gas

NASA Astrophysics Data System (ADS)

Kim, Sun-Kook; Won, Byeong-Cheol; Rhi, Seok-Ho; Kim, Shi-Ho; Yoo, Jeong-Ho; Jang, Ju-Chan

2011-05-01

The present experimental and computational study investigates a new exhaust gas waste heat recovery system for hybrid vehicles, using a thermoelectric module (TEM) and heat pipes to produce electric power. It proposes a new thermoelectric generation (TEG) system, working with heat pipes to produce electricity from a limited hot surface area. The current TEG system is directly connected to the exhaust pipe, and the amount of electricity generated by the TEMs is directly proportional to their heated area. Current exhaust pipes fail to offer a sufficiently large hot surface area for the high-efficiency waste heat recovery required. To overcome this, a new TEG system has been designed to have an enlarged hot surface area by the addition of ten heat pipes, which act as highly efficient heat transfer devices and can transmit the heat to many TEMs. As designed, this new waste heat recovery system produces a maximum 350 W when the hot exhaust gas heats the evaporator surface of the heat pipe to 170°C; this promises great possibilities for application of this technology in future energy-efficient hybrid vehicles.

EBSD Analysis of Relationship Between Microstructural Features and Toughness of a Medium-Carbon Quenching and Partitioning Bainitic Steel

NASA Astrophysics Data System (ADS)

Li, Qiangguo; Huang, Xuefei; Huang, Weigang

2017-12-01

A multiphase microstructure of bainite, martensite and retained austenite in a 0.3C bainitic steel was obtained by a novel bainite isothermal transformation plus quenching and partitioning (B-QP) process. The correlations between microstructural features and toughness were investigated by electron backscatter diffraction (EBSD), and the results showed that the multiphase microstructure containing approximately 50% bainite exhibits higher strength (1617 MPa), greater elongation (18.6%) and greater impact toughness (103 J) than the full martensite. The EBSD analysis indicated that the multiphase microstructure with a smaller average local misorientation (1.22°) has a lower inner stress concentration possibility and that the first formed bainitic ferrite plates in the multiphase microstructure can refine subsequently generated packets and blocks. The corresponding packet and block average size decrease from 11.9 and 2.3 to 8.4 and 1.6 μm, respectively. A boundary misorientation analysis indicated that the multiphase microstructure has a higher percentage of high-angle boundaries (67.1%) than the full martensite (57.9%) because of the larger numbers and smaller sizes of packets and blocks. The packet boundary obstructs crack propagation more effectively than the block boundary.

Results of the Workshop on Two-Phase Flow, Fluid Stability and Dynamics: Issues in Power, Propulsion, and Advanced Life Support Systems

NASA Technical Reports Server (NTRS)

McQuillen, John; Rame, Enrique; Kassemi, Mohammad; Singh, Bhim; Motil, Brian

2003-01-01

The Two-phase Flow, Fluid Stability and Dynamics Workshop was held on May 15, 2003 in Cleveland, Ohio to define a coherent scientific research plan and roadmap that addresses the multiphase fluid problems associated with NASA s technology development program. The workshop participants, from academia, industry and government, prioritized various multiphase issues and generated a research plan and roadmap to resolve them. This report presents a prioritization of the various multiphase flow and fluid stability phenomena related primarily to power, propulsion, fluid and thermal management and advanced life support; and a plan to address these issues in a logical and timely fashion using analysis, ground-based and space-flight experiments.

A two-stage adaptive stochastic collocation method on nested sparse grids for multiphase flow in randomly heterogeneous porous media

NASA Astrophysics Data System (ADS)

Liao, Qinzhuo; Zhang, Dongxiao; Tchelepi, Hamdi

2017-02-01

A new computational method is proposed for efficient uncertainty quantification of multiphase flow in porous media with stochastic permeability. For pressure estimation, it combines the dimension-adaptive stochastic collocation method on Smolyak sparse grids and the Kronrod-Patterson-Hermite nested quadrature formulas. For saturation estimation, an additional stage is developed, in which the pressure and velocity samples are first generated by the sparse grid interpolation and then substituted into the transport equation to solve for the saturation samples, to address the low regularity problem of the saturation. Numerical examples are presented for multiphase flow with stochastic permeability fields to demonstrate accuracy and efficiency of the proposed two-stage adaptive stochastic collocation method on nested sparse grids.

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

Gougar, Hans

This document outlines the development of a high fidelity, best estimate nuclear power plant severe transient simulation capability that will complement or enhance the integral system codes historically used for licensing and analysis of severe accidents. As with other tools in the Risk Informed Safety Margin Characterization (RISMC) Toolkit, the ultimate user of Enhanced Severe Transient Analysis and Prevention (ESTAP) capability is the plant decision-maker; the deliverable to that customer is a modern, simulation-based safety analysis capability, applicable to a much broader class of safety issues than is traditional Light Water Reactor (LWR) licensing analysis. Currently, the RISMC pathway’s majormore » emphasis is placed on developing RELAP-7, a next-generation safety analysis code, and on showing how to use RELAP-7 to analyze margin from a modern point of view: that is, by characterizing margin in terms of the probabilistic spectra of the “loads” applied to systems, structures, and components (SSCs), and the “capacity” of those SSCs to resist those loads without failing. The first objective of the ESTAP task, and the focus of one task of this effort, is to augment RELAP-7 analyses with user-selected multi-dimensional, multi-phase models of specific plant components to simulate complex phenomena that may lead to, or exacerbate, severe transients and core damage. Such phenomena include: coolant crossflow between PWR assemblies during a severe reactivity transient, stratified single or two-phase coolant flow in primary coolant piping, inhomogeneous mixing of emergency coolant water or boric acid with hot primary coolant, and water hammer. These are well-documented phenomena associated with plant transients but that are generally not captured in system codes. They are, however, generally limited to specific components, structures, and operating conditions. The second ESTAP task is to similarly augment a severe (post-core damage) accident integral analyses code with high fidelity simulations that would allow investigation of multi-dimensional, multi-phase containment phenomena that are only treated approximately in established codes.« less

Application of numerical grid generation for improved CFD analysis of multiphase screw machines

NASA Astrophysics Data System (ADS)

Rane, S.; Kovačević, A.

2017-08-01

Algebraic grid generation is widely used for discretization of the working domain of twin screw machines. Algebraic grid generation is fast and has good control over the placement of grid nodes. However, the desired qualities of grid which should be able to handle multiphase flows such as oil injection, may be difficult to achieve at times. In order to obtain fast solution of multiphase screw machines, it is important to further improve the quality and robustness of the computational grid. In this paper, a deforming grid of a twin screw machine is generated using algebraic transfinite interpolation to produce initial mesh upon which an elliptic partial differential equations (PDE) of the Poisson’s form is solved numerically to produce smooth final computational mesh. The quality of numerical cells and their distribution obtained by the differential method is greatly improved. In addition, a similar procedure was introduced to fully smoothen the transition of the partitioning rack curve between the rotors thus improving continuous movement of grid nodes and in turn improve robustness and speed of the Computational Fluid Dynamic (CFD) solver. Analysis of an oil injected twin screw compressor is presented to compare the improvements in grid quality factors in the regions of importance such as interlobe space, radial tip and the core of the rotor. The proposed method that combines algebraic and differential grid generation offer significant improvement in grid quality and robustness of numerical solution.

Finite element residual stress analysis of induction heating bended ferritic steel piping

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

Kima, Jong Sung; Kim, Kyoung-Soo; Oh, Young-Jin

2014-10-06

Recently, there is a trend to apply the piping bended by induction heating process to nuclear power plants. Residual stress can be generated due to thermo-mechanical mechanism during the induction heating bending process. It is well-known that the residual stress has important effect on crack initiation and growth. The previous studies have focused on the thickness variation. In part, some studies were performed for residual stress evaluation of the austenitic stainless steel piping bended by induction heating. It is difficult to find the residual stresses of the ferritic steel piping bended by the induction heating. The study assessed the residualmore » stresses of induction heating bended ferriticsteel piping via finite element analysis. As a result, it was identified that high residual stresses are generated on local outersurface region of the induction heating bended ferritic piping.« less

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

Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J.

As part of the Phase II testing at the HDR Test Facility in Kahl/Main, FRG, two series of high-level seismic/vibrational experiments were performed. In the first of these (SHAG) a coast-down shaker, mounted on the reactor operating floor and capable of generating 1000 tonnes of force, was used to investigate full-scale structural response, soil-structure interaction (SSI), and piping/equipment response at load levels equivalent to those of a design basis earthquake. The HDR soil/structure system was tested to incipient failure exhibiting highly nonlinear response. In the load transmission from structure to piping/equipment significant response amplifications and shifts to higher frequencies occurred.more » The performance of various pipe support configurations was evaluated. This latter effort was continued in the second series of tests (SHAM), in which an in-plant piping system was investigated at simulated seismic loads (generated by two servo-hydraulic actuators each capable of generating 40 tonnes of force), that exceeded design levels manifold and resulted in considerable pipe plastification and failure of some supports (snubbers). The evaluation of six different support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is essential to limiting pipe stresses. Pipe strains at loads exceeding the design level eightfold were still tolerable, indicating that pipe failure even under extreme seismic loads is unlikely inspite of multiple support failures. Conservatively, an excess capacity (margin) of at least four was estimated for the piping system, and the pipe damping was found to be 4%. Comparisons of linear and nonlinear computational results with measurements showed that analytical predictions have wide scatter and do not necessarily yield conservative responses, underpredicting, in particular, peak support forces.« less

Aluminum/ammonia heat pipe gas generation and long term system impact for the Space Telescope's Wide Field Planetary Camera

NASA Technical Reports Server (NTRS)

Jones, J. A.

1983-01-01

In the Space Telescope's Wide Field Planetary Camera (WFPC) project, eight heat pipes (HPs) are used to remove heat from the camera's inner electronic sensors to the spacecraft's outer, cold radiator surface. For proper device functioning and maximization of the signal-to-noise ratios, the Charge Coupled Devices (CCD's) must be maintained at -95 C or lower. Thermoelectric coolers (TEC's) cool the CCD's, and heat pipes deliver each TEC's nominal six to eight watts of heat to the space radiator, which reaches an equilibrium temperature between -15 C to -70 C. An initial problem was related to the difficulty to produce gas-free aluminum/ammonia heat pipes. An investigation was, therefore, conducted to determine the cause of the gas generation and the impact of this gas on CCD cooling. In order to study the effect of gas slugs in the WFPC system, a separate HP was made. Attention is given to fabrication, testing, and heat pipe gas generation chemistry studies.

NASA technology utilization survey on composite materials

NASA Technical Reports Server (NTRS)

Leeds, M. A.; Schwartz, S.; Holm, G. J.; Krainess, A. M.; Wykes, D. M.; Delzell, M. T.; Veazie, W. H., Jr.

1972-01-01

NASA and NASA-funded contractor contributions to the field of composite materials are surveyed. Existing and potential non-aerospace applications of the newer composite materials are emphasized. Economic factors for selection of a composite for a particular application are weight savings, performance (high strength, high elastic modulus, low coefficient of expansion, heat resistance, corrosion resistance,), longer service life, and reduced maintenance. Applications for composites in agriculture, chemical and petrochemical industries, construction, consumer goods, machinery, power generation and distribution, transportation, biomedicine, and safety are presented. With the continuing trend toward further cost reductions, composites warrant consideration in a wide range of non-aerospace applications. Composite materials discussed include filamentary reinforced materials, laminates, multiphase alloys, solid multiphase lubricants, and multiphase ceramics. New processes developed to aid in fabrication of composites are given.

A two-stage adaptive stochastic collocation method on nested sparse grids for multiphase flow in randomly heterogeneous porous media

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

Liao, Qinzhuo, E-mail: liaoqz@pku.edu.cn; Zhang, Dongxiao; Tchelepi, Hamdi

A new computational method is proposed for efficient uncertainty quantification of multiphase flow in porous media with stochastic permeability. For pressure estimation, it combines the dimension-adaptive stochastic collocation method on Smolyak sparse grids and the Kronrod–Patterson–Hermite nested quadrature formulas. For saturation estimation, an additional stage is developed, in which the pressure and velocity samples are first generated by the sparse grid interpolation and then substituted into the transport equation to solve for the saturation samples, to address the low regularity problem of the saturation. Numerical examples are presented for multiphase flow with stochastic permeability fields to demonstrate accuracy and efficiencymore » of the proposed two-stage adaptive stochastic collocation method on nested sparse grids.« less

Model of the hydrodynamic loads applied on a rotating halfbridge belonging to a circular settling tank

NASA Astrophysics Data System (ADS)

Dascalescu, A. E.; Lazaroiu, G.; Scupi, A. A.; Oanta, E.

2016-08-01

The rotating half-bridge of a settling tank is employed to sweep the sludge from the wastewater and to vacuum and sent it to the central collector. It has a complex geometry but the main beam may be considered a slender bar loaded by the following category of forces: concentrated forces produced by the weight of the scrapping system of blades, suction pipes, local sludge collecting chamber, plus the sludge in the horizontal sludge transporting pipes; forces produced by the access bridge; buoyant forces produced by the floating barrels according to Archimedes’ principle; distributed forces produced by the weight of the main bridge; hydrodynamic forces. In order to evaluate the hydrodynamic loads we have conceived a numerical model based on the finite volume method, using the ANSYS-Fluent software. To model the flow we used the equations of Reynolds Averaged Navier-Stokes (RANS) for liquids together with Volume of Fluid model (VOF) for multiphase flows. For turbulent model k-epsilon we used the equation for turbulent kinetic energy k and dissipation epsilon. These results will be used to increase the accuracy of the loads’ sub-model in the theoretical models, e. the finite element model and the analytical model.

DNS study of speed of sound in two-phase flows with phase change

NASA Astrophysics Data System (ADS)

Fu, Kai; Deng, Xiaolong

2017-11-01

Heat transfer through pipe flow is important for the safety of thermal power plants. Normally it is considered incompressible. However, in some conditions compressibility effects could deteriorate the heat transfer efficiency and even result in pipe rupture, especially when there is obvious phase change, due to the much lower sound speed in liquid-gas mixture flows. Based on the stratified multiphase flow model (Chang and Liou, JCP 2007), we present a new approach to simulate the sound speed in 3-D compressible two-phase dispersed flows, in which each face is divided into gas-gas, gas-liquid, and liquid-liquid parts via reconstruction by volume fraction, and fluxes are calculated correspondingly. Applying it to well-distributed air-water bubbly flows, comparing with the experiment measurements in air water mixture (Karplus, JASA 1957), the effects of adiabaticity, viscosity, and isothermality are examined. Under viscous and isothermal condition, the simulation results match the experimental ones very well, showing the DNS study with current method is an effective way for the sound speed of complex two-phase dispersed flows. Including the two-phase Riemann solver with phase change (Fechter et al., JCP 2017), more complex problems can be numerically studied.

Computation of three-dimensional multiphase flow dynamics by Fully-Coupled Immersed Flow (FCIF) solver

NASA Astrophysics Data System (ADS)

Miao, Sha; Hendrickson, Kelli; Liu, Yuming

2017-12-01

This work presents a Fully-Coupled Immersed Flow (FCIF) solver for the three-dimensional simulation of fluid-fluid interaction by coupling two distinct flow solvers using an Immersed Boundary (IB) method. The FCIF solver captures dynamic interactions between two fluids with disparate flow properties, while retaining the desirable simplicity of non-boundary-conforming grids. For illustration, we couple an IB-based unsteady Reynolds Averaged Navier Stokes (uRANS) simulator with a depth-integrated (long-wave) solver for the application of slug development with turbulent gas and laminar liquid. We perform a series of validations including turbulent/laminar flows over prescribed wavy boundaries and freely-evolving viscous fluids. These confirm the effectiveness and accuracy of both one-way and two-way coupling in the FCIF solver. Finally, we present a simulation example of the evolution from a stratified turbulent/laminar flow through the initiation of a slug that nearly bridges the channel. The results show both the interfacial wave dynamics excited by the turbulent gas forcing and the influence of the liquid on the gas turbulence. These results demonstrate that the FCIF solver effectively captures the essential physics of gas-liquid interaction and can serve as a useful tool for the mechanistic study of slug generation in two-phase gas/liquid flows in channels and pipes.

Observation of Dispersive Shock Waves, Solitons, and Their Interactions in Viscous Fluid Conduits.

PubMed

Maiden, Michelle D; Lowman, Nicholas K; Anderson, Dalton V; Schubert, Marika E; Hoefer, Mark A

2016-04-29

Dispersive shock waves and solitons are fundamental nonlinear excitations in dispersive media, but dispersive shock wave studies to date have been severely constrained. Here, we report on a novel dispersive hydrodynamic test bed: the effectively frictionless dynamics of interfacial waves between two high viscosity contrast, miscible, low Reynolds number Stokes fluids. This scenario is realized by injecting from below a lighter, viscous fluid into a column filled with high viscosity fluid. The injected fluid forms a deformable pipe whose diameter is proportional to the injection rate, enabling precise control over the generation of symmetric interfacial waves. Buoyancy drives nonlinear interfacial self-steepening, while normal stresses give rise to the dispersion of interfacial waves. Extremely slow mass diffusion and mass conservation imply that the interfacial waves are effectively dissipationless. This enables high fidelity observations of large amplitude dispersive shock waves in this spatially extended system, found to agree quantitatively with a nonlinear wave averaging theory. Furthermore, several highly coherent phenomena are investigated including dispersive shock wave backflow, the refraction or absorption of solitons by dispersive shock waves, and the multiphase merging of two dispersive shock waves. The complex, coherent, nonlinear mixing of dispersive shock waves and solitons observed here are universal features of dissipationless, dispersive hydrodynamic flows.

Heat pipe methanator

DOEpatents

Ranken, William A.; Kemme, Joseph E.

1976-07-27

A heat pipe methanator for converting coal gas to methane. Gravity return heat pipes are employed to remove the heat of reaction from the methanation promoting catalyst, transmitting a portion of this heat to an incoming gas pre-heat section and delivering the remainder to a steam generating heat exchanger.

PipeOnline 2.0: automated EST processing and functional data sorting.

PubMed

Ayoubi, Patricia; Jin, Xiaojing; Leite, Saul; Liu, Xianghui; Martajaja, Jeson; Abduraham, Abdurashid; Wan, Qiaolan; Yan, Wei; Misawa, Eduardo; Prade, Rolf A

2002-11-01

Expressed sequence tags (ESTs) are generated and deposited in the public domain, as redundant, unannotated, single-pass reactions, with virtually no biological content. PipeOnline automatically analyses and transforms large collections of raw DNA-sequence data from chromatograms or FASTA files by calling the quality of bases, screening and removing vector sequences, assembling and rewriting consensus sequences of redundant input files into a unigene EST data set and finally through translation, amino acid sequence similarity searches, annotation of public databases and functional data. PipeOnline generates an annotated database, retaining the processed unigene sequence, clone/file history, alignments with similar sequences, and proposed functional classification, if available. Functional annotation is automatic and based on a novel method that relies on homology of amino acid sequence multiplicity within GenBank records. Records are examined through a function ordered browser or keyword queries with automated export of results. PipeOnline offers customization for individual projects (MyPipeOnline), automated updating and alert service. PipeOnline is available at http://stress-genomics.org.

Stepper motor control that adjusts to motor loading

NASA Technical Reports Server (NTRS)

Howard, David E. (Inventor); Nola, Frank J. (Inventor)

2000-01-01

A system and method are provided for controlling a stepper motor having a rotor and a multi-phase stator. Sinusoidal command signals define a commanded position of the motor's rotor. An actual position of the rotor is sensed as a function of an electrical angle between the actual position and the commanded position. The actual position is defined by sinusoidal position signals. An adjustment signal is generated using the sinusoidal command signals and sinusoidal position signals. The adjustment signal is defined as a function of the cosine of the electrical angle. The adjustment signal is multiplied by each sinusoidal command signal to generate a corresponding set of excitation signals, each of which is applied to a corresponding phase of the multi-phase stator.

CaSO4 Scale Formation on Vibrated Piping System in the Presence Citric Acid

NASA Astrophysics Data System (ADS)

Mangestiyono, W.; Jamari, J.; Muryanto, S.; Bayuseno, A. P.

2018-02-01

Vibration in many industries commonly generated by the operation mechanical equipment such as extruder, mixer, blower, compressor, turbine, generator etc. Vibration propagates into the floor and attacks the pipe around those mechanical equipment. In this paper, the influence of vibration in a pipe on the CaSO4 scale formation was investigated to understand the effect of vibration on the kinetics, mass of scale, crystal phases and crystal polymorph. To generate vibration force, mechanical equipment was prepared consisted of electrical motor, crankshaft, connecting rod and a vibration table at where test pipe section mounted. Deposition rate increased significantly when the vibration affected to the system i.e. 0.5997 and 1.6705 gr/hr for vibration frequency 4.00 and 8.00 Hz. The addition 10.00 ppm of citric acid declined the deposition rate of 8 Hz experiment from 3.4599 gr/hr to 2.2865 gr/hr.

Reentry trajectory optimization with waypoint and no-fly zone constraints using multiphase convex programming

NASA Astrophysics Data System (ADS)

Zhao, Dang-Jun; Song, Zheng-Yu

2017-08-01

This study proposes a multiphase convex programming approach for rapid reentry trajectory generation that satisfies path, waypoint and no-fly zone (NFZ) constraints on Common Aerial Vehicles (CAVs). Because the time when the vehicle reaches the waypoint is unknown, the trajectory of the vehicle is divided into several phases according to the prescribed waypoints, rendering a multiphase optimization problem with free final time. Due to the requirement of rapidity, the minimum flight time of each phase index is preferred over other indices in this research. The sequential linearization is used to approximate the nonlinear dynamics of the vehicle as well as the nonlinear concave path constraints on the heat rate, dynamic pressure, and normal load; meanwhile, the convexification techniques are proposed to relax the concave constraints on control variables. Next, the original multiphase optimization problem is reformulated as a standard second-order convex programming problem. Theoretical analysis is conducted to show that the original problem and the converted problem have the same solution. Numerical results are presented to demonstrate that the proposed approach is efficient and effective.

A Designer Fluid For Aluminum Phase Change Devices. Performance Enhancement in Copper Heat Pipes Performance Enhancement in Copper Heat Pipes. Volume 3

DTIC Science & Technology

2016-11-17

out dynamics of a designer fluid were investigated experimentally in a flat grooved heat pipe. Generated coatings were observed during heat pipe... experimental temperature distributions matched well. Uncertainties in the closure properties were the major source of error. 15. SUBJECT TERMS...72  Results and Discussion ( Experimental Results for IAS 2 in Grooved Wick #1

Pipe wall damage detection by electromagnetic acoustic transducer generated guided waves in absence of defect signals.

PubMed

Vasiljevic, Milos; Kundu, Tribikram; Grill, Wolfgang; Twerdowski, Evgeny

2008-05-01

Most investigators emphasize the importance of detecting the reflected signal from the defect to determine if the pipe wall has any damage and to predict the damage location. However, often the small signal from the defect is hidden behind the other arriving wave modes and signal noise. To overcome the difficulties associated with the identification of the small defect signal in the time history plots, in this paper the time history is analyzed well after the arrival of the first defect signal, and after different wave modes have propagated multiple times through the pipe. It is shown that the defective pipe can be clearly identified by analyzing these late arriving diffuse ultrasonic signals. Multiple reflections and scattering of the propagating wave modes by the defect and pipe ends do not hamper the defect detection capability; on the contrary, it apparently stabilizes the signal and makes it easier to distinguish the defective pipe from the defect-free pipe. This paper also highlights difficulties associated with the interpretation of the recorded time histories due to mode conversion by the defect. The design of electro-magnetic acoustic transducers used to generate and receive the guided waves in the pipe is briefly described in the paper.

Internal pipe attachment mechanism

DOEpatents

Bast, Richard M.; Chesnut, Dwayne A.; Henning, Carl D.; Lennon, Joseph P.; Pastrnak, John W.; Smith, Joseph A.

1994-01-01

An attachment mechanism for repairing or extending fluid carrying pipes, casings, conduits, etc. utilizing one-way motion of spring tempered fingers to provide a mechanical connection between the attachment mechanism and the pipe. The spring tempered fingers flex to permit insertion into a pipe to a desired insertion depth. The mechanical connection is accomplished by reversing the insertion motion and the mechanical leverage in the fingers forces them outwardly against the inner wall of the pipe. A seal is generated by crushing a sealing assembly by the action of setting the mechanical connection.

Internal pipe attachment mechanism

DOEpatents

Bast, R.M.; Chesnut, D.A.; Henning, C.D.; Lennon, J.P.; Pastrnak, J.W.; Smith, J.A.

1994-12-13

An attachment mechanism is described for repairing or extending fluid carrying pipes, casings, conduits, etc. utilizing one-way motion of spring tempered fingers to provide a mechanical connection between the attachment mechanism and the pipe. The spring tempered fingers flex to permit insertion into a pipe to a desired insertion depth. The mechanical connection is accomplished by reversing the insertion motion and the mechanical leverage in the fingers forces them outwardly against the inner wall of the pipe. A seal is generated by crushing a sealing assembly by the action of setting the mechanical connection. 6 figures.

Branch-pipe-routing approach for ships using improved genetic algorithm

NASA Astrophysics Data System (ADS)

Sui, Haiteng; Niu, Wentie

2016-09-01

Branch-pipe routing plays fundamental and critical roles in ship-pipe design. The branch-pipe-routing problem is a complex combinatorial optimization problem and is thus difficult to solve when depending only on human experts. A modified genetic-algorithm-based approach is proposed in this paper to solve this problem. The simplified layout space is first divided into threedimensional (3D) grids to build its mathematical model. Branch pipes in layout space are regarded as a combination of several two-point pipes, and the pipe route between two connection points is generated using an improved maze algorithm. The coding of branch pipes is then defined, and the genetic operators are devised, especially the complete crossover strategy that greatly accelerates the convergence speed. Finally, simulation tests demonstrate the performance of proposed method.

Multiphasic Health Testing in the Clinic Setting

PubMed Central

LaDou, Joseph

1971-01-01

The economy of automated multiphasic health testing (amht) activities patterned after the high-volume Kaiser program can be realized in low-volume settings. amht units have been operated at daily volumes of 20 patients in three separate clinical environments. These programs have displayed economics entirely compatible with cost figures published by the established high-volume centers. This experience, plus the expanding capability of small, general purpose, digital computers (minicomputers) indicates that a group of six or more physicians generating 20 laboratory appraisals per day can economically justify a completely automated multiphasic health testing facility. This system would reside in the clinic or hospital where it is used and can be configured to do analyses such as electrocardiography and generate laboratory reports, and communicate with large computer systems in university medical centers. Experience indicates that the most effective means of implementing these benefits of automation is to make them directly available to the medical community with the physician playing the central role. Economic justification of a dedicated computer through low-volume health testing then allows, as a side benefit, automation of administrative as well as other diagnostic activities—for example, patient billing, computer-aided diagnosis, and computer-aided therapeutics. PMID:4935771

Raw water clarification by flotation with microbubbles and nanobubbles generated with a multiphase pump.

PubMed

Azevedo, A; Etchepare, R; Rubio, J

2017-05-01

Raw water clarification by flotation was studied by injecting air into a centrifugal multiphase pump to generate microbubbles (MBs) and nanobubbles (NBs). Measurements of gas dispersion parameters were performed and optimal conditions were obtained using a pump pressure of 4 bar. Values showed a bubble Sauter diameter of 75 μm, an air holdup of 1.2%, a bubble surface area flux of 34 s -1 and an NB concentration of 1 × 10 8 NBs mL -1 (measuring 220 nm). Then, a study compared flotation with bubbles formed with the multiphase pump (F-MP) to lamellar settling at the clarification stage of a water treatment plant (WTP), in Brazil. The F-MP showed a higher separation efficiency at high hydraulic loads (9-15 m h -1 ), even without the use of a polymer, reaching 2 NTU (10-25 NTU raw water feed), which was much lower than the technical goal of the WTP (5 NTU). The results and the technical aspects are discussed, and it is concluded that the employment of MBs and NBs with pumps widens new research lines and applications in modern flotation.

Heat-Pipe-Associated Localized Thermoelectric Power Generation System

NASA Astrophysics Data System (ADS)

Kim, Pan-Jo; Rhi, Seok-Ho; Lee, Kye-Bock; Hwang, Hyun-Chang; Lee, Ji-Su; Jang, Ju-Chan; Lee, Wook-Hyun; Lee, Ki-Woo

2014-06-01

The present study focused on how to improve the maximum power output of a thermoelectric generator (TEG) system and move heat to any suitable space using a TEG associated with a loop thermosyphon (loop-type heat pipe). An experimental study was carried out to investigate the power output, the temperature difference of the thermoelectric module (TEM), and the heat transfer performance associated with the characteristic of the researched heat pipe. Currently, internal combustion engines lose more than 35% of their fuel energy as recyclable heat in the exhaust gas, but it is not easy to recycle waste heat using TEGs because of the limited space in vehicles. There are various advantages to use of TEGs over other power sources, such as the absence of moving parts, a long lifetime, and a compact system configuration. The present study presents a novel TEG concept to transfer heat from the heat source to the sink. This technology can transfer waste heat to any location. This simple and novel design for a TEG can be applied to future hybrid cars. The present TEG system with a heat pipe can transfer heat and generate power of around 1.8 V with T TEM = 58°C. The heat transfer performance of a loop-type heat pipe with various working fluids was investigated, with water at high heat flux (90 W) and 0.05% TiO2 nanofluid at low heat flux (30 W to 70 W) showing the best performance in terms of power generation. The heat pipe can transfer the heat to any location where the TEM is installed.

Viscous Flow through Pipes of Various Cross-Sections

ERIC Educational Resources Information Center

Lekner, John

2007-01-01

An interesting variety of pipe cross-sectional shapes can be generated, for which the Navier-Stokes equations can be solved exactly. The simplest cases include the known solutions for elliptical and equilateral triangle cross-sections. Students can find pipe cross-sections from solutions of Laplace's equation in two dimensions, and then plot the…

Leak and Pipe Detection Method and System

NASA Technical Reports Server (NTRS)

Youngquist, Robert C. (Inventor)

2003-01-01

A method and system for locating leaks of conductive fluids from non-conductive pipes and other structures or for locat- ing non-conductive pipes or structures having conductive fluid contained therein, employ a charge generator to apply a time varying charge to the conductive fluid, and a capaci- tive type detector that can detect the variable charge that is induced in the fluid. The capacitive detector, which prefer- ably includes a handheld housing, employs a large conduc- tive pickup plate that is used to locate the pipe or leak by scanning the plate over the ground and detecting the induced charge that is generated when the plate comes in close proximity to the pipe or leak. If a leak is encountered, the resulting signal will appear over an area larger than expected for a buried pipe, assuming the leak provides an electrically conductive path between the flow and the wet surrounding ground. The detector uses any suitable type of indicator device, such as a pair of headphones that enable an operator to hear the detected signal as a chirping sound, for example.

Turbulence kinetic energy equation for dilute suspensions

NASA Technical Reports Server (NTRS)

Abou-Arab, T. W.; Roco, M. C.

1989-01-01

A multiphase turbulence closure model is presented which employs one transport equation, namely the turbulence kinetic energy equation. The proposed form of this equation is different from the earlier formulations in some aspects. The power spectrum of the carrier fluid is divided into two regions, which interact in different ways and at different rates with the suspended particles as a function of the particle-eddy size ratio and density ratio. The length scale is described algebraically. A mass/time averaging procedure for the momentum and kinetic energy equations is adopted. The resulting turbulence correlations are modeled under less retrictive assumptions comparative to previous work. The closures for the momentum and kinetic energy equations are given. Comparisons of the predictions with experimental results on liquid-solid jet and gas-solid pipe flow show satisfactory agreement.

Split and sealing of dislocated pipes at the front of a growing crystal

NASA Astrophysics Data System (ADS)

Gutkin, M. Yu.; Sheinerman, A. G.

2004-07-01

A model is suggested for the split of dislocated pipes at the front a growing crystal. Within the model, the pipe split occurs through the generation of a dislocation semi-loop at the pipe and crystal surfaces and its subsequent expansion into the crystal interior. The strain energy of such a dislocation semi-loop as well as the stress field of a dislocated pipe perpendicular to a flat crystal surface are calculated. The parameter regions are determined at which the expansion of the dislocation semi-loop is energetically favorable and, thus, the pipe split becomes irreversible. A mechanism is proposed for the formation of a stable semi-loop resulting in the split and possible subsequent overgrowth of the dislocated pipe.

Sensory aspects and water quality impacts of chlorinated and chloraminated drinking water in contact with HDPE and cPVC pipe.

PubMed

Heim, Timothy H; Dietrich, Andrea M

2007-02-01

Pipes constructed with high-density polyethylene (HDPE) or chlorinated polyvinyl chloride (cPVC) are commonly used in drinking water distribution systems and premise plumbing. In this comprehensive investigation, the effects on odor, organic chemical release, trihalomethane (THM) formation, free chlorine demand and monochloramine demand were determined for water exposed to HDPE and cPVC pipes. The study was conducted in accordance with the Utility Quick Test (UQT), a migration/leaching protocol for analysis of materials in contact with drinking water. The sensory panel consistently attributed a weak to moderate intensity of a "waxy/plastic/citrus" odor to the water from the HDPE pipes but not the cPVC-contacted water samples. The odor intensity generated by the HDPE pipe remained relatively constant for multiple water flushes, and the odor descriptors were affected by disinfectant type. Water samples stored in both types of pipe showed a significant increase in the leaching of organic compounds when compared to glass controls, with HDPE producing 0.14 microgTOC/cm(2) pipe surface, which was significantly greater than the TOC release from cPVC. Water stored in both types of pipe showed disinfectant demands of 0.1-0.9 microg disinfectant/cm(2) pipe surface, with HDPE exerting more demand than cPVC. No THMs were detected in chlorinated water exposed to the pipes. The results demonstrate the impact that synthetic plumbing materials can have on sensory and chemical water quality, as well as the significant variations in drinking water quality generated from different materials.

Numerical and Analytical Model of an Electrodynamic Dust Shield for Solar Panels on Mars

NASA Technical Reports Server (NTRS)

Calle, C. I.; Linell, B.; Chen, A.; Meyer, J.; Clements, S.; Mazumder, M. K.

2006-01-01

Masuda and collaborators at the University of Tokyo developed a method to confine and transport particles called the electric curtain in which a series of parallel electrodes connected to an AC source generates a traveling wave that acts as a contactless conveyor. The curtain electrodes can be excited by a single-phase or a multi-phase AC voltage. A multi-phase curtain produces a non-uniform traveling wave that provides controlled transport of those particles [1-6]. Multi-phase electric curtains from two to six phases have been developed and studied by several research groups [7-9]. We have developed an Electrodynamic Dust Shield prototype using threephase AC voltage electrodes to remove dust from surfaces. The purpose of the modeling work presented here is to research and to better understand the physics governing the electrodynamic shield, as well as to advance and to support the experimental dust shield research.

46 CFR 58.25-20 - Piping for steering gear.

Code of Federal Regulations, 2011 CFR

2011-10-01

... MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-20 Piping for steering gear. (a) Pressure piping must comply with subpart 58.30 of this part. (b) Relief valves must be fitted in any part of a hydraulic system that can be isolated and in which pressure can be generated from the power units or from external...

46 CFR 58.25-20 - Piping for steering gear.

Code of Federal Regulations, 2013 CFR

2013-10-01

... MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-20 Piping for steering gear. (a) Pressure piping must comply with subpart 58.30 of this part. (b) Relief valves must be fitted in any part of a hydraulic system that can be isolated and in which pressure can be generated from the power units or from external...

46 CFR 58.25-20 - Piping for steering gear.

Code of Federal Regulations, 2012 CFR

2012-10-01

... MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-20 Piping for steering gear. (a) Pressure piping must comply with subpart 58.30 of this part. (b) Relief valves must be fitted in any part of a hydraulic system that can be isolated and in which pressure can be generated from the power units or from external...

46 CFR 58.25-20 - Piping for steering gear.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-20 Piping for steering gear. (a) Pressure piping must comply with subpart 58.30 of this part. (b) Relief valves must be fitted in any part of a hydraulic system that can be isolated and in which pressure can be generated from the power units or from external...

46 CFR 58.25-20 - Piping for steering gear.

Code of Federal Regulations, 2014 CFR

2014-10-01

... MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-20 Piping for steering gear. (a) Pressure piping must comply with subpart 58.30 of this part. (b) Relief valves must be fitted in any part of a hydraulic system that can be isolated and in which pressure can be generated from the power units or from external...

Numerical simulation of cavitation flow characteristic on Pelton turbine bucket surface

NASA Astrophysics Data System (ADS)

Zeng, C. J.; Xiao, Y. X.; Zhu, W.; Yao, Y. Y.; Wang, Z. W.

2015-01-01

The internal flow in the rotating bucket of Pelton turbine is free water sheet flow with moving boundary. The runner operates under atmospheric and the cavitation in the bucket is still a controversial problem. While more and more field practice proved that there exists cavitation in the Pelton turbine bucket and the cavitation erosion may occur at the worst which will damage the bucket. So a well prediction about the cavitation flow on the bucket surface of Pelton turbine and the followed cavitation erosion characteristic can effectively guide the optimization of Pelton runner bucket and the stable operation of unit. This paper will investigate the appropriate numerical model and method for the unsteady 3D water-air-vapour multiphase cavitation flow which may occur on the Pelton bucket surface. The computational domain will include the nozzle pipe flow, semi-free surface jet and runner domain. Via comparing the numerical results of different turbulence, cavity and multiphase models, this paper will determine the suitable numerical model and method for the simulation of cavitation on the Pelton bucket surface. In order to investigate the conditions corresponding to the cavitation phenomena on the bucket surface, this paper will adopt the suitable model to simulate the various operational conditions of different water head and needle travel. Then, the characteristics of cavitation flow the development process of cavitation will be analysed in in great detail.

Theoretical analysis of multiphase flow during oil-well drilling by a conservative model

NASA Astrophysics Data System (ADS)

Nicolas-Lopez, Ruben

2005-11-01

In order to decrease cost and improve drilling operations is necessary a better understood of the flow mechanisms. Therefore, it was carried out a multiphase conservative model that includes three mass equations and a momentum equation. Also, the measured geothermal gradient is utilized by state equations for estimating physical properties of the phases flowing. The mathematical model is solved by numerical conservative schemes. It is used to analyze the interaction among solid-liquid-gas phases. The circulating system consists as follow, the circulating fluid is pumped downward into the drilling pipe until the bottom of the open hole then it flows through the drill bit, and at this point formation cuttings are incorporated to the circulating fluid and carried upward to the surface. The mixture returns up to the surface by an annular flow area. The real operational conditions are fed to conservative model and the results are matched up to field measurements in several oil wells. Mainly, flow rates, drilling rate, well and tool geometries are data to estimate the profiles of pressure, mixture density, equivalent circulating density, gas fraction and solid carrying capacity. Even though the problem is very complex, the model describes, properly, the hydrodynamics of drilling techniques applied at oil fields. *Authors want to thank to Instituto Mexicano del Petroleo and Petroleos Mexicanos for supporting this research.

Gas pipe explorer robot

NASA Technical Reports Server (NTRS)

Wilcox, Brian (Inventor)

2004-01-01

A gas pipe explorer formed of a plurality of connecting elements, and an articulation element between the connected elements. The connected elements include drive capabilities, and the articulation element allows the connected elements to traverse gas pipes of arbitrary shapes and sizes. A sensor may sends the characteristics of the gas pipe, and the communication element may send back those sends characteristics. The communication can be wired, over a tether connecting the device to a remote end. Alternatively, the connection can be wireless, driven by either a generator or a battery.

A measurement device for electromagnetic flow tomography

NASA Astrophysics Data System (ADS)

Vauhkonen, M.; Hänninen, A.; Lehtikangas, O.

2018-01-01

Electromagnetic flow meters have succesfully been used in many industries to measure the mean flow velocity of conductive liquids. This technology works reliably in single phase flows with axisymmetric flow profiles but can be inaccurate with asymmetric flows, which are encountered, for example, in multiphase flows, pipe elbows and T-junctions. Some computational techniques and measurement devices with multiple excitation coils and measurement electrodes have recently been proposed to be used in cases of asymmetric flows. In earlier studies, we proposed a computational approach for electromagnetic flow tomography (EMFT) for estimating velocity fields utilizing several excitation coils and a set of measurement electrodes attached to the surface of the pipe. This approach has been shown to work well with simulated data but has not been tested extensively with real measurements. In this paper, an EMFT system with four excitation coils and 16 measurement electrodes is introduced. The system is capable of using both square wave and sinusoidal coil current excitations and all the coils can be excited individually, also enabling parallel excitations with multiple frequencies. The studies undertaken in the paper demonstrate that the proposed EMFT system, together with the earlier introduced velocity field reconstruction approach, is capable of producing reliable velocify field estimates in a laboratory environment with both axisymmetric and asymmetric single phase flows.

Mount St. Helens (Washington, USA) and World Trade Center (New York, USA) collapse: a fluid dynamic analogy

NASA Astrophysics Data System (ADS)

Doronzo, Domenico; de Tullio, Marco; Pascazio, Giuseppe; Dellino, Pierfrancesco

2013-04-01

When a skyscraper collapses, the non-fragmented material is rapidly deposited close to the source, whereas the fragmented counterpart is loaded turbulently in the associated currents. Indeed, on impact with the ground, collapses of volcanic columns, domes, or sectors of volcanoes generate thick deposits of coarser material, and from there on the finer material is suspended over the landscape, to be re-deposited far away in thin deposits. Here, we explore the multiphase fluid dynamic behavior of the World Trade Center (New York, USA) collapse, which on 11 September 2001 followed the fragmentation of the Twin Towers, and generated shear dusty currents. These currents had a multiphase and turbulent behavior, and resemble the volcanic flow generated during the 18 May 1980 explosive eruption of Mount St. Helens (Washington, USA), in which a sector of the volcano collapsed, then a highly mobile, multiphase turbulent current followed and heavily interacted with the surrounding landscape. This analogy allows to focus on the comparison between volcanic and skyscraper collapse. A computational fluid dynamic investigation, along with a locally refined Cartesian grid, are adopted to simulate numerically the propagation of the 11 September dusty currents in Manhattan. Results of flow dynamic pressure, the parameter of volcanic hazard, and particle deposition reveal that the pressure can locally increase up to a factor 10 because of flow-building interaction. Also, the surrounding buildings make the urban setting as of a high turbulence and exponential decay of deposit thickness.

Methods, systems and apparatus for controlling third harmonic voltage when operating a multi-space machine in an overmodulation region

DOEpatents

Perisic, Milun; Kinoshita, Michael H; Ranson, Ray M; Gallegos-Lopez, Gabriel

2014-06-03

Methods, system and apparatus are provided for controlling third harmonic voltages when operating a multi-phase machine in an overmodulation region. The multi-phase machine can be, for example, a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided. For example, when the reference voltage vector is determined to be within the overmodulation region, an angle of the reference voltage vector can be modified to generate a reference voltage overmodulation control angle, and a magnitude of the reference voltage vector can be modified, based on the reference voltage overmodulation control angle, to generate a modified magnitude of the reference voltage vector. By modifying the reference voltage vector, voltage command signals that control a five-phase inverter module can be optimized to increase output voltages generated by the five-phase inverter module.

Apparatus for measuring the decontamination factor of a multiple filter air-cleaning system

DOEpatents

Ortiz, John P.

1986-01-01

An apparatus for measuring the overall decontamination factor of first and second filters located in a plenum. The first filter separates the plenum's upstream and intermediate chambers. The second filter separates the plenum's intermediate and downstream chambers. The apparatus comprises an aerosol generator that generates a challenge aerosol. An upstream collector collects unfiltered aerosol which is piped to first and second dilution stages and then to a laser aerosol spectrometer. An intermediate collector collects challenge aerosol that penetrates the first filter. The filtered aerosol is piped to the first dilution stage, diluted, and then piped to the laser aerosol spectrometer which detects single particles. A downstream collector collects challenge aerosol that penetrates both filters. The twice-filtered aerosol is piped to the aerosol spectrometer. A pump and several valves control the movement of aerosol within the apparatus.

Apparatus for measuring the decontamination factor of a multiple filter air-cleaning system

DOEpatents

Ortiz, J.P.

1985-07-03

An apparatus for measuring the overall decontamination factors of first and second filters located in a plenum. The first filter separates the plenum's upstream and intermediate chambers. The second filter separates the plenum's intermediate and downstream chambers. The apparatus comprises an aerosol generator that generates a challenge aerosol. An upstream collector collects unfiltered aerosol which is piped to first and second dilution stages and then to a laser aerosol spectrometer. An intermediate collector collects challenge aerosol that penetrates the first filter. The filtered aerosol is piped to the first dilution stage, diluted, and then piped to the laser aerosol spectrometer which detects single particles. A downstream collector collects challenge aerosol that penetrates both filters. The twice-filtered aerosol is piped to the aerosol spectrometer. A pump and several valves control the movement of aerosol within the apparatus.

FOREWORD: International Symposium of Cavitation and Multiphase Flow (ISCM 2014)

NASA Astrophysics Data System (ADS)

Wu, Yulin

2015-01-01

The International Symposium on Cavitation and Multiphase Flow (ISCM 2014) was held in Beijing, China during 18th-21st October, 2014, which was jointly organized by Tsinghua University, Beijing, China and Jiangsu University, Zhenjiang, China. The co-organizer was the State Key Laboratory of Hydroscience and Engineering, Beijing, China. Cavitation and multiphase flow is one of paramount topics of fluid mechanics with many engineering applications covering a broad range of topics, e.g. hydraulic machinery, biomedical engineering, chemical and process industry. In order to improve the performances of engineering facilities (e.g. hydraulic turbines) and to accelerate the development of techniques for medical treatment of serious diseases (e.g. tumors), it is essential to improve our understanding of cavitation and Multiphase Flow. For example, the present development towards the advanced hydrodynamic systems (e.g. space engine, propeller, hydraulic machinery system) often requires that the systems run under cavitating conditions and the risk of cavitation erosion needs to be controlled. The purpose of the ISCM 2014 was to discuss the state-of-the-art cavitation and multiphase flow research and their up-to-date applications, and to foster discussion and exchange of knowledge, and to provide an opportunity for the researchers, engineers and graduate students to report their latest outputs in these fields. Furthermore, the participants were also encouraged to present their work in progress with short lead time and discuss the encountered problems. ISCM 2014 covers all aspects of cavitation and Multiphase Flow, e.g. both fundamental and applied research with a focus on physical insights, numerical modelling and applications in engineering. Some specific topics are: Cavitating and Multiphase Flow in hydroturbines, pumps, propellers etc. Numerical simulation techniques Cavitation and multiphase flow erosion and anti-erosion techniques Measurement techniques for cavitation and multiphase flow detection Fluid-structure interaction induced by cavitation and multiphase flow Multi-scale modelling of cavitating flows and Multiphase Flow Cavitation nuclei: theory and experiments Supercavitation and its applications Synergetic effects of cavitation and silt-laden erosion Shock waves and microjets generated by cavitation Nonlinear oscillations of gas and vapour bubbles Fundamentals of physics of acoustic cavitation Sonochemistry and sonoluminescence Biomedical applications of cavitation effects Ultrasonic cavitation for molten metal treatment Cavitation for enhanced heat transfer The ISCM 2014 brought together 95 scientists, researchers and graduate students from 11 countries, affiliated with universities, technology centers and industrial firms to debate topics related to advanced technologies for cavitation and Multiphase Flow, which would enhance the sustainable development of cavitation and Multiphase Flow in interdisciplinary sciences and technology. The technical committee selected 54 technical papers on the following topics: (i) Hydrodynamic Cavitation, (ii) Super Cavitation, (iii) Pump Cavitation, (iv) Acoustic Cavitation, (v) Interdisciplinary Research of Cavitation and Multi-Phase Flows, and 13 invited plenary and invited forum lectures, which were presented at the symposium, to be included in the proceedings. All the papers of ISCM 2014, which are published in this Volume of IOP Conference Series: Materials Science and Engineering, had been peer reviewed through processes administered by the editors of the ISCM 2014, those are Yulin WU, Shouqi YUAN, Zhengwei WANG, Shuhong LIU, Xingqi LUO, Fujun WANG and Guoyu WANG. The papers published in this Volume include 54 technical papers and 3 full length texts of the invited lectures. We sincerely hope that the International Symposium on Cavitation and Multiphase Flow is a significant step forward in the world wide efforts to address the present challenges in the modern science and technology. Professor Yulin WU Chairman of the Local Organizing Committee International Symposium on Cavitation and Multiphase Flow (ISCM 2014) October, 2014

Application of a transient heat transfer model for bundled, multiphase pipelines

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

Brown, T.S.; Clapham, J.; Danielson, T.J.

1996-12-31

A computer model has been developed which accurately describes transient heat transfer in pipeline bundles. An arbitrary number of internal pipelines containing different fluids, flowing in either direction along with the input of heat to one or more of the fluids can be accommodated. The model is coupled to the transient, multiphase flow simulator OLGA. The lines containing the multiphase production fluids are modeled by OLGA, and the heat transfer between the internal lines, carrier pipe, and surroundings is handled by the bundle model. The model has been applied extensively to the design of a subsea, heated bundle system formore » the Britannia gas condensate field in the North Sea. The 15-km bundle system contains a 14{double_prime} production line, an 8{double_prime} test line, a 3{double_prime} methanol line, and a 12{double_prime} internal heating medium line within a 37.25{double_prime} carrier. The heating medium (water) flows in the internal heating medium line and in the annulus at 82,500 BPD. The primary purpose of the bundle system is to avoid the formation of hydrates. A secondary purpose is to avoid the deposition of paraffin. The bundle model was used to (1) compare the merits of two coaxial lines vs. a single bundle; (2) optimize the insulation levels on the carrier and internal lines; (3) determine the minimum time required to heat up the bundle; (4) determine heat input requirements to avoid hydrates throughout the field life, (5) determine temperature profiles along the lines for a range of production rates; (6) study ruptures of the production line into the bundle annulus; (7) determine minimum temperatures during depressurization; and (8) determine cool-down times. The results of these studies were used to size lines, select insulation levels, assess erosion potential, design for thermal expansion-induced stresses, and to select materials of construction.« less

High temperature helical tubular receiver for concentrating solar power system

NASA Astrophysics Data System (ADS)

Hossain, Nazmul

In the field of conventional cleaner power generation technology, concentrating solar power systems have introduced remarkable opportunity. In a solar power tower, solar energy concentrated by the heliostats at a single point produces very high temperature. Falling solid particles or heat transfer fluid passing through that high temperature region absorbs heat to generate electricity. Increasing the residence time will result in more heat gain and increase efficiency. A novel design of solar receiver for both fluid and solid particle is approached in this paper which can increase residence time resulting in higher temperature gain in one cycle compared to conventional receivers. The helical tubular solar receiver placed at the focused sunlight region meets the higher outlet temperature and efficiency. A vertical tubular receiver is modeled and analyzed for single phase flow with molten salt as heat transfer fluid and alloy625 as heat transfer material. The result is compared to a journal paper of similar numerical and experimental setup for validating our modeling. New types of helical tubular solar receivers are modeled and analyzed with heat transfer fluid turbulent flow in single phase, and granular particle and air plug flow in multiphase to observe the temperature rise in one cyclic operation. The Discrete Ordinate radiation model is used for numerical analysis with simulation software Ansys Fluent 15.0. The Eulerian granular multiphase model is used for multiphase flow. Applying the same modeling parameters and boundary conditions, the results of vertical and helical receivers are compared. With a helical receiver, higher temperature gain of heat transfer fluid is achieved in one cycle for both single phase and multiphase flow compared to the vertical receiver. Performance is also observed by varying dimension of helical receiver.

Experimental Measurements and Mathematical Modeling of Static and Dynamic Characteristics of Water Flow in a Long Pipe

NASA Astrophysics Data System (ADS)

Jablonska, J.; Kozubkova, M.

2017-08-01

Static and dynamic characteristics of flow in technical practice are very important and serious problem and can be solved by experimental measurement or mathematical modeling. Unsteady flow presents time changes of the flow and water hammer can be an example of this phenomenon. Water hammer is caused by rapid changes in the water flow by means the closure or opening of the control valve. The authors deal with by hydraulic hammer at the multiphase flow (water and air), its one-dimensional modeling (Matlab SimHydraulics) and modeling with the use of the finite volume method (Ansys Fluent) in article. The circuit elements are defined by static and dynamic characteristics. The results are verified with measurements. The article evaluates different approaches, their advantages, disadvantages and specifics in solving of water hammer.

Drill pipe threaded nipple connection design development

NASA Astrophysics Data System (ADS)

Saruev, A. L.; Saruev, L. A.; Vasenin, S. S.

2015-11-01

The paper presents the analysis of the behavior of the drill pipe nipple connection under the additional load generated by power pulses. The strain wave propagation through the nipple thread connection of drill pipes to the bottomhole is studied in this paper. The improved design of the nipple thread connection is suggested using the obtained experimental and theoretical data. The suggested connection design allows not only the efficient transmission of strain wave energy to a drill bit but also the automation of making-up and breaking-out drill pipes.

Design Issues Affecting Pipings Associated with a New Moisture Separator Reheater

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

Hyung-Keun, Kim; Jae-Kyoung, Cho

2006-07-01

This paper summarizes the piping design effects on a New Moisture Separator Reheater (MSR) in Shin-Kori Nuclear Power Plant Units 1 and 2 (SKN 1 and 2) being under the construction in Korea. This SKN 1 and 2 has the same arrangement of a Turbine-Generator set as one of Korea Standard Nuclear Plant Units ( OPR 1000 ) in commercial operation. The Turbine-Generator Supplier has developed a new Moisture Separator Reheater which has first and second stage heating steam supply connections respectively, at both ends of the shell side of the vessel in comparison to MSR of OPR 1000 whichmore » has first and second stage heating steam supply connections at only one end. The different locations of reheaters in MSR cause changes in the associated pipings such as 2. stage reheater heating steam, 2. stage reheater drain, shell drain, drain tank location and tank condensate drainage pipings. (authors)« less

Phase I Source Investigation, Heckathorn Superfund Site, Richmond, California

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

Kohn, Nancy P; Evans, Nathan R

This report represents Phase I of a multi-phase approach to a source investigation of DDT at the Heckathorn Superfund Site, Richmond, California, the former site of a pesticide packaging plant, and the adjacent waterway, the Lauritzen Channel. Potential identified sources of contamination were from sloughed material from undredged areas (such as side banks) and from outfall pipes. Objectives of Phase I included the (1) evaluation of pesticide concentrations associated with discharge from outfalls, (2) identification of additional outfalls in the area, (3) identification of type, quantity, and distribution of sediment under the Levin pier, (4) quantification of pesticide concentrations inmore » sediment under the pier, and (5) evaluation of sediment structure and slope stability under the pier. Field operations included the collection of sediment directly from inside the mouths of outfall pipes, when possible, or the deployment of specially designed particle traps where direct sampling was problematic. Passive water samplers were placed at the end of known outfall pipes and analyzed for DDT and other pesticides of concern. Underwater dive surveys were conducted beneath the Levin pier to document type, slope, and thickness of sediment. Samples were collected at locations of interest and analyzed for contaminants. Also sampled was soil from bank areas, which were suspected of potentially contributing to continued DDT contamination of the Lauritzen Channel through erosion and groundwater leaching. The Phase I Source Investigation was successful in identifying significant sources of DDT contamination to Lauritzen Channel sediment. Undredged sediment beneath the Levin pier that has been redistributed to the channel is a likely source. Two outfalls tested bear further investigation. Not as well-defined are the contributions of bank erosional material and groundwater leaching. Subsequent investigations will be based on the results of this first phase.« less

ENVIRONMENTALLY-BENIGN MULTIPHASE CATALYSIS. (R826034)

EPA Science Inventory

Environmental concerns stemming from the use of conventional solvents and from hazardous waste generation have propelled research efforts aimed at developing benign chemical processing techniques that either eliminate or significantly mitigate pollution at the source. This pap...

Thermal Vacuum Testing of Swift XRT Ethane Heat Pipes

NASA Technical Reports Server (NTRS)

Kobel, Mark; Ku, Jentung

2003-01-01

This paper presents the results obtained from a recent ethane heat pipe program. Three identical ethane heat pipes were tested individually, and then two selected heat pipes were tested collectively in their system configuration. Heat transport, thermal conductance, and non-condensable gas tests were performed on each heat pipe. To gain insight into the reflux operation as seen at spacecraft level ground testing, the test fixture was oriented in a vertical configuration. The system level test included a computer-controlled heater designed to emulate the heat load generated at the thermoelectric cooler interface. The system performance was successfully characterized for a wide range of environmental conditions while staying within the operating limits.

Development of an Efficient Meso- scale Multi-phase Flow Solver in Nuclear Applications

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

Lee, Taehun

2015-10-20

The proposed research aims at formulating a predictive high-order Lattice Boltzmann Equation for multi-phase flows relevant to nuclear energy related application - namely, saturated and sub-cooled boiling in reactors, and liquid- liquid mixing and extraction for fuel cycle separation. An efficient flow solver will be developed based on the Finite Element based Lattice Boltzmann Method (FE- LBM), accounting for phase-change heat transfer and capable of treating multiple phases over length scales from the submicron to the meter. A thermal LBM will be developed in order to handle adjustable Prandtl number, arbitrary specific heat ratio, a wide range of temperature variations,more » better numerical stability during liquid-vapor phase change, and full thermo-hydrodynamic consistency. Two-phase FE-LBM will be extended to liquid–liquid–gas multi-phase flows for application to high-fidelity simulations building up from the meso-scale up to the equipment sub-component scale. While several relevant applications exist, the initial applications for demonstration of the efficient methods to be developed as part of this project include numerical investigations of Critical Heat Flux (CHF) phenomena in nuclear reactor fuel bundles, and liquid-liquid mixing and interfacial area generation for liquid-liquid separations. In addition, targeted experiments will be conducted for validation of this advanced multi-phase model.« less

Multi-channel infrared thermometer

DOEpatents

Ulrickson, Michael A.

1986-01-01

A device for measuring the two-dimensional temperature profile of a surface comprises imaging optics for generating an image of the light radiating from the surface; an infrared detector array having a plurality of detectors; and a light pipe array positioned between the imaging optics and the detector array for sampling, transmitting, and distributing the image over the detector surfaces. The light pipe array includes one light pipe for each detector in the detector array.

Means and method for vapor generation

DOEpatents

Carlson, Larry W.

1984-01-01

A liquid, in heat transfer contact with a surface heated to a temperature well above the vaporization temperature of the liquid, will undergo a multiphase (liquid-vapor) transformation from 0% vapor to 100% vapor. During this transition, the temperature driving force or heat flux and the coefficients of heat transfer across the fluid-solid interface, and the vapor percentage influence the type of heating of the fluid--starting as "feedwater" heating where no vapors are present, progressing to "nucleate" heating where vaporization begins and some vapors are present, and concluding with "film" heating where only vapors are present. Unstable heating between nucleate and film heating can occur, accompanied by possibly large and rapid temperature shifts in the structures. This invention provides for injecting into the region of potential unstable heating and proximate the heated surface superheated vapors in sufficient quantities operable to rapidly increase the vapor percentage of the multiphase mixture by perhaps 10-30% and thereby effectively shift the multiphase mixture beyond the unstable heating region and up to the stable film heating region.

Multiphase mean curvature flows with high mobility contrasts: A phase-field approach, with applications to nanowires

NASA Astrophysics Data System (ADS)

Bretin, Elie; Danescu, Alexandre; Penuelas, José; Masnou, Simon

2018-07-01

The structure of many multiphase systems is governed by an energy that penalizes the area of interfaces between phases weighted by surface tension coefficients. However, interface evolution laws depend also on interface mobility coefficients. Having in mind some applications where highly contrasted or even degenerate mobilities are involved, for which classical phase field models are inapplicable, we propose a new effective phase field approach to approximate multiphase mean curvature flows with mobilities. The key aspect of our model is to incorporate the mobilities not in the phase field energy (which is conventionally the case) but in the metric which determines the gradient flow. We show the consistency of such an approach by a formal analysis of the sharp interface limit. We also propose an efficient numerical scheme which allows us to illustrate the advantages of the model on various examples, as the wetting of droplets on solid surfaces or the simulation of nanowires growth generated by the so-called vapor-liquid-solid method.

Means and method for vapor generation

DOEpatents

Carlson, L.W.

A liquid, in heat transfer contact with a surface heated to a temperature well above the vaporization temperature of the liquid, will undergo a multiphase (liquid-vapor) transformation from 0% vapor to 100% vapor. During this transition, the temperature driving force or heat flux and the coefficients of heat transfer across the fluid-solid interface, and the vapor percentage influence the type of heating of the fluid - starting as feedwater heating where no vapors are present, progressing to nucleate heating where vaporization begins and some vapors are present, and concluding with film heating where only vapors are present. Unstable heating between nucleate and film heating can occur, accompanied by possibly large and rapid temperature shifts in the structures. This invention provides for injecting into the region of potential unstable heating and proximate the heated surface superheated vapors in sufficient quantities operable to rapidly increase the vapor percentage of the multiphase mixture by perhaps 10 to 30% and thereby effectively shift the multiphase mixture beyond the unstable heating region and up to the stable film heating region.

Optimal Number of Thermoelectric Couples in a Heat Pipe Assisted Thermoelectric Generator for Waste Heat Recovery

NASA Astrophysics Data System (ADS)

Liu, Tongjun; Wang, Tongcai; Luan, Weiling; Cao, Qimin

2017-05-01

Waste heat recovery through thermoelectric generators is a promising way to improve energy conversion efficiency. This paper proposes a type of heat pipe assisted thermoelectric generator (HP-TEG) system. The expandable evaporator and condenser surface of the heat pipe facilitates the intensive assembly of thermoelectric (TE) modules to compose a compact device. Compared with a conventional layer structure thermoelectric generator, this system is feasible for the installment of more TE couples, thus increasing power output. To investigate the performance of the HP-TEG and the optimal number of TE couples, a theoretical model was presented and verified by experiment results. Further theoretical analysis results showed the performance of the HP-TEG could be further improved by optimizing the parameters, including the inlet air temperature, the thermal resistance of the heating section, and thermal resistance of the cooling structure. Moreover, applying a proper number of TE couples is important to acquire the best power output performance.

Ultrasonic fluid flow measurement method and apparatus

DOEpatents

Kronberg, J.W.

1993-10-12

An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible. 3 figures.

Ultrasonic fluid flow measurement method and apparatus

DOEpatents

Kronberg, James W.

1993-01-01

An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible.

Origin and evolution of Sariñena Lake (central Ebro Basin): A piping-based model

NASA Astrophysics Data System (ADS)

Castañeda, Carmen; Javier Gracia, F.; Rodríguez-Ochoa, Rafael; Zarroca, Mario; Roqué, Carles; Linares, Rogelio; Desir, Gloria

2017-08-01

The origin and nature of the numerous lakes in the central Ebro Basin have been interpreted according to the prevailing arid or semiarid conditions, the easily-eroded materials and the solubility of the gypsum- and/or carbonate-rich Tertiary/Cenozoic substratum, involving important dissolution (karstic) and/or aeolian deflation. However, the origin of Sariñena Lake, the largest in the central Ebro Basin, remains unknown since the typical lake-generating processes in the region are not applicable. This work provides significant clues to the genesis and evolution of Sariñena Lake in a regional context. The combination of geomorphological mapping and high resolution LiDAR data together with sedimentological observations, the characterisation of soils and sediments around the lake, and the application of high-resolution geophysical techniques suggest that piping is the major genetic process driving the evolution of the Sariñena depression and lake. Field evidence demonstrates that piping is, at present, the most important erosive process in the region, generating significant collapse and surface lowering. Sariñena Lake is located within a deep endorheic depression excavated from Na-rich Tertiary materials. This work hypothesises that once an early, fluvially-originated palustrine area had developed, the progressive lowering of the regional water table linked to regional fluvial incision favoured the establishment of a hydrological gradient high enough to trigger piping processes within the claystones and siltstones underlying the original palustrine area. The Quaternary evolution of the Sariñena lacustrine basin was then controlled by successive water table fluctuations, linked to different phases of incision and alluvial deposition in the surrounding fluvial systems. All the evidence supporting a piping-related origin for this lake, together with examples of lakes generated by similar processes in different contexts, is used to propose a new genetic type of lacustrine depression, generated by piping processes under favourable conditions.

Investigation of Counter-Flow in a Heat Pipe-Thermoelectric Generator (HPTEG)

NASA Astrophysics Data System (ADS)

Remeli, Muhammad Fairuz; Singh, Baljit; Affandi, Nor Dalila Nor; Ding, Lai Chet; Date, Abhijit; Akbarzadeh, Aliakbar

2017-05-01

This study explores a method of generating electricity while recovering waste heat through the integration of heat pipes and thermoelectric generators (i.e. HPTEG system). The simultaneous waste heat recovery and power generation processes are achieved without the use of any moving parts. The HPTEG system consists of bismuth telluride thermoelectric generators (TEG), which are sandwiched between two finned pipes to achieve a temperature gradient across the TEG for electricity generation. A counter-flow heat exchanger was built using two separate air ducts. The air ducts were thermally coupled using the HPTEG modules. The evaporator section of the heat pipe absorbed the waste heat in a hot air duct. The heat was then transferred across the TEG surfaces. The condenser section of the HPTEG collected the excess heat from the TEG cold side before releasing it to the cold air duct. A 2-kW electrical heater was installed in the hot air duct to simulate the exhaust gas. An air blower was installed at the inlet of each duct to direct the flow of air into the ducts. A theoretical model was developed for predicting the performance of the HPTEG system using the effectiveness-number of transfer units method. The developed model was able to predict the thermal and electrical output of the HPTEG, along with the rate of heat transfer. The results showed that by increasing the cold air velocity, the effectiveness of the heat exchanger was able to be increased from approximately 52% to 58%. As a consequence of the improved heat transfer, maximum power output of 4.3 W was obtained.

Multi-speed multi-phase resolver converter

NASA Technical Reports Server (NTRS)

Alhorn, Dean (Inventor); Howard, David (Inventor)

1994-01-01

A multiphase converter circuit generates a plurality of sinusoidal outputs of displaced phase and given speed value from the output of an angular resolver system attachable to a motor excited by these multi-phase outputs, the resolver system having a lower speed value than that of the motor. The angular resolver system provides in parallel format sequential digital numbers indicative of the amount of rotation of the shaft of an angular position sensor associated with the angular resolver system. These numbers are used to excite simultaneously identical addresses of a plurality of addressable memory systems, each memory system having stored therein at sequential addresses sequential values of a sinusoidal wavetrain of a given number of sinusoids. The stored wavetrain values represent sinusoids displaced from each other in phase according to the number of output phases desired. A digital-to-analog converter associated with each memory system converts each accessed word to a corresponding analog value to generate attendant to rotation of the angular resolver a sinusoidal wave of proper phase at each of the plurality of outputs. By properly orienting the angular resolver system with respect to the rotor of the motor, essentially ripple-free torque is supplied to the rotor. The angular resolver system may employ an analog resolver feeding an integrated circuit resolver-to-digital converter to produce the requisite digital values serving as addresses. Alternative versions employing incremental or absolute encoders are also described.

Multi-speed multi-phase resolver converter

NASA Technical Reports Server (NTRS)

Alhorn, Dean C. (Inventor); Howard, David E. (Inventor)

1995-01-01

A multiphase converter circuit generates a plurality of sinusoidal outputs of displaced phase and given speed value from the output of an angular resolver system attachable to a motor excited by these multi-phase outputs, the resolver system having a lower speed value than that of the motor. The angular resolver system provides in parallel format sequential digital numbers indicative of the amount of rotation of the shaft of an angular position sensor associated with the angular resolver system. These numbers are used to excite simultaneously identical addresses of a plurality of addressable memory systems, each memory system having stored therein at sequential addresses sequential values of a sinusoidal wavetrain of a given number of sinusoids. The stored wavetrain values represent sinusoids displaced from each other in phase according to the number of output phases desired. A digital-to-analog converter associated with each memory system converts each accessed word to a corresponding analog value to generate attendant to rotation of the angular resolver a sinusoidal wave of proper phase at each of the plurality of outputs. By properly orienting the angular resolver system with respect to the rotor of the motor, essentially ripple-free torque is supplied to the rotor. The angular resolver system may employ an analog resolver feeding an integrated circuit resolver-to-digital converter to produce the requisite digital values serving as addresses. Alternative versions employing incremental or absolute encoders are also described.

Landslides and tsunamis predicted by incompressible smoothed particle hydrodynamics (SPH) with application to the 1958 Lituya Bay event and idealized experiment.

PubMed

Xenakis, A M; Lind, S J; Stansby, P K; Rogers, B D

2017-03-01

Tsunamis caused by landslides may result in significant destruction of the surroundings with both societal and industrial impact. The 1958 Lituya Bay landslide and tsunami is a recent and well-documented terrestrial landslide generating a tsunami with a run-up of 524 m. Although recent computational techniques have shown good performance in the estimation of the run-up height, they fail to capture all the physical processes, in particular, the landslide-entry profile and interaction with the water. Smoothed particle hydrodynamics (SPH) is a versatile numerical technique for describing free-surface and multi-phase flows, particularly those that exhibit highly nonlinear deformation in landslide-generated tsunamis. In the current work, the novel multi-phase incompressible SPH method with shifting is applied to the Lituya Bay tsunami and landslide and is the first methodology able to reproduce realistically both the run-up and landslide-entry as documented in a benchmark experiment. The method is the first paper to develop a realistic implementation of the physics that in addition to the non-Newtonian rheology of the landslide includes turbulence in the water phase and soil saturation. Sensitivity to the experimental initial conditions is also considered. This work demonstrates the ability of the proposed method in modelling challenging environmental multi-phase, non-Newtonian and turbulent flows.

Landslides and tsunamis predicted by incompressible smoothed particle hydrodynamics (SPH) with application to the 1958 Lituya Bay event and idealized experiment

PubMed Central

Lind, S. J.; Stansby, P. K.; Rogers, B. D.

2017-01-01

Tsunamis caused by landslides may result in significant destruction of the surroundings with both societal and industrial impact. The 1958 Lituya Bay landslide and tsunami is a recent and well-documented terrestrial landslide generating a tsunami with a run-up of 524 m. Although recent computational techniques have shown good performance in the estimation of the run-up height, they fail to capture all the physical processes, in particular, the landslide-entry profile and interaction with the water. Smoothed particle hydrodynamics (SPH) is a versatile numerical technique for describing free-surface and multi-phase flows, particularly those that exhibit highly nonlinear deformation in landslide-generated tsunamis. In the current work, the novel multi-phase incompressible SPH method with shifting is applied to the Lituya Bay tsunami and landslide and is the first methodology able to reproduce realistically both the run-up and landslide-entry as documented in a benchmark experiment. The method is the first paper to develop a realistic implementation of the physics that in addition to the non-Newtonian rheology of the landslide includes turbulence in the water phase and soil saturation. Sensitivity to the experimental initial conditions is also considered. This work demonstrates the ability of the proposed method in modelling challenging environmental multi-phase, non-Newtonian and turbulent flows. PMID:28413334

Multi-phase-fluid discrimination with local fibre-optical probes: III. Three-phase flows

NASA Astrophysics Data System (ADS)

Fordham, E. J.; Ramos, R. T.; Holmes, A.; Simonian, S.; Huang, S.-M.; Lenn, C. P.

1999-12-01

Local fibre-optical sensors (or `local probes') for immiscible-fluid discrimination are demonstrated in three-phase (oil/water/gas) flows. The probes are made from standard silica fibres with plane oblique facets polished at the fibre tip, with surface treatment for wettability control. They use total internal reflection to distinguish among drops, bubbles and other regions of fluid in multi-phase flows, on the basis of refractive-index contrast. Dual probes, using two sensors each with a quasi-binary output, are used to determine profiles of three-phase volume fraction in a flow of kerosene, water and air in a pipe. The individual sensors used discriminate oil from `not-oil' and gas from liquid; their logical combination discriminates among the three phases. Companion papers deal with the sensor designs used and quantitative results achieved in the simpler two-phase cases of liquid/liquid flows and gas/liquid flows.

Evaluation of the Webler-Brown model for estimating tetrachloroethylene exposure from vinyl-lined asbestos-cement pipes

PubMed Central

Spence, Lisa A; Aschengrau, Ann; Gallagher, Lisa E; Webster, Thomas F; Heeren, Timothy C; Ozonoff, David M

2008-01-01

Background From May 1968 through March 1980, vinyl-lined asbestos-cement (VL/AC) water distribution pipes were installed in New England to avoid taste and odor problems associated with asbestos-cement pipes. The vinyl resin was applied to the inner pipe surface in a solution of tetrachloroethylene (perchloroethylene, PCE). Substantial amounts of PCE remained in the liner and subsequently leached into public drinking water supplies. Methods Once aware of the leaching problem and prior to remediation (April-November 1980), Massachusetts regulators collected drinking water samples from VL/AC pipes to determine the extent and severity of the PCE contamination. This study compares newly obtained historical records of PCE concentrations in water samples (n = 88) with concentrations estimated using an exposure model employed in epidemiologic studies on the cancer risk associated with PCE-contaminated drinking water. The exposure model was developed by Webler and Brown to estimate the mass of PCE delivered to subjects' residences. Results The mean and median measured PCE concentrations in the water samples were 66 and 0.5 μg/L, respectively, and the range extended from non-detectable to 2432 μg/L. The model-generated concentration estimates and water sample concentrations were moderately correlated (Spearman rank correlation coefficient = 0.48, p < 0.0001). Correlations were higher in samples taken at taps and spigots vs. hydrants (ρ = 0.84 vs. 0.34), in areas with simple vs. complex geometry (ρ = 0.51 vs. 0.38), and near pipes installed in 1973–1976 vs. other years (ρ = 0.56 vs. 0.42 for 1968–1972 and 0.37 for 1977–1980). Overall, 24% of the variance in measured PCE concentrations was explained by the model-generated concentration estimates (p < 0.0001). Almost half of the water samples had undetectable concentrations of PCE. Undetectable levels were more common in areas with the earliest installed VL/AC pipes, at the beginning and middle of VL/AC pipes, at hydrants, and in complex pipe configurations. Conclusion PCE concentration estimates generated using the Webler-Brown model were moderately correlated with measured water concentrations. The present analysis suggests that the exposure assessment process used in prior epidemiological studies could be improved with more accurate characterization of water flow. This study illustrates one method of validating an exposure model in an epidemiological study when historical measurements are not available. PMID:18518975

Evaluation of the Webler-Brown model for estimating tetrachloroethylene exposure from vinyl-lined asbestos-cement pipes.

PubMed

Spence, Lisa A; Aschengrau, Ann; Gallagher, Lisa E; Webster, Thomas F; Heeren, Timothy C; Ozonoff, David M

2008-06-02

From May 1968 through March 1980, vinyl-lined asbestos-cement (VL/AC) water distribution pipes were installed in New England to avoid taste and odor problems associated with asbestos-cement pipes. The vinyl resin was applied to the inner pipe surface in a solution of tetrachloroethylene (perchloroethylene, PCE). Substantial amounts of PCE remained in the liner and subsequently leached into public drinking water supplies. Once aware of the leaching problem and prior to remediation (April-November 1980), Massachusetts regulators collected drinking water samples from VL/AC pipes to determine the extent and severity of the PCE contamination. This study compares newly obtained historical records of PCE concentrations in water samples (n = 88) with concentrations estimated using an exposure model employed in epidemiologic studies on the cancer risk associated with PCE-contaminated drinking water. The exposure model was developed by Webler and Brown to estimate the mass of PCE delivered to subjects' residences. The mean and median measured PCE concentrations in the water samples were 66 and 0.5 microg/L, respectively, and the range extended from non-detectable to 2432 microg/L. The model-generated concentration estimates and water sample concentrations were moderately correlated (Spearman rank correlation coefficient = 0.48, p < 0.0001). Correlations were higher in samples taken at taps and spigots vs. hydrants (rho = 0.84 vs. 0.34), in areas with simple vs. complex geometry (rho = 0.51 vs. 0.38), and near pipes installed in 1973-1976 vs. other years (rho = 0.56 vs. 0.42 for 1968-1972 and 0.37 for 1977-1980). Overall, 24% of the variance in measured PCE concentrations was explained by the model-generated concentration estimates (p < 0.0001). Almost half of the water samples had undetectable concentrations of PCE. Undetectable levels were more common in areas with the earliest installed VL/AC pipes, at the beginning and middle of VL/AC pipes, at hydrants, and in complex pipe configurations. PCE concentration estimates generated using the Webler-Brown model were moderately correlated with measured water concentrations. The present analysis suggests that the exposure assessment process used in prior epidemiological studies could be improved with more accurate characterization of water flow. This study illustrates one method of validating an exposure model in an epidemiological study when historical measurements are not available.

Valve malfunction detection apparatus

NASA Astrophysics Data System (ADS)

Burley, Richard K.

1993-07-01

A detection system is provided for sensing a malfunction of a valve having an outlet connected to an end of a first pipe through which pressurized fluid may be flowed in a downstream direction away from the valve. The system includes a bypass pipe connected at its opposite ends to the first pipe and operative to bypass a portion of the fluid flow therethrough around a predetermined section thereof. A housing is interiorly divided by a flexible diaphragm into first and second opposite chambers which are respectively communicated with the first pipe section and the bypass pipe, the diaphragm being spring-biased toward the second chamber. The diaphragm housing cooperates with check valves and orifices connected in the two pipes to create and maintain a negative pressure in the first pipe section in response to closure of the valve during pressurized flow through the first pipe. A pressure switch senses the negative pressure and transmits a signal indicative thereof to a computer. Upon cessation of the signal while the valve is still closed, the computer responsively generates a signal indicating that the valve, or another portion of the detection system, is leaking.

Valve malfunction detection apparatus

NASA Technical Reports Server (NTRS)

Burley, Richard K. (Inventor)

1993-01-01

A detection system is provided for sensing a malfunction of a valve having an outlet connected to an end of a first pipe through which pressurized fluid may be flowed in a downstream direction away from the valve. The system includes a bypass pipe connected at its opposite ends to the first pipe and operative to bypass a portion of the fluid flow therethrough around a predetermined section thereof. A housing is interiorly divided by a flexible diaphragm into first and second opposite chambers which are respectively communicated with the first pipe section and the bypass pipe, the diaphragm being spring-biased toward the second chamber. The diaphragm housing cooperates with check valves and orifices connected in the two pipes to create and maintain a negative pressure in the first pipe section in response to closure of the valve during pressurized flow through the first pipe. A pressure switch senses the negative pressure and transmits a signal indicative thereof to a computer. Upon cessation of the signal while the valve is still closed, the computer responsively generates a signal indicating that the valve, or another portion of the detection system, is leaking.

Detection of underground water distribution piping system and leakages using ground penetrating radar (GPR)

NASA Astrophysics Data System (ADS)

Amran, Tengku Sarah Tengku; Ismail, Mohamad Pauzi; Ahmad, Mohamad Ridzuan; Amin, Mohamad Syafiq Mohd; Sani, Suhairy; Masenwat, Noor Azreen; Ismail, Mohd Azmi; Hamid, Shu-Hazri Abdul

2017-01-01

A water pipe is any pipe or tubes designed to transport and deliver water or treated drinking with appropriate quality, quantity and pressure to consumers. The varieties include large diameter main pipes, which supply entire towns, smaller branch lines that supply a street or group of buildings or small diameter pipes located within individual buildings. This distribution system (underground) is used to describe collectively the facilities used to supply water from its source to the point of usage. Therefore, a leaking in the underground water distribution piping system increases the likelihood of safe water leaving the source or treatment facility becoming contaminated before reaching the consumer. Most importantly, leaking can result in wastage of water which is precious natural resources. Furthermore, they create substantial damage to the transportation system and structure within urban and suburban environments. This paper presents a study on the possibility of using ground penetrating radar (GPR) with frequency of 1GHz to detect pipes and leakages in underground water distribution piping system. Series of laboratory experiment was designed to investigate the capability and efficiency of GPR in detecting underground pipes (metal and PVC) and water leakages. The data was divided into two parts: 1. detecting/locating underground water pipe, 2. detecting leakage of underground water pipe. Despite its simplicity, the attained data is proved to generate a satisfactory result indicating GPR is capable and efficient, in which it is able to detect the underground pipe and presence of leak of the underground pipe.

Localised surface plasmon-like resonance generated by microwave electromagnetic waves in pipe defects

NASA Astrophysics Data System (ADS)

Alobaidi, Wissam M.; Nima, Zeid A.; Sandgren, Eric

2018-01-01

Localised surface plasmon (LSP)-like resonance phenomena were simulated in COMSOL Multiphysics™, and the electric field enhancement was evaluated in eight pipe defects using the microwave band from 1.80 to 3.00 GHz and analysed by finite element analysis (FEA). The simulation was carried out, in each defect case, on a pipe that has 762 mm length and 152.4 mm inner diameter, and 12.7 mm pipe wall thickness. Defects were positioned in the middle of the pipe and were named as follows; SD: Square Defect, FCD: fillet corner defect, FD: fillet defect, HCD: half circle defect, TCD: triangle corner defect, TD: triangle defect, ZD: zigzag defect, GD: gear defect. The LSP electric field, and scattering parametric (S21, and S11) waves were evaluated in all cases and found to be strongly dependent on the size and the shape of the defect rather than the pipe and or the medium materials.

Flow Energy Piezoelectric Bimorph Nozzle Harvester

NASA Technical Reports Server (NTRS)

Walkemeyer, Phillip E. (Inventor); Tosi, Phillipe (Inventor); Corbett, Thomas Gary (Inventor); Hall, Jeffrey L. (Inventor); Lee, Hyeong Jae (Inventor); Arrazola, Alvaro Jose (Inventor); Sherrit, Stewart (Inventor); Colonius, Tim (Inventor); Kim, Namhyo (Inventor); Sun, Kai (Inventor)

2016-01-01

A flow energy harvesting device having a harvester pipe includes a flow inlet that receives flow from a primary pipe, a flow outlet that returns the flow into the primary pipe, and a flow diverter within the harvester pipe having an inlet section coupled to the flow inlet, a flow constriction section coupled to the inlet section and positioned at a midpoint of the harvester pipe and having a spline shape with a substantially reduced flow opening size at a constriction point along the spline shape, and an outlet section coupled to the constriction section. The harvester pipe may further include a piezoelectric structure extending from the inlet section through the constriction section and point such that the fluid flow past the constriction point results in oscillatory pressure amplitude inducing vibrations in the piezoelectric structure sufficient to cause a direct piezoelectric effect and to generate electrical power for harvesting.

Apparatus for inspecting piping

DOEpatents

Zollingger, W. Thor; Appel, D. Keith; Park, Larry R.

1995-01-01

An inspection rabbit for inspecting piping systems having severe bends therein. The rabbit consists of a flexible, modular body containing a miniaturized eddy current inspection probe, a self-contained power supply for proper operation of the rabbit, an outer surface that allows ease of movement through piping systems and means for transmitting data generated by the inspection device. The body is preferably made of flexible polyvinyl chloride (PVC) tubing or, alternatively, silicone rubber with a shrink wrapping of polytetrafluoroethylene (TEFLON.RTM.). The body is formed to contain the power supply, preferably a plurality of batteries, and a spool of communication wire that connects to a data processing computer external to the piping system.

High-Fidelity Generalization Method of Cells for Inelastic Periodic Multiphase Materials

NASA Technical Reports Server (NTRS)

Aboudi, Jacob; Pindera, Marek-Jerzy; Arnold, Steven M.

2002-01-01

An extension of a recently-developed linear thermoelastic theory for multiphase periodic materials is presented which admits inelastic behavior of the constituent phases. The extended theory is capable of accurately estimating both the effective inelastic response of a periodic multiphase composite and the local stress and strain fields in the individual phases. The model is presently limited to materials characterized by constituent phases that are continuous in one direction, but arbitrarily distributed within the repeating unit cell which characterizes the material's periodic microstructure. The model's analytical framework is based on the homogenization technique for periodic media, but the method of solution for the local displacement and stress fields borrows concepts previously employed by the authors in constructing the higher-order theory for functionally graded materials, in contrast with the standard finite-element solution method typically used in conjunction with the homogenization technique. The present approach produces a closed-form macroscopic constitutive equation for a periodic multiphase material valid for both uniaxial and multiaxial loading. The model's predictive accuracy in generating both the effective inelastic stress-strain response and the local stress said inelastic strain fields is demonstrated by comparison with the results of an analytical inelastic solution for the axisymmetric and axial shear response of a unidirectional composite based on the concentric cylinder model, and with finite-element results for transverse loading.

Sulfation of Eggshell Proteins by Pipe Defines Dorsal-Ventral Polarity in the Drosophila embryo

PubMed Central

Zhang, Zhenyu; Stevens, Leslie M.; Stein, David

2009-01-01

Summary Drosophila embryonic dorsal-ventral (DV) polarity is controlled by a group of sequentially acting serine proteases located in the fluid-filled perivitelline space between the embryonic membrane and the eggshell, which generate the ligand for the Toll receptor on the ventral side of the embryo [1, 2, 3]. Spatial control of the protease cascade relies on the Pipe sulfotransferase, a fly homologue of vertebrate glycosaminoglycan modifying enzymes [4, 5, 6], which is expressed in ventral cells of the follicular epithelium surrounding the developing oocyte. The identification of the Pipe enzymatic target has remained a major gap in our understanding of the mechanism controlling the perivitelline protease cascade, and hence embryonic DV patterning. Here we show that the protein Vitelline Membrane-Like (VML) [7] undergoes Pipe-dependent sulfation and, consistent with a role in conveying positional information from the egg chamber to the embryo, becomes incorporated into the eggshell at a position corresponding to the location of the follicle cells from which it was secreted. Although VML influences embryonic DV pattern in a sensitized genetic background, VML is not essential for DV axis formation, suggesting that there is redundancy in the composition of the Pipe enzymatic target. Correspondingly, we find that additional structural components of the vitelline membrane undergo Pipe-dependent sulfation. In identifying the elusive targets of Pipe, this ork points to the vitelline membrane as the source of signals that generate the Drosophila DV axis and provides a framework for understanding the mechanism controlling spatially-specific activation of serine protease activity during embryonic pattern formation. PMID:19540119

Non-contact feature detection using ultrasonic Lamb waves

DOEpatents

Sinha, Dipen N [Los Alamos, NM

2011-06-28

Apparatus and method for non-contact ultrasonic detection of features on or within the walls of hollow pipes are described. An air-coupled, high-power ultrasonic transducer for generating guided waves in the pipe wall, and a high-sensitivity, air-coupled transducer for detecting these waves, are disposed at a distance apart and at chosen angle with respect to the surface of the pipe, either inside of or outside of the pipe. Measurements may be made in reflection or transmission modes depending on the relative position of the transducers and the pipe. Data are taken by sweeping the frequency of the incident ultrasonic waves, using a tracking narrow-band filter to reduce detected noise, and transforming the frequency domain data into the time domain using fast Fourier transformation, if required.

Investigation of arterial gas occlusions. [effect of noncondensable gases on high performance heat pipes

NASA Technical Reports Server (NTRS)

Saaski, E. W.

1974-01-01

The effect of noncondensable gases on high-performance arterial heat pipes was investigated both analytically and experimentally. Models have been generated which characterize the dissolution of gases in condensate, and the diffusional loss of dissolved gases from condensate in arterial flow. These processes, and others, were used to postulate stability criteria for arterial heat pipes under isothermal and non-isothermal condensate flow conditions. A rigorous second-order gas-loaded heat pipe model, incorporating axial conduction and one-dimensional vapor transport, was produced and used for thermal and gas studies. A Freon-22 (CHCIF2) heat pipe was used with helium and xenon to validate modeling. With helium, experimental data compared well with theory. Unusual gas-control effects with xenon were attributed to high solubility.

An experimental study on the compatibility of acetone with aluminum flat-plate heat pipes

NASA Astrophysics Data System (ADS)

Hsieh, Jui-Ching; Lin, David T. W.; Huang, Hsin-Jung; Yang, Tzu-Wei

2014-04-01

This study investigates the compatibility of aluminum flat-plate heat pipes (FPHPs) used for filling acetone as a working fluid after long-term operation of and the non-condensable gas (NCG) exhausting process. The rate of NCG generation substantially decreased after conducting the NCG exhausting process, proving the compatibility of acetone with the aluminum FPHPs. However, the thermal resistance was not enhanced because hydroxide bayerite (Al(OH)3) was generated as a product of the reaction.

Ultrasonic Device Would Open Pipe Bombs

NASA Technical Reports Server (NTRS)

El-Raheb, Michael S.; Adams, Marc A.; Zwissler, James G.

1991-01-01

Piezoelectric ultrasonic transducer, energized by frequency generator and power supply, vibrates shell of pipe bomb while hardly disturbing explosive inner material. Frequency-control circuitry senses resonance in shell and holds generator at that frequency to induce fatigue cracking in threads of end cap. In addition to disarming bombs, ultrasonically induced fatigue may have other applications. In manufacturing, replaces some machining and cutting operations. In repair of equipment, cleanly and quickly disassembles corroded parts. In demolition of buildings used to dismember steel framework safely and controllably.

Improved Design Process Part of the Ship Producibility Program of the National Shipbuilding Research Program

DTIC Science & Technology

1977-04-01

Exh and Escape Fresh Water Feed Treatment Cargo Oil Tank Cleaning Diesel Generator Piping Piping Material Schedule List of Motors and... tank length frame and stiffener spacing, etc. One yard buys only mill edge plates, and one yard buys only cold flange quality plates. 2-13 C. POST...gage boards, all interconnecting piping and valves, and all mounted on a common foundation, or a pump room assembled on a tank top unit. Use of packages

Non-Newtonian Liquid Flow through Small Diameter Piping Components: CFD Analysis

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Tarun Kanti; Das, Sudip Kumar

2016-10-01

Computational Fluid Dynamics (CFD) analysis have been carried out to evaluate the frictional pressure drop across the horizontal pipeline and different piping components, like elbows, orifices, gate and globe valves for non-Newtonian liquid through 0.0127 m pipe line. The mesh generation is done using GAMBIT 6.3 and FLUENT 6.3 is used for CFD analysis. The CFD results are verified with our earlier published experimental data. The CFD results show the very good agreement with the experimental values.

Apparatus for generating coherent infrared energy of selected wavelength

DOEpatents

Stevens, C.G.

A tunable source of coherent infrared energy includes a heat pipe having an intermediate region at which cesium is heated to vaporizing temperature and end regions at which the vapor is condensed and returned to the intermediate region for reheating and recirculation. Optical pumping light is directed along the axis of the heat pipe through a first end window to stimulate emission of coherent infrared energy which is transmitted out through an opposite end window. A porous walled tubulation extends along the axis of the heat pipe and defines a region in which cesium vapor is further heated to a temperature sufficient to dissociate cesium dimers which would decrease efficiency by absorbing pump light. Efficient generation of any desired infrared wavelength is realized by varying the wavelength of the pump light.

Use of heat pipes in electronic hardware

NASA Technical Reports Server (NTRS)

Graves, J. R.

1977-01-01

A modular, multiple output power converter was developed in order to reduce costs of space hardware in future missions. The converter is of reduced size and weight, and utilizes advanced heat removal techniques, in the form of heat pipes which remove internally generated heat more effectively than conventional methods.

Multiphase flow microfluidics for the production of single or multiple emulsions for drug delivery.

PubMed

Zhao, Chun-Xia

2013-11-01

Considerable effort has been directed towards developing novel drug delivery systems. Microfluidics, capable of generating monodisperse single and multiple emulsion droplets, executing precise control and operations on these droplets, is a powerful tool for fabricating complex systems (microparticles, microcapsules, microgels) with uniform size, narrow size distribution and desired properties, which have great potential in drug delivery applications. This review presents an overview of the state-of-the-art multiphase flow microfluidics for the production of single emulsions or multiple emulsions for drug delivery. The review starts with a brief introduction of the approaches for making single and multiple emulsions, followed by presentation of some potential drug delivery systems (microparticles, microcapsules and microgels) fabricated in microfluidic devices using single or multiple emulsions as templates. The design principles, manufacturing processes and properties of these drug delivery systems are also discussed and compared. Furthermore, drug encapsulation and drug release (including passive and active controlled release) are provided and compared highlighting some key findings and insights. Finally, site-targeting delivery using multiphase flow microfluidics is also briefly introduced. Copyright © 2013 Elsevier B.V. All rights reserved.

Optimal Power Flow in Multiphase Radial Networks with Delta Connections: Preprint

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

Zhao, Changhong; Dall-Anese, Emiliano; Low, Steven H.

This paper focuses on multiphase radial distribution networks with mixed wye and delta connections, and proposes a semidefinite relaxation of the AC optimal power flow (OPF) problem. Two multiphase power-flow models are developed to facilitate the integration of delta-connected generation units/loads in the OPF problem. The first model extends traditional branch flow models - and it is referred to as extended branch flow model (EBFM). The second model leverages a linear relationship between per-phase power injections and delta connections, which holds under a balanced voltage approximation (BVA). Based on these models, pertinent OPF problems are formulated and relaxed to semidefinitemore » programs (SDPs). Numerical studies on IEEE test feeders show that SDP relaxations can be solved efficiently by a generic optimization solver. Numerical evidences indicate that solving the resultant SDP under BVA is faster than under EBFM. Moreover, both SDP solutions are numerically exact with respect to voltages and branch flows. It is also shown that the SDP solution under BVA has a small optimality gap, while the BVA model is accurate in the sense that it reflects actual system voltages.« less

Generating a Multiphase Equation of State with Swarm Intelligence

NASA Astrophysics Data System (ADS)

Cox, Geoffrey

2017-06-01

Hydrocode calculations require knowledge of the variation of pressure of a material with density and temperature, which is given by the equation of state. An accurate model needs to account for discontinuities in energy, density and properties of a material across a phase boundary. When generating a multiphase equation of state the modeller attempts to balance the agreement between the available data for compression, expansion and phase boundary location. However, this can prove difficult because minor adjustments in the equation of state for a single phase can have a large impact on the overall phase diagram. Recently, Cox and Christie described a method for combining statistical-mechanics-based condensed matter physics models with a stochastic analysis technique called particle swarm optimisation. The models produced show good agreement with experiment over a wide range of pressure-temperature space. This talk details the general implementation of this technique, shows example results, and describes the types of analysis that can be performed with this method.

Multiphase flow calculation software

DOEpatents

Fincke, James R.

2003-04-15

Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.

Experimental and analytical study of water pipe's rupture for damage identification purposes

NASA Astrophysics Data System (ADS)

Papakonstantinou, Konstantinos G.; Shinozuka, Masanobu; Beikae, Mohsen

2011-04-01

A malfunction, local damage or sudden pipe break of a pipeline system can trigger significant flow variations. As shown in the paper, pressure variations and pipe vibrations are two strongly correlated parameters. A sudden change in the flow velocity and pressure of a pipeline system can induce pipe vibrations. Thus, based on acceleration data, a rapid detection and localization of a possible damage may be carried out by inexpensive, nonintrusive monitoring techniques. To illustrate this approach, an experiment on a single pipe was conducted in the laboratory. Pressure gauges and accelerometers were installed and their correlation was checked during an artificially created transient flow. The experimental findings validated the correlation between the parameters. The interaction between pressure variations and pipe vibrations was also theoretically justified. The developed analytical model explains the connection among flow pressure, velocity, pressure wave propagation and pipe vibration. The proposed method provides a rapid, efficient and practical way to identify and locate sudden failures of a pipeline system and sets firm foundations for the development and implementation of an advanced, new generation Supervisory Control and Data Acquisition (SCADA) system for continuous health monitoring of pipe networks.

Comparison and validation of acoustic response models for wind noise reduction pipe arrays

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

Marty, Julien; Denis, Stéphane; Gabrielson, Thomas

The detection capability of the infrasound component of the International Monitoring System (IMS) is tightly linked to the performance of its wind noise reduction systems. The wind noise reduction solution implemented at all IMS infrasound measurement systems consists of a spatial distribution of air inlets connected to the infrasound sensor through a network of pipes. This system, usually referred to as “pipe array,” has proven its efficiency in operational conditions. The objective of this paper is to present the results of the comparison and validation of three distinct acoustic response models for pipe arrays. The characteristics of the models andmore » the results obtained for a defined set of pipe array configurations are described. A field experiment using a newly developed infrasound generator, dedicated to the validation of these models, is then presented. The comparison between the modeled and empirical acoustic responses shows that two of the three models can be confidently used to estimate pipe array acoustic responses. Lastly, this study paves the way to the deconvolution of IMS infrasound data from pipe array responses and to the optimization of pipe array design to IMS applications.« less

Comparison and validation of acoustic response models for wind noise reduction pipe arrays

DOE PAGES

Marty, Julien; Denis, Stéphane; Gabrielson, Thomas; ...

2017-02-13

The detection capability of the infrasound component of the International Monitoring System (IMS) is tightly linked to the performance of its wind noise reduction systems. The wind noise reduction solution implemented at all IMS infrasound measurement systems consists of a spatial distribution of air inlets connected to the infrasound sensor through a network of pipes. This system, usually referred to as “pipe array,” has proven its efficiency in operational conditions. The objective of this paper is to present the results of the comparison and validation of three distinct acoustic response models for pipe arrays. The characteristics of the models andmore » the results obtained for a defined set of pipe array configurations are described. A field experiment using a newly developed infrasound generator, dedicated to the validation of these models, is then presented. The comparison between the modeled and empirical acoustic responses shows that two of the three models can be confidently used to estimate pipe array acoustic responses. Lastly, this study paves the way to the deconvolution of IMS infrasound data from pipe array responses and to the optimization of pipe array design to IMS applications.« less

Mitigating Climate Change with Ocean Pipes: Influencing Land Temperature and Hydrology and Termination Overshoot Risk

NASA Astrophysics Data System (ADS)

Kwiatkowski, L.; Caldeira, K.; Ricke, K.

2014-12-01

With increasing risk of dangerous climate change geoengineering solutions to Earth's climate problems have attracted much attention. One proposed geoengineering approach considers the use of ocean pipes as a means to increase ocean carbon uptake and the storage of thermal energy in the deep ocean. We use a latest generation Earth System Model (ESM) to perform simulations of idealised extreme implementations of ocean pipes. In our simulations, downward transport of thermal energy by ocean pipes strongly cools the near surface atmosphere - by up to 11°C on a global mean. The ocean pipes cause net thermal energy to be transported from the terrestrial environment to the deep ocean while increasing the global net transport of water to land. By cooling the ocean surface more than the land, ocean pipes tend to promote a monsoonal-type circulation, resulting in increased water vapour transport to land. Throughout their implementation, ocean pipes prevent energy from escaping to space, increasing the amount of energy stored in Earth's climate system despite reductions in surface temperature. As a consequence, our results indicate that an abrupt termination of ocean pipes could cause dramatic increases in surface temperatures beyond that which would have been obtained had ocean pipes not been implemented.

Detection of surface cracking in steel pipes based on vibration data using a multi-class support vector machine classifier

NASA Astrophysics Data System (ADS)

Mustapha, S.; Braytee, A.; Ye, L.

2017-04-01

In this study, we focused at the development and verification of a robust framework for surface crack detection in steel pipes using measured vibration responses; with the presence of multiple progressive damage occurring in different locations within the structure. Feature selection, dimensionality reduction, and multi-class support vector machine were established for this purpose. Nine damage cases, at different locations, orientations and length, were introduced into the pipe structure. The pipe was impacted 300 times using an impact hammer, after each damage case, the vibration data were collected using 3 PZT wafers which were installed on the outer surface of the pipe. At first, damage sensitive features were extracted using the frequency response function approach followed by recursive feature elimination for dimensionality reduction. Then, a multi-class support vector machine learning algorithm was employed to train the data and generate a statistical model. Once the model is established, decision values and distances from the hyper-plane were generated for the new collected data using the trained model. This process was repeated on the data collected from each sensor. Overall, using a single sensor for training and testing led to a very high accuracy reaching 98% in the assessment of the 9 damage cases used in this study.

Direct measurement of toxicants inhaled by water pipe users in the natural environment using a real-time in situ sampling technique.

PubMed

Katurji, M; Daher, N; Sheheitli, H; Saleh, R; Shihadeh, A

2010-11-01

While narghile water pipe smoking has become a global phenomenon, knowledge regarding its toxicant content and delivery, addictive properties, and health consequences is sorely lagging. One challenge in measuring toxicant content of the smoke in the laboratory is the large number of simplifying assumptions that must be made to model a "typical" smoking session using a smoking machine, resulting in uncertainty over the obtained toxicant yields. In this study, we develop an alternative approach in which smoke generated by a human water pipe user is sampled directly during the smoking session. The method, dubbed real-time in situ sampling (RINS), required developing a self-powered portable instrument capable of automatically sampling a fixed fraction of the smoke generated by the user. Instrument performance was validated in the laboratory, and the instrument was deployed in a field study involving 43 ad libitum water pipe use sessions in Beirut area cafés in which we measured inhaled nicotine, carbon monoxide (CO), and water pipe ma'ssel-derived "tar." We found that users drew a mean of 119 L of smoke containing 150 mg of CO, 4 mg of nicotine, and 602 mg of ma'ssel-derived "tar" during a single use session (mean duration = 61 min). These first direct measurements of toxicant delivery demonstrate that ordinary water pipe use involves inhaling large quantities of CO, nicotine, and dry particulate matter. Results are compared with those obtained using the Beirut method smoking machine protocol.

Impact of treatment on Pb release from full and partially replaced harvested Lead Service Lines (LSLs).

PubMed

Cartier, Clément; Doré, Evelyne; Laroche, Laurent; Nour, Shokoufeh; Edwards, Marc; Prévost, Michèle

2013-02-01

Release of lead from 80% partially replaced service lines was compared to full lead service lines using harvested-stabilized lead pipes and field brass connectors. After more than a year of stabilization, lead release was consistent with field samples. Over the relatively short duration partial replacement of lead pipe by copper pipe (3 months), generated high lead release, attributed to galvanic corrosion, resulting in a final outcome for lead release that was even worse than for a full lead pipe. Increased lead release was especially evident at higher flow rates. Orthophosphate reduced lead release from full lead pipes by 64%. For partially replaced samples with copper, lead concentrations were unchanged by phosphate dosing at moderate flow (103 ± 265 vs 169 ± 349 μg/L) and were increased to very high levels when sampled at high flow rates (1001 ± 1808 vs 257 ± 224 μg/L). The increase lead release was in the form of particulate lead (>90%). In comparison to the condition without treatment, increased sulfate treatment had little impact on lead release from 100%-Pb rigs but reduced lead release from partially replaced lead pipes with copper. Our results also raise questions concerning protocols based on short 30 min stagnation (as those used in Canada) due to their incapacity to consider particulate lead release generated mostly after longer stagnation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Experimental Verification of Steel Pipe Collapse under Vacuum Pressure Conditions

NASA Astrophysics Data System (ADS)

Autrique, R.; Rodal, E.

2016-11-01

Steel pipes are used widely in hydroelectric systems and in pumping systems. Both systems are subject to hydraulic transient effects caused by changes in boundary conditions, such as sudden valve closures, pump failures, or accidents. Water column separation, and its associated vaporization pressure inside the pipe, can cause the collapse of thin walled steel pipes subject to atmospheric pressure, as happened during the well known Oigawa Power Plant accident in Japan, in 1950. The conditions under which thin walled pipes subject to external pressure can collapse have been studied mathematically since the second half of the XIX century, with classical authors Southwell and Von Mises obtaining definitive equations for long and short pipes in the second decade of the XX century, in which the fundamental variables are the diameter to thickness ratio D/t and the length to diameter ratio L/D. In this paper, the predicted critical D/t ratio for steel pipe collapse is verified experimentally, in a physical model able to reproduce hydraulic transients, generating vacuum pressures through rapid upstream valve closures.

Light Pipe Energy Savings Calculator

NASA Astrophysics Data System (ADS)

Owens, Erin; Behringer, Ernest R.

2009-04-01

Dependence on fossil fuels is unsustainable and therefore a shift to renewable energy sources such as sunlight is required. Light pipes provide a way to utilize sunlight for interior lighting, and can reduce the need for fossil fuel-generated electrical energy. Because consumers considering light pipe installation may be more strongly motivated by cost considerations than by sustainability arguments, an easy means to examine the corresponding costs and benefits is needed to facilitate informed decision-making. The purpose of this American Physical Society Physics and Society Fellowship project is to create a Web-based calculator to allow users to quantify the possible cost savings for their specific light pipe application. Initial calculations show that the illumination provided by light pipes can replace electric light use during the day, and in many cases can supply greater illumination levels than those typically given by electric lighting. While the installation cost of a light pipe is significantly greater than the avoided cost of electricity over the lifetime of the light pipe at current prices, savings may be realized if electricity prices increase.

Stopped-pipe wind instruments: Acoustics of the panpipes

NASA Astrophysics Data System (ADS)

Fletcher, N. H.

2005-01-01

Stopped-pipe jet-excited musical instruments are known in many cultures, those best-known today being the panpipes or syrinx of Eastern Europe and of the Peruvian Andes. Although the playing style differs, in each case the instrument consists of a set of graduated bamboo pipes excited by blowing across the open tops. Details of the excitation aerodynamics warrant examination, particularly as the higher notes contain amplitudes of the even harmonics approaching those of the odd harmonics expected from a stopped pipe. Analysis shows that the jet offset is controlled by the fluid dynamics of the jet, and is such that appreciable even-harmonic excitation is generated. The theory is largely confirmed by measurements on a player. .

Stopped-pipe wind instruments: acoustics of the panpipes.

PubMed

Fletcher, N H

2005-01-01

Stopped-pipe jet-excited musical instruments are known in many cultures, those best-known today being the panpipes or syrinx of Eastern Europe and of the Peruvian Andes. Although the playing style differs, in each case the instrument consists of a set of graduated bamboo pipes excited by blowing across the open tops. Details of the excitation aerodynamics warrant examination, particularly as the higher notes contain amplitudes of the even harmonics approaching those of the odd harmonics expected from a stopped pipe. Analysis shows that the jet offset is controlled by the fluid dynamics of the jet, and is such that appreciable even-harmonic excitation is generated. The theory is largely confirmed by measurements on a player.

Solids feed nozzle for fluidized bed

DOEpatents

Zielinski, Edward A.

1982-01-01

The vertical fuel pipe of a fluidized bed extends up through the perforated support structure of the bed to discharge granulated solid fuel into the expanded bed. A cap, as a deflecting structure, is supported above the discharge of the fuel pipe and is shaped and arranged to divert the carrier fluid and granulated fuel into the combusting bed. The diverter structure is spaced above the end of the fuel pipe and provided with a configuration on its underside to form a venturi section which generates a low pressure in the stream into which the granules of solid fuel are drawn to lengthen their residence time in the combustion zone of the bed adjacent the fuel pipe.

Apparatus for inspecting piping

DOEpatents

Zollingger, W.T.; Appel, D.K.; Park, L.R.

1995-03-21

An inspection rabbit is described for inspecting piping systems having severe bends therein. The rabbit consists of a flexible, modular body containing a miniaturized eddy current inspection probe, a self-contained power supply for proper operation of the rabbit, an outer surface that allows ease of movement through piping systems and means for transmitting data generated by the inspection device. The body is preferably made of flexible polyvinyl chloride (PVC) tubing or, alternatively, silicone rubber with a shrink wrapping of polytetrafluoroethylene (TEFLON{trademark}). The body is formed to contain the power supply, preferably a plurality of batteries, and a spool of communication wire that connects to a data processing computer external to the piping system. 6 figures.

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

Jensen, Brian James

There is a scientific need to obtain new data to constrain and refine next generation multi-phase equation-of-state (EOS) for metals. Experiments are needed to locate phase boundaries, determine transition kinetic times, and to obtain EOS and Hugoniot data for relevant phases. The objectives of the current work was to examine the multiphase properties for cerium including the dynamic melt boundary and the low-pressure solid-solid phase transition through the critical point. These objectives were addressed by performing plate impact experiment that used multiple experimental configuration including front-surface impact experiments to directly measure transition kinetics, multislug experiments that used the overtake methodmore » to measure sound speeds at pressure, and preheat experiments to map out phase boundaries. Preliminary data and analysis obtained for cerium will be presented.« less

Tree Hydraulics: How Sap Rises

ERIC Educational Resources Information Center

Denny, Mark

2012-01-01

Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

Comparison of Two-Phase Pipe Flow in OpenFOAM with a Mechanistic Model

NASA Astrophysics Data System (ADS)

Shuard, Adrian M.; Mahmud, Hisham B.; King, Andrew J.

2016-03-01

Two-phase pipe flow is a common occurrence in many industrial applications such as power generation and oil and gas transportation. Accurate prediction of liquid holdup and pressure drop is of vast importance to ensure effective design and operation of fluid transport systems. In this paper, a Computational Fluid Dynamics (CFD) study of a two-phase flow of air and water is performed using OpenFOAM. The two-phase solver, interFoam is used to identify flow patterns and generate values of liquid holdup and pressure drop, which are compared to results obtained from a two-phase mechanistic model developed by Petalas and Aziz (2002). A total of 60 simulations have been performed at three separate pipe inclinations of 0°, +10° and -10° respectively. A three dimensional, 0.052m diameter pipe of 4m length is used with the Shear Stress Transport (SST) k - ɷ turbulence model to solve the turbulent mixtures of air and water. Results show that the flow pattern behaviour and numerical values of liquid holdup and pressure drop compare reasonably well to the mechanistic model.

Concrete filled steel pipe inspection using electro magnetic acoustic transducer (EMAT)

NASA Astrophysics Data System (ADS)

Na, Won-Bae; Kundu, Tribikram; Ryu, Yeon-Sun; Kim, Jeong-Tae

2005-05-01

Concrete-filled steel pipes are usually exposed in hostile environments such as seawater and deicing materials. The outside corrosion of the steel pipe can reduce the wall thickness and the corrosion-induced delamination of internal concrete can increase internal volume or pressure. In addition, the void that can possibly exist in the pipe reduces the bending resistance. To avoid structural failure due to this type of deterioration, appropriate inspection and repair techniques are to be developed. Guided wave techniques have strong potentials for this kind of inspection because of long-distance inspection capability. Among different transducer-coupling mechanism, electro-magnetic acoustic transducers (EMATs) give relatively consistent results in comparison to piezoelectric transducers since they do not need any couplant. In this study EMATs are used for transmitting and receiving cylindrical guided waves through concrete-filled steel pipes. Through time history curves and wavelet transform, it is shown that EMAT-generated cylindrical guided wave techniques have good potential for the interface inspection of concrete-filled steel pipes.

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

Chattopadhyay, J.; Dutta, B.K.; Kushwaha, H.S.

Leak-Before-Break (LBB) is being used to design the primary heat transport piping system of 500 MWe Indian Pressurized Heavy Water Reactors (IPHWR). The work is categorized in three directions to demonstrate three levels of safety against sudden catastrophic break. Level 1 is inherent in the design procedure of piping system as per ASME Sec.III with a well defined factor of safety. Level 2 consists of fatigue crack growth study of a postulated part-through flaw at the inside surface of pipes. Level 3 is stability analysis of a postulated leakage size flaw under the maximum credible loading condition. Developmental work relatedmore » to demonstration of level 2 and level 3 confidence is described in this paper. In a case study on fatigue crack growth on PHT straight pipes for level 2, negligible crack growth is predicted for the life of the reactor. For level 3 analysis, the R6 method has been adopted. A database to evaluate SIF of elbows with throughwall flaws under combined internal pressure and bending moment has been generated to provide one of the inputs for R6 method. The methodology of safety assessment of elbow using R6 method has been demonstrated for a typical pump discharge elbow. In this analysis, limit load of the cracked elbow has been determined by carrying out elasto-plastic finite element analysis. The limit load results compared well with those given by Miller. However, it requires further study to give a general form of limit load solution. On the experimental front, a set of small diameter pipe fracture experiments have been carried out at room temperature and 300{degrees}C. Two important observations of the experiments are - appreciable drop in maximum load at 300{degrees}C in case of SS pipes and out-of-plane crack growth in case of CS pipes. Experimental load deflection curves are finally compared with five J-estimation schemes predictions. A material database of PHT piping materials is also being generated for use in LBB analysis.« less

Acoustic cross-correlation flowmeter for solid-gas flow

DOEpatents

Sheen, S.H.; Raptis, A.C.

1984-05-14

Apparatus for measuring particle velocity in a solid-gas flow within a pipe includes: first and second transmitting transducers for transmitting first and second ultrasonic signals into the pipe at first and second locations, respectively, along the pipe; an acoustic decoupler, positioned between said first and second transmitting transducers, for acoustically isolating said first and second signals from one another; first and second detecting transducers for detecting said first and second signals and for generating first and second detected signals; and means for cross-correlating said first and second output signals.

EVALUATION OF METHODS FOR THE DETERMINATION OF DIESEL-GENERATED FINE PARTICULATE MATTER: PHYSICAL CHARACTERIZATION OF RESULTS

EPA Science Inventory

A multi-phase instrument comparison study was conducted on two different diesel engines on a dynamometer to compare commonly used particulate matter (PM) measurement techniques while sampling the same diesel exhaust aerosol and to evaluate inter- and intra-method variability. In...

NETL Crosscutting Research Video Series: Multiphase Flow

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

Li, Tingwen; Vaidheeswaran, Avinash

For over 30 years, NETL’s work in multiphase flow science has served as one of the cornerstones of the lab’s research portfolio. Multiphase flow refers to the simultaneous flow of gases, liquids and/or solid materials. The goal of the multiphase flow science team is to provide computational modeling tools to help offset the risk and cost of multiphase reactor development.

Jet pump assisted arterial heat pipe

NASA Technical Reports Server (NTRS)

Bienert, W. B.; Ducao, A. S.; Trimmer, D. S.

1978-01-01

This paper discusses the concept of an arterial heat pipe with a capillary driven jet pump. The jet pump generates a suction which pumps vapor and noncondensible gas from the artery. The suction also forces liquid into the artery and maintains it in a primed condition. A theoretical model was developed which predicts the existence of two stable ranges. Up to a certain tilt the artery will prime by itself once a heat load is applied to the heat pipe. At higher tilts, the jet pump can maintain the artery in a primed condition but self-priming is not possible. A prototype heat pipe was tested which self-primed up to a tilt of 1.9 cm, with a heat load of 500 watts. The heat pipe continued to prime reliably when operated as a VCHP, i.e., after a large amount of noncondensible gas was introduced.

Study on the residual stress relaxation in girth-welded steel pipes under bending load using diffraction methods

DOE PAGES

Hempel, Nico; Bunn, Jeffrey R.; Nitschke-Pagel, Thomas; ...

2017-02-02

This research is dedicated to the experimental investigation of the residual stress relaxation in girth-welded pipes due to quasi-static bending loads. Ferritic-pearlitic steel pipes are welded with two passes, resulting in a characteristic residual stress state with high tensile residual stresses at the weld root. Also, four-point bending is applied to generate axial load stress causing changes in the residual stress state. These are determined both on the outer and inner surfaces of the pipes, as well as in the pipe wall, using X-ray and neutron diffraction. Focusing on the effect of tensile load stress, it is revealed that notmore » only the tensile residual stresses are reduced due to exceeding the yield stress, but also the compressive residual stresses for equilibrium reasons. Furthermore, residual stress relaxation occurs both parallel and perpendicular to the applied load stress.« less

Study on the residual stress relaxation in girth-welded steel pipes under bending load using diffraction methods

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

Hempel, Nico; Bunn, Jeffrey R.; Nitschke-Pagel, Thomas

This research is dedicated to the experimental investigation of the residual stress relaxation in girth-welded pipes due to quasi-static bending loads. Ferritic-pearlitic steel pipes are welded with two passes, resulting in a characteristic residual stress state with high tensile residual stresses at the weld root. Also, four-point bending is applied to generate axial load stress causing changes in the residual stress state. These are determined both on the outer and inner surfaces of the pipes, as well as in the pipe wall, using X-ray and neutron diffraction. Focusing on the effect of tensile load stress, it is revealed that notmore » only the tensile residual stresses are reduced due to exceeding the yield stress, but also the compressive residual stresses for equilibrium reasons. Furthermore, residual stress relaxation occurs both parallel and perpendicular to the applied load stress.« less

Method for noninvasive determination of acoustic properties of fluids inside pipes

DOEpatents

None

2016-08-02

A method for determining the composition of fluids flowing through pipes from noninvasive measurements of acoustic properties of the fluid is described. The method includes exciting a first transducer located on the external surface of the pipe through which the fluid under investigation is flowing, to generate an ultrasound chirp signal, as opposed to conventional pulses. The chirp signal is received by a second transducer disposed on the external surface of the pipe opposing the location of the first transducer, from which the transit time through the fluid is determined and the sound speed of the ultrasound in the fluid is calculated. The composition of a fluid is calculated from the sound speed therein. The fluid density may also be derived from measurements of sound attenuation. Several signal processing approaches are described for extracting the transit time information from the data with the effects of the pipe wall having been subtracted.

Development of an Unsaturated Region Below a Perennial River

NASA Astrophysics Data System (ADS)

Su, G. W.; Zhou, Q.; Constantz, J.; Hatch, C.

2004-12-01

Field observations at the Russian River Bank Filtration Facility in Sonoma County, California indicate that an unsaturated region exists below the streambed near two adjacent groundwater pumping wells located along the riverbank. Understanding the conditions that give rise to unsaturated flow below the streambed is critical for improving and optimizing riverbank well pumping operations. To investigate the development of an unsaturated region below a perennial river near pumping wells, a three-dimensional model was developed using the multi-phase subsurface flow model, TOUGH2. The model is based on the region around the two pumping wells in the Russian River Bank Filtration Facility. The pumping wells consist of 9 perforated pipes that are projected horizontally into the aquifer at a depth of approximately 20 m below the land surface. A grid was developed for the TOUGH2 model with finer resolution near the wells to represent individual pipes. The effect of varying the pumping operation and the streambed permeability on the extent of the unsaturated region was investigated with the TOUGH2 model. The formation remained saturated below the streambed when only one of the wells was pumped at a rate of 1600 m3/hr, but an unsaturated region developed below the streambed when the two wells each pumped at a rate of 1600 m3/hr. This unsaturated region was deeper when the permeability of the streambed was lower than the aquifer material compared to when the streambed and aquifer permeabilities were the same.

Apparatus and method for acoustic monitoring of steam quality and flow

DOEpatents

Sinha, Dipen N.; Pantea, Cristian

2016-09-13

An apparatus and method for noninvasively monitoring steam quality and flow and in pipes or conduits bearing flowing steam, are described. By measuring the acoustic vibrations generated in steam-carrying conduits by the flowing steam either by direct contact with the pipe or remotely thereto, converting the measured acoustic vibrations into a frequency spectrum characteristic of the natural resonance vibrations of the pipe, and monitoring the amplitude and/or the frequency of one or more chosen resonance frequencies, changes in the steam quality in the pipe are determined. The steam flow rate and the steam quality are inversely related, and changes in the steam flow rate are calculated from changes in the steam quality once suitable calibration curves are obtained.

Capacitance probe for detection of anomalies in non-metallic plastic pipe

DOEpatents

Mathur, Mahendra P.; Spenik, James L.; Condon, Christopher M.; Anderson, Rodney; Driscoll, Daniel J.; Fincham, Jr., William L.; Monazam, Esmail R.

2010-11-23

The disclosure relates to analysis of materials using a capacitive sensor to detect anomalies through comparison of measured capacitances. The capacitive sensor is used in conjunction with a capacitance measurement device, a location device, and a processor in order to generate a capacitance versus location output which may be inspected for the detection and localization of anomalies within the material under test. The components may be carried as payload on an inspection vehicle which may traverse through a pipe interior, allowing evaluation of nonmetallic or plastic pipes when the piping exterior is not accessible. In an embodiment, supporting components are solid-state devices powered by a low voltage on-board power supply, providing for use in environments where voltage levels may be restricted.

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

Kozluk, M.J.; Vijay, D.K.

Postulated catastrophic rupture of high-energy piping systems is the fundamental criterion used for the safety design basis of both light and heavy water nuclear generating stations. Historically, the criterion has been applied by assuming a nonmechanistic instantaneous double-ended guillotine rupture of the largest diameter pipes inside of containment. Nonmechanistic, meaning that the assumption of an instantaneous guillotine rupture has not been based on stresses in the pipe, failure mechanisms, toughness of the piping material, nor the dynamics of the ruptured pipe ends as they separate. This postulated instantaneous double-ended guillotine rupture of a pipe was a convenient simplifying assumption thatmore » resulted in a conservative accident scenario. This conservative accident scenario has now become entrenched as the design basis accident for: containment design, shutdown system design, emergency fuel cooling systems design, and to establish environmental qualification temperature and pressure conditions. The requirement to address dynamic effects associated with the postulated pipe rupture subsequently evolved. The dynamic effects include: potential missiles, pipe whipping, blowdown jets, and thermal-hydraulic transients. Recent advances in fracture mechanics research have demonstrated that certain pipes under specific conditions cannot crack in ways that result in an instantaneous guillotine rupture. Canadian utilities are now using mechanistic fracture mechanics and leak-before-break assessments on a case-by-case basis, in limited applications, to support licensing cases which seek exemption from the need to consider the various dynamic effects associated with postulated instantaneous catastrophic rupture of high-energy piping systems inside and outside of containment.« less

Fiscal and policy implications of selling pipe tobacco for roll-your-own cigarettes in the United States.

PubMed

Morris, Daniel S; Tynan, Michael A

2012-01-01

The Federal excise tax was increased for tobacco products on April 1, 2009. While excise tax rates prior to the increase were the same for roll-your-own (RYO) and pipe tobacco, the tax on pipe tobacco was $21.95 per pound less than the tax on RYO tobacco after the increase. Subsequently, tobacco manufacturers began labeling loose tobacco as pipe tobacco and marketing these products to RYO consumers at a lower price. Retailers refer to these products as "dual purpose" or "dual use" pipe tobacco. Data on tobacco tax collections comes from the Alcohol and Tobacco Tax and Trade Bureau. Joinpoint software was used to identify changes in sales trends. Estimates were generated for the amount of pipe tobacco sold for RYO use and for Federal and state tax revenue lost through August 2011. Approximately 45 million pounds of pipe tobacco has been sold for RYO use from April 2009 to August 2011, lowering state and Federal revenue by over $1.3 billion. Marketing pipe tobacco as "dual purpose" and selling it for RYO use provides an opportunity to avoid paying higher cigarette prices. This blunts the public health impact excise tax increases would otherwise have on reducing tobacco use through higher prices. Selling pipe tobacco for RYO use decreases state and Federal revenue and also avoids regulations on flavored tobacco, banned descriptors, prohibitions on shipping, and reporting requirements.

Cargo systems manual: Heat Pipe Performance (HPP) STS-66

NASA Technical Reports Server (NTRS)

Napp, Robert

1994-01-01

The purpose of the cargo systems manual (CSM) is to provide a payload reference document for payload and shuttle flight operations personnel during shuttle mission planning, training, and flight operations. It includes orbiter-to-payload interface information and payload system information (including operationally pertinent payload safety data) that is directly applicable to the Mission Operations Directorate (MOD) role in the payload mission. The primary objectives of the heat pipe performance (HPP) are to obtain quantitative data on the thermal performance of heat pipes in a microgravity environment. This information will increase understanding of the behavior of heat pipes in space and be useful for application to design improvements in heat pipes and associated systems. The purpose of HPP-2 is to establish a complete one-g and zero-g data base for axial groove heat pipes. This data will be used to update and correlate data generated from a heat pipe design computer program called Grooved Analysis Program (GAP). The HPP-2 objectives are to: determine heat transport capacity and conductance for open/closed grooved heat pipes and different Freon volumes (nominal, under, and overcharged) using a uniform heat load; determine heat transport capacity and conductance for single/multiple evaporators using asymmetric heat loads; obtain precise static, spin, and rewicking data points for undercharged pipes; investigate heat flux limits (asymmetric heat loads); and determine effects of positive body force on thermal performance.

NETL Crosscutting Research Video Series: Multiphase Flow (Short Version)

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

None

For over 30 years, NETL’s work in multiphase flow science has served as one of the cornerstones of the lab’s research portfolio. Multiphase flow refers to the simultaneous flow of gases, liquids and/or solid materials. The goal of the multiphase flow science team is to provide computational modeling tools to help offset the risk and cost of multiphase reactor development.

A Heat Pipe Coupled Planar Thermionic Converter: Performance Characterization, Nondestructive Testing, and Evaluation.

DTIC Science & Technology

1992-03-15

Pipes, Computer Modelling, Nondestructive Testing. Tomography , Planar Converter, Cesium Reservoir 19. ABSTRACT (Continue on reverse if necessary and...Investigation ........................ 32 4.3 Computed Tomography ................................ 33 4.4 X-Ray Radiography...25 3.4 LEOS generated output data for Mo-Re converter ................ 26 4.1 Distance along converter imaged by the computed tomography

Apparatus for generating coherent infrared energy of selected wavelength

DOEpatents

Stevens, Charles G.

1985-01-01

A tunable source (11) of coherent infrared energy includes a heat pipe (12) having an intermediate region (24) at which cesium (22) is heated to vaporizing temperature and end regions (27, 28) at which the vapor is condensed and returned to the intermediate region (24) for reheating and recirculation. Optical pumping light (43) is directed along the axis of the heat pipe (12) through a first end window (17) to stimulate emission of coherent infrared energy which is transmitted out through an opposite end window (18). A porous walled tubulation (44) extends along the axis of the heat pipe (12) and defines a region (46) in which cesium vapor is further heated to a temperature sufficient to dissociate cesium dimers which would decrease efficiency by absorbing pump light (43). Efficient generation of any desired infrared wavelength is realized by varying the wavelength of the pump light (43).

Convex Relaxation of OPF in Multiphase Radial Networks with Wye and Delta Connections

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

Zhao, Changhong; Dall-Anese, Emiliano; Low, Steven

2017-08-01

This panel presentation focuses on multiphase radial distribution networks with wye and delta connections, and proposes a semidefinite relaxation of the AC optimal power flow (OPF) problem. Two multiphase power flow models are developed to facilitate the integration of delta-connected loads or generation resources in the OPF problem. The first model is referred to as the extended branch flow model (EBFM). The second model leverages a linear relationship between phase-to-ground power injections and delta connections that holds under a balanced voltage approximation (BVA). Based on these models, pertinent OPF problems are formulated and relaxed to semidefinite programs (SDPs). Numerical studiesmore » on IEEE test feeders show that the proposed SDP relaxations can be solved efficiently by a generic optimization solver. Numerical evidence also indicates that solving the resultant SDP under BVA is faster than under EBFM. Moreover, both SDP solutions are numerically exact with respect to voltages and branch flows. It is further shown that the SDP solution under BVA has a small optimality gap, and the BVA model is accurate in the sense that it reproduces actual system voltages.« less

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

Jablonská, Jana, E-mail: jana.jablonska@vsb.cz; Kozubková, Milada, E-mail: milada.kozubkova@vsb.cz

Cavitation today is a very important problem that is solved by means of experimental and mathematical methods. The article deals with the generation of cavitation in convergent divergent nozzle of rectangular cross section. Measurement of pressure, flow rate, temperature, amount of dissolved air in the liquid and visualization of cavitation area using high-speed camera was performed for different flow rates. The measurement results were generalized by dimensionless analysis, which allows easy detection of cavitation in the nozzle. For numerical simulation the multiphase mathematical model of cavitation consisting of water and vapor was created. During verification the disagreement with the measurementsmore » for higher flow rates was proved, therefore the model was extended to multiphase mathematical model (water, vapor and air), due to release of dissolved air. For the mathematical modeling the multiphase turbulence RNG k-ε model for low Reynolds number flow with vapor and air cavitation was used. Subsequently the sizes of the cavitation area were verified. In article the inlet pressure and loss coefficient depending on the amount of air added to the mathematical model are evaluated. On the basis of the approach it may be create a methodology to estimate the amount of released air added at the inlet to the modeled area.« less

Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal fluid flow

USGS Publications Warehouse

Hutnak, M.; Hurwitz, S.; Ingebritsen, S.E.; Hsieh, P.A.

2009-01-01

Ground surface displacement (GSD) in large calderas is often interpreted as resulting from magma intrusion at depth. Recent advances in geodetic measurements of GSD, notably interferometric synthetic aperture radar, reveal complex and multifaceted deformation patterns that often require complex source models to explain the observed GSD. Although hydrothermal fluids have been discussed as a possible deformation agent, very few quantitative studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent increases in the power and availability of computing resources allow robust quantitative assessment of the complex time-variant thermal interplay between aqueous fluid flow and crustal deformation. We carry out numerical simulations of multiphase (liquid-gas), multicomponent (H 2O-CO2) hydrothermal fluid flow and poroelastic deformation using a range of realistic physical parameters and processes. Hydrothermal fluid injection, circulation, and gas formation can generate complex, temporally and spatially varying patterns of GSD, with deformation rates, magnitudes, and geometries (including subsidence) similar to those observed in several large calderas. The potential for both rapid and gradual deformation resulting from magma-derived fluids suggests that hydrothermal fluid circulation may help explain deformation episodes at calderas that have not culminated in magmatic eruption.

A Data Management System for Multi-Phase Case-Control Studies

PubMed Central

Gibeau, Joanne M.; Steinfeldt, Lois C.; Stine, Mark J.; Tullis, Katherine V.; Lynch, H. Keith

1983-01-01

The design of a computerized system for the management of data in multi-phase epidemiologic case-control studies is described. Typical study phases include case-control selection, abstracting of data from medical records, and interview of study subjects or next of kin. In consultation with project personnel, requirements for the system were established: integration of data from all study phases into one data base, accurate follow-up of subjects through the study, sophisticated data editing capabilities, ready accessibility of specified programs to project personnel, and generation of current status and exception reports for project managment. SIR (Scientific Information Retrieval), a commercially available data base management system, was selected as the foundation of this system. The system forms a comprehensive data management system applicable to many types of public health research studies.

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

Kornfeldt, H.; Bjoerk, K.O.; Ekstroem, P.

The protection against dynamic effects in connection with potential pipe breaks has been implemented in different ways in the development of BWR reactor designs. First-generation plant designs reflect code requirements in effect at that time which means that no piping restraint systems were designed and built into those plants. Modern designs have, in contrast, implemented full protection against damage in connection with postulated pipe breaks, as required in current codes and regulations. Moderns standards and current regulatory demands can be met for the older plants by backfitting pipe whip restraint hardware. This could lead to several practical difficulties as thesemore » installations were not anticipated in the original plant design and layout. Meeting the new demands by analysis would in this situation have great advantages. Application of leak-before-break criteria gives an alternative opportunity of meeting modem standards in reactor safety design. Analysis takes into account data specific to BWR primary system operation, actual pipe material properties, piping loads and leak detection capability. Special attention must be given to ensure that the data used reflects actual plant conditions.« less

Acoustic cross-correlation flowmeter for solid-gas flow

DOEpatents

Sheen, Shuh-Haw; Raptis, Apostolos C.

1986-01-01

Apparatus for measuring particle velocity in a solid-gas flow within a pipe includes: first and second transmitting transducers for transmitting first and second ultrasonic signals into the pipe at first and second locations, respectively, along the pipe; an acoustic decoupler, positioned between said first and second transmitting transducers, for acoustically isolating said first and second signals from one another; first and second detecting transducers for detecting said first and second signals and for generating first and second detected signals in response to said first and second detected signals; and means for cross-correlating said first and second output signals.

Heat pipe thermal conditioning panel

NASA Technical Reports Server (NTRS)

Saaski, E. W.; Loose, J. D.; Mccoy, K. E.

1974-01-01

Thermal control of electronic hardware and experiments on future space vehicles is critical to proper functioning and long life. Thermal conditioning panels (cold plates) are a baseline control technique in current conceptual studies. Heat generating components mounted on the panels are typically cooled by fluid flowing through integral channels within the panel. However, replacing the pumped fluid coolant loop within the panel with heat pipes offers attractive advantages in weight, reliability, and installation. This report describes the development and fabrication of two large 0.76 x 0.76 m heat pipe thermal conditioning panels to verify performance and establish the design concept.

1. Pipe Floor Rear Corridor, view to the southeast. The ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Pipe Floor Rear Corridor, view to the southeast. The wall of Unit 2 turbine pit is visible in the right foreground. The pipe and valve cluster in the right foreground is part of the blow down valve for Unit 2. This valve allows the water in the draft chest to be lowered (i.e., 'blown down') so that the unit can be motored (i.e., run like an electric motor rather than an electric power generator). - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

Guangdong Zhu | NREL

Science.gov Websites

Guangdong.Zhu@nrel.gov | 303-275-4497 Guangdong joined the Thermal Systems Group at NREL in 2010 and is working collectors is performed. He is also involved in optical and thermal modeling and economic analysis of solar , and presentations in the areas of multiphase flow, power generation systems, and solar thermal power

Flutter Instability of a Fluid-Conveying Fluid-Immersed Pipe Affixed to a Rigid Body

DTIC Science & Technology

2011-01-01

rigid body, denoted by y in Fig. 4, is small. This is in addition to the Euler– Bernoulli beam assumption that the slope of the tail is small everywhere...here. These include the efficiency with which the prime mover can generate fluid momentum , pipe losses, and external drag acting on both the hull and the

A bubble detection system for propellant filling pipeline

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

Wen, Wen; Zong, Guanghua; Bi, Shusheng

2014-06-15

This paper proposes a bubble detection system based on the ultrasound transmission method, mainly for probing high-speed bubbles in the satellite propellant filling pipeline. First, three common ultrasonic detection methods are compared and the ultrasound transmission method is used in this paper. Then, the ultrasound beam in a vertical pipe is investigated, suggesting that the width of the beam used for detection is usually smaller than the internal diameter of the pipe, which means that when bubbles move close to the pipe wall, they may escape from being detected. A special device is designed to solve this problem. It canmore » generate the spiral flow to force all the bubbles to ascend along the central line of the pipe. In the end, experiments are implemented to evaluate the performance of this system. Bubbles of five different sizes are generated and detected. Experiment results show that the sizes and quantity of bubbles can be estimated by this system. Also, the bubbles of different radii can be distinguished from each other. The numerical relationship between the ultrasound attenuation and the bubble radius is acquired and it can be utilized for estimating the unknown bubble size and measuring the total bubble volume.« less

The defectiveness of measurement data in the inclinometer mesurement in the insertion-type aperture and an introduction about the crrection

NASA Astrophysics Data System (ADS)

Homma, H.; Fujisawa, K.; Chiba, S.; Ootsuka, Y.; Higuchi, K.; Suganuma, T.

2010-12-01

Since 1975, the insertion type borehole inclinometer has been used to measure an underground lateral deformation in the civil engineering works field in Japan. The borehole inclinometer is used for a lot of landslide investigations as an effective measuring instrument to judge the slide surface position and the rate of slip. On the other hand, it became popular to be able to gather cores at 100% collection rate by the core-pack-tube method having been developed in the drilling survey. As a result, because the grasp accuracy of geological features had improved greatly, it became clear there was a case where the measurement data of the borehole inclinometer did not obviously show the displacement of the ground. As a result,to correct data even if the method of setting up the guide pipe is examined so as not to generate defective data , some engineers where such the realities were understood have been examining it about the correction method. Therefore, there is a case where there is no standards united about the methods of measuring the insertion type borehole inclinometer, and defective data is used still as a result of the observation though the ratio of defective data has decreased. The Pubic Works Research Institute landslide team and three private company companies of Japan did a joint research from these on the generation of defective data between fiscal year 2008 and fiscal year 2009 to prevent it. And, they made the manual that brought the matter to do an appropriate borehole inclinometer (Insertion type borehole inclinometer measurement manual on the landslide ground). In various experiments executed by a joint research, to prevent defective data being generated, it has been understood that the installation of the guide pipe is most important. The following two problems occur if a defective installation of the guide pipe is caused. (1)S shape data in graph (2)Disorder of flat direction of displacement (1) Because filling work at the time of the guide pipe setting is not enough, a gap occurs between a drill hole and a guide pipe. The grout material of the cement system is used standard in Japan. However, the landslide mass flows out easily in general because there are a lot of cracks in addition to low the groundwater level. Therefore we work on filling with paccar, and it is necessary to let a guide pipe and the ground. (2)The direction of the displacement that data shows is different from the direction of the movement of the actual ground. In this data, the product of the guide pipe twists, and both of the twist when setting it up are causes of generation. However, it is almost impossible to prevent this. Therefore, the twist is corrected measuring the azimuth of the guide tube with a simple type borehole camera. The insertion type clinometer in the aperture is a measure used in many landslide, but a guide pipe and revision of certain setting of the ground and the torsion of the guide pipe are necessary to get right data. And, this manual may be useful internationally.

Fiscal and Policy Implications of Selling Pipe Tobacco for Roll-Your-Own Cigarettes in the United States

PubMed Central

Morris, Daniel S.; Tynan, Michael A.

2012-01-01

Background The Federal excise tax was increased for tobacco products on April 1, 2009. While excise tax rates prior to the increase were the same for roll-your-own (RYO) and pipe tobacco, the tax on pipe tobacco was $21.95 per pound less than the tax on RYO tobacco after the increase. Subsequently, tobacco manufacturers began labeling loose tobacco as pipe tobacco and marketing these products to RYO consumers at a lower price. Retailers refer to these products as “dual purpose" or “dual use" pipe tobacco. Methods Data on tobacco tax collections comes from the Alcohol and Tobacco Tax and Trade Bureau. Joinpoint software was used to identify changes in sales trends. Estimates were generated for the amount of pipe tobacco sold for RYO use and for Federal and state tax revenue lost through August 2011. Results Approximately 45 million pounds of pipe tobacco has been sold for RYO use from April 2009 to August 2011, lowering state and Federal revenue by over $1.3 billion. Conclusions Marketing pipe tobacco as “dual purpose" and selling it for RYO use provides an opportunity to avoid paying higher cigarette prices. This blunts the public health impact excise tax increases would otherwise have on reducing tobacco use through higher prices. Selling pipe tobacco for RYO use decreases state and Federal revenue and also avoids regulations on flavored tobacco, banned descriptors, prohibitions on shipping, and reporting requirements. PMID:22567159

Pore-scale study of multiphase reactive transport in fibrous electrodes of vanadium redox flow batteries

DOE PAGES

Chen, Li; He, YaLing; Tao, Wen -Quan; ...

2017-07-21

The electrode of a vanadium redox flow battery generally is a carbon fibre-based porous medium, in which important physicochemical processes occur. In this work, pore-scale simulations are performed to study complex multiphase flow and reactive transport in the electrode by using the lattice Boltzmann method (LBM). Four hundred fibrous electrodes with different fibre diameters and porosities are reconstructed. Both the permeability and diffusivity of the reconstructed electrodes are predicted and compared with empirical relationships in the literature. Reactive surface area of the electrodes is also evaluated and it is found that existing empirical relationship overestimates the reactive surface under lowermore » porosities. Further, a pore-scale electrochemical reaction model is developed to study the effects of fibre diameter and porosity on electrolyte flow, V II/V III transport, and electrochemical reaction at the electrolyte-fibre surface. Finally, evolution of bubble cluster generated by the side reaction is studied by adopting a LB multiphase flow model. Effects of porosity, fibre diameter, gas saturation and solid surface wettability on average bubble diameter and reduction of reactive surface area due to coverage of bubbles on solid surface are investigated in detail. It is found that gas coverage ratio is always lower than that adopted in the continuum model in the literature. Furthermore, the current pore-scale studies successfully reveal the complex multiphase flow and reactive transport processes in the electrode, and the simulation results can be further upscaled to improve the accuracy of the current continuum-scale models.« less

TOUGH2: A general-purpose numerical simulator for multiphase nonisothermal flows

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

Pruess, K.

1991-06-01

Numerical simulators for multiphase fluid and heat flows in permeable media have been under development at Lawrence Berkeley Laboratory for more than 10 yr. Real geofluids contain noncondensible gases and dissolved solids in addition to water, and the desire to model such `compositional` systems led to the development of a flexible multicomponent, multiphase simulation architecture known as MULKOM. The design of MULKOM was based on the recognition that the mass-and energy-balance equations for multiphase fluid and heat flows in multicomponent systems have the same mathematical form, regardless of the number and nature of fluid components and phases present. Application ofmore » MULKOM to different fluid mixtures, such as water and air, or water, oil, and gas, is possible by means of appropriate `equation-of-state` (EOS) modules, which provide all thermophysical and transport parameters of the fluid mixture and the permeable medium as a function of a suitable set of primary thermodynamic variables. Investigations of thermal and hydrologic effects from emplacement of heat-generating nuclear wastes into partially water-saturated formations prompted the development and release of a specialized version of MULKOM for nonisothermal flow of water and air, named TOUGH. TOUGH is an acronym for `transport of unsaturated groundwater and heat` and is also an allusion to the tuff formations at Yucca Mountain, Nevada. The TOUGH2 code is intended to supersede TOUGH. It offers all the capabilities of TOUGH and includes a considerably more general subset of MULKOM modules with added capabilities. The paper briefly describes the simulation methodology and user features.« less

Modeling of Thermal Performance of Multiphase Nuclear Fuel Cell Under Variable Gravity Conditions

NASA Technical Reports Server (NTRS)

Ding, Z.; Anghaie, S.

1996-01-01

A unique numerical method has been developed to model the dynamic processes of bulk evaporation and condensation processes, associated with internal heat generation and natural convection under different gravity levels. The internal energy formulation, for the bulk liquid-vapor phase change problems in an encapsulated container, was employed. The equations, governing the conservation of mass, momentum and energy for both phases involved in phase change, were solved. The thermal performance of a multiphase uranium tetra-fluoride fuel element under zero gravity, micro-gravity and normal gravity conditions has been investigated. The modeling yielded results including the evolution of the bulk liquid-vapor phase change process, the evolution of the liquid-vapor interface, the formation and development of the liquid film covering the side wall surface, the temperature distribution and the convection flow field in the fuel element. The strong dependence of the thermal performance of such multiphase nuclear fuel cell on the gravity condition has been revealed. Under all three gravity conditions, 0-g, 10(exp -3)-g, and 1-g, the liquid film is formed and covers the entire side wall. The liquid film covering the side wall is more isothermalized at the wall surface, which can prevent the side wall from being over-heated. As the gravity increases, the liquid film is thinner, the temperature gradient is larger across the liquid film and smaller across the vapor phase. This investigation provides valuable information about the thermal performance of multi-phase nuclear fuel element for the potential space and ground applications.

Melt Segregation and Tidal Heating at Io

NASA Astrophysics Data System (ADS)

Rajendar, A.; Dufek, J.; Roberts, J. H.; Paty, C. S.

2011-12-01

Recent evidence of melt beneath Io's surface (Khurana et al., 2010) and repeated observation of volcanic activity and features consistent with volcanic activity at the surface (e.g. Veeder et al, 1994; Rathbun et al., 2004; Lopes-Gautier et al., 1999; Smith et al., 1979) has raised further questions about the structure of the Galilean moon and the processes that shape it. In this study we examine the thermal state, melt fraction, and multiphase dynamics of melt segregation within Io's interior. Using a coupled multiphase dynamics and tidal heating model we explore the location, spatial extent, and temporal residence times of melt in Io's subsurface, as well as response to orbital parameters. In a thermally evolving body subject to tidal forcing, in which melt production and migration takes place, feedback can occur with respect to the physical and thermal properties. We explore this feedback to produce a thermal model of Io, taking into account the rate of tidal heating and fluid motion within the interior. First, a layered model of the internal structure is assumed. The equations of motion for forced oscillations in a layered spherical body are then solved using the propagator matrix method (Sabadini and Vermeesen, 2004) to obtain the displacements and strains due to tidal motion (Roberts and Nimmo, 2008). From this, the radial distribution of tidal heat generation within Io is calculated. This radial heating profile is then used as input for a multi-phase fluid model in order to obtain an estimate of the radial temperature distribution and thus the material properties and melt fractions. In the multiphase model individual phases (melt and solid residue) separately conserve mass, momentum and enthalpy (Dufek and Bachmann, 2010) allowing us to explore melt segregation phenomena. Enthalpy closure is provided by the MELTS (Ghiorso and Sack, 1995) thermodynamics algorithm, which is called at each point in space. This accounts for the partitioning between latent and sensible heat, and updates the physical properties of the melt and solid phase such as density and heat capacity. With this approach we explore the sensitivity of melt generation and the time between melt production and eruption (the residence time) to mantle chemistry and the layered structure of the moon.

Experimental and theoretical analysis on the effect of inclination on metal powder sintered heat pipe radiator with natural convection cooling

NASA Astrophysics Data System (ADS)

Cong, Li; Qifei, Jian; Wu, Shifeng

2017-02-01

An experimental study and theoretical analysis of heat transfer performance of a sintered heat pipe radiator that implemented in a 50 L domestic semiconductor refrigerator have been conducted to examine the effect of inclination angle, combined with a minimum entropy generation analysis. The experiment results suggest that inclination angle has influences on both the evaporator and condenser section, and the performance of the heat pipe radiator is more sensitive to the inclination change in negative inclined than in positive inclined position. When the heat pipe radiator is in negative inclination angle position, large amplitude of variation on the thermal resistance of this heat pipe radiator is observed. As the thermal load is below 58.89 W, the influence of inclination angle on the overall thermal resistance is not that apparent as compared to the other three thermal loads. Thermal resistance of heat pipe radiator decreases by 82.86 % in inclination of 60° at the set of 138.46 W, compared to horizontal position. Based on the analysis results in this paper, in order to achieve a better heat transfer performance of the heat pipe radiator, it is recommended that the heat pipe radiator be mounted in positive inclination angle positions (30°-90°), where the condenser is above the evaporator.

Carrier fluid temperature data in vertical ground heat exchangers with a varying pipe separation.

PubMed

Makasis, Nikolas; Narsilio, Guillermo A; Bidarmaghz, Asal; Johnston, Ian W

2018-06-01

The dataset in this article is related to shallow geothermal energy systems, which efficiently provide renewable heating and cooling to buildings, and specifically to the performance of the vertical ground heat exchangers (GHE) embedded in the ground. GHEs incorporate pipes with a circulating (carrier) fluid, exchanging heat between the ground and the building. The data show the average and inlet temperatures of the carrier fluid circulating in the pipes embedded in the GHEs (which directly relate to the performance of these systems). These temperatures were generated using detailed finite element modelling and comprise part of the daily output of various one-year simulations, accounting for numerous design parameters (including different pipe geometries) and ground conditions. An expanded explanation of the data as well as comprehensive analyses on how they were used can be found in the article titled "Ground-source heat pump systems: the effect of variable pipe separation in ground heat exchangers" (Makasis N, Narsilio GA, Bidarmaghz A, Johnston IW, 2018) [1].

Measurement of Rapid Protein Diffusion in the Cytoplasm by Photo-Converted Intensity Profile Expansion.

PubMed

Gura Sadovsky, Rotem; Brielle, Shlomi; Kaganovich, Daniel; England, Jeremy L

2017-03-14

The fluorescence microscopy methods presently used to characterize protein motion in cells infer protein motion from indirect observables, rather than measuring protein motion directly. Operationalizing these methods requires expertise that can constitute a barrier to their broad utilization. Here, we have developed PIPE (photo-converted intensity profile expansion) to directly measure the motion of tagged proteins and quantify it using an effective diffusion coefficient. PIPE works by pulsing photo-convertible fluorescent proteins, generating a peaked fluorescence signal at the pulsed region, and analyzing the spatial expansion of the signal. We demonstrate PIPE's success in measuring accurate diffusion coefficients in silico and in vitro and compare effective diffusion coefficients of native cellular proteins and free fluorophores in vivo. We apply PIPE to measure diffusion anomality in the cell and use it to distinguish free fluorophores from native cellular proteins. PIPE's direct measurement and ease of use make it appealing for cell biologists. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Thermodynamic analysis of alternate energy carriers, hydrogen and chemical heat pipes

NASA Technical Reports Server (NTRS)

Cox, K. E.; Carty, R. H.; Conger, W. L.; Soliman, M. A.; Funk, J. E.

1976-01-01

The paper discusses the production concept and efficiency of two new energy transmission and storage media intended to overcome the disadvantages of electricity as an overall energy carrier. These media are hydrogen produced by water-splitting and the chemical heat pipe. Hydrogen can be transported or stored, and burned as energy is needed, forming only water and thus obviating pollution problems. The chemical heat pipe envisions a system in which heat is stored as the heat of reaction in chemical species. The thermodynamic analysis of these two methods is discussed in terms of first-law and second-law efficiency. It is concluded that chemical heat pipes offer large advantages over thermochemical hydrogen generation schemes on a first-law efficiency basis except for the degradation of thermal energy in temperature thus providing a source of low-temperature (800 K) heat for process heat applications. On a second-law efficiency basis, hydrogen schemes are superior in that the amount of available work is greater as compared to chemical heat pipes.

Development of Conductivity Sensors for Multi-Phase Flow Local Measurements at the Polytechnic University of Valencia (UPV) and University Jaume I of Castellon (UJI).

PubMed

Muñoz-Cobo, José Luis; Chiva, Sergio; Méndez, Santos; Monrós, Guillem; Escrivá, Alberto; Cuadros, José Luis

2017-05-10

This paper describes all the procedures and methods currently used at UPV (Universitat Politécnica de Valencia) and UJI (University Jaume I) for the development and use of sensors for multi-phase flow analysis in vertical pipes. This paper also describes the methods that we use to obtain the values of the two-phase flow magnitudes from the sensor signals and the validation and cross-verification methods developed to check the consistency of the results obtained for these magnitudes with the sensors. First, we provide information about the procedures used to build the multi-sensor conductivity probes and some of the tests performed with different materials to avoid sensor degradation issues. In addition, we provide information about the characteristics of the electric circuits that feed the sensors. Then the data acquisition of the conductivity probe, the signal conditioning and the data processing including the device that have been designed to automatize all the measurement process of moving the sensors inside the channels by means of stepper electric motors controlled by computer are shown in operation. Then, we explain the methods used for bubble identification and categorization. Finally, we describe the methodology used to obtain the two-phase flow information from the sensor signals. This includes the following items: void fraction, gas velocity, Sauter mean diameter and interfacial area concentration. The last part of this paper is devoted to the conductance probes developed for the annular flow analysis, which includes the analysis of the interfacial waves produced in annular flow and that requires a different type of sensor.

Development of Conductivity Sensors for Multi-Phase Flow Local Measurements at the Polytechnic University of Valencia (UPV) and University Jaume I of Castellon (UJI)

PubMed Central

Muñoz-Cobo, José Luis; Chiva, Sergio; Méndez, Santos; Monrós, Guillem; Escrivá, Alberto; Cuadros, José Luis

2017-01-01

This paper describes all the procedures and methods currently used at UPV (Universitat Politécnica de Valencia) and UJI (University Jaume I) for the development and use of sensors for multi-phase flow analysis in vertical pipes. This paper also describes the methods that we use to obtain the values of the two-phase flow magnitudes from the sensor signals and the validation and cross-verification methods developed to check the consistency of the results obtained for these magnitudes with the sensors. First, we provide information about the procedures used to build the multi-sensor conductivity probes and some of the tests performed with different materials to avoid sensor degradation issues. In addition, we provide information about the characteristics of the electric circuits that feed the sensors. Then the data acquisition of the conductivity probe, the signal conditioning and the data processing including the device that have been designed to automatize all the measurement process of moving the sensors inside the channels by means of stepper electric motors controlled by computer are shown in operation. Then, we explain the methods used for bubble identification and categorization. Finally, we describe the methodology used to obtain the two-phase flow information from the sensor signals. This includes the following items: void fraction, gas velocity, Sauter mean diameter and interfacial area concentration. The last part of this paper is devoted to the conductance probes developed for the annular flow analysis, which includes the analysis of the interfacial waves produced in annular flow and that requires a different type of sensor. PMID:28489035

EDITORIAL: Measurement techniques for multiphase flows Measurement techniques for multiphase flows

NASA Astrophysics Data System (ADS)

Okamoto, Koji; Murai, Yuichi

2009-11-01

Research on multiphase flows is very important for industrial applications, including power stations, vehicles, engines, food processing and so on. Multiphase flows originally have nonlinear features because of multiphase systems. The interaction between the phases plays a very interesting role in the flows. The nonlinear interaction causes the multiphase flows to be very complicated. Therefore techniques for measuring multiphase flows are very useful in helping to understand the nonlinear phenomena. The state-of-the-art measurement techniques were presented and discussed at the sixth International Symposium on Measurement Techniques for Multiphase Flows (ISMTMF2008) held in Okinawa, Japan, on 15-17 December 2008. This special feature of Measurement Science and Technology includes selected papers from ISMTMF2008. Okinawa has a long history as the Ryukyus Kingdom. China, Japan and many western Pacific countries have had cultural and economic exchanges through Okinawa for over 1000 years. Much technical and scientific information was exchanged at the symposium in Okinawa. The proceedings of ISMTMF2008 apart from these special featured papers were published in Journal of Physics: Conference Series vol. 147 (2009). We would like to express special thanks to all the contributors to the symposium and this special feature. This special feature will be a milestone in measurement techniques for multiphase flows.

Centrifugal compressor modifications and their effect on high-frequency pipe wall vibration

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

Motriuk, R.W.; Harvey, D.P.

1998-08-01

High-frequency pulsation generated by centrifugal compressors, with pressure wave-lengths much smaller than the attached pipe diameter, can cause fatigue failures of the compressor internals, impair compressor performance, and damage the attached compressor piping. There are numerous sources producing pulsation in centrifugal compressors. Some of them are discussed in literature at large (Japikse, 1995; Niese, 1976). NGTL has experienced extreme high-frequency discharge pulsation and pipe wall vibration on many of its radial inlet high-flow centrifugal gas compressor facilities. These pulsations led to several piping attachment failures and compressor internal component failures while the compressor operated within the design envelope. This papermore » considers several pulsation conditions at an NGTL compression facility which resulted in unacceptable piping vibration. Significant vibration attenuation was achieved by modifying the compressor (pulsation source) through removal of the diffuser vanes and partial removal of the inlet guide vanes (IGV). Direct comparison of the changes in vibration, pulsation, and performance are made for each of the modifications. The vibration problem, probable causes, options available to address the problem, and the results of implementation are reviewed. The effects of diffuser vane removal on discharge pipe wall vibration as well as changes in compressor performance are described.« less

Life Test Approach for Refractory Metal/Sodium Heat Pipes

NASA Technical Reports Server (NTRS)

Martin, James J.; Reid, Robert S.

2006-01-01

Heat pipe life tests described in the literature have seldom been conducted on a systematic basis. Typically one or more heat pipes are built and tested for an extended period at a single temperature with simple condenser loading. This paper describes an approach to generate carefully controlled data that can conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. Approximately 10 years of operational life might be compressed into 3 years of laboratory testing through a combination of increased temperature and mass fluence. Two specific test series have been identified and include: investigation of long term corrosion rates based on the guidelines contained in ASTM G-68-80 (using 7 heat pipes); and investigation of corrosion trends in a cross correlation sequence at various temperatures and mass fluences based on a central composite test design (using 9 heat pipes). The heat pipes selected for demonstration purposes are fabricated from a Mo-44.5%Re alloy with a length of 0.3 meters and a diameter of 1.59 cm(to conserve material) with a condenser to evaporator length ratio of approximately 3. The wick is a crescent annular design formed from 400-mesh Mo-Re alloy material hot isostatically pressed to produce a final wick core of 20 microns or less.

Absorption generator for solar-powered air-conditioner

NASA Technical Reports Server (NTRS)

Lowen, D. J.; Murray, J. G.

1977-01-01

Device passes solar-heated water through coils. Hot lithium Bromide/Water solution leaves through central stand-pipe, and water vapor leaves through refrigerant outlet at top. Matching generation temperature to collector efficiency helps cut costs.

Nanoparticle Additives for Multiphase Systems: Synthesis, Formulation and Characterization

DTIC Science & Technology

2012-01-01

ADDITIVES FOR MULTIPHASE SYSTEMS: SYNTHESIS , FORMULATION AND CHARACTERIZATION Vinod Kanniah University of Kentucky, vinodkanniah@gmail.com This Doctoral...UKnowledge@lsv.uky.edu. Recommended Citation Kanniah, Vinod, "NANOPARTICLE ADDITIVES FOR MULTIPHASE SYSTEMS: SYNTHESIS , FORMULATION AND CHARACTERIZATION...00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Nanoparticle Additives for Multiphase Systems: Synthesis , Formulation and Characterization 5a

Modeling the GPR response of leaking, buried pipes

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

Powers, M.H.; Olhoeft, G.R.

1996-11-01

Using a 2.5D, dispersive, full waveform GPR modeling program that generates complete GPR response profiles in minutes on a Pentium PC, the effects of leaking versus non-leaking buried pipes are examined. The program accounts for the dispersive, lossy nature of subsurface materials to GPR wave propagation, and accepts complex functions of dielectric permittivity and magnetic permeability versus frequency through Cole-Cole parameters fit to laboratory data. Steel and plastic pipes containing a DNAPL chlorinated solvent, an LNAPL hydrocarbon, and natural gas are modeled in a surrounding medium of wet, moist, and dry sand. Leaking fluids are found to be more detectablemore » when the sand around the pipes is fully water saturated. The short runtimes of the modeling program and its execution on a PC make it a useful tool for exploring various subsurface models.« less

Hybrid sodium heat pipe receivers for dish/Stirling systems

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

Laing, D.; Reusch, M.

1997-12-31

The design of a hybrid solar/gas heat pipe receiver for the SBP 9 kW dish/Stirling system using a United Stirling AB V160 Stirling engine and the results of on-sun testing in alternative and parallel mode will be reported. The receiver is designed to transfer a thermal power of 35 kW. The heat pipe operates at around 800 C, working fluid is sodium. Operational options are solar-only, gas augmented and gas-only mode. Also the design of a second generation hybrid heat pipe receiver currently developed under a EU-funded project, based on the experience gained with the first hybrid receiver, will bemore » reported. This receiver is designed for the improved SPB/L. and C.-10 kW dish/Stirling system with the reworked SOLO V161 Stirling engine.« less

Development concept for a small, split-core, heat-pipe-cooled nuclear reactor

NASA Technical Reports Server (NTRS)

Lantz, E.; Breitwieser, R.; Niederauer, G. F.

1974-01-01

There have been two main deterrents to the development of semiportable nuclear reactors. One is the high development costs; the other is the inability to satisfy with assurance the questions of operational safety. This report shows how a split-core, heat-pipe cooled reactor could conceptually eliminate these deterrents, and examines and summarizes recent work on split-core, heat-pipe reactors. A concept for a small reactor that could be developed at a comparatively low cost is presented. The concept would extend the technology of subcritical radioisotope thermoelectric generators using 238 PuO2 to the evolution of critical space power reactors using 239 PuO2.

Problems with the random number generator RANF implemented on the CDC cyber 205

NASA Astrophysics Data System (ADS)

Kalle, Claus; Wansleben, Stephan

1984-10-01

We show that using RANF may lead to wrong results when lattice models are simulated by Monte Carlo methods. We present a shift-register sequence random number generator which generates two random numbers per cycle on a two pipe CDC Cyber 205.

The three-dimensional structure of swirl-switching in bent pipe flow

DOE PAGES

Hufnagel, Lorenz; Canton, Jacopo; Örlü, Ramis; ...

2017-11-27

Swirl-switching is a low-frequency oscillatory phenomenon which affects the Dean vortices in bent pipes and may cause fatigue in piping systems. Despite thirty years worth of research, the mechanism that causes these oscillations and the frequencies that characterise them remain unclear. In this paper, we show that a three-dimensional wave-like structure is responsible for the low-frequency switching of the dominant Dean vortex. The present study, performed via direct numerical simulation, focuses on the turbulent flow through amore » $$90^{\\circ }$$pipe bend preceded and followed by straight pipe segments. A pipe with curvature 0.3 (defined as ratio between pipe radius and bend radius) is studied for a bulk Reynolds number $$Re=11\\,700$$, corresponding to a friction Reynolds number $$Re_{\\unicode[STIX]{x1D70F}}\\approx 360$$. Synthetic turbulence is generated at the inflow section and used instead of the classical recycling method in order to avoid the interference between recycling and swirl-switching frequencies. The flow field is analysed by three-dimensional proper orthogonal decomposition (POD) which for the first time allows the identification of the source of swirl-switching: a wave-like structure that originates in the pipe bend. Contrary to some previous studies, the flow in the upstream pipe does not show any direct influence on the swirl-switching modes. Finally, our analysis further shows that a three-dimensional characterisation of the modes is crucial to understand the mechanism, and that reconstructions based on two-dimensional POD modes are incomplete.« less

The three-dimensional structure of swirl-switching in bent pipe flow

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

Hufnagel, Lorenz; Canton, Jacopo; Örlü, Ramis

Swirl-switching is a low-frequency oscillatory phenomenon which affects the Dean vortices in bent pipes and may cause fatigue in piping systems. Despite thirty years worth of research, the mechanism that causes these oscillations and the frequencies that characterise them remain unclear. In this paper, we show that a three-dimensional wave-like structure is responsible for the low-frequency switching of the dominant Dean vortex. The present study, performed via direct numerical simulation, focuses on the turbulent flow through amore » $$90^{\\circ }$$pipe bend preceded and followed by straight pipe segments. A pipe with curvature 0.3 (defined as ratio between pipe radius and bend radius) is studied for a bulk Reynolds number $$Re=11\\,700$$, corresponding to a friction Reynolds number $$Re_{\\unicode[STIX]{x1D70F}}\\approx 360$$. Synthetic turbulence is generated at the inflow section and used instead of the classical recycling method in order to avoid the interference between recycling and swirl-switching frequencies. The flow field is analysed by three-dimensional proper orthogonal decomposition (POD) which for the first time allows the identification of the source of swirl-switching: a wave-like structure that originates in the pipe bend. Contrary to some previous studies, the flow in the upstream pipe does not show any direct influence on the swirl-switching modes. Finally, our analysis further shows that a three-dimensional characterisation of the modes is crucial to understand the mechanism, and that reconstructions based on two-dimensional POD modes are incomplete.« less

Life Test Results for Water Heat Pipes Operating at 200 °C to 300 °C

NASA Astrophysics Data System (ADS)

Rosenfeld, John H.; Gernert, Nelson J.

2008-01-01

For lunar or planetary bases to be viable, a robust electric generating system will be required for powering the habitat. Water heat pipes offer an attractive solution for lunar base heat rejection, and would serve as a qualification for them on other long duration missions. Successful operation near the upper end of water operating range is a requirement for the application. Results are reported for life tests on water heat pipes that were operated at various temperatures between 200 °C and 300 °C. Tests were conducted on twenty three gravity-assisted water heat pipes. Eleven titanium/water heat pipes and ten Monel/water heat pipes were tested at temperatures above 200 °C. Two cupronickel heat pipes were also assembled and tested. Titanium alloys tested included CP-2 titanium, as well as two beta-titanium alloys, namely 15-3 and Nitinol alloys. Some of the titanium alloy life tests used wicks fabricated from CP-2 titanium screen or porous felt. Monel alloys tested included 400 and K-500 alloys. Some of the Monel heat pipes contained copper/nickel wicks that were fabricated by brazing nickel-plated copper felt metal wicks. Although most of the envelope/material combinations exhibit favorable results at 200 °C, some of the combinations failed at higher temperatures. Causes of failure included stress-creep of envelopes and corrosion at axial or end cap welds. This information represents a significant advance in selection of materials for 200 °C to 300 °C water heat pipes. Life testing work is being continued.

Heat Rejection Concepts for Brayton Power Conversion Systems

NASA Technical Reports Server (NTRS)

Siamidis, John; Mason, Lee; Beach, Duane; Yuko, James

2005-01-01

This paper describes potential heat rejection design concepts for closed Brayton cycle (CBC) power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) applications. The Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Space Brayton conversion system designs tend to optimize at efficiencies of about 20 to 25 percent with radiator temperatures in the 400 to 600 K range. A notional HRS was developed for a 100 kWe-class Brayton power system that uses a pumped sodium-potassium (NaK) heat transport loop coupled to a water heat pipe radiator. The radiator panels employ a sandwich construction consisting of regularly-spaced circular heat pipes contained within two composite facesheets. Heat transfer from the NaK fluid to the heat pipes is accomplished by inserting the evaporator sections into the NaK duct channel. The paper evaluates various design parameters including heat pipe diameter, heat pipe spacing, and facesheet thickness. Parameters were varied to compare design options on the basis of NaK pump pressure rise and required power, heat pipe unit power and radial flux, radiator panel areal mass, and overall HRS mass.

Field testing model predictions of foam coverage and bubble content in the surf zone

NASA Astrophysics Data System (ADS)

Shi, F.; Kirby, J. T.; Ma, G.; Holman, R. A.; Chickadel, C. C.

2012-12-01

Field-scale modeling of surfzone bubbles and foam coverage is challenging in terms of the computational intensity of multi-phase bubble models based on Navier-Stokes/VOF formulation. In this study, we developed the NHWAVE-bubble package, which includes a 3D non-hydrostatic wave model NHWAVE (Ma et al., 2012), a multi-phase bubble model and a foam model. NHWAVE uses a surface and bottom following sigma coordinate system, making it more applicable to 3D modeling of nearshore waves and circulation in a large-scale field domain. It has been extended to include a multiphase description of polydisperse bubble populations following the approach applied in a 3D VOF model by Ma et al. (2012). A model of a foam layer on the water surface is specified in the model package using a shallow water formulation based on a balance of drag forces due to wind and water column motion. Foam mass conservation includes source and sink terms representing outgassing of the water column, direct foam generation due to surface agitation, and erosion due to bubble bursting. The model is applied in a field scale domain at FRF, Duck, NC where optical data in either visible band (ARGUS) or infrared band were collected during 2010 Surf Zone Optics experiments. The decay of image brightness or intensity following the passage of wave crests is presumably tied to both decay of bubble populations and foam coverage after passage of a broken wave crest. Infrared imagery is likely to provide more detailed information which could separate active breaking from passive foam decay on the surface. Model results will be compared with the measurements with an attention to distinguishing between active generation and passive decay of the foam signature on the water surface.

Technical data on new engineering products

NASA Astrophysics Data System (ADS)

1985-02-01

New grades of permanently magnetic materials; automatic digital radiolocator; bench winder; analog induction gauge; programmable pulse generator; portable defibrillators; pipe welders; two-component electromagnetic log; sulphur content analyzer; peristaltic pumps; function generators; welding manipulator; and tonsiometer are described.

Modeling of pulsating heat pipes.

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

Givler, Richard C.; Martinez, Mario J.

This report summarizes the results of a computer model that describes the behavior of pulsating heat pipes (PHP). The purpose of the project was to develop a highly efficient (as compared to the heat transfer capability of solid copper) thermal groundplane (TGP) using silicon carbide (SiC) as the substrate material and water as the working fluid. The objective of this project is to develop a multi-physics model for this complex phenomenon to assist with an understanding of how PHPs operate and to be able to understand how various parameters (geometry, fill ratio, materials, working fluid, etc.) affect its performance. Themore » physical processes describing a PHP are highly coupled. Understanding its operation is further complicated by the non-equilibrium nature of the interplay between evaporation/condensation, bubble growth and collapse or coalescence, and the coupled response of the multiphase fluid dynamics among the different channels. A comprehensive theory of operation and design tools for PHPs is still an unrealized task. In the following we first analyze, in some detail, a simple model that has been proposed to describe PHP behavior. Although it includes fundamental features of a PHP, it also makes some assumptions to keep the model tractable. In an effort to improve on current modeling practice, we constructed a model for a PHP using some unique features available in FLOW-3D, version 9.2-3 (Flow Science, 2007). We believe that this flow modeling software retains more of the salient features of a PHP and thus, provides a closer representation of its behavior.« less

Heat pipe solar receiver with thermal energy storage

NASA Technical Reports Server (NTRS)

Zimmerman, W. F.

1981-01-01

An HPSR Stirling engine generator system featuring latent heat thermal energy storge, excellent thermal stability and self regulating, effective thermal transport at low system delta T is described. The system was supported by component technology testing of heat pipes and of thermal storage and energy transport models which define the expected performance of the system. Preliminary and detailed design efforts were completed and manufacturing of HPSR components has begun.

Characterization of a high performance ultra-thin heat pipe cooling module for mobile hand held electronic devices

NASA Astrophysics Data System (ADS)

Ahamed, Mohammad Shahed; Saito, Yuji; Mashiko, Koichi; Mochizuki, Masataka

2017-11-01

In recent years, heat pipes have been widely used in various hand held mobile electronic devices such as smart phones, tablet PCs, digital cameras. With the development of technology these devices have different user friendly features and applications; which require very high clock speeds of the processor. In general, a high clock speed generates a lot of heat, which needs to be spreaded or removed to eliminate the hot spot on the processor surface. However, it is a challenging task to achieve proper cooling of such electronic devices mentioned above because of their confined spaces and concentrated heat sources. Regarding this challenge, we introduced an ultra-thin heat pipe; this heat pipe consists of a special fiber wick structure named as "Center Fiber Wick" which can provide sufficient vapor space on the both sides of the wick structure. We also developed a cooling module that uses this kind of ultra-thin heat pipe to eliminate the hot spot issue. This cooling module consists of an ultra-thin heat pipe and a metal plate. By changing the width, the flattened thickness and the effective length of the ultra-thin heat pipe, several experiments have been conducted to characterize the thermal properties of the developed cooling module. In addition, other experiments were also conducted to determine the effects of changes in the number of heat pipes in a single module. Characterization and comparison of the module have also been conducted both experimentally and theoretically.

Compressed Air/Vacuum Transportation Techniques

NASA Astrophysics Data System (ADS)

Guha, Shyamal

2011-03-01

General theory of compressed air/vacuum transportation will be presented. In this transportation, a vehicle (such as an automobile or a rail car) is powered either by compressed air or by air at near vacuum pressure. Four version of such transportation is feasible. In all versions, a ``c-shaped'' plastic or ceramic pipe lies buried a few inches under the ground surface. This pipe carries compressed air or air at near vacuum pressure. In type I transportation, a vehicle draws compressed air (or vacuum) from this buried pipe. Using turbine or reciprocating air cylinder, mechanical power is generated from compressed air (or from vacuum). This mechanical power transferred to the wheels of an automobile (or a rail car) drives the vehicle. In type II-IV transportation techniques, a horizontal force is generated inside the plastic (or ceramic) pipe. A set of vertical and horizontal steel bars is used to transmit this force to the automobile on the road (or to a rail car on rail track). The proposed transportation system has following merits: virtually accident free; highly energy efficient; pollution free and it will not contribute to carbon dioxide emission. Some developmental work on this transportation will be needed before it can be used by the traveling public. The entire transportation system could be computer controlled.

Modal content of noise generated by a coaxial jet in a pipe

NASA Technical Reports Server (NTRS)

Kerschen, E. J.; Johnston, J. P.

1978-01-01

Noise generated by air flow through a coaxial obstruction in a long, straight pipe was investigated with concentration on the modal characteristics of the noise field inside the pipe and downstream of the restriction. Two measurement techniques were developed for separation of the noise into the acoustic duct modes. The instantaneous mode separation technique uses four microphones, equally spaced in the circumferential direction, at the same axial location. The time-averaged mode separation technique uses three microphones mounted at the same axial location. A matrix operation on time-averaged data produces the modal pressure levels. This technique requires the restrictive assumption that the acoustic modes are uncorrelated with each other. The measured modal pressure spectra were converted to modal power spectra and integrated over the frequency range 200-6000 Hz. The acoustic efficiency levels (acoustic power normalized by jet kinetic energy flow), when plotted vs. jet Mach number, showed a strong dependence on the ratio of restriction diameter to pipe diameter. The acoustic energy flow analyses based on the thermodynamic energy equation and on the results of Mohring both resulted in orthogonality properties for the eigenfunctions of the radial mode shape equation. These orthogonality relationships involve the eigenvalues and derivatives of the radial mode shape functions.

Design and analysis of compound flexible skin based on deformable honeycomb

NASA Astrophysics Data System (ADS)

Zou, Tingting; Zhou, Li

2017-04-01

In this study, we focused at the development and verification of a robust framework for surface crack detection in steel pipes using measured vibration responses; with the presence of multiple progressive damage occurring in different locations within the structure. Feature selection, dimensionality reduction, and multi-class support vector machine were established for this purpose. Nine damage cases, at different locations, orientations and length, were introduced into the pipe structure. The pipe was impacted 300 times using an impact hammer, after each damage case, the vibration data were collected using 3 PZT wafers which were installed on the outer surface of the pipe. At first, damage sensitive features were extracted using the frequency response function approach followed by recursive feature elimination for dimensionality reduction. Then, a multi-class support vector machine learning algorithm was employed to train the data and generate a statistical model. Once the model is established, decision values and distances from the hyper-plane were generated for the new collected data using the trained model. This process was repeated on the data collected from each sensor. Overall, using a single sensor for training and testing led to a very high accuracy reaching 98% in the assessment of the 9 damage cases used in this study.

Fluid-particle characteristics in fully-developed cluster-induced turbulence

NASA Astrophysics Data System (ADS)

Capecelatro, Jesse; Desjardins, Olivier; Fox, Rodney

2014-11-01

In this study, we present a theoretical framework for collisional fluid-particle turbulence. To identify the key mechanisms responsible for energy exchange between the two phases, an Eulerian-Lagrangian strategy is used to simulate fully-developed cluster-inudced turbulence (CIT) under a range of Reynolds numbers, where fluctuations in particle concentration generate and sustain the carrier-phase turbulence. Using a novel filtering approach, a length-scale separation between the correlated particle velocity and uncorrelated granular temperature (GT) is achieved. This separation allows us to extract the instantaneous Eulerian volume fraction, velocity and GT fields from the Lagrangian data. Direct comparisons can thus be made with the relevant terms that appear in the multiphase turbulence model. It is shown that the granular pressure is highly anisotropic, and thus additional transport equations (as opposed to a single equation for GT) are necessary in formulating a predictive multiphase turbulence model. In addition to reporting the relevant contributions to the Reynolds stresses of each phase, two-point statistics, integral length/timescales, averages conditioned on the local volume fraction, and PDFs of the key multiphase statistics are presented and discussed. The research reported in this paper is partially supported by the HPC equipment purchased through U.S. National Science Foundation MRI Grant Number CNS 1229081 and CRI Grant Number 1205413.

Development and assessement of the GECKO-A multiphase modelling tool for the atmospheric oxidation of biogenic organic compounds

NASA Astrophysics Data System (ADS)

Valorso, Richard; Raventos-Duran, Teresa; Aumont, Bernard; Camredon, Marie; Ng, Nga L.; Seinfeld, John H.

2010-05-01

The evaluation of the impacts of secondary organics on pollution episodes, climate and the tropospheric oxidizing capacity requires modelling tools that track the identity and reactivity of organic carbon in the various stages down to the ultimate oxidation products. The fully explicit representation of hydrocarbon oxidation, from the initial compounds to the final product CO2, requires a very large number of chemical reactions and intermediate species, far in excess of the number that can be reasonably written manually. We developed a "self generating approach" to explicitly describe (i) the gas phase oxidation schemes of organic compounds under general tropospheric conditions and (ii) the partitioning of secondary organics between gas and condensed phases. This approach was codified in a computer program, GECKO-A (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere). This method allows prediction of multiphase mass budget using first principles. However, due to computational limitations, fully explicit chemical schemes can only be generated for species up to C8. We recently implemented a reduction protocol in GECKO-A to allow the generation of oxidation schemes for long chain organics. This protocol was applied to develop highly detailed oxidation schemes for biogenic compounds. The relevance of the generated schemes was assessed using experiments performed in the Caltech smog chamber for various NOx conditions. The first results show a systematic overestimation of the simulated SOA concentrations by GECKO-A. Several hypotheses were tested to find the origin of the discrepancies beetwen model and measurements.

46 CFR 169.675 - Generators and motors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... with a nameplate of corrosion-resistant material marked with the following information as applicable... having only electrically driven fire and bilge pumps must have two generators. One of these generators... at the lowest part of the frame for attaching a drain pipe or drain plug. (f) Except as provided in...

Practical aspects and uncertainty analysis of biological effective dose (BED) regarding its three-dimensional calculation in multiphase radiotherapy treatment plans

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

Kauweloa, Kevin I., E-mail: Kauweloa@livemail.uthscsa.edu; Gutierrez, Alonso N.; Bergamo, Angelo

2014-07-15

Purpose: There is a growing interest in the radiation oncology community to use the biological effective dose (BED) rather than the physical dose (PD) in treatment plan evaluation and optimization due to its stronger correlation with radiobiological effects. Radiotherapy patients may receive treatments involving a single only phase or multiple phases (e.g., primary and boost). Since most treatment planning systems cannot calculate the analytical BED distribution in multiphase treatments, an approximate multiphase BED expression, which is based on the total physical dose distribution, has been used. The purpose of this paper is to reveal the mathematical properties of the approximatemore » BED formulation, relative to the true BED. Methods: The mathematical properties of the approximate multiphase BED equation are analyzed and evaluated. In order to better understand the accuracy of the approximate multiphase BED equation, the true multiphase BED equation was derived and the mathematical differences between the true and approximate multiphase BED equations were determined. The magnitude of its inaccuracies under common clinical circumstances was also studied. All calculations were performed on a voxel-by-voxel basis using the three-dimensional dose matrices. Results: Results showed that the approximate multiphase BED equation is accurate only when the dose-per-fractions (DPFs) in both the first and second phases are equal, which occur when the dose distribution does not significantly change between the phases. In the case of heterogeneous dose distributions, which significantly vary between the phases, there are fewer occurrences of equal DPFs and hence the inaccuracy of the approximate multiphase BED is greater. These characteristics are usually seen in the dose distributions being delivered to organs at risk rather than to targets. Conclusions: The finding of this study indicates that the true multiphase BED equation should be implemented in the treatment planning systems due to the inconsistent accuracy of the approximate multiphase BED equation in most of the clinical situations.« less

Guided Wave Sensing In a Carbon Steel Pipe Using a Laser Vibrometer System

NASA Astrophysics Data System (ADS)

Ruíz Toledo, Abelardo; Salazar Soler, Jordi; Chávez Domínguez, Juan Antonio; García Hernández, Miguel Jesús; Turó Peroy, Antoni

2010-05-01

Non-Destructive Evaluation (NDE) techniques have achieved a great development during the last decades as a valuable tool for material characterization, manufacturing control and structural integrity tests. Among these tools, the guided wave technology has been rapidly extended because it reduces inspection time and costs compared to the ordinary point by point testing in large structures, as well as because of the possibility of inspecting under insulation and coating conditions. This fast development has motivated the creation of several inspection and material characterization systems including different technologies which can be combined with this technique. Different measurements systems based on laser techniques have been presented in order to inspect pipes, plates and diverse structures. Many of them are experimental systems of high cost and complexity which combine the employment of a laser for generation of waves in the structure and an interferometer for detection. Some of them employ air-coupled ultrasound generation transducers, with high losses in air and which demand high energy for exciting waves in materials of high stiffness. The combined employment of a commercial vibrometer system for Lamb wave sensing in plates has been successfully shown in the literature. In this paper we present a measurement system based on the combined employment of a piezoelectric wedge transducer and a laser vibrometer to sense guided acoustic waves in carbon steel pipes. The measurement system here presented is mainly compounded of an angular wedge transducer, employed to generate the guided wave and a commercial laser vibrometer used in the detection process. The wedge transducer is excited by means of a signal function generator whose output signal has been amplified with a power signal amplifier. A high precision positioning system is employed to place the laser beam at different points through the pipe surface. The signal detected by the laser vibrometer system is amplified with a signal amplifier and then it is displayed in a digital storage oscilloscope. This set-up offers the possibility of analyzing in a simpler way the wave propagation and the material evaluation in pipes of certain wall thickness. The material characterization considering distinct wave propagation modes can be easily achieved, changing the different incident angles of the wedge piezoelectric probe and their combined employment with several driving signals. Moreover, this experimental sensing system offers other possibilities of inspecting and analyzing the wave propagation in some features (bends, flange joints, welds,…) of the pipe surface which cause very large reflections and mode conversions and which in practice limits the inspection range when are inspected with conventional receiving transducer arrangements.

Studies on the influence of axial bends on ultrasonic guided waves in hollow cylinders (pipes)

NASA Astrophysics Data System (ADS)

Verma, Bhupesh; Balasubramaniam, Krishnan; Rajagopal, Prabhu

2013-01-01

Ultrasonic guided waves in hollow cylinders (pipes) are today widely applied as rapid screening tools in the inspection of straight pipe segments in oil, power generation and petrochemical processing industries. However, the characteristics of guided wave propagation across features such as bends in the pipe network are complicated, hampering a wider application of the developed techniques. Although a growing number of studies in recent years have considered guided wave propagation across elbows and U-type bends, the topic is still not very well understood for a general bend angle φ, mean bend radius R and pipe thickness b. Here we use 3D Finite Element (FE) simulation to illumine the propagation of fundamental guided pipe modes across bends of several different angles φ. Two different bend radius regimes, R/λ ≈ 1 and 10 (where λ denotes the wavelength of the mode studied) are considered, exemplifying 'sharp' and gradual or 'slow' bends. Different typical pipe thicknesses b within these regimes are also studied. The results confirm the expectation that different bend radius regimes affect the waves differently. Further, while as observed in earlier studies, at moderate bend radii, fundamental modes travel almost unaffected by an elbow (bend angle φ = 90 degrees), we find that as the bend angle is reduced, there is a progressively larger extent of mode-conversion. These trends and results are validated using experiments.

Investigation of thermal-fluid mechanical characteristics of the Capillary Pump Loop

NASA Technical Reports Server (NTRS)

Kiper, Ali M.

1991-01-01

The main purpose is the experimental and analytical study of behavior of the Capillary Pump Loop (CPL) heat pipe system during the transient mode of operating by applying a step heat pulse to one or more evaporators. Prediction of the CPL behavior when subjected to pulse heat loading requires further study before the transient response of CPL system can be fully understood. The following tasks are discussed: (1) exploratory testing of a CPL heat pipe for transient operational conditions which could generate the type of oscillatory inlet temperature behavior observed in an earlier testing of NASA/GSFC CPL-2 heat pipe system; (2) analytical investigation of the CPL inlet section temperature oscillations; (3) design, construction and testing of a bench-top CPL test system for study of the CPL transient operation; and (4) transient analysis of a CPL heat pipe by applying a step power input to the evaporators.

Three dimensional contact/impact methodology

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

Kulak, R.F.

1987-01-01

The simulation of three-dimensional interface mechanics between reactor components and structures during static contact or dynamic impact is necessary to realistically evaluate their structural integrity to off-normal loads. In our studies of postulated core energy release events, we have found that significant structure-structure interactions occur in some reactor vessel head closure designs and that fluid-structure interactions occur within the reactor vessel. Other examples in which three-dimensional interface mechanics play an important role are: (1) impact response of shipping casks containing spent fuel, (2) whipping pipe impact on reinforced concrete panels or pipe-to-pipe impact after a pipe break, (3) aircraft crashmore » on secondary containment structures, (4) missiles generated by turbine failures or tornados, and (5) drops of heavy components due to lifting accidents. The above is a partial list of reactor safety problems that require adequate treatment of interface mechanics and are discussed in this paper.« less

Qualification of coolants and cooling pipes for future high-energy-particle detectors

NASA Astrophysics Data System (ADS)

Ilie, Sorin; Tavlet, Marc

2001-12-01

In the next generation of high-energy-particle detectors to be installed at the Large Hadron Collider (LHC) at CERN, materials and components will be exposed to a significant level of ionising radiation. Silicon detectors and related electronics will have to be cooled down to -20 °C and therefore appropriate cooling fluids and cooling pipes have to be selected. Analytical methods such as UV-visible and FT-IR spectrometries, electronic microscopy and gas chromatography were used to characterise the radiation-induced effects on some organic coolants irradiated with both gamma and neutron fields. Some impurities were identified as a major source for radio-induced polymerisation and also for hydrofluoric acid (HF) evolution. Mechanical tests were performed to assess the operability of the rubber hoses and plastic pipes. Possible synergistic effects between the pipe material and the environment had to be considered.

Hybrid Heat Pipes for Lunar and Martian Surface and High Heat Flux Space Applications

NASA Technical Reports Server (NTRS)

Ababneh, Mohammed T.; Tarau, Calin; Anderson, William G.; Farmer, Jeffery T.; Alvarez-Hernandez, Angel R.

2016-01-01

Novel hybrid wick heat 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 heat pipes will be capable of operating at the higher heat flux 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 heat 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.

Oscillatory multiphase flow strategy for chemistry and biology.

PubMed

Abolhasani, Milad; Jensen, Klavs F

2016-07-19

Continuous multiphase flow strategies are commonly employed for high-throughput parameter screening of physical, chemical, and biological processes as well as continuous preparation of a wide range of fine chemicals and micro/nano particles with processing times up to 10 min. The inter-dependency of mixing and residence times, and their direct correlation with reactor length have limited the adaptation of multiphase flow strategies for studies of processes with relatively long processing times (0.5-24 h). In this frontier article, we describe an oscillatory multiphase flow strategy to decouple mixing and residence times and enable investigation of longer timescale experiments than typically feasible with conventional continuous multiphase flow approaches. We review current oscillatory multiphase flow technologies, provide an overview of the advancements of this relatively new strategy in chemistry and biology, and close with a perspective on future opportunities.

The design and fabrication of a Stirling engine heat exchanger module with an integral heat pipe

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey G.

1988-01-01

The conceptual design of a free-piston Stirling Space Engine (SSE) intended for space power applications has been generated. The engine was designed to produce 25 kW of electric power with heat supplied by a nuclear reactor. A novel heat exchanger module was designed to reduce the number of critical joints in the heat exchanger assembly while also incorporating a heat pipe as the link between the engine and the heat source. Two inexpensive verification tests are proposed. The SSE heat exchanger module is described and the operating conditions for the module are outlined. The design process of the heat exchanger modules, including the sodium heat pipe, is briefly described. Similarities between the proposed SSE heat exchanger modules and the LeRC test modules for two test engines are presented. The benefits and weaknesses of using a sodium heat pipe to transport heat to a Stirling engine are discussed. Similarly, the problems encountered when using a true heat pipe, as opposed to a more simple reflux boiler, are described. The instruments incorporated into the modules and the test program are also outlined.

Multiphase flow modelling of explosive volcanic eruptions using adaptive unstructured meshes

NASA Astrophysics Data System (ADS)

Jacobs, Christian T.; Collins, Gareth S.; Piggott, Matthew D.; Kramer, Stephan C.

2014-05-01

Explosive volcanic eruptions generate highly energetic plumes of hot gas and ash particles that produce diagnostic deposits and pose an extreme environmental hazard. The formation, dispersion and collapse of these volcanic plumes are complex multiscale processes that are extremely challenging to simulate numerically. Accurate description of particle and droplet aggregation, movement and settling requires a model capable of capturing the dynamics on a range of scales (from cm to km) and a model that can correctly describe the important multiphase interactions that take place. However, even the most advanced models of eruption dynamics to date are restricted by the fixed mesh-based approaches that they employ. The research presented herein describes the development of a compressible multiphase flow model within Fluidity, a combined finite element / control volume computational fluid dynamics (CFD) code, for the study of explosive volcanic eruptions. Fluidity adopts a state-of-the-art adaptive unstructured mesh-based approach to discretise the domain and focus numerical resolution only in areas important to the dynamics, while decreasing resolution where it is not needed as a simulation progresses. This allows the accurate but economical representation of the flow dynamics throughout time, and potentially allows large multi-scale problems to become tractable in complex 3D domains. The multiphase flow model is verified with the method of manufactured solutions, and validated by simulating published gas-solid shock tube experiments and comparing the numerical results against pressure gauge data. The application of the model considers an idealised 7 km by 7 km domain in which the violent eruption of hot gas and volcanic ash high into the atmosphere is simulated. Although the simulations do not correspond to a particular eruption case study, the key flow features observed in a typical explosive eruption event are successfully captured. These include a shock wave resulting from the sudden high-velocity inflow of gas and ash; the formation of a particle-laden plume rising several hundred metres into the atmosphere; the eventual collapse of the plume which generates a volcanic ash fountain and a fast ground-hugging pyroclastic density current; and the growth of a dilute convective region that rises above the ash fountain as a result of buoyancy effects. The results from Fluidity are also compared with results from MFIX, a fixed structured mesh-based multiphase flow code, that uses the same set-up. The key flow features are also captured in MFIX, providing at least some confidence in the plausibility of the numerical results in the absence of quantitative field data. Finally, it is shown by a convergence analysis that Fluidity offers the same solution accuracy for reduced computational cost using an adaptive mesh, compared to the same simulation performed with a uniform fixed mesh.

Multiphase OH oxidation kinetics of organic aerosol: The role of particle phase state and relative humidity

NASA Astrophysics Data System (ADS)

Slade, Jonathan H.; Knopf, Daniel A.

2014-07-01

Organic aerosol can exhibit different phase states in response to changes in relative humidity (RH), thereby influencing heterogeneous reaction rates with trace gas species. OH radical uptake by laboratory-generated levoglucosan and methyl-nitrocatechol particles, serving as surrogates for biomass burning aerosol, is determined as a function of RH. Increasing RH lowers the viscosity of amorphous levoglucosan aerosol particles enabling enhanced OH uptake. Conversely, OH uptake by methyl-nitrocatechol aerosol particles is suppressed at higher RH as a result of competitive coadsorption of H2O that occupies reactive sites. This is shown to have substantial impacts on organic aerosol lifetimes with respect to OH oxidation. The results emphasize the importance of organic aerosol phase state to accurately describe the multiphase chemical kinetics and thus chemical aging process in atmospheric models to better represent the evolution of organic aerosol and its role in air quality and climate.

Multi-phased anaerobic baffled reactor treating food waste.

PubMed

Ahamed, A; Chen, C-L; Rajagopal, R; Wu, D; Mao, Y; Ho, I J R; Lim, J W; Wang, J-Y

2015-04-01

This study was conducted to identify the performance of a multi-phased anaerobic baffled reactor (MP-ABR) with food waste (FW) as the substrate for biogas production and thereby to promote an efficient energy recovery and treatment method for the wastes with high organic solid content through phase separation. A four-chambered ABR was operated at an HRT of 30 days with an OLR of 0.5-1.0 g-VS/Ld for a period of 175 days at 35 ± 1°C. Consistent overall removal efficiencies of 85.3% (CODt), 94.5% (CODs), 89.6% (VFA) and 86.4% (VS) were observed throughout the experiment displaying a great potential to treat FW. Biogas generated was 215.57 mL/g-VS removed d. Phase separation was observed and supported by the COD and VFA trends, and an efficient recovery of bioenergy from FW was achieved. Copyright © 2015 Elsevier Ltd. All rights reserved.

Design of Refractory Metal Life Test Heat Pipe and Calorimeter

NASA Technical Reports Server (NTRS)

Martin, J. J.; Reid, R. S.; Bragg-Sitton, S. M.

2010-01-01

Heat pipe life tests have seldom been conducted on a systematic basis. Typically, one or more heat pipes are built and tested for an extended period at a single temperature with simple condenser loading. Results are often reported describing the wall material, working fluid, test temperature, test duration, and occasionally the nature of any failure. Important information such as design details, processing procedures, material assay, power throughput, and radial power density are usually not mentioned. We propose to develop methods to generate carefully controlled data that conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. The test approach detailed in this Technical Publication will use 16 Mo-44.5%Re alloy/sodium heat pipe units that have an approximate12-in length and 5/8-in diameter. Two specific test series have been identified: (1) Long-term corrosion rates based on ASTM-G-68-80 (G-series) and (2) corrosion trends in a cross-correlation sequence at various temperatures and mass fluences based on a Fisher multifactor design (F-series). Evaluation of the heat pipe hardware will be performed in test chambers purged with an inert purified gas (helium or helium/argon mixture) at low pressure (10-100 torr) to provide thermal coupling between the heat pipe condenser and calorimeter. The final pressure will be selected to minimize the potential for voltage breakdown between the heat pipe and radio frequency (RF) induction coil (RF heating is currently the planned method of powering the heat pipes). The proposed calorimeter is constructed from a copper alloy and relies on a laminar flow water-coolant channel design to absorb and transport energy

On the scattering of elastic waves from a non-axisymmetric defect in a coated pipe.

PubMed

Duan, Wenbo; Kirby, Ray; Mudge, Peter

2016-02-01

Viscoelastic coatings are often used to protect pipelines in the oil and gas industry. However, over time defects and areas of corrosion often form in these pipelines and so it is desirable to monitor the structural integrity of these coated pipes using techniques similar to those used on uncoated pipelines. A common approach is to use ultrasonic guided waves that work on the pulse-echo principle; however, the energy in the guided waves can be heavily attenuated by the coating and so significantly reduce the effective range of these techniques. Accordingly, it is desirable to develop a better understanding of how these waves propagate in coated pipes with a view to optimising test methodologies, and so this article uses a hybrid SAFE-finite element approach to model scattering from non-axisymmetric defects in coated pipes. Predictions are generated in the time and frequency domain and it is shown that the longitudinal family of modes is likely to have a longer range in coated pipes when compared to torsional modes. Moreover, it is observed that the energy velocity of modes in a coated pipe is very similar to the group velocity of equivalent modes in uncoated pipes. It is also observed that the coating does not induce any additional mode conversion over and above that seen for an uncoated pipe when an incident wave is scattered by a defect. Accordingly, it is shown that when studying coated pipes one need account only for the attenuation imparted by the coating so that one may normally neglect the effect of coating on modal dispersion and scattering. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Multi-channel infrared thermometer

DOEpatents

Ulrickson, M.A.

A device for measuring the two-dimensional temperature profile of a surface comprises imaging optics for generating an image of the light radiating from the surface; an infrared detector array having a plurality of detectors; and optical means positioned between the imaging optics and the detector array for sampling, transmitting, and distributing the image over the detector surfaces. The optical means may be a light pipe array having one light pipe for each detector in the detector array.

Shaken Snow Globes: Kinematic Tracers of the Multiphase Condensation Cascade in Massive Galaxies, Groups, and Clusters

NASA Astrophysics Data System (ADS)

Gaspari, M.; McDonald, M.; Hamer, S. L.; Brighenti, F.; Temi, P.; Gendron-Marsolais, M.; Hlavacek-Larrondo, J.; Edge, A. C.; Werner, N.; Tozzi, P.; Sun, M.; Stone, J. M.; Tremblay, G. R.; Hogan, M. T.; Eckert, D.; Ettori, S.; Yu, H.; Biffi, V.; Planelles, S.

2018-02-01

We propose a novel method to constrain turbulence and bulk motions in massive galaxies, galaxy groups, and clusters, exploring both simulations and observations. As emerged in the recent picture of top-down multiphase condensation, hot gaseous halos are tightly linked to all other phases in terms of cospatiality and thermodynamics. While hot halos (∼107 K) are perturbed by subsonic turbulence, warm (∼104 K) ionized and neutral filaments condense out of the turbulent eddies. The peaks condense into cold molecular clouds (<100 K) raining in the core via chaotic cold accretion (CCA). We show that all phases are tightly linked in terms of the ensemble (wide-aperture) velocity dispersion along the line of sight. The correlation arises in complementary long-term AGN feedback simulations and high-resolution CCA runs, and is corroborated by the combined Hitomi and new Integral Field Unit measurements in the Perseus cluster. The ensemble multiphase gas distributions (from the UV to the radio band) are characterized by substantial spectral line broadening (σ v,los ≈ 100–200 {km} {{{s}}}-1) with a mild line shift. On the other hand, pencil-beam detections (as H I absorption against the AGN backlight) sample the small-scale clouds displaying smaller broadening and significant line shifts of up to several 100 {km} {{{s}}}-1 (for those falling toward the AGN), with increased scatter due to the turbulence intermittency. We present new ensemble σ v,los of the warm Hα+[N II] gas in 72 observed cluster/group cores: the constraints are consistent with the simulations and can be used as robust proxies for the turbulent velocities, in particular for the challenging hot plasma (otherwise requiring extremely long X-ray exposures). Finally, we show that the physically motivated criterion C ≡ t cool/t eddy ≈ 1 best traces the condensation extent region and the presence of multiphase gas in observed clusters and groups. The ensemble method can be applied to many available spectroscopic data sets and can substantially advance our understanding of multiphase halos in light of the next-generation multiwavelength missions.

Advanced subsystems development

NASA Technical Reports Server (NTRS)

Livingston, F. R.

1978-01-01

The concept design for a small (less than 10 MWe) solar thermal electric generating plant was completed using projected 1985 technology. The systems requirements were defined and specified. The components, including an engineering prototype for one 15 kWe module of the generating plant, were conceptually designed. Significant features of the small solar thermal power plant were identified as the following: (1) 15 kWe Stirling-cycle engine/alternator with constant power output; (2) 10 meter point-focusing paraboloidal concentrator with cantilevered cellular glass reflecting panels; (3) primary heat pipe with 800 C output solar cavity receiver; (4) secondary heat pipe with molten salt thermal energy storage unit; (5) electric energy transport system; and (6) advanced battery energy storage capability.

Noise generated by flow through large butterfly valves

NASA Technical Reports Server (NTRS)

Huff, Ronald G.

1987-01-01

A large butterfly valve (1.37 m diam) was acoustically tested to measure the noise generated and propagating in both the upstream and downstream directions. The experimental investigation used wall mounted pressure transducers to measure the fluctuating component of the pipe static pressure upstream and downstream of the valve. Microphones upstream of the pipe inlet and located in a plenum were used to measure the noise radiated from the valve in the upstream direction. Comparison of the wall pressure downstream of the valve to a prediction were made. Reasonable agreement was obtained with the valve operating at a choked condition. The noise upstream of the valve is 30 dB less than that measured downstream.

Steam generator feedwater nozzle transition piece replacement experience at Salem Unit 1

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

Patten, D.B.; Perrin, J.S.; Roberts, A.T.

Cracking of steam generator feedwater piping adjacent to the feedwater nozzles has been a recurring problem since 1979 at Salem Unit 1 owned and operated by Public Service Electric and Gas Company. In addition to the cracking problem, erosion-corrosion at the leading edge of the feedwater nozzle thermal sleeve was also observed in 1992. To provide a long-term solution for the pipe cracking and thermal sleeve erosion-corrosion problems, a unique transition piece forging was specially designed, fabricated, and installed for each of the four steam generators during the 1995 outage. This paper discusses the design, fabrication, and installation of themore » transition piece forgings at Salem Unit 1, and the experiences gained from this project. It is believed that these experiences may help other utilities when planning similar replacements in the future.« less

Preliminary Feasibility Study of a Hybrid Solar and Modular Pumped Storage Hydro System at Biosphere 2

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

Lansey, Kevin; Hortsman, Chris

2016-10-01

In this study, the preliminary feasibility of a hybrid solar and modular pumped storage system designed for high energy independence at Biosphere 2 is assessed. The system consists of an array of solar PV panels that generate electricity during the day to power both Biosphere 2 and a pump that sends water through a pipe to a tank at a high elevation. When solar power is not available, the water is released back down the pipe towards a tank at a lower elevation, where it passes through a hydraulic water turbine to generate hydroelectricity to power Biosphere 2. The hybridmore » system is sized to generate and store enough energy to enable Biosphere 2 to operate without a grid interconnection on an average day.« less

Insoluble coatings for Stirling engine heat pipe condenser surfaces

NASA Astrophysics Data System (ADS)

Dussinger, Peter M.

1993-09-01

The work done by Thermacore, Inc., Lancaster, Pennsylvania, for the Phase 1, 1992 SBIR National Aeronautics and Space Administration Contract, 'Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces' is described. The work was performed between January 1992 and July 1992. Stirling heat engines are being developed for electrical power generation use on manned and unmanned earth orbital and planetary missions. Dish Stirling solar systems and nuclear reactor Stirling systems are two of the most promising applications of the Stirling engine electrical power generation technology. The sources of thermal energy used to drive the Stirling engine typically are non-uniform in temperature and heat flux. Liquid metal heat pipe receivers are used as thermal transformers and isothermalizers to deliver the thermal energy at a uniform high temperature to the heat input section of the Stirling engine. The use of a heat pipe receiver greatly enhances system efficiency and potential life span. One issue that is raised during the design phase of heat pipe receivers is the potential solubility corrosion of the Stirling engine heat input section by the liquid metal working fluid. This Phase 1 effort initiated a program to evaluate and demonstrate coatings, applied to nickel based Stirling engine heater head materials, that are practically 'insoluble' in sodium, potassium, and NaK. This program initiated a study of nickel aluminide as a coating and developed and demonstrated a heat pipe test vehicle that can be used to test candidate materials and coatings. Nickel 200 and nickel aluminide coated Nickel 200 were tested for 1000 hours at 800 C at a condensation heat flux of 25 W/sq cm. Subsequent analyses of the samples showed no visible sign of solubility corrosion of either coated or uncoated samples. The analysis technique, photomicrographs at 200X, has a resolution of better than 2.5 microns (.0001 in). The results indicate that the heat pipe environment is not directly comparable to liquid metal pumped loop data, that nickel aluminide is still a leading candidate for solubility corrosion protection, and that longer duration tests are required to reach a definitive conclusion whether coatings are required at all. Should further testing be required, the test vehicle and analytical tools were developed.

Insoluble coatings for Stirling engine heat pipe condenser surfaces

NASA Technical Reports Server (NTRS)

Dussinger, Peter M.

1993-01-01

The work done by Thermacore, Inc., Lancaster, Pennsylvania, for the Phase 1, 1992 SBIR National Aeronautics and Space Administration Contract, 'Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces' is described. The work was performed between January 1992 and July 1992. Stirling heat engines are being developed for electrical power generation use on manned and unmanned earth orbital and planetary missions. Dish Stirling solar systems and nuclear reactor Stirling systems are two of the most promising applications of the Stirling engine electrical power generation technology. The sources of thermal energy used to drive the Stirling engine typically are non-uniform in temperature and heat flux. Liquid metal heat pipe receivers are used as thermal transformers and isothermalizers to deliver the thermal energy at a uniform high temperature to the heat input section of the Stirling engine. The use of a heat pipe receiver greatly enhances system efficiency and potential life span. One issue that is raised during the design phase of heat pipe receivers is the potential solubility corrosion of the Stirling engine heat input section by the liquid metal working fluid. This Phase 1 effort initiated a program to evaluate and demonstrate coatings, applied to nickel based Stirling engine heater head materials, that are practically 'insoluble' in sodium, potassium, and NaK. This program initiated a study of nickel aluminide as a coating and developed and demonstrated a heat pipe test vehicle that can be used to test candidate materials and coatings. Nickel 200 and nickel aluminide coated Nickel 200 were tested for 1000 hours at 800 C at a condensation heat flux of 25 W/sq cm. Subsequent analyses of the samples showed no visible sign of solubility corrosion of either coated or uncoated samples. The analysis technique, photomicrographs at 200X, has a resolution of better than 2.5 microns (.0001 in). The results indicate that the heat pipe environment is not directly comparable to liquid metal pumped loop data, that nickel aluminide is still a leading candidate for solubility corrosion protection, and that longer duration tests are required to reach a definitive conclusion whether coatings are required at all. Should further testing be required, the test vehicle and analytical tools were developed.

Manifold, bus support and coupling arrangement for solid oxide fuel cells

DOEpatents

Parry, Gareth W.

1989-01-01

Individual, tubular solid oxide fuel cells (SOFCs) are assembled into bundles called a module within a housing, with a plurality of modules arranged end-to-end in a linear, stacked configuration called a string. A common set of piping comprised of a suitable high temperture resistant material (1) provides fuel and air to each module housing, (2) serves as electrically conducting buses, and (3) provides structural support for a string of SOFC modules. The piping thus forms a manfold for directing fuel and air to each module in a string and makes electrical contact with the module's anode and cathode to conduct the DC power generated by the SOFC. The piping also provides structureal support for each individual module and maintains each string of modules as a structurally integral unit for ensuring high strength in a large 3-dimensional array of SOFC modules. Ceramic collars are used to connect fuel and air inlet piping to each of the electrodes in an SOFC module and provide (1) electrical insulation for the current carrying bus bars and gas manifolds, (2) damping for the fuel and air inlet piping, and (3) proper spacing between the fuel and air inlet piping to prevent contact between these tubes and possible damage to the SOFC.

Breccia pipes in the Karoo Basin, South Africa, as conduits for metamorphic gases to the Early Jurassic atmosphere

NASA Astrophysics Data System (ADS)

Silkoset, Petter; Svensen, Henrik; Planke, Sverre

2014-05-01

The Toarcian (Early Jurassic) event was manifested by globally elevated temperatures and anoxic ocean conditions that particularly affected shallow marine taxa. The event coincided with the emplacement of the vast Karoo-Ferrar Large Igneous Province. Among the suggestions for trigger mechanisms for the climatic perturbation is metamorphic methane generation from black shale around the sills in the Karoo Basin, South Africa. The sill emplacement provides a mechanism for voluminous in-situ production and emission of greenhouse gases, and establishes a distinct link between basin-trapped and atmospheric carbon. In the lower stratigraphic levels of the Karoo Basin, black shales are metamorphosed around sills and the sediments are cut by a large number of pipe structures with metamorphic haloes. The pipes are vertical, cylindrical structures that contain brecciated and baked sediments with variable input of magmatic material. Here, we present borehole, petrographic, geochemical and field data from breccia pipes and contact aureoles based on field campaigns over a number of years (2004-2014). The metamorphism around the pipes show equivalent metamorphic grade as the sediments around nearby sills, suggesting a more prominent phreatomagmatic component than previously thought. The stratigraphic position of pipes and the breccia characteristics strengthens the hypothesis of a key role in the Toarcian carbon isotope excursion.

Recent advances in quantitative analysis of fluid interfaces in multiphase fluid flow measured by synchrotron-based x-ray microtomography

NASA Astrophysics Data System (ADS)

Schlueter, S.; Sheppard, A.; Wildenschild, D.

2013-12-01

Imaging of fluid interfaces in three-dimensional porous media via x-ray microtomography is an efficient means to test thermodynamically derived predictions on the relationship between capillary pressure, fluid saturation and specific interfacial area (Pc-Sw-Anw) in partially saturated porous media. Various experimental studies exist to date that validate the uniqueness of the Pc-Sw-Anw relationship under static conditions and with current technological progress direct imaging of moving interfaces under dynamic conditions is also becoming available. Image acquisition and subsequent image processing currently involves many steps each prone to operator bias, like merging different scans of the same sample obtained at different beam energies into a single image or the generation of isosurfaces from the segmented multiphase image on which the interface properties are usually calculated. We demonstrate that with recent advancements in (i) image enhancement methods, (ii) multiphase segmentation methods and (iii) methods of structural analysis we can considerably decrease the time and cost of image acquisition and the uncertainty associated with the measurement of interfacial properties. In particular, we highlight three notorious problems in multiphase image processing and provide efficient solutions for each: (i) Due to noise, partial volume effects, and imbalanced volume fractions, automated histogram-based threshold detection methods frequently fail. However, these impairments can be mitigated with modern denoising methods, special treatment of gray value edges and adaptive histogram equilization, such that most of the standard methods for threshold detection (Otsu, fuzzy c-means, minimum error, maximum entropy) coincide at the same set of values. (ii) Partial volume effects due to blur may produce apparent water films around solid surfaces that alter the specific fluid-fluid interfacial area (Anw) considerably. In a synthetic test image some local segmentation methods like Bayesian Markov random field, converging active contours and watershed segmentation reduced the error in Anw associated with apparent water films from 21% to 6-11%. (iii) The generation of isosurfaces from the segmented data usually requires a lot of postprocessing in order to smooth the surface and check for consistency errors. This can be avoided by calculating specific interfacial areas directly on the segmented voxel image by means of Minkowski functionals which is highly efficient and less error prone.

Two-phase working fluids for the temperature range 100-350 C. [in heat pipes for solar applications

NASA Technical Reports Server (NTRS)

Saaski, E. W.; Tower, L.

1977-01-01

The decomposition and corrosion of two-phase heat transfer liquids and metal envelopes have been investigated on the basis of molecular, bond strengths and chemical thermodynamics. Potentially stable heat transfer fluids for the temperature range 100 to 350 C have been identified, and reflux heat pipe tests initiated with 10 fluids and carbon steel and aluminum envelopes to experimentally establish corrosion behavior and noncondensable gas generation rates.

Needleless Electrospinning Experimental Study and Nanofiber Application in Semiconductor Packaging

NASA Astrophysics Data System (ADS)

Sun, Tianwei

Electronics especially mobile electronics such as smart phones, tablet PCs, notebooks and digital cameras are undergoing rapid development nowadays and have thoroughly changed our lives. With the requirement of more transistors, higher power, smaller size, lighter weight and even bendability, thermal management of these devices became one of the key challenges. Compared to active heat management system, heat pipe, which is a passive fluidic system, is considered promising to solve this problem. However, traditional heat pipes have size, weight and capillary limitation. Thus new type of heat pipe with smaller size, lighter weight and higher capillary pressure is needed. Nanofiber has been proved with superior properties and has been applied in multiple areas. This study discussed the possibility of applying nanofiber in heat pipe as new wick structure. In this study, a needleless electrospinning device with high productivity rate was built onsite to systematically investigate the effect of processing parameters on fiber properties as well as to generate nanofiber mat to evaluate its capability in electronics cooling. Polyethylene oxide (PEO) and Polyvinyl Alcohol (PVA) nanofibers were generated. Tensiometer was used for wettability measurement. The results show that independent parameters including spinneret type, working distance, solution concentration and polymer type are strongly correlated with fiber morphology compared to other parameters. The results also show that the fabricated nanofiber mat has high capillary pressure.

Multiphase porous media modelling: A novel approach to predicting food processing performance.

PubMed

Khan, Md Imran H; Joardder, M U H; Kumar, Chandan; Karim, M A

2018-03-04

The development of a physics-based model of food processing is essential to improve the quality of processed food and optimize energy consumption. Food materials, particularly plant-based food materials, are complex in nature as they are porous and have hygroscopic properties. A multiphase porous media model for simultaneous heat and mass transfer can provide a realistic understanding of transport processes and thus can help to optimize energy consumption and improve food quality. Although the development of a multiphase porous media model for food processing is a challenging task because of its complexity, many researchers have attempted it. The primary aim of this paper is to present a comprehensive review of the multiphase models available in the literature for different methods of food processing, such as drying, frying, cooking, baking, heating, and roasting. A critical review of the parameters that should be considered for multiphase modelling is presented which includes input parameters, material properties, simulation techniques and the hypotheses. A discussion on the general trends in outcomes, such as moisture saturation, temperature profile, pressure variation, and evaporation patterns, is also presented. The paper concludes by considering key issues in the existing multiphase models and future directions for development of multiphase models.

Cheaper Synthesis Of Multipole-Brushless-dc-Motor Current

NASA Technical Reports Server (NTRS)

Alhorn, Dean C.; Howard, David E.

1994-01-01

Circuit converts output of single two-phase shaft-angle resolver to that of multi-speed three-phase shaft-angle resolver. Converter circuit applicable to generation of multispeed, multiphase shaft-angle-resolver signals from single two-phase shaft-angle resolver. Combination of converter circuit and single two-phase shaft-angle resolver offer advantages in cost, weight, size, and complexity. Design readily adaptable to two-phase motor.

Investigation of scaling characteristics for defining design environments due to transient ground winds and near-field, nonlinear acoustic fields

NASA Technical Reports Server (NTRS)

Shih, C. C.

1973-01-01

In order to establish a foundation of scaling laws for the highly nonlinear waves associated with the launch vehicle, the basic knowledge of the relationships among the paramaters pertinent to the energy dissipation process associated with the propagation of nonlinear pressure waves in thermoviscous media is required. The problem of interest is to experimentally investigate the temporal and spacial velocity profiles of fluid flow in a 3-inch open-end pipe of various lengths, produced by the propagation of nonlinear pressure waves for various diaphragm burst pressures of a pressure wave generator. As a result, temporal and spacial characteristics of wave propagation for a parametric set of nonlinear pressure waves in the pipe containing air under atmospheric conditions were determined. Velocity measurements at five sections along the pipes of up to 210 ft. in length were made with hot-film anemometers for five pressure waves produced by a piston. The piston was derived with diaphragm burst pressures at 20, 40, 60, 80 and 100 psi in the driver chamber of the pressure wave generator.

Internal structure of multiphase zinc-blende wurtzite gallium nitride nanowires.

PubMed

Jacobs, B W; Ayres, V M; Crimp, M A; McElroy, K

2008-10-08

In this paper, the internal structure of novel multiphase gallium nitride nanowires in which multiple zinc-blende and wurtzite crystalline domains grow simultaneously along the entire length of the nanowire is investigated. Orientation relationships within the multiphase nanowires are identified using high-resolution transmission electron microscopy of nanowire cross-sections fabricated with a focused ion beam system. A coherent interface between the zinc-blende and wurtzite phases is identified. A mechanism for catalyst-free vapor-solid multiphase nanowire nucleation and growth is proposed.

Advances in multiphase flow measurements using magnetic resonance relaxometry

NASA Astrophysics Data System (ADS)

Kantzas, Apostolos; Kryuchkov, Sergey; Chandrasekaran, Blake

2009-02-01

When it comes to the measurement of bitumen and water content as they are produced from thermally exploited reservoirs (cyclic steam stimulation or steam assisted gravity drainage) most of the current tools that are available in the market fail. This was demonstrated previously when our group introduced the first concept of a magnetic resonance based water-cut meter. The use of magnetic resonance as a potential tool for fluid cut metering from thermally produced heavy oil and bitumen reservoirs is revisited. At first a review of the work to date is presented. Our recent approach in the tackling of this problem follows. A patented process is coupled with a patented pipe design that can be used inside a magnetic field and can capture fluids up to 260°C and 4.2MPa. The paper describes the technical advances to this goal and offers a first glimpse of field data from an actual thermal facility for bitumen production. The paper also addresses an approach for converting the current discrete measurement device into a continuous measurement system. Preliminary results for this new concept are also presented.

Geyser periodicity and the response of geysers to deformation

USGS Publications Warehouse

Ingebritsen, S.E.; Rojstaczer, S.A.

1996-01-01

Numerical simulations of multiphase fluid and heat transport through a porous medium define combinations of rock properties and boundary conditions which lead to geyser-like periodic discharge. Within the rather narrow range of conditions that allow geyser-like behavior, eruption frequency and discharge are highly sensitive to the intrinsic permeabilities of the geyser conduit and the surrounding rock matrix, to the relative permeability functions assumed, and to pressure gradients in the matrix. In theory, heats pipes (concomitant upward flow of steam and downward flow of liquid) can exist under similar conditions, but our simulations suggest that the periodic solution is more stable. Simulated time series of geyser discharge are chaotic, but integrated quantities such as eruption frequency and mass discharge per eruption are free of chaos. These results may explain the observed sensitivity of natural geysers to small strains such as those caused by remote earthquakes, if ground motion is sufficient to induce permeability changes. Changes in geyser behavior caused by minor preseismic deformation, periodic surface loading, and Earth tides are more difficult to explain in the context of our current model. Copyright 1996 by the American Geophysical Union.

Zebra Mussel Chemical Control Guide, Version 2.0

DTIC Science & Technology

2015-07-01

delivery systems, including potable water treatment, agriculture, industry, power generation, and fire protection. Since this invasive organism’s...delivery systems, including potable water treatment, agriculture, industry, power generation, and fire protection (Mackie and Claudi 2010). Zebra mussels...generators, pipes, valves, sensing equipment (level, flow, and pressure) and fire protection (Mackie and Claudi 2010; Prescott et al. 2014). Other USACE

Detection of active noise control on the standard motorcycle exhaust Supra X 125 D using PVC pipe technique form Y

NASA Astrophysics Data System (ADS)

Isranuri, I.; Alfisyahrin; Nasution, A. R.

2018-02-01

This detection aims to obtain noise reduction on the supra X 125D motorcycle exhaust by using the Active Noise Control Method. The technique is done using a Y-shaped PVC pipe to be bolted on the exhaust, which then branch Y PVC is placed loudspeaker with impermeable conditions. The function of this loudspeaker is as a secondary noise to counter the primary noise of the sound of exhaust motorcycle Supra X 125D. The sound generator in this study is the ISD 4004 module, which serves to generate noise to counter the source noise. How this ISD 4004 module works is by recording source noise then recording the source noise and then reversed the phase 180° by phase reversing circuit. So that, the noise generated by the sound generator will hit the source noise and encounter or such as addition of two different phase of sound will result in noise reduction when detected at the end of the Y-shaped PVC pipe. Inverted phase reversed using feed-back resistor 1 kΩ and 2 kΩ input resistors, 16V capacitor 2500μf and as amplifier using ICL 7660 and TL 702 CP. Test results on the highest 1000 rpm rotation engine speed on the Z axis of 2 dB, and at the highest 2000 rpm rotation engine speed also occurs on the Z axis of 1.5 dB.

Development of axisymmetric lattice Boltzmann flux solver for complex multiphase flows

NASA Astrophysics Data System (ADS)

Wang, Yan; Shu, Chang; Yang, Li-Ming; Yuan, Hai-Zhuan

2018-05-01

This paper presents an axisymmetric lattice Boltzmann flux solver (LBFS) for simulating axisymmetric multiphase flows. In the solver, the two-dimensional (2D) multiphase LBFS is applied to reconstruct macroscopic fluxes excluding axisymmetric effects. Source terms accounting for axisymmetric effects are introduced directly into the governing equations. As compared to conventional axisymmetric multiphase lattice Boltzmann (LB) method, the present solver has the kinetic feature for flux evaluation and avoids complex derivations of external forcing terms. In addition, the present solver also saves considerable computational efforts in comparison with three-dimensional (3D) computations. The capability of the proposed solver in simulating complex multiphase flows is demonstrated by studying single bubble rising in a circular tube. The obtained results compare well with the published data.

Retrospective multi-phase non-contrast-enhanced magnetic resonance angiography (ROMANCE MRA) for robust angiogram separation in the presence of cardiac arrhythmia.

PubMed

Kim, Hahnsung; Park, Suhyung; Kim, Eung Yeop; Park, Jaeseok

2018-09-01

To develop a novel, retrospective multi-phase non-contrast-enhanced MRA (ROMANCE MRA) in a single acquisition for robust angiogram separation even in the presence of cardiac arrhythmia. In the proposed ROMANCE MRA, data were continuously acquired over all cardiac phases using retrospective, multi-phase flow-sensitive single-slab 3D fast spin echo (FSE) with variable refocusing flip angles, while an external pulse oximeter was in sync with pulse repetitions in FSE to record real-time information on cardiac cycles. Data were then sorted into k-bin space using the real-time cardiac information. Angiograms were reconstructed directly from k-bin space by solving a constrained optimization problem with both subtraction-induced sparsity and low rank priors. Peripheral MRA was performed in normal volunteers with/without caffeine consumption and a volunteer with cardiac arrhythmia using conventional fresh blood imaging (FBI) and the proposed ROMANCE MRA for comparison. The proposed ROMANCE MRA shows superior performance in accurately delineating both major and small vessel branches with robust background suppression if compared with conventional FBI. Even in the presence of irregular heartbeats, the proposed method exhibits clear depiction of angiograms over conventional methods within clinically reasonable imaging time. We successfully demonstrated the feasibility of the proposed ROMANCE MRA in generating robust angiograms with background suppression. © 2018 International Society for Magnetic Resonance in Medicine.

Determining the hydraulic and fracture properties of the Coal Seam Gas well by numerical modelling and GLUE analysis

NASA Astrophysics Data System (ADS)

Askarimarnani, Sara; Willgoose, Garry; Fityus, Stephen

2017-04-01

Coal seam gas (CSG) is a form of natural gas that occurs in some coal seams. Coal seams have natural fractures with dual-porosity systems and low permeability. In the CSG industry, hydraulic fracturing is applied to increase the permeability and extract the gas more efficiently from the coal seam. The industry claims that it can design fracking patterns. Whether this is true or not, the public (and regulators) requires assurance that once a well has been fracked that the fracking has occurred according to plan and that the fracked well is safe. Thus defensible post-fracking testing methodologies for gas generating wells are required. In 2009 a fracked well HB02, owned by AGL, near Broke, NSW, Australia was subjected to "traditional" water pump-testing as part of this assurance process. Interpretation with well Type Curves and simple single phase (i.e. only water, no gas) highlighted deficiencies in traditional water well approaches with a systemic deviation from the qualitative characteristic of well drawdown curves (e.g. concavity versus convexity of drawdown with time). Accordingly a multiphase (i.e. water and methane) model of the well was developed and compared with the observed data. This paper will discuss the results of this multiphase testing using the TOUGH2 model and its EOS7C constitutive model. A key objective was to test a methodology, based on GLUE monte-carlo calibration technique, to calibrate the characteristics of the frack using the well test drawdown curve. GLUE involves a sensitivity analysis of how changes in the fracture properties change the well hydraulics through and analysis of the drawdown curve and changes in the cone of depression. This was undertaken by changing the native coal, fracture, and gas parameters to see how changing those parameters changed the match between simulations and the observed well drawdown. Results from the GLUE analysis show how much information is contained in the well drawdown curve for estimating field scale coal and gas generation properties, the fracture geometry, and the proponent characteristics. The results with the multiphase model show a better match to the drawdown than using a single phase model but the differences between the best fit drawdowns were small, and smaller than the difference between the best fit and field data. However, the parameters derived to generate these best fits for each model were very different. We conclude that while satisfactory fits with single phase groundwater models (e.g. MODFLOW, FEFLOW) can be achieved the parameters derived will not be realistic, with potential implications for drawdowns and water yields for gas field modelling. Multiphase models are thus required and we will discuss some of the limitations of TOUGH2 for the CSG problem.

Experience with wear-resistant materials at the Homer City Coal Cleaning Plant

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

Williams, W.R.

1984-10-01

The Homer City Coal Cleaning Plant is a multistream, dual-circuit facility with a total capacity of 1.22 x 10/sup 6/ Kg/hr (1200 TPH) raw feed and serves the three generating units of the Pennsylvania Electric Company's Homer City Generating Station. The complicated multi-cleaning circuit design requires considerably more power and piping (10.6 km/35,000 ft of plus 5 cm/2 in. process piping) than a more conventional plant of the same capacity. Coupled with the maintenance intensive aspects of the plant is the requirement to have a high availability due to the mine mouth-to-cleaning plant-to-generating station philosophy under which it operates. Thesemore » factors required a dedicated effort to improve equipment wear characteristics. Experiences in the use of a variety of wear and corrosion resistant materials at the Homer City Coal Cleaning Plant are described.« less

Methods for compressible multiphase flows and their applications

NASA Astrophysics Data System (ADS)

Kim, H.; Choe, Y.; Kim, H.; Min, D.; Kim, C.

2018-06-01

This paper presents an efficient and robust numerical framework to deal with multiphase real-fluid flows and their broad spectrum of engineering applications. A homogeneous mixture model incorporated with a real-fluid equation of state and a phase change model is considered to calculate complex multiphase problems. As robust and accurate numerical methods to handle multiphase shocks and phase interfaces over a wide range of flow speeds, the AUSMPW+_N and RoeM_N schemes with a system preconditioning method are presented. These methods are assessed by extensive validation problems with various types of equation of state and phase change models. Representative realistic multiphase phenomena, including the flow inside a thermal vapor compressor, pressurization in a cryogenic tank, and unsteady cavitating flow around a wedge, are then investigated as application problems. With appropriate physical modeling followed by robust and accurate numerical treatments, compressible multiphase flow physics such as phase changes, shock discontinuities, and their interactions are well captured, confirming the suitability of the proposed numerical framework to wide engineering applications.

Numerical and experimental analysis of heat pipes with application in concentrated solar power systems

NASA Astrophysics Data System (ADS)

Mahdavi, Mahboobe

Thermal energy storage systems as an integral part of concentrated solar power plants improve the performance of the system by mitigating the mismatch between the energy supply and the energy demand. Using a phase change material (PCM) to store energy increases the energy density, hence, reduces the size and cost of the system. However, the performance is limited by the low thermal conductivity of the PCM, which decreases the heat transfer rate between the heat source and PCM, which therefore prolongs the melting, or solidification process, and results in overheating the interface wall. To address this issue, heat pipes are embedded in the PCM to enhance the heat transfer from the receiver to the PCM, and from the PCM to the heat sink during charging and discharging processes, respectively. In the current study, the thermal-fluid phenomenon inside a heat pipe was investigated. The heat pipe network is specifically configured to be implemented in a thermal energy storage unit for a concentrated solar power system. The configuration allows for simultaneous power generation and energy storage for later use. The network is composed of a main heat pipe and an array of secondary heat pipes. The primary heat pipe has a disk-shaped evaporator and a disk-shaped condenser, which are connected via an adiabatic section. The secondary heat pipes are attached to the condenser of the primary heat pipe and they are surrounded by PCM. The other side of the condenser is connected to a heat engine and serves as its heat acceptor. The applied thermal energy to the disk-shaped evaporator changes the phase of working fluid in the wick structure from liquid to vapor. The vapor pressure drives it through the adiabatic section to the condenser where the vapor condenses and releases its heat to a heat engine. It should be noted that the condensed working fluid is returned to the evaporator by the capillary forces of the wick. The extra heat is then delivered to the phase change material through the secondary heat pipes. During the discharging process, secondary heat pipes serve as evaporators and transfer the stored energy to the heat engine. (Abstract shortened by ProQuest.).

Technical Report on NETL's Non Newtonian Multiphase Slurry Workshop: A path forward to understanding non-Newtonian multiphase slurry flows

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

Guenther, Chris; Garg, Rahul

2013-08-19

The Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) sponsored a workshop on non-Newtonian multiphase slurry at NETL’s Morgantown campus August 19 and 20, 2013. The objective of this special two-day meeting of 20-30 invited experts from industry, National Labs and academia was to identify and address technical issues associated with handling non-Newtonian multiphase slurries across various facilities managed by DOE. Particular emphasis during this workshop was placed on applications managed by the Office of Environmental Management (EM). The workshop was preceded by two webinars wherein personnel from ORP and NETL provided background information on the Hanford WTP projectmore » and discussed the critical design challenges facing this project. In non-Newtonian fluids, viscosity is not constant and exhibits a complex dependence on applied shear stress or deformation. Many applications under EM’s tank farm mission involve non-Newtonian slurries that are multiphase in nature; tank farm storage and handling, slurry transport, and mixing all involve multiphase flow dynamics, which require an improved understanding of the mechanisms responsible for rheological changes in non-Newtonian multiphase slurries (NNMS). To discuss the issues in predicting the behavior of NNMS, the workshop focused on two topic areas: (1) State-of-the-art in non-Newtonian Multiphase Slurry Flow, and (2) Scaling up with Confidence and Ensuring Safe and Reliable Long-Term Operation.« less

A Senior Project-Based Multiphase Motor Drive System Development

ERIC Educational Resources Information Center

Abdel-Khalik, Ayman S.; Massoud, Ahmed M.; Ahmed, Shehab

2016-01-01

Adjustable-speed drives based on multiphase motors are of significant interest for safety-critical applications that necessitate wide fault-tolerant capabilities and high system reliability. Although multiphase machines are based on the same conceptual theory as three-phase machines, most undergraduate electrical machines and electric drives…

Use of a corrugated beam pipe as a passive deflector for bunch length measurements

NASA Astrophysics Data System (ADS)

Seok, Jimin; Chung, Moses; Kang, Heung-Sik; Min, Chang-Ki; Na, Donghyun

2018-02-01

We report the experimental demonstration of bunch length measurements using a corrugated metallic beam pipe as a passive deflector. The corrugated beam pipe has been adopted for reducing longitudinal chirping after the bunch compressors in several XFEL facilities worldwide. In the meantime, there have been attempts to measure the electron bunch's longitudinal current profile using the dipole wakefields generated in the corrugated pipe. Nevertheless, the bunch shape reconstructed from the nonlinearly deflected beam suffers from significant distortion, particularly near the head of the bunch. In this paper, we introduce an iterative process to improve the resolution of the bunch shape reconstruction. The astra and elegant simulations have been performed for pencil beam and cigar beam cases, in order to verify the effectiveness of the reconstruction process. To overcome the undesirable effects of transverse beam spreads, a measurement scheme involving both the corrugated beam pipe and the spectrometer magnet has been employed, both of which do not require a dedicated (and likely very expensive) rf system. A proof-of-principle experiment was carried out at Pohang Accelerator Laboratory (PAL) Injector Test Facility (ITF), and its results are discussed together with a comparison with the rf deflector measurement.

Engine room, showing engine generator foundation and inlet louvers, looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Engine room, showing engine generator foundation and inlet louvers, looking southwest. Note fuel gauge on west wall, left of fuse box, and exhaust pipe through south wall. - Western Union Telegraph Company, Jennerstown Relay, Laurel Summit Road off U.S. 30, Laughlintown, Westmoreland County, PA

Economic optimization of the energy transport component of a large distributed solar power plant

NASA Technical Reports Server (NTRS)

Turner, R. H.

1976-01-01

A solar thermal power plant with a field of collectors, each locally heating some transport fluid, requires a pipe network system for eventual delivery of energy power generation equipment. For a given collector distribution and pipe network geometry, a technique is herein developed which manipulates basic cost information and physical data in order to design an energy transport system consistent with minimized cost constrained by a calculated technical performance. For a given transport fluid and collector conditions, the method determines the network pipe diameter and pipe thickness distribution and also insulation thickness distribution associated with minimum system cost; these relative distributions are unique. Transport losses, including pump work and heat leak, are calculated operating expenses and impact the total system cost. The minimum cost system is readily selected. The technique is demonstrated on six candidate transport fluids to emphasize which parameters dominate the system cost and to provide basic decision data. Three different power plant output sizes are evaluated in each case to determine severity of diseconomy of scale.

Separation dynamics of dense dispersions in laminar pipe flows: An experimental and numerical study

NASA Astrophysics Data System (ADS)

Voulgaropoulos, Victor; Jamshidi, Rashid; Zainal Abidin, M. I. I.; Angeli, Panagiota

2017-11-01

The physical mechanisms governing the separation of dense liquid dispersed flows in pipes are not well understood. In this work, both experiments and numerical simulations are performed to investigate these mechanisms. Liquid-liquid dispersions are generated using a static mixer and their evolution is studied along a horizontal pipe (26mm ID) at laminar flow and input dispersed phase volume fractions up to 50%. To conduct optical measurements (PLIF and PIV) in the dense dispersions, the refractive index of both liquids is matched. Measurements are carried out at two axial locations downstream the mixer (15D and 135D, where D is the pipe diameter). Homogeneous dispersions, observed at 15D, segregate at 135D. The packing of the drops results in asymmetric velocity profiles and high slip velocities. The mixture approach is used in the numerical simulations, including gravity and shear-induced diffusion of drops. The predictions on separation and on velocity fields agree well with the experiments. Research funded by Chevron.

The modelling of symmetric airfoil vortex generators

NASA Technical Reports Server (NTRS)

Reichert, B. A.; Wendt, B. J.

1996-01-01

An experimental study is conducted to determine the dependence of vortex generator geometry and impinging flow conditions on shed vortex circulation and crossplane peak vorticity for one type of vortex generator. The vortex generator is a symmetric airfoil having a NACA 0012 cross-sectional profile. The geometry and flow parameters varied include angle-of-attack alfa, chordlength c, span h, and Mach number M. The vortex generators are mounted either in isolation or in a symmetric counter-rotating array configuration on the inside surface of a straight pipe. The turbulent boundary layer thickness to pipe radius ratio is delta/R = 0. 17. Circulation and peak vorticity data are derived from crossplane velocity measurements conducted at or about 1 chord downstream of the vortex generator trailing edge. Shed vortex circulation is observed to be proportional to M, alfa, and h/delta. With these parameters held constant, circulation is observed to fall off in monotonic fashion with increasing airfoil aspect ratio AR. Shed vortex peak vorticity is also observed to be proportional to M, alfa, and h/delta. Unlike circulation, however, peak vorticity is observed to increase with increasing aspect ratio, reaching a peak value at AR approx. 2.0 before falling off.

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

Swamy, S.A.; Mandava, P.R.; Bhowmick, D.C.

The leak-before-break (LBB) methodology is accepted as a technically justifiable approach for eliminating postulation of Double-Ended Guillotine Breaks (DEGB) in high energy piping systems. This is the result of extensive research, development, and rigorous evaluations by the NRC and the commercial nuclear power industry since the early 1970s. The DEGB postulation is responsible for the many hundreds of pipe whip restraints and jet shields found in commercial nuclear plants. These restraints and jet shields not only cost many millions of dollars, but also cause plant congestion leading to reduced reliability in inservice inspection and increased man-rem exposure. While use ofmore » leak-before-break technology saved hundreds of millions of dollars in backfit costs to many operating Westinghouse plants, value-impacts resulting from the application of this technology for future plants are greater on a per plant basis. These benefits will be highlighted in this paper. The LBB technology has been applied extensively to high energy piping systems in operating plants. However, there are differences between the application of LBB technology to an operating plant and to a new plant design. In this paper an approach is proposed which is suitable for application of LBB to a new plant design such as the Westinghouse AP600. The approach is based on generating Bounding Analyses Curves (BAC) for the candidate piping systems. The general methodology and criteria used for developing the BACs are based on modified GDC-4 and Standard Review Plan (SRP) 3.6.3. The BAC allows advance evaluation of the piping system from the LBB standpoint thereby assuring LBB conformance for the piping system. The piping designer can use the results of the BACs to determine acceptability of design loads and make modifications (in terms of piping layout and support configurations) as necessary at the design stage to assure LBB for the, piping systems under consideration.« less

Life Test Approach for Refractory Metal/Sodium Heat Pipes

NASA Astrophysics Data System (ADS)

Martin, James J.; Reid, Robert S.

2006-01-01

Heat pipe life tests described in the literature have seldom been conducted on a systematic basis. Typically one or more heat pipes are built and tested for an extended period at a single temperature with simple condenser loading. The objective of this work was to establish an approach to generate carefully controlled data that can conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. Approximately 10 years of operational life might be compressed into 3 years of laboratory testing through a combination of increased temperature and mass fluence. To accomplish this goal test series have been identified, based on American Society for Testing and Materials (ASTM) specifications, to investigate long term corrosion rates. The heat pipes selected for demonstration purposes are fabricated from a Molybdenum-44.5%Rhenium refractory metal alloy and include an internal crescent annular wick design formed by hot isostatic pressing. A processing methodology has been devised that incorporates vacuum distillation filling with an integrated purity sampling technique for the sodium working fluid. Energy is supplied by radio frequency induction coils coupled to the heat pipe evaporator with an input range of 1 to 5 kW per unit while a static gas gap coupled water calorimeter provides condenser cooling for heat pipe temperatures ranging from 1123 to 1323 K. The test chamber's atmosphere would require active purification to maintain low oxygen concentrations at an operating pressure of approximately 75 torr. The test is designed to operate round-the-clock with 6-month non-destructive inspection intervals to identify the onset and level of corrosion. At longer intervals specific heat pipes are destructively evaluated to verify the non-destructive observations. Accomplishments prior to project cancellation included successful demonstration of the heat pipe wick fabrication technique, establishment of all engineering designs, baselined operational test requirements and procurement/assembly of supporting test hardware systems.

GPM Avionics Module Heat Pipes Design and Performance Test Results

NASA Technical Reports Server (NTRS)

Ottenstein, Laura; DeChristopher, Mike

2011-01-01

The Global Precipitation Measurement (GPM) mission is an international network of satellites that provide the next-generation global observations of rain and snow. The GPM core satellite carries an advanced radar / radiometer system to measure precipitation from space and serve as a reference standard to unify precipitation measurements from a constellation of research and operational satellites. Through improved measurements of precipitation globally, the GPM mission will help to advance our understanding of Earth's water and energy cycle, improve forecasting of extreme events that cause natural hazards and disasters, and extend current capabilities in using accurate and timely information of precipitation to directly benefit society. The avionics module on the core satellite contains a number of electronics boxes which are cooled by a network of aluminum/ammonia heat pipes and a honeycomb radiator which contains thirteen embedded aluminum/ammonia heat pipes. All heat pipes were individually tested by the vendor (Advanced Cooling Technologies, Inc.) prior to delivery. Following delivery to NASA, the flight avionics radiator and the flight spare transport heat pipes were mounted to flight-like test structure and a system level thermal vacuum test was performed. This test, which used simulators in place of all electronics boxes, was done to verify the operation of the thermal control system as a whole. This presentation will discuss the design of the avionics module heat pipes, and then discuss performance tests results for the individual heat pipes prior to delivery and for the system level thermal vacuum test. All heat pipes met their performance requirements. However, it was found that the power was too low in some instances to start all of the smaller radiator spreader heat pipes when they were tested in a reflux configuration (which is the nominal test configuration). Although this lowered the efficiency of the radiator somewhat, it did not impact the operating temperatures of the electronics boxes.

Inter-rater reliability of the PIPES tool: validation of a surgical capacity index for use in resource-limited settings.

PubMed

Markin, Abraham; Barbero, Roxana; Leow, Jeffrey J; Groen, Reinou S; Perlman, Greg; Habermann, Elizabeth B; Apelgren, Keith N; Kushner, Adam L; Nwomeh, Benedict C

2014-09-01

In response to the need for simple, rapid means of quantifying surgical capacity in low resource settings, Surgeons OverSeas (SOS) developed the personnel, infrastructure, procedures, equipment and supplies (PIPES) tool. The present investigation assessed the inter-rater reliability of the PIPES tool. As part of a government assessment of surgical services in Santa Cruz, Bolivia, the PIPES tool was translated into Spanish and applied in interviews with physicians at 31 public hospitals. An additional interview was conducted with nurses at a convenience sample of 25 of these hospitals. Physician and nurse responses were then compared to generate an estimate of reliability. For dichotomous survey items, inter-rater reliability between physicians and nurses was assessed using the Cohen's kappa statistic and percent agreement. The Pearson correlation coefficient was used to assess agreement for continuous items. Cohen's kappa was 0.46 for infrastructure, 0.43 for procedures, 0.26 for equipment, and 0 for supplies sections. The median correlation coefficient was 0.91 for continuous items. Correlation was 0.79 for the PIPES index, and ranged from 0.32 to 0.98 for continuous response items. Reliability of the PIPES tool was moderate for the infrastructure and procedures sections, fair for the equipment section, and poor for supplies section when comparing surgeons' responses to nurses' responses-an extremely rigorous test of reliability. These results indicate that the PIPES tool is an effective measure of surgical capacity but that the equipment and supplies sections may need to be revised.

Water table variability and runoff generation in an eroded peatland, South Pennines, UK

NASA Astrophysics Data System (ADS)

Daniels, S. M.; Agnew, C. T.; Allott, T. E. H.; Evans, M. G.

2008-10-01

SummaryHydrological monitoring in an eroded South Pennine peatland shows that persistent and frequent water table drawdowns occur at gully edge locations, defining a deeper and thicker acrotelm than is observed in intact peatlands (an erosional acrotelm). Antecedent water table elevation is a key control on the hydrological response to precipitation events, in particular runoff percent, the timing of peak discharges and maximum water table elevations. Significant discharge is generated whilst water table elevations are relatively low at gully edge locations, and this has a strong influence on flow pathways. Four characteristics of runoff response are recognised: (i) the rapid development of macropore/pipe flow at the start of the storm; (ii) peat rewetting, water table elevation increase and continued macropore/pipe flow; (iii) maximum water table elevations and peak stream discharge with throughflow occurring within the erosional acrotelm and rapid flow through the subsurface macropore/pipe network; (iv) rapidly declining water table elevations and stream flow following the cessation of rainfall. Gully edge peats provide a key linkage between the hillslope hydrological system and channel flow so that their influence on the hydrological functioning of the peatlands is disproportionate to their aerial extent within the catchment. Future climate change may lead to further degradation of the bogs and a reinforcement of the importance of erosion gullies to runoff generation and water quality.

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

Muhleman, T.; Dempsey, P.

Although reduced activity has left its mark on engineering budgets and many projects have been delayed, industry remains committed to research and development. This year's emphasis is offshore where new-generation semi-submersibles are under construction for Arctic waters and where equipment technology is reaching maturity. Improved tubulars such as new process-forged drill pipe, special alloy, corrosion-resistant pipe and new tool joint designs are finding eager markets both on and offshore. And back in the office, microcomputers, a curiosity a few years ago, are making significant advances in improving drilling and production operations. Specific examples of this new technology include: Two high-tech,more » high-risk floaters Hard rock sidewall coring tool New torque-resistant tool joint Two improved riser connection systems Breakthrough in drill pipe manufacturing Power-packed portable drilling computer.« less

Thin Wall Pipe Ultrasonic Inspection through Paint Coating

NASA Astrophysics Data System (ADS)

Predoi, Mihai Valentin; Petre, Cristian Cătălin

Classical ultrasonic inspection of welds is currently done for plates thicker than 8 mm. The inspection of but welds in thin walled pipes has considerable implementation difficulties, due to guided waves dominating ultrasonic pulses propagation. Generation of purely symmetric modes, either torsional or longitudinal, requires a circumferential uniform distribution of transducers and dedicated inspection equipment, which are increasing the inspection costs. Moreover, if the surface is paint coated, the received signals are close to the detection level. The present work implies a single transducer, coupled to the painted surface. The proper choice of the guided mode and frequency range, allows the detection of a standard, small diameter through thickness hole. In this way, the inspection of pipe welds can use the same equipment as for thick materials, with only wedge adaptation.

1. GENERAL VIEW OF FISK STREET ELECTRIC GENERATING STATION COMPLEX, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. GENERAL VIEW OF FISK STREET ELECTRIC GENERATING STATION COMPLEX, LOOKING SOUTH; IN THE CENTER, BEHIND THE STACK IS THE GENERATING STATION BUILT IN 1959; THE TALL METAL-CLAD BUILDING CONTAINS A COAL BUNKER, COAL PULVERIZER, FURNACE, BOILER, SUPER-HEATER, STEAM PIPES, AND HOT-AIR DUCTS. TO THE RIGHT OF THIS 1959 GENERATING STATION IS THE ORIGINAL POWERHOUSE. - Commonwealth Electric Company, Fisk Street Electrical Generating Station, 1111 West Cermak Avenue, Chicago, Cook County, IL

Cause and Effect of Feedback: Multiphase Gas in Cluster Cores Heated by AGN Jets

NASA Astrophysics Data System (ADS)

Gaspari, M.; Ruszkowski, M.; Sharma, P.

2012-02-01

Multiwavelength data indicate that the X-ray-emitting plasma in the cores of galaxy clusters is not cooling catastrophically. To a large extent, cooling is offset by heating due to active galactic nuclei (AGNs) via jets. The cool-core clusters, with cooler/denser plasmas, show multiphase gas and signs of some cooling in their cores. These observations suggest that the cool core is locally thermally unstable while maintaining global thermal equilibrium. Using high-resolution, three-dimensional simulations we study the formation of multiphase gas in cluster cores heated by collimated bipolar AGN jets. Our key conclusion is that spatially extended multiphase filaments form only when the instantaneous ratio of the thermal instability and free-fall timescales (t TI/t ff) falls below a critical threshold of ≈10. When this happens, dense cold gas decouples from the hot intracluster medium (ICM) phase and generates inhomogeneous and spatially extended Hα filaments. These cold gas clumps and filaments "rain" down onto the central regions of the core, forming a cold rotating torus and in part feeding the supermassive black hole. Consequently, the self-regulated feedback enhances AGN heating and the core returns to a higher entropy level with t TI/t ff > 10. Eventually, the core reaches quasi-stable global thermal equilibrium, and cold filaments condense out of the hot ICM whenever t TI/t ff <~ 10. This occurs despite the fact that the energy from AGN jets is supplied to the core in a highly anisotropic fashion. The effective spatial redistribution of heat is enabled in part by the turbulent motions in the wake of freely falling cold filaments. Increased AGN activity can locally reverse the cold gas flow, launching cold filamentary gas away from the cluster center. Our criterion for the condensation of spatially extended cold gas is in agreement with observations and previous idealized simulations.

Dual-layer DECT for multiphasic hepatic CT with 50 percent iodine load: a matched-pair comparison with a 120 kVp protocol.

PubMed

Nagayama, Yasunori; Nakaura, Takeshi; Oda, Seitaro; Utsunomiya, Daisuke; Funama, Yoshinori; Iyama, Yuji; Taguchi, Narumi; Namimoto, Tomohiro; Yuki, Hideaki; Kidoh, Masafumi; Hirata, Kenichiro; Nakagawa, Masataka; Yamashita, Yasuyuki

2018-04-01

To evaluate the image quality and lesion conspicuity of virtual-monochromatic-imaging (VMI) with dual-layer DECT (DL-DECT) for reduced-iodine-load multiphasic-hepatic CT. Forty-five adults with renal dysfunction who had undergone hepatic DL-DECT with 300-mgI/kg were included. VMI (40-70-keV, DL-DECT-VMI) was generated at each enhancement phase. As controls, 45 matched patients undergoing standard 120-kVp protocol (120-kVp, 600-mgI/kg, and iterative reconstruction) were included. We compared the size-specific dose estimate (SSDE), image noise, CT attenuation, and contrast-to-noise ratio (CNR) between protocols. Two radiologists scored the image quality and lesion conspicuity. SSDE was significantly lower in DL-DECT group (p < 0.01). Image noise of DL-DECT-VMI was almost constant at each keV (differences of ≤15%) and equivalent to or lower than of 120-kVp. As the energy decreased, CT attenuation and CNR gradually increased; the values of 55-60 keV images were almost equivalent to those of standard 120-kVp. The highest scores for overall quality and lesion conspicuity were assigned at 40-keV followed by 45 to 55-keV, all of which were similar to or better than of 120-kVp. For multiphasic-hepatic CT with 50% iodine-load, DL-DECT-VMI at 40- to 55-keV provides equivalent or better image quality and lesion conspicuity without increasing radiation dose compared with standard 120-kVp protocol. • 40-55-keV yields optimal image quality for half-iodine-load multiphasic-hepatic CT with DL-DECT. • DL-DECT protocol decreases radiation exposure compared with 120-kVp scans with iterative reconstruction. • 40-keV images maximise conspicuity of hepatocellular carcinoma especially at hepatic-arterial phase.

SU-E-T-436: Accelerated Gated IMRT: A Feasibility Study for Lung Cancer Patients

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

Gilles, M; Boussion, N; Visvikis, D

Purpose: To evaluate the feasibility of delivering a gated Intensity Modulated Radiotherapy (IMRT) treatment using multiple respiratory phases in order to account for all anatomic changes during free breathing and accelerate the gated treatment without increasing the dose per fraction. Methods: For 7 patients with lung cancer, IMRT treatment plans were generated on a full inspiration (FI) Computed Tomography (CT) and a Mid Intensity Position (MIP) CT. Moreover, in order to achieve an accelerated gated IMRT, multiple respiratory phase plans were calculated: 2-phase plans including the FI and the full expiration phases, and 3-phase plans by adding the mid-inspiration phase.more » In order to assess the tolerance limits, plans' doses were registered and summed to the FI-based plan. Mean dose received by Organs at Risk (OARs) and target volumes were used to compare obtained plans. Results: The mean dose differences between the FI plans and the multi-phase plans never exceeded 0.4 Gy (Fig. 1). Concerning the clinical target volume these differences were even smaller: less than 0.1 Gy for both the 2-phase and 3-phase plans. Regarding the MIP treatment plan, higher doses in different healthy structures were observed, with a relative mean increase of 0.4 to 1.5 Gy. Finally, compared to the prescribed dose, the FI as well as the multi-phase plans were associated with a mean difference of 0.4 Gy, whereas in the case of MIP a higher mean difference of 0.6 Gy was observed. Conclusion: The doses obtained while planning a multi-phase gated IMRT treatment were within the tolerance limits. Compared to MIP, a better healthy tissue sparing was observed in the case of treatment planning based on one or multiple phases. Future work will consist in testing the multi-phase treatment delivery while accounting for the multileaf collimator speed constraints.« less

Pore-scale Simulation and Imaging of Multi-phase Flow and Transport in Porous Media (Invited)

NASA Astrophysics Data System (ADS)

Crawshaw, J.; Welch, N.; Daher, I.; Yang, J.; Shah, S.; Grey, F.; Boek, E.

2013-12-01

We combine multi-scale imaging and computer simulation of multi-phase flow and reactive transport in rock samples to enhance our fundamental understanding of long term CO2 storage in rock formations. The imaging techniques include Confocal Laser Scanning Microscopy (CLSM), micro-CT and medical CT scanning, with spatial resolutions ranging from sub-micron to mm respectively. First, we report a new sample preparation technique to study micro-porosity in carbonates using CLSM in 3 dimensions. Second, we use micro-CT scanning to generate high resolution 3D pore space images of carbonate and cap rock samples. In addition, we employ micro-CT to image the processes of evaporation in fractures and cap rock degradation due to exposure to CO2 flow. Third, we use medical CT scanning to image spontaneous imbibition in carbonate rock samples. Our imaging studies are complemented by computer simulations of multi-phase flow and transport, using the 3D pore space images obtained from the scanning experiments. We have developed a massively parallel lattice-Boltzmann (LB) code to calculate the single phase flow field in these pore space images. The resulting flow fields are then used to calculate hydrodynamic dispersion using a novel scheme to predict probability distributions for molecular displacements using the LB method and a streamline algorithm, modified for optimal solid boundary conditions. We calculate solute transport on pore-space images of rock cores with increasing degree of heterogeneity: a bead pack, Bentheimer sandstone and Portland carbonate. We observe that for homogeneous rock samples, such as bead packs, the displacement distribution remains Gaussian with time increasing. In the more heterogeneous rocks, on the other hand, the displacement distribution develops a stagnant part. We observe that the fraction of trapped solute increases from the beadpack (0 %) to Bentheimer sandstone (1.5 %) to Portland carbonate (8.1 %), in excellent agreement with PFG-NMR experiments. We then use our preferred multi-phase model to directly calculate flow in pore space images of two different sandstones and observe excellent agreement with experimental relative permeabilities. Also we calculate cluster size distributions in good agreement with experimental studies. Our analysis shows that the simulations are able to predict both multi-phase flow and transport properties directly on large 3D pore space images of real rocks. Pore space images, left and velocity distributions, right (Yang and Boek, 2013)

Three Dimensional Simulations of Multiphase Flows Using a Lattice Boltzmann Method Suitable for High Density Ratios - 12126

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

Gokaltun, Seckin; McDaniel, Dwayne; Roelant, David

2012-07-01

Multiphase flows involving gas and liquid phases can be observed in engineering operations at various Department of Energy sites, such as mixing of slurries using pulsed-air mixers and hydrogen gas generation in liquid waste tanks etc. The dynamics of the gas phase in the liquid domain play an important role in the mixing effectiveness of the pulsed-air mixers or in the level of gas pressure build-up in waste tanks. To understand such effects, computational fluid dynamics methods (CFD) can be utilized by developing a three-dimensional computerized multiphase flow model that can predict accurately the behavior of gas motion inside liquid-filledmore » tanks by solving the governing mathematical equations that represent the physics of the phenomena. In this paper, such a CFD method, lattice Boltzmann method (LBM), is presented that can model multiphase flows accurately and efficiently. LBM is favored over traditional Navier-Stokes based computational models since interfacial forces are handled more effectively in LBM. The LBM is easier to program, more efficient to solve on parallel computers, and has the ability to capture the interface between different fluid phases intrinsically. The LBM used in this paper can solve for the incompressible and viscous flow field in three dimensions, while at the same time, solve the Cahn-Hillard equation to track the position of the gas-liquid interface specifically when the density and viscosity ratios between the two fluids are high. This feature is of primary importance since the previous LBM models proposed for multiphase flows become unstable when the density ratio is larger than 10. The ability to provide stable and accurate simulations at large density ratios becomes important when the simulation case involves fluids such as air and water with a density ratio around 1000 that are common to many engineering problems. In order to demonstrate the capability of the 3D LBM method at high density ratios, a static bubble simulation is conducted to solve for the pressure difference between the inside and outside of a gas bubble in a liquid domain. Once the results show that the method is in agreement with the Laplace law, buoyant bubble simulations are conducted. The initial results obtained for bubble shape during the rising process was found to be in agreement with the theoretical expectations. (authors)« less

Lidar and Electro-Optics for Atmospheric Hazard Sensing and Mitigation

NASA Technical Reports Server (NTRS)

Clark, Ivan O.

2012-01-01

This paper provides an overview of the research and development efforts of the Lidar and Electro-Optics element of NASA's Aviation Safety Program. This element is seeking to improve the understanding of the atmospheric environments encountered by aviation and to provide enhanced situation awareness for atmospheric hazards. The improved understanding of atmospheric conditions is specifically to develop sensor signatures for atmospheric hazards. The current emphasis is on kinetic air hazards such as turbulence, aircraft wake vortices, mountain rotors, and windshear. Additional efforts are underway to identify and quantify the hazards arising from multi-phase atmospheric conditions including liquid and solid hydrometeors and volcanic ash. When the multi-phase conditions act as obscurants that result in reduced visual awareness, the element seeks to mitigate the hazards associated with these diminished visual environments. The overall purpose of these efforts is to enable safety improvements for air transport class and business jet class aircraft as the transition to the Next Generation Air Transportation System occurs.

Compact acoustic refrigerator

DOEpatents

Bennett, G.A.

1992-11-24

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

Space-Time Dependent Transport, Activation, and Dose Rates for Radioactivated Fluids.

NASA Astrophysics Data System (ADS)

Gavazza, Sergio

Two methods are developed to calculate the space - and time-dependent mass transport of radionuclides, their production and decay, and the associated dose rates generated from the radioactivated fluids flowing through pipes. The work couples space- and time-dependent phenomena, treated as only space- or time-dependent in the open literature. The transport and activation methodology (TAM) is used to numerically calculate space- and time-dependent transport and activation of radionuclides in fluids flowing through pipes exposed to radiation fields, and volumetric radioactive sources created by radionuclide motions. The computer program Radionuclide Activation and Transport in Pipe (RNATPA1) performs the numerical calculations required in TAM. The gamma ray dose methodology (GAM) is used to numerically calculate space- and time-dependent gamma ray dose equivalent rates from the volumetric radioactive sources determined by TAM. The computer program Gamma Ray Dose Equivalent Rate (GRDOSER) performs the numerical calculations required in GAM. The scope of conditions considered by TAM and GAM herein include (a) laminar flow in straight pipe, (b)recirculating flow schemes, (c) time-independent fluid velocity distributions, (d) space-dependent monoenergetic neutron flux distribution, (e) space- and time-dependent activation process of a single parent nuclide and transport and decay of a single daughter radionuclide, and (f) assessment of space- and time-dependent gamma ray dose rates, outside the pipe, generated by the space- and time-dependent source term distributions inside of it. The methodologies, however, can be easily extended to include all the situations of interest for solving the phenomena addressed in this dissertation. A comparison is made from results obtained by the described calculational procedures with analytical expressions. The physics of the problems addressed by the new technique and the increased accuracy versus non -space and time-dependent methods are presented. The value of the methods is also discussed. It has been demonstrated that TAM and GAM can be used to enhance the understanding of the space- and time-dependent mass transport of radionuclides, their production and decay, and the associated dose rates related to radioactivated fluids flowing through pipes.

Heat-transfer analysis of double-pipe heat exchangers for indirect-cycle SCW NPP

NASA Astrophysics Data System (ADS)

Thind, Harwinder

SuperCritical-Water-cooled Reactors (SCWRs) are being developed as one of the Generation-IV nuclear-reactor concepts. SuperCritical Water (SCW) Nuclear Power Plants (NPPs) are expected to have much higher operating parameters compared to current NPPs, i.e., pressure of about 25 MPa and outlet temperature up to 625 °C. This study presents the heat transfer analysis of an intermediate Heat exchanger (HX) design for indirect-cycle concepts of Pressure-Tube (PT) and Pressure-Vessel (PV) SCWRs. Thermodynamic configurations with an intermediate HX gives a possibility to have a single-reheat option for PT and PV SCWRs without introducing steam-reheat channels into a reactor. Similar to the current CANDU and Pressurized Water Reactor (PWR) NPPs, steam generators separate the primary loop from the secondary loop. In this way, the primary loop can be completely enclosed in a reactor containment building. This study analyzes the heat transfer from a SCW primary (reactor) loop to a SCW and Super-Heated Steam (SHS) secondary (turbine) loop using a double-pipe intermediate HX. The numerical model is developed with MATLAB and NIST REFPROP software. Water from the primary loop flows through the inner pipe, and water from the secondary loop flows through the annulus in the counter direction of the double-pipe HX. The analysis on the double-pipe HX shows temperature and profiles of thermophysical properties along the heated length of the HX. It was found that the pseudocritical region has a significant effect on the temperature profiles and heat-transfer area of the HX. An analysis shows the effect of variation in pressure, temperature, mass flow rate, and pipe size on the pseudocritical region and the heat-transfer area of the HX. The results from the numerical model can be used to optimize the heat-transfer area of the HX. The higher pressure difference on the hot side and higher temperature difference between the hot and cold sides reduces the pseudocritical-region length, thus decreases the heat-transfer surface area of the HX.

Balanced Flow Metering and Conditioning: Technology for Fluid Systems

NASA Technical Reports Server (NTRS)

Kelley, Anthony R.

2006-01-01

Revolutionary new technology that creates balanced conditions across the face of a multi-hole orifice plate has been developed, patented and exclusively licensed for commercialization. This balanced flow technology simultaneously measures mass flow rate, volumetric flow rate, and fluid density with little or no straight pipe run requirements. Initially, the balanced plate was a drop in replacement for a traditional orifice plate, but testing revealed substantially better performance as compared to the orifice plate such as, 10 times better accuracy, 2 times faster (shorter distance) pressure recovery, 15 times less acoustic noise energy generation, and 2.5 times less permanent pressure loss. During 2004 testing at MSFC, testing revealed several configurations of the balanced flow meter that match the accuracy of Venturi meters while having only slightly more permanent pressure loss. However, the balanced meter only requires a 0.25 inch plate and has no upstream or downstream straight pipe requirements. As a fluid conditioning device, the fluid usually reaches fully developed flow within 1 pipe diameter of the balanced conditioning plate. This paper will describe the basic balanced flow metering technology, provide performance details generated by testing to date and provide implementation details along with calculations required for differing degrees of flow metering accuracy.

Evaluation of tumor response to intra-arterial chemoembolization of hepatocellular carcinoma: Comparison of contrast-enhanced ultrasound with multiphase computed tomography.

PubMed

Paul, S B; Dhamija, E; Gamanagatti, S R; Sreenivas, V; Yadav, D P; Jain, S; Shalimar; Acharya, S K

2017-03-01

To compare the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) with that of multiphase computed tomography (CT) in the evaluation of tumor response to transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). Fifty patients (41 men, 9 women; mean age, 53 years±12.5 [SD]) with a total of 70 HCCs (mean size, 5cm±3 [SD]) were evaluated. Post-TACE therapeutic assessment of HCC was done at 4 weeks. Patients with TACE done earlier and reporting with suspicion for recurrence were also included. Patients with hepatic masses seen on ultrasound were enrolled and subjected to CEUS, multiphase CT and magnetic resonance imaging (MRI). Hyperenhancing area at the tumor site on arterial phase of CEUS/multiphase CT/MRI was termed as residual disease (RD), the patterns of which were described on CEUS. Diagnostic accuracies of CEUS and MPCT were compared to that of MRI that was used as the reference standard. CEUS detected RD in 43/70 HCCs (61%). RD had a heterogeneous pattern in 22/43 HCCs (51%). Sensitivities of CEUS and multiphase CT were 94% (34/36; 95% CI: 81-99%) and 50% (18/36; 95% CI: 33-67%) respectively. Significant difference in sensitivity was found between CEUS and multiphase CT (P=0.0001). CEUS and multiphase CT had 100% specificity (95% CI: 83-100%). CEUS is a useful technique for detecting RD in HCC after TACE. For long term surveillance, CEUS should be complemented with multiphase CT/MRI for a comprehensive evaluation. Copyright © 2016 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Ring-Like Enhancement of Hepatocellular Carcinoma in Gadoxetic Acid-Enhanced Multiphasic Hepatic Arterial Phase Imaging With Differential Subsampling With Cartesian Ordering.

PubMed

Ichikawa, Shintaro; Motosugi, Utaroh; Oishi, Naoki; Shimizu, Tatsuya; Wakayama, Tetsuya; Enomoto, Nobuyuki; Matsuda, Masanori; Onishi, Hiroshi

2018-04-01

The aim of this study was to evaluate the efficacy of multiphasic hepatic arterial phase (HAP) imaging using DISCO (differential subsampling with Cartesian ordering) in increasing the confidence of diagnosis of hepatocellular carcinoma (HCC). This retrospective study was approved by the institutional review board, and the requirement for informed patient consent was waived. Consecutive patients (from 2 study periods) with malignant liver nodules were examined by gadoxetic acid-enhanced magnetic resonance imaging using either multiphasic (6 phases; n = 135) or single (n = 230) HAP imaging, which revealed 519 liver nodules other than benign ones (HCC, 497; cholangiocarcinoma, 11; metastases, 10; and malignant lymphoma, 1). All nodules were scored in accordance with the Liver Imaging Reporting and Data System (LI-RADS v2014), with or without consideration of ring-like enhancement in multiphasic HAP images as a major feature. In the multiphasic HAP group, 178 of 191 HCCs were scored as LR-3 to LR-5 (3 [1.69%], 85 [47.8%], and 90 [50.6%], respectively). Upon considering ring-like enhancement in multiphasic HAP images as a major feature, 5 more HCCs were scored as LR-5 (95 [53.4%]), which was a significantly more confident diagnosis than that with single HAP images (295 of 306 HCCs scored as LR-3 to LR-5: 13 [4.41%], 147 [49.8%], and 135 [45.8%], respectively; P = 0.0296). There was no significant difference in false-positive or false-negative diagnoses between the multiphasic and single HAP groups (P = 0.8400 and 0.1043, respectively). Multiphasic HAP imaging can improve the confidence of diagnosis of HCCs in gadoxetic acid-enhanced magnetic resonance imaging.

Amphibolite boudins in marble on Naxos, Greece: 3D analysis of multiphase deformation on a retrograde P-T path

NASA Astrophysics Data System (ADS)

Virgo, Simon; von Hagke, Christoph; Urai, Janos L.

2017-04-01

Boudins are periodic structures that form by layer parallel extension in mechanically layered rocks. The characteristics of boudins such as orientation and geometry provide constraints on the paleo stress field as well as the rheology of the rocks during deformation. However, most characterizations of boudinage are based on 2D observations and do not consider the 3-dimensional complexity and potentially non-coaxial polyphase genesis of boudinage structures. In marble quarries in the high grade complex on Naxos, Greece, we studied spectacular outcrops of amphibolite and pegmatite boudins, in combination with serial slicing of quarried blocks to reconstruct the 3D boudin structures. We identified five boudin generations with two distinct generations of early, high grade pinch-and-swell followed by two generations of brittle shearband and torn boudins formed along the retrograde path under greenschist facies conditions. The five generations of boudinage indicate that E-W compression is the main mode of deformation in the marbles. The axis of extension changes from subvertical during pinch-and swell deformation to subhorizontal N-S extension at later stages of deformation. Later phases of boudinage are influenced by existing boudin geometries, producing complex structures in 3D. In 2D section the complexity is not directly apparent and reveals itself only after statistical analysis of long continuous sections. Apart from implications for the regional geology, our findings highlight the importance of 3D characterization of boudinage structures for boudin classification. The insights we gain from the analysis of multiphase boudinage structures on Naxos are the basis for quantitative boudin analysis to infer rheology, effective stress, vorticity and strain, and establish a boudin classification scheme with appeal to a complete mechanics.

Shock Driven Multiphase Instabilities in Scramjet Applications

NASA Astrophysics Data System (ADS)

McFarland, Jacob

2016-11-01

Shock driven multiphase instabilities (SDMI) arise in many applications from dust production in supernovae to ejecta distribution in explosions. At the limit of small, fast reacting particles the instability evolves similar to the Richtmyer-Meshkov (RM) instability. However, as additional particle effects such as lag, phase change, and collisions become significant the required parameter space becomes much larger and the instability deviates significantly from the RM instability. In scramjet engines the SDMI arises during a cold start where liquid fuel droplets are injected and processed by shock and expansion waves. In this case the particle evaporation and mixing is important to starting and sustaining combustion, but the particles are large and slow to react, creating significant multiphase effects. This talk will examine multiphase mixing in scramjet relevant conditions in 3D multiphase hydrodynamic simulations using the FLASH code from the University of Chicago FLASH center.

Feasibility of leakage detection in lake pressure pipes using the Distributed Temperature Sensing Technology

NASA Astrophysics Data System (ADS)

Apperl, Benjamin; Pressl, Alexander; Schulz, Karsten

2016-04-01

This contribution describes a feasibility study carried out in the laboratory for the detection of leakages in lake pressure pipes using high-resolution fiber-optic temperature measurements (DTS). The usage of the DTS technology provides spatiotemporal high-resolution temperature measurements along a fibre optic cable. An opto-electrical device serves both as a light emitter as well as a spectrometer for measuring the scattering of light. The fiber optic cable serves as linear sensor. Measurements can be taken at a spatial resolution of up to 25 cm with a temperature accuracy of higher than 0.1 °C. The first warmer days after the winter stagnation provoke a temperature rise of superficial layers of lakes with barely stable temperature stratification. The warmer layer in the epilimnion differs 4 °C to 5 °C compared to the cold layers in the meta- or hypolimnion before water circulation in spring starts. The warmer water from the surface layer can be rinsed on the entire length of the pipe. Water intrudes at leakages by generating a slightly negative pressure in the pipe. This provokes a local temperature change, in case that the penetrating water (seawater) differs in temperature from the water pumped through the pipe. These temperature changes should be detectable and localized with a DTS cable introduced in the pipe. A laboratory experiment was carried out to determine feasibility as well as limits and problems of this methodology. A 6 m long pipe, submerged in a water tank at constant temperature, was rinsed with water 5-10 °C warmer than the water in the tank. Temperature measurements were taken continuously along the pipe. A negative pressure of 0.1 bar provoked the intrusion of colder water from the tank into the pipe through the leakages, resulting in local temperature changes. Experiments where conducted with different temperature gradients, leakage sizes, number of leaks as well as with different positioning of the DTS cable inside the pipe. Results showed that already small leakages (4mm) can be detected. Problems have arisen from the inside positioning of DTS cable, measuring a reduced temperature difference in the transition layer at the inside wall of the pipe.

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

Chen, Li; He, YaLing; Tao, Wen -Quan

The electrode of a vanadium redox flow battery generally is a carbon fibre-based porous medium, in which important physicochemical processes occur. In this work, pore-scale simulations are performed to study complex multiphase flow and reactive transport in the electrode by using the lattice Boltzmann method (LBM). Four hundred fibrous electrodes with different fibre diameters and porosities are reconstructed. Both the permeability and diffusivity of the reconstructed electrodes are predicted and compared with empirical relationships in the literature. Reactive surface area of the electrodes is also evaluated and it is found that existing empirical relationship overestimates the reactive surface under lowermore » porosities. Further, a pore-scale electrochemical reaction model is developed to study the effects of fibre diameter and porosity on electrolyte flow, V II/V III transport, and electrochemical reaction at the electrolyte-fibre surface. Finally, evolution of bubble cluster generated by the side reaction is studied by adopting a LB multiphase flow model. Effects of porosity, fibre diameter, gas saturation and solid surface wettability on average bubble diameter and reduction of reactive surface area due to coverage of bubbles on solid surface are investigated in detail. It is found that gas coverage ratio is always lower than that adopted in the continuum model in the literature. Furthermore, the current pore-scale studies successfully reveal the complex multiphase flow and reactive transport processes in the electrode, and the simulation results can be further upscaled to improve the accuracy of the current continuum-scale models.« less

Multiphase nanodomains in a strained BaTiO3 film on a GdScO3 substrate

NASA Astrophysics Data System (ADS)

Kobayashi, Shunsuke; Inoue, Kazutoshi; Kato, Takeharu; Ikuhara, Yuichi; Yamamoto, Takahisa

2018-02-01

Controlling the crystal structure of ferroelectric materials via epitaxial strain, which is a well-known technique in strain engineering, can lead to the formation of unique domain structures generating non-intrinsic phenomena such as electronic conductivity, photovoltages, and enhanced piezoelectric characteristics. Strained BaTiO3 films are promising ferroelectric materials as theoretical modeling predicts that different domain morphologies can introduce additional properties not observed in conventional BaTiO3 ceramics. To rationally design materials for practical application, a thorough understanding of the formation mechanisms and stabilities of different domain structures in strained BaTiO3 films is required. However, there have been very few experimental reports on this topic, and details about the domain structures in strained BaTiO3 films are currently lacking. In this paper, we report multiphase nanodomains in a strained BaTiO3 film deposited on an orthorhombic GdScO3 substrate. The phase-transition behavior of the strained BaTiO3 film reveals that it contains multiple phases at room temperature; the film first undergoes a phase-transition upon heating at around 550 K, and then a paraelectric phase forms at temperatures above 690 K. A picometer-scale analysis of the Ti ion displacements, using an advanced scanning transmission electron microscopy technique, is used to characterize the complex multiphase nanodomains, providing useful insights into the control of domain structures in BaTiO3 films by applying epitaxial strain.

Modelling the gas kinematics of an atypical Ly α emitting compact dwarf galaxy

NASA Astrophysics Data System (ADS)

Forero-Romero, Jaime E.; Gronke, Max; Remolina-Gutiérrez, Maria Camila; Garavito-Camargo, Nicolás; Dijkstra, Mark

2018-02-01

Star-forming compact dwarf galaxies (CDGs) resemble the expected pristine conditions of the first galaxies in the Universe and are the best systems to test models on primordial galaxy formation and evolution. Here, we report on one of such CDGs, Tololo 1214-277, which presents a broad, single peaked, highly symmetric Ly α emission line that had evaded theoretical interpretation so far. In this paper, we reproduce for the first time these line features with two different physically motivated kinematic models: an interstellar medium composed by outflowing clumps with random motions and an homogeneous gaseous sphere undergoing solid body rotation. The multiphase model requires a clump velocity dispersion of 54.3 ± 0.6 km s-1 with outflows of 54.3 ± 5.1 km s-1 , while the bulk rotation velocity is constrained to be 348^{+75}_{-48} km s-1. We argue that the results from the multiphase model provide a correct interpretation of the data. In that case, the clump velocity dispersion implies a dynamical mass of 2 × 109 M⊙, 10 times its baryonic mass. If future kinematic maps of Tololo 1214-277 confirm the velocities suggested by the multiphase model, it would provide additional support to expect such kinematic state in primordial galaxies, opening the opportunity to use the models and methods presented in this paper to constrain the physics of star formation and feedback in the early generation of Ly α -emitting galaxies.

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

Tanaka, T.; Kameyama, M.; Urabe, Y.

At present, cast duplex stainless steel has been used for the primary coolant piping of PWRs in Japan and joints of dissimilar material have been applied for welding to reactor vessels and steam generators. For the primary coolant piping of the next APWR plants, application of low alloy steel that results in designing main loops with the same material is being studied. It means that there is no need to weld low alloy steel with stainless steel and that makes it possible to reduce the welding length. Attenuation of Ultra Sonic Wave Intensity is lower for low alloy steel thanmore » for stainless steel and they have advantageous inspection characteristics. In addition to that, the thermal expansion rate is smaller for low alloy steel than for stainless steel. In consideration of the above features of low alloy steel, the overall reliability of primary coolant piping is expected to be improved. Therefore, for the evaluation of crack stability of low alloy steel piping to be applied for primary loops, elastic-plastic future mechanics analysis was performed by means of a three-dimensioned FEM. The evaluation results for the low alloy steel pipings show that cracks will not grow into unstable fractures under maximum design load conditions, even when such a circumferential crack is assumed to be 6 times the size of the wall thickness.« less

First Annual Progress Report on Transmission of Information by Acoustic Communication along Metal Pathways in Nuclear Facilities

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

Heifetz, A.; Bakhtiari, S.; Huang, X.

The objective of this project is to develop and demonstrate methods for transmission of information in nuclear facilities by acoustic means along existing in-place metal piping infrastructure. Pipes are omnipresent in a nuclear facility, and penetrate enclosures and partitions, such as the containment building wall. In the envisioned acoustic communication (AC) system, packets of information will be transmitted as guided acoustic waves along pipes. Performance of AC hardware and network protocols for efficient and secure communications under development in this project will be eventually evaluated in a representative nuclear power plant environment. Research efforts in the first year of thismore » project have been focused on identification of appropriate transducers, and evaluation of their performance for information transmission along nuclear-grade metallic pipes. COMSOL computer simulations were performed to study acoustic wave generation, propagation, and attenuation on pipes. An experimental benchtop system was used to evaluate signal attenuation and spectral dispersion using piezo-electric transducers (PZTs) and electromagnetic acoustic transducers (EMATs). Communication protocols under evaluation consisted on-off keying (OOK) signal modulation, in particular amplitude shift keying (ASK) and phase shift keying (PSK). Tradeoffs between signal power and communication data rate were considered for ASK and PSK coding schemes.« less

Reconstruction of Porous Media with Multiple Solid Phases

PubMed

Losic; Thovert; Adler

1997-02-15

A process is proposed to generate three-dimensional multiphase porous media with fixed phase probabilities and an overall correlation function. By varying the parameters, a specific phase can be located either at the interface between two phases or within a single phase. When the interfacial phase has a relatively small probability, its shape can be chosen as granular or lamellar. The influence of a third phase on the macroscopic conductivity of a medium is illustrated.

Terahertz inline wall thickness monitoring system for plastic pipe extrusion

NASA Astrophysics Data System (ADS)

Hauck, J.; Stich, D.; Heidemeyer, P.; Bastian, M.; Hochrein, T.

2014-05-01

Conventional and commercially available inline wall thickness monitoring systems for pipe extrusion are usually based on ultrasonic or x-ray technology. Disadvantages of ultrasonic systems are the usual need of water as a coupling media and the high damping in thick walled or foamed pipes. For x-ray systems special safety requirements have to be taken into account because of the ionizing radiation. The terahertz (THz) technology offers a novel approach to solve these problems. THz waves have many properties which are suitable for the non-destructive testing of plastics. The absorption of electrical isolators is typically very low and the radiation is non-ionizing in comparison to x-rays. Through the electromagnetic origin of the THz waves they can be used for contact free measurements. Foams show a much lower absorption in contrast to acoustic waves. The developed system uses THz pulses which are generated by stimulating photoconductive switches with femtosecond laser pulses. The time of flight of THz pulses can be determined with a resolution in the magnitude of several ten femtoseconds. Hence the thickness of an object like plastic pipes can be determined with a high accuracy by measuring the time delay between two reflections on materials interfaces e.g. at the pipe's inner and outer surface, similar to the ultrasonic technique. Knowing the refractive index of the sample the absolute layer thickness from the transit time difference can be calculated easily. This method in principle also allows the measurement of multilayer systems and the characterization of foamed pipes.

Sills, aureoles and pipes in the Karoo Basin, South Africa, as triggers for Early Jurassic environmental changes

NASA Astrophysics Data System (ADS)

Svensen, Henrik H.; Planke, Sverre; Silkoset, Petter; Hammer, Øyvind; Iyer, Karthik; Schmid, Dani W.; Chevallier, Luc

2017-04-01

Most of the Large Igneous Provinces (LIPs) formed during the last 260 million years are associated with climatic change, oceanic anoxia, or extinctions in marine and terrestrial environments. Current hypotheses involve A) degassing of carbon either from oceans or shallow sea-bed reservoirs, B) carbon and sulfur degassing from flood basalts, C) degassing from sedimentary basins heavily intruded by LIPs. Here we present new data on gas generation and degassing from the Karoo LIP, based on fieldwork, borehole studies (geochemistry, petrography), and thermal modeling. Our data expand and corroborate earlier work on the sub-volcanic processes in the Karoo Basin. We show that 1) hundreds of breccia pipes are rooted in Early Jurassic sill complexes and contact aureoles within the organic-rich Ecca Group, 2) statistical analyses reveal a fractal distribution of pipes and that they are overdispersed at small scales (<50 m), but clustered at larger scales (>800 m), 3) contact aureoles show a reduction in organic matter content towards the sill contacts, reduced to zero in the nearest zones, producing more carbon gas compared to thermal model calculations, 4) we find up to 3 permil reduction in the d13C of the organic matter remaining in the aureoles, and finally 5) some pipes contain recent oil seeps. We conclude that the sill-pipe system released thermogenic gases to the Early Jurassic atmosphere and that the pipes may have acted as permanent fluid flow pathways.

Cutting Electricity Costs in Miami-Dade County, Florida

ScienceCinema

Alvarez, Carlos; Oliver, LeAnn; Kronheim, Steve; Gonzalez, Jorge; Woods-Richardson, Kathleen

2018-02-06

Miami-Dade County, Florida will be piping methane gas from their regional landfill to the adjacent wastewater plant to generate a significant portion of the massive facility's future electricity needs.

Multiphase flow modeling and simulation of explosive volcanic eruptions

NASA Astrophysics Data System (ADS)

Neri, Augusto

Recent worldwide volcanic activity, such as eruptions at Mt. St. Helens, Washington, in 1980, Mt. Pinatubo, Philippines, in 1991, as well as the ongoing eruption at Montserrat, West Indies, highlighted again the complex nature of explosive volcanic eruptions as well as the tremendous risk associated to them. In the year 2000, about 500 million people are expected to live under the shadow of an active volcano. The understanding of pyroclastic dispersion processes produced by explosive eruptions is, therefore, of primary interest, not only from the scientific point of view, but also for the huge worldwide risk associated with them. The thesis deals with an interdisciplinary research aimed at the modeling and simulation of explosive volcanic eruptions by using multiphase thermo-fluid-dynamic models. The first part of the work was dedicated to the understanding and validation of recently developed kinetic theory of two-phase flow. The hydrodynamics of fluid catalytic cracking particles in the IIT riser were simulated and compared with lab experiments. Simulation results confirm the validity of the kinetic theory approach. Transport of solids in the riser is due to dense clusters. On a time-average basis the bottom of the riser and the walls are dense, in agreement with IIT experimental data. The low frequency of oscillation (about 0.2 Hz) is also in agreement with data. The second part of the work was devoted to the development of transient two-dimensional multiphase and multicomponent flow models of pyroclastic dispersion processes. In particular, the dynamics of ground-hugging high-speed and high-temperature pyroclastic flows generated by the collapse of volcanic columns or by impulsive discrete explosions, was investigated. The model accounts for the mechanical and thermal non-equilibrium between a multicomponent gas phase and N different solid phases representative of pyroclastic particles of different sizes. Pyroclastic dispersion dynamics describes the formation of the initial vertical jet, the column collapse, and the building of the pyroclastic fountain, followed by the generation of radially spreading pyroclastic flows. The development of thermal convective instabilities in the flow lead to the formation of co-ignimbritic or phoenix clouds. Simulation results strongly highlight the importance of the multiphase flow formulation of the mixture. Large particles tend to segregate and sediment along the ground, whereas fine particles tend to form ascending buoyant plumes. Mixtures rich in fine grained particles produce larger runout of the flow and larger ascending plumes than mixtures rich in coarse particles. Simulation results appear to be qualitatively in agreement with field observations, but require to be fully validated by the simulation of well-known test cases.

Uncovering a Salt Giant. Deep-Sea Record of Mediterranean Messinian Events (DREAM) multi-phase drilling project

NASA Astrophysics Data System (ADS)

Camerlenghi, Angelo; Aoisi, Vanni; Lofi, Johanna; Hübscher, Christian; deLange, Gert; Flecker, Rachel; Garcia-Castellanos, Daniel; Gorini, Christian; Gvirtzman, Zohar; Krijgsman, Wout; Lugli, Stefano; Makowsky, Yizhaq; Manzi, Vinicio; McGenity, Terry; Panieri, Giuliana; Rabineau, Marina; Roveri, Marco; Sierro, Francisco Javier; Waldmann, Nicolas

2014-05-01

In May 2013, the DREAM MagellanPlus Workshop was held in Brisighella (Italy). The initiative builds from recent activities by various research groups to identify potential sites to perform deep-sea scientific drilling in the Mediterranean Sea across the deep Messinian Salinity Crisis (MSC) sedimentary record. In this workshop three generations of scientists were gathered: those who participated in formulation of the deep desiccated model, through DSDP Leg 13 drilling in 1973; those who are actively involved in present-day MSC research; and the next generation (PhD students and young post-docs). The purpose of the workshop was to identify locations for multiple-site drilling (including riser-drilling) in the Mediterranean Sea that would contribute to solve the several open questions still existing about the causes, processes, timing and consequences at local and planetary scale of an outstanding case of natural environmental change in the recent Earth history: the Messinian Salinity Crisis in the Mediterranean Sea. The product of the workshop is the identification of the structure of an experimental design of site characterization, riser-less and riser drilling, sampling, measurements, and down-hole analyses that will be the core for at least one compelling and feasible multiple phase drilling proposal. Particular focus has been given to reviewing seismic site survey data available from different research groups at pan-Mediterranean basin scale, to the assessment of additional site survey activity including 3D seismics, and to ways of establishing firm links with oil and gas industry. The scientific community behind the DREAM initiative is willing to proceed with the submission to IODP of a Multi-phase Drilling Project including several drilling proposals addressing specific drilling objectives, all linked to the driving objectives of the MSC drilling and understanding . A series of critical drilling targets were identified to address the still open questions related to the MSC event. Several proposal ideas also emerged to support the Multi-phase drilling project concept: Salt tectonics and fluids, Deep stratigraphic and crustal drilling in the Gulf of Lion (deriving from the GOLD drilling project), Deep stratigraphic and crustal drilling in the Ionian Sea, Deep Biosphere, Sapropels, and the Red Sea. A second MagellanPlus workshop held in January 2014 in Paris (France), has proceeded a step further towards the drafting of the Multi-phase Drilling Project and a set of pre-proposals for submission to IODP.

Multiphase Fluid Dynamics for Spacecraft Applications

NASA Astrophysics Data System (ADS)

Shyy, W.; Sim, J.

2011-09-01

Multiphase flows involving moving interfaces between different fluids/phases are observed in nature as well as in a wide range of engineering applications. With the recent development of high fidelity computational techniques, a number of challenging multiphase flow problems can now be computed. We introduce the basic notion of the main categories of multiphase flow computation; Lagrangian, Eulerian, and Eulerian-Lagrangian techniques to represent and follow interface, and sharp and continuous interface methods to model interfacial dynamics. The marker-based adaptive Eulerian-Lagrangian method, which is one of the most popular methods, is highlighted with microgravity and space applications including droplet collision and spacecraft liquid fuel tank surface stability.

Single and multiphase inclusions in metapelitic garnets of the Rhodope Metamorphic Province, NE Greece.

PubMed

Mposkos, Evripidis; Perraki, Maria; Palikari, Sarra

2009-08-01

Single and multiphase inclusions in garnet porphyroblasts from the diamond-bearing pelitic gneisses were studied by means of combined Raman Spectroscopy and Electron Scanning Microscopy (SEM/EDX). They are either randomly distributed or with preferred orientation within the garnet host and their dimensions vary from less than 5 up to 60 microm. In the single-phase inclusions quartz, rutile, kyanite and graphite dominate. Biotite, zircon, apatite, monazite and allanite are also common. Two types of multiphase inclusions were recognized, hydrous silicate (Type I) and silicate-carbonate (Type II) ones. The carbon-bearing multiphase inclusions predominantly consist of Mg-siderite+graphite+CO(2)+muscovite+quartz formed by a high density carboniferous fluid rich in Fe, Mg, Si and less Ca, Mn, Al and K trapped in the growing garnet in a prograde stage of metamorphism at high-pressure (HP) conditions. The carbon-free multiphase inclusions predominantly consist of biotite+quartz+rutile+/-kyanite+muscovite formed through decompression-dehydration/melting reactions of pre-existing phengite. Single and multiphase inclusions are characterized by polygonal to negative crystal shape formed by dissolution-reprecipitation mechanism between the garnet host and the inclusions during the long lasting cooling period (>100 Ma) of the Kimi Complex.

Smoothed Particle Hydrodynamics: A consistent model for interfacial multiphase fluid flow simulations

NASA Astrophysics Data System (ADS)

Krimi, Abdelkader; Rezoug, Mehdi; Khelladi, Sofiane; Nogueira, Xesús; Deligant, Michael; Ramírez, Luis

2018-04-01

In this work, a consistent Smoothed Particle Hydrodynamics (SPH) model to deal with interfacial multiphase fluid flows simulation is proposed. A modification to the Continuum Stress Surface formulation (CSS) [1] to enhance the stability near the fluid interface is developed in the framework of the SPH method. A non-conservative first-order consistency operator is used to compute the divergence of stress surface tensor. This formulation benefits of all the advantages of the one proposed by Adami et al. [2] and, in addition, it can be applied to more than two phases fluid flow simulations. Moreover, the generalized wall boundary conditions [3] are modified in order to be well adapted to multiphase fluid flows with different density and viscosity. In order to allow the application of this technique to wall-bounded multiphase flows, a modification of generalized wall boundary conditions is presented here for using the SPH method. In this work we also present a particle redistribution strategy as an extension of the damping technique presented in [3] to smooth the initial transient phase of gravitational multiphase fluid flow simulations. Several computational tests are investigated to show the accuracy, convergence and applicability of the proposed SPH interfacial multiphase model.

PREFACE: The 6th International Symposium on Measurement Techniques for Multiphase Flows

NASA Astrophysics Data System (ADS)

Okamoto, Koji; Murai, Yuichi

2009-02-01

Research on multi-phase flows is very important for industrial applications, including power stations, vehicles, engines, food processing, and so on. Also, from the environmental viewpoint, multi-phase flows need to be investigated to overcome global warming. Multi-phase flows originally have non-linear features because they are multi-phased. The interaction between the phases plays a very interesting role in the flows. The non-linear interaction causes the multi-phase flows to be very difficult to understand phenomena. The International Symposium on Measurement Techniques for Multi-phase Flows (ISMTMF) is a unique symposium. The target of the symposium is to exchange the state-of-the-art knowledge on the measurement techniques for non-linear multi-phase flows. Measurement technique is the key technology to understanding non-linear phenomena. The ISMTMF began in 1995 in Nanjing, China. The symposium has continuously been held every two or three years. The ISMTMF-2008 was held in Okinawa, Japan as the 6th symposium of ISMTMF on 15-17 December 2008. Okinawa has a long history as the Ryukyus Kingdom. China and Japan have had cultural and economic exchanges through Okinawa for more than 1000 years. Please enjoy Okinawa and experience its history to enhance our international communication. The present symposium was attended by 124 participants, the program included 107 contributions with 5 plenary lectures, 2 keynote lectures, and 100 oral regular paper presentations. The topics include, besides the ordinary measurement techniques for multiphase flows, acoustic and electric sensors, bubbles and microbubbles, computed tomography, gas-liquid interface, laser-imaging and PIV, oil/coal/drop and spray, solid and powder, spectral and multi-physics. This volume includes the presented papers at ISMTMF-2008. In addition to this volume, ten selected papers will be published in a special issue of Measurement Science and Technology. We would like to express special thanks to all the participants and the contributors to the symposium, and also to the supporting organizations; The Japanese Society for Multiphase Flow, The Chinese Society for Measurement, National Natural Science Foundation of China, The Chinese Academy of Science, and University of the Ryukyus, Okinawa, Japan. Koji Okamoto Chair of 6th ISMTMF and proceedings editor The University of Tokyo, Japan Yuichi Murai Proceedings co-editor Hokkaido University, Japan

Targeting specific azimuthal modes using wall changes in turbulent pipe flow

NASA Astrophysics Data System (ADS)

van Buren, Tyler; Hellström, Leo; Marusic, Ivan; Smits, Alexander

2017-11-01

We experimentally study turbulent pipe flow at Re =3486 using stereoscopic particle image velocimetry. Using pipe inserts with non-circular geometry to perturb the flow upstream of the measurement location, we excite specific naturally occurring energetic modes. We consider inserts that directly manipulate the flow momentum (vortex generators), and/or induce secondary flows through Reynolds stresses (sinusoidally varying wall shape). These inserts substantially change the mean flow, and produce distinct regions of low and high momentum corresponding to the mode being excited. The inserts add energy in the targeted modes while simultaneously reducing the energy in the non-excited azimuthal modes. In addition, inserts designed to excite two modes simultaneously exhibit non-linear interactions. Supported under ONR Grant N00014-15-1-2402, Program Manager/Director Thomas Fu and the Australian Research Council.

Downhole steam generator using low pressure fuel and air supply

DOEpatents

Fox, Ronald L.

1983-01-01

An apparatus for generation of steam in a borehole for penetration into an earth formation wherein a spiral, tubular heat exchanger is used in the combustion chamber to isolate the combustion process from the water being superheated for conversion into steam. The isolation allows combustion of a relatively low pressure oxidant and fuel mixture for generating high enthalpy steam. The fuel is preheated by feedback of combustion gases from the top of the combustion chamber through a fuel preheater chamber. The hot exhaust gases of combustion at the bottom of the combustion chamber, after flowing over the heat exchanger enter an exhaust passage and pipe. The exhaust pipe is mounted inside the water supply line heating the water flowing into the heat exchanger. After being superheated in the heat exchanger, the water is ejected through an expansion nozzle and converts into steam prior to penetration into the earth formation. Pressure responsive doors are provided at a steam outlet downstream of the nozzle and close when the steam pressure is lost due to flameout.

Remote and in situ sensing products in chemical reaction using a flexible terahertz pipe waveguide.

PubMed

You, Borwen; Lu, Ja-Yu

2016-08-08

The feasibility of remote chemical detection is experimentally demonstrated by using a Teflon pipe as a scanning arm in a continuous-terahertz wave sensing and imaging system. Different tablets with distinct mixed ratios of aluminum and polyethylene powders are well distinguished by measuring the power reflectivities of 0.4 THz wave associated with their distinct terahertz refractive indices. Given its refractive index sensitivity and fast response, the reflective terahertz sensing system can be used to real-time trace and quantitatively analyze the ammonium-chloride aerosols produced by the chemical reaction between hydrochloric acid and ammonia vapors. With a tightly focusing terahertz beam spot, the spatial and concentration distributions of the generated chemical product are successfully mapped out by the 1D scan of the flexible pipe probe. In consideration of the responsitivity, power stability, and focused spot size of the system, its detection limit for the ammonium-chloride aerosol is estimated to be approximately 165 nmol/mm². The reliable and compact terahertz pipe scan system is potentially suitable for practical applications, such as biomedical or industrial fiber endoscopy.

NASA National Combustion Code Simulations

NASA Technical Reports Server (NTRS)

Iannetti, Anthony; Davoudzadeh, Farhad

2001-01-01

A systematic effort is in progress to further validate the National Combustion Code (NCC) that has been developed at NASA Glenn Research Center (GRC) for comprehensive modeling and simulation of aerospace combustion systems. The validation efforts include numerical simulation of the gas-phase combustor experiments conducted at the Center for Turbulence Research (CTR), Stanford University, followed by comparison and evaluation of the computed results with the experimental data. Presently, at GRC, a numerical model of the experimental gaseous combustor is built to simulate the experimental model. The constructed numerical geometry includes the flow development sections for air annulus and fuel pipe, 24 channel air and fuel swirlers, hub, combustor, and tail pipe. Furthermore, a three-dimensional multi-block, multi-grid grid (1.6 million grid points, 3-levels of multi-grid) is generated. Computational simulation of the gaseous combustor flow field operating on methane fuel has started. The computational domain includes the whole flow regime starting from the fuel pipe and the air annulus, through the 12 air and 12 fuel channels, in the combustion region and through the tail pipe.

Analysis and improvement of the cavity structure of steam receiver of 1MWe solar tower power plant

NASA Astrophysics Data System (ADS)

Yu, Qiang; Wang, Zhifeng; Zhu, Lingzhi

2017-06-01

The central receiver, which plays a dominant role in the radiation-heat conversion, is one of the most important components in the solar tower power plants. Its performance can directly affect the efficiency of the entire solar power generation system. In general, the performance of the central receiver is mainly determined by two aspects: the first is the receiver structure and arrangement of heating pipes, the other is the integral control and operation strategy. The former is the internal essence of the receiver and the latter is extrinsic. In this paper, the latter is temporarily not in the scope of the discussion. According to the previous cavity structure and arrangement of the heating pipes, it is found that there are varying degrees of deformation to the heating pipes, especially for the superheated pipes. In order to make some improvement for the cavity receiver, firstly, the most likely causes were analyzed according to the previous structure. Secondly, a possible cavity structure was proposed according to the calculation results. The results show that the performance of the receiver is better than the previous one.

Measurements of terahertz radiation generated using a metallic, corrugated pipe

DOE PAGES

Bane, Karl; Stupakov, Gennady; Antipov, Sergey; ...

2016-11-23

Here, a method for producing narrow-band THz radiation proposes passing an ultra-relativistic beam through a metallic pipe with small periodic corrugations. We present results of a measurement of such an arrangement at Brookhaven's Accelerator Test Facility (ATF). Our pipe was copper and was 5 cm long; the aperture was cylindrically symmetric, with a 1 mm (radius) bore and a corrugation depth (peak-to-peak) of 60 µm. In the experiment we measured both the effect on the beam of the structure wakefield and the spectral properties of the radiation excited by the beam. We began by injecting a relatively long beam comparedmore » to the wavelength of the radiation, but with short rise time, to excite the structure, and then used a downstream spectrometer to infer the radiation wavelength. This was followed by injecting a shorter bunch, and then using an interferometer (also downstream of the corrugated pipe) to measure the spectrum of the induced THz radiation. For the THz pulse we obtain and compare with calculations: the central frequency, the bandwidth, and the spectral power—compared to a diffraction radiation background signal.« less

Measurements of terahertz radiation generated using a metallic, corrugated pipe

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

Bane, Karl; Stupakov, Gennady; Antipov, Sergey

Here, a method for producing narrow-band THz radiation proposes passing an ultra-relativistic beam through a metallic pipe with small periodic corrugations. We present results of a measurement of such an arrangement at Brookhaven's Accelerator Test Facility (ATF). Our pipe was copper and was 5 cm long; the aperture was cylindrically symmetric, with a 1 mm (radius) bore and a corrugation depth (peak-to-peak) of 60 µm. In the experiment we measured both the effect on the beam of the structure wakefield and the spectral properties of the radiation excited by the beam. We began by injecting a relatively long beam comparedmore » to the wavelength of the radiation, but with short rise time, to excite the structure, and then used a downstream spectrometer to infer the radiation wavelength. This was followed by injecting a shorter bunch, and then using an interferometer (also downstream of the corrugated pipe) to measure the spectrum of the induced THz radiation. For the THz pulse we obtain and compare with calculations: the central frequency, the bandwidth, and the spectral power—compared to a diffraction radiation background signal.« less

Void fraction development in gas-liquid flow after a U-bend in a vertically upwards serpentine-configuration large-diameter pipe

NASA Astrophysics Data System (ADS)

Almabrok, Almabrok A.; Aliyu, Aliyu M.; Baba, Yahaya D.; Lao, Liyun; Yeung, Hoi

2018-01-01

We investigate the effect of a return U-bend on flow behaviour in the vertical upward section of a large-diameter pipe. A wire mesh sensor was employed to study the void fraction distributions at axial distances of 5, 28 and 47 pipe diameters after the upstream bottom bend. The study found that, the bottom bend has considerable impacts on up-flow behaviour. In all conditions, centrifugal action causes appreciable misdistribution in the adjacent straight section. Plots from WMS measurements show that flow asymmetry significantly reduces along the axis at L/D = 47. Regime maps generated from three axial locations showed that, in addition to bubbly, intermittent and annular flows, oscillatory flow occurred particularly when gas and liquid flow rates were relatively low. At this position, mean void fractions were in agreement with those from other large-pipe studies, and comparisons were made with existing void fraction correlations. Among the correlations surveyed, drift flux-type correlations were found to give the best predictive results.

Thermocapillary phenomena and performance limitations of a wickless heat pipe in microgravity.

PubMed

Kundan, Akshay; Plawsky, Joel L; Wayner, Peter C; Chao, David F; Sicker, Ronald J; Motil, Brian J; Lorik, Tibor; Chestney, Louis; Eustace, John; Zoldak, John

2015-04-10

A counterintuitive, thermocapillary-induced limit to heat- pipe performance was observed that is not predicted by current thermal-fluid models. Heat pipes operate under a number of physical constraints including the capillary, boiling, sonic, and entrainment limits that fundamentally affect their performance. Temperature gradients near the heated end may be high enough to generate significant Marangoni forces that oppose the return flow of liquid from the cold end. These forces are believed to exacerbate dry out conditions and force the capillary limit to be reached prematurely. Using a combination of image and thermal data from experiments conducted on the International Space Station with a transparent heat pipe, we show that in the presence of significant Marangoni forces, dry out is not the initial mechanism limiting performance, but that the physical cause is exactly the opposite behavior: flooding of the hot end with liquid. The observed effect is a consequence of the competition between capillary and Marangoni-induced forces. The temperature signature of flooding is virtually identical to dry out, making diagnosis difficult without direct visual observation of the vapor-liquid interface.

Simulation of Liquid Droplet in Air and on a Solid Surface

NASA Astrophysics Data System (ADS)

Launglucknavalai, Kevin

Although multiphase gas and liquid phenomena occurs widely in engineering problems, many aspects of multiphase interaction like within droplet dynamics are still not quantified. This study aims to qualify the Lattice Boltzmann (LBM) Interparticle Potential multiphase computational method in order to build a foundation for future multiphase research. This study consists of two overall sections. The first section in Chapter 2 focuses on understanding the LBM method and Interparticle Potential model. It outlines the LBM method and how it relates to macroscopic fluid dynamics. The standard form of LBM is obtained. The perturbation solution obtaining the Navier-Stokes equations from the LBM equation is presented. Finally, the Interparticle Potential model is incorporated into the numerical LBM method. The second section in Chapter 3 presents the verification and validation cases to confirm the behavior of the single-phase and multiphase LBM models. Experimental and analytical results are used briefly to compare with numerical results when possible using Poiseuille channel flow and flow over a cylinder. While presenting the numerical results, practical considerations like converting LBM scale variables to physical scale variables are considered. Multiphase results are verified using Laplaces law and artificial behaviors of the model are explored. In this study, a better understanding of the LBM method and Interparticle Potential model is gained. This allows the numerical method to be used for comparison with experimental results in the future and provides a better understanding of multiphase physics overall.

A novel anti-frictional multiphase layer produced by plasma nitriding of PVD titanium coated ZL205A aluminum alloy

NASA Astrophysics Data System (ADS)

Lu, C.; Yao, J. W.; Wang, Y. X.; Zhu, Y. D.; Guo, J. H.; Wang, Y.; Fu, H. Y.; Chen, Z. B.; Yan, M. F.

2018-02-01

The heat treatment (consisting of solid solution and aging), is integrated with the nitriding process of titanium coated ZL205A aluminum alloy to improve the surface and matrix mechanical properties simultaneously. Two-step duplex treatment is adopted to prepare the gradient multiphase layer on a magnesium-free ZL205A aluminum-copper based alloy. Firstly, pure titanium film is deposited on the aluminum alloy substrate using magnetron sputtering. Secondly, the Ti-coated specimen is nitrided at the solid solution temperature of the substrate alloying elements in a gas mixture of N2 and H2 and aged at 175 °C. The microstructure evolution, microhardness as well as the wear resistance of obtained multiphase layers are investigated by means of scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometer (EDS), microhardness tester and pin-on-disc tribometer. The multiphase layer, dominated by TiN0.3 or Al3Ti, is prepared with significantly increased layer depth after duplex treatment. The surface hardness of multiphase layer is remarkably improved from 23.7HV to 457HV. The core matrix hardness is also increased to 65HV after aging. The wear rate of the multiphase layer decreases about 55.22% and 49.28% in comparison with the aged and Ti coated specimens, respectively. The predominant wear mechanism for the multiphase layer is abrasive and oxidation, but severe adhesive wear for the aged and Ti coated specimens.

Features of a SINDA/FLUINT model of a liquid oxygen supply line

NASA Astrophysics Data System (ADS)

Simmonds, Boris G.

1993-11-01

The modeling features used in a steady-state heat transfer problem using SINDA/FLUINT are described. The problem modeled is a 125 feet long, 3 inch diameter pipe, filled with liquid oxygen flow driven by a given pressure gradient. The pipe is fully insulated in five sections. Three sections of 1 inch thick spray-on foam and two sections of vacuum jacket. The model evaluates friction, turns losses and convection heat transfer between the fluid and the pipe wall. There is conduction through the foam insulation with temperature dependent thermal conductivity. The vacuum space is modeled with radiation and gas molecular conduction, if present, in the annular gap. Heat is transferred between the outer surface and surrounding ambient by natural convection and radiation; and, by axial conduction along the pipe and through the vacuum jacket spacers and welded seal flanges. The model makes extensive use of SINDA/FLUINT basic capabilities such as the GEN option for nodes and conductors (to generate groups of nodes or conductors), the SIV option (to generate single, temperature varying conductors), the SIM option (for multiple, temperature varying conductors) and the M HX macros for fluids (to generate strings of lumps, paths, and ties representing a diabatic duct). It calls subroutine CONTRN (returns the relative location in the G-array of a network conductor, given an actual conductor number) enabling an extensive manipulation of conductor (calculates an assignment of their values) with DO loops. Models like this illustrate to the new and even to the old SINDA/FLUINT user, features of the program that are not so obvious or known, and that are extremely handy when trying to take advantage of both, the automation of the DATA headers and make surgical modifications to specific parameters of the thermal or fluid elements in the OPERATIONS portion of the model.

Features of a SINDA/FLUINT model of a liquid oxygen supply line

NASA Technical Reports Server (NTRS)

Simmonds, Boris G.

1993-01-01

The modeling features used in a steady-state heat transfer problem using SINDA/FLUINT are described. The problem modeled is a 125 feet long, 3 inch diameter pipe, filled with liquid oxygen flow driven by a given pressure gradient. The pipe is fully insulated in five sections. Three sections of 1 inch thick spray-on foam and two sections of vacuum jacket. The model evaluates friction, turns losses and convection heat transfer between the fluid and the pipe wall. There is conduction through the foam insulation with temperature dependent thermal conductivity. The vacuum space is modeled with radiation and gas molecular conduction, if present, in the annular gap. Heat is transferred between the outer surface and surrounding ambient by natural convection and radiation; and, by axial conduction along the pipe and through the vacuum jacket spacers and welded seal flanges. The model makes extensive use of SINDA/FLUINT basic capabilities such as the GEN option for nodes and conductors (to generate groups of nodes or conductors), the SIV option (to generate single, temperature varying conductors), the SIM option (for multiple, temperature varying conductors) and the M HX macros for fluids (to generate strings of lumps, paths, and ties representing a diabatic duct). It calls subroutine CONTRN (returns the relative location in the G-array of a network conductor, given an actual conductor number) enabling an extensive manipulation of conductor (calculates an assignment of their values) with DO loops. Models like this illustrate to the new and even to the old SINDA/FLUINT user, features of the program that are not so obvious or known, and that are extremely handy when trying to take advantage of both, the automation of the DATA headers and make surgical modifications to specific parameters of the thermal or fluid elements in the OPERATIONS portion of the model.

Acetylcholinesterase-Based Electrochemical Multiphase Microreactor for Detection of Organophosphorous Compounds (Preprint)

DTIC Science & Technology

2007-04-01

target molecules, we are interested in incorporating the existing, liquid AChE sensor chemistry into a multiphase microreactor . The multiphase... microreactor will play a critical role in combining microsensor technology with analytical biochemistry and increase reaction time, sensitivity and... microreactor with a micro-scale gas- liquid interface, 2) to adapt AChE biochemistry into the microreactor in order to develop an electrochemical biosensor for

Comprehensive Approaches to Multiphase Flows in Geophysics - Application to nonisothermal, nonhomogenous, unsteady, large-scale, turbulent dusty clouds I. Hydrodynamic and Thermodynamic RANS and LES Models

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

S. Dartevelle

2005-09-05

The objective of this manuscript is to fully derive a geophysical multiphase model able to ''accommodate'' different multiphase turbulence approaches; viz., the Reynolds Averaged Navier-Stokes (RANS), the Large Eddy Simulation (LES), or hybrid RANSLES. This manuscript is the first part of a larger geophysical multiphase project--lead by LANL--that aims to develop comprehensive modeling tools for large-scale, atmospheric, transient-buoyancy dusty jets and plume (e.g., plinian clouds, nuclear ''mushrooms'', ''supercell'' forest fire plumes) and for boundary-dominated geophysical multiphase gravity currents (e.g., dusty surges, diluted pyroclastic flows, dusty gravity currents in street canyons). LES is a partially deterministic approach constructed on either amore » spatial- or a temporal-separation between the large and small scales of the flow, whereas RANS is an entirely probabilistic approach constructed on a statistical separation between an ensemble-averaged mean and higher-order statistical moments (the so-called ''fluctuating parts''). Within this specific multiphase context, both turbulence approaches are built up upon the same phasic binary-valued ''function of presence''. This function of presence formally describes the occurrence--or not--of any phase at a given position and time and, therefore, allows to derive the same basic multiphase Navier-Stokes model for either the RANS or the LES frameworks. The only differences between these turbulence frameworks are the closures for the various ''turbulence'' terms involving the unknown variables from the fluctuating (RANS) or from the subgrid (LES) parts. Even though the hydrodynamic and thermodynamic models for RANS and LES have the same set of Partial Differential Equations, the physical interpretations of these PDEs cannot be the same, i.e., RANS models an averaged field, while LES simulates a filtered field. In this manuscript, we also demonstrate that this multiphase model fully fulfills the second law of thermodynamics and fulfills the necessary requirements for a well-posed initial-value problem. In the next manuscripts, we will further develop specific closures for multiphase RANS, LES, and hybrid-LES.« less

Acceleration of MCNP calculations for small pipes configurations by using Weigth Windows Importance cards created by the SN-3D ATTILA

NASA Astrophysics Data System (ADS)

Castanier, Eric; Paterne, Loic; Louis, Céline

2017-09-01

In the nuclear engineering, you have to manage time and precision. Especially in shielding design, you have to be more accurate and efficient to reduce cost (shielding thickness optimization), and for this, you use 3D codes. In this paper, we want to see if we can easily applicate the CADIS methods for design shielding of small pipes which go through large concrete walls. We assess the impact of the WW generated by the 3D-deterministic code ATTILA versus WW directly generated by MCNP (iterative and manual process). The comparison is based on the quality of the convergence (estimated relative error (σ), Variance of Variance (VOV) and Figure of Merit (FOM)), on time (computer time + modelling) and on the implement for the engineer.

High temperature ultrasonic transducers for the generation of guided waves for non-destructive evaluation of pipes

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

Sinding, K.; Searfass, C.; Malarich, N.

2014-02-18

Applications for non-destructive evaluation and structural health monitoring of steam generators require ultrasonic transducers capable of withstanding the high temperatures of the pipes and heat exchangers. These applications require a strong coupling of the transducer to the heat exchanger’s complex geometry at the elevated temperatures. Our objective is to use spray-on piezo-electrics for depositing comb transducers onto the curved surfaces. This paper shows results for composite transducers such as lead zirconate titanate/ bismuth titanate and bismuth titanate/ lithium niobate. The comb transducers were prepared by precision laser ablation. The feasibility of producing second harmonic waves in rods with these spay-onmore » comb transducers was demonstrated and paves the way toward measuring material degradation early-on before crack initiation occurs.« less

The Hydrothermal System of the Bushveld Complex, South Africa - An Analog for Subduction Zone Hydrothermal Systems

NASA Astrophysics Data System (ADS)

Boudreau, A. E.; Connolly, J. A.

2017-12-01

Crystallization of the 2.06 Ga Bushveld magma formed a 9 km (maximum) sequence of ultramafic and mafic rocks that generated a large volume of country fluid as it thermally metamorphosed a 3+ km section of previously unaltered underlying sedimentary rocks of the Transvaal sequence - a geometry similar to that seen as subducting lithospheric slabs are heated by overlying mantle rocks. The presence of a diatreme (breccia pipe) and other large, pipe-like features in the Bushveld Complex suggest that overpressured fluids generated during dehydration of the footwall sediments rapidly penetrate the lower portions of the complex. Numeric modeling of the footwall dehydration similarly suggests that most of the country fluids will be confined to pipe-like channels as it percolates into the Bushveld sill. Modeling also suggests that the maximum extent of the metamorphic aureole was reached at about the same time that the Main zone began to crystallize. It is suggested that rapid inflation of the Bushveld sill induced the sudden and catastrophic expulsion of overpressured country fluids (the "whoopee cushion" effect) to both generate the diatreme and contaminate the Main zone magma, resulting in the Main zone enrichment in a crustal Sr isotopic signature. By analogy, it is also suggested that hydration melting in the mantle wedge is episodically driven by similar sudden influxes of slab fluids that are able to retain their geochemical and isotopic character by rapid channeled influx.

Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) scores generated from the MMPI-2 and MMPI-2-RF test booklets: internal structure comparability in a sample of criminal defendants.

PubMed

Tarescavage, Anthony M; Alosco, Michael L; Ben-Porath, Yossef S; Wood, Arcangela; Luna-Jones, Lynn

2015-04-01

We investigated the internal structure comparability of Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) scores derived from the MMPI-2 and MMPI-2-RF booklets in a sample of 320 criminal defendants (229 males and 54 females). After exclusion of invalid protocols, the final sample consisted of 96 defendants who were administered the MMPI-2-RF booklet and 83 who completed the MMPI-2. No statistically significant differences in MMPI-2-RF invalidity rates were observed between the two forms. Individuals in the final sample who completed the MMPI-2-RF did not statistically differ on demographics or referral question from those who were administered the MMPI-2 booklet. Independent t tests showed no statistically significant differences between MMPI-2-RF scores generated with the MMPI-2 and MMPI-2-RF booklets on the test's substantive scales. Statistically significant small differences were observed on the revised Variable Response Inconsistency (VRIN-r) and True Response Inconsistency (TRIN-r) scales. Cronbach's alpha and standard errors of measurement were approximately equal between the booklets for all MMPI-2-RF scales. Finally, MMPI-2-RF intercorrelations produced from the two forms yielded mostly small and a few medium differences, indicating that discriminant validity and test structure are maintained. Overall, our findings reflect the internal structure comparability of MMPI-2-RF scale scores generated from MMPI-2 and MMPI-2-RF booklets. Implications of these results and limitations of these findings are discussed. © The Author(s) 2014.

77 FR 28626 - Biweekly Notice, Applications and Amendments to Facility Operating Licenses and Combined Licenses...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-15

... Water System, the Auxiliary Building Filtered Ventilation Exhaust System, or the Diesel Generators... nuclear service water system (NSWS) for a time period of 14 days. Basis for proposed no significant... the diesel generator buildings in the event of a leak or a break in the system piping. The probability...

Hybrid Solution-Adaptive Unstructured Cartesian Method for Large-Eddy Simulation of Detonation in Multi-Phase Turbulent Reactive Mixtures

DTIC Science & Technology

2012-03-27

pulse- detonation engines ( PDE ), stage separation, supersonic cav- ity oscillations, hypersonic aerodynamics, detonation induced structural...ADAPTIVE UNSTRUCTURED CARTESIAN METHOD FOR LARGE-EDDY SIMULATION OF DETONATION IN MULTI-PHASE TURBULENT REACTIVE MIXTURES 5b. GRANT NUMBER FA9550...CCL Report TR-2012-03-03 Hybrid Solution-Adaptive Unstructured Cartesian Method for Large-Eddy Simulation of Detonation in Multi-Phase Turbulent

Mixing and Demixing Processes in Multiphase Flows With Application to Propulsion Systems

NASA Technical Reports Server (NTRS)

Decker, Rand (Editor); Schafer, Charles F. (Editor)

1988-01-01

A workshop on transport processes in multiphase flow was held at the Marshall Space Flight Center on February 25 and 26, 1988. The program, abstracts and text of the presentations at this workshop are presented. The objective of the workshop was to enhance our understanding of mass, momentum, and energy transport processes in laminar and turbulent multiphase shear flows in combustion and propulsion environments.

A compressible two-phase model for dispersed particle flows with application from dense to dilute regimes

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

McGrath, Thomas P., E-mail: thomas.p.mcgrath@navy.mil; St Clair, Jeffrey G.; Department of Mechanical and Aerospace Engineering, University of Florida, 231 MAE-A, P.O. Box 116250, Gainesville, Florida 32611

2016-05-07

Multiphase flows are present in many important fields ranging from multiphase explosions to chemical processing. An important subset of multiphase flow applications involves dispersed materials, such as particles, droplets, and bubbles. This work presents an Eulerian–Eulerian model for multiphase flows containing dispersed particles surrounded by a continuous media such as air or water. Following a large body of multiphase literature, the driving force for particle acceleration is modeled as a direct function of both the continuous-phase pressure gradient and the gradient of intergranular stress existing within the particle phase. While the application of these two components of driving force ismore » well accepted in much of the literature, other models exist in which the particle-phase pressure gradient itself drives particle motion. The multiphase model treats all phases as compressible and is derived to ensure adherence to the 2nd Law of Thermodynamics. The governing equations are presented and discussed, and a characteristic analysis shows the model to be hyperbolic, with a degeneracy in the case that the intergranular stress, which is modeled as a configuration pressure, is zero. Finally, results from a two sample problems involving shock-induced particle dispersion are presented. The results agree well with experimental measurements, providing initial confidence in the proposed model.« less

MOBI: Microgravity Observations of Bubble Interactions

NASA Technical Reports Server (NTRS)

Koch, Donald L.; Sangani, Ashok

2004-01-01

One of the greatest uncertainties affecting the design of multiphase flow technologies for space exploration is the spatial distribution of phases that will arise in microgravity or reduced gravity. On Earth, buoyancy-driven motion predominates whereas the shearing of the bubble suspension controls its behavior in microgravity. We are conducting a series of ground-based experiments and a flight experiment spanning the full range of ratios of buoyancy to shear. These include: (1) bubbles rising in a quiescent liquid in a vertical channel; (2) weak shear flow induced by slightly inclining the channel; (3) moderate shear flow in a terrestrial vertical pipe flow; and (4) shearing of a bubble suspension in a cylindrical Couette cell in microgravity. We consider nearly monodisperse suspensions of 1 to 1.8 mm diameter bubbles in aqueous electrolyte solutions. The liquid velocity disturbance produced by bubbles in this size range can often be described using an inviscid analysis. Electrolytic solutions lead to hydrophilic repulsion forces that stabilize the bubble suspension without causing Marangoni stresses. We will discuss the mechanisms that control the flow behavior and phase distribution in the ground-based experiments and speculate on the factors that may influence the suspension flow and bubble volume fraction distribution in the flight experiment.

Methods and apparatus for cooling wind turbine generators

DOEpatents

Salamah, Samir A [Niskayuna, NY; Gadre, Aniruddha Dattatraya [Rexford, NY; Garg, Jivtesh [Schenectady, NY; Bagepalli, Bharat Sampathkumaran [Niskayuna, NY; Jansen, Patrick Lee [Alplaus, NY; Carl, Jr., Ralph James

2008-10-28

A wind turbine generator includes a stator having a core and a plurality of stator windings circumferentially spaced about a generator longitudinal axis. A rotor is rotatable about the generator longitudinal axis, and the rotor includes a plurality of magnetic elements coupled to the rotor and cooperating with the stator windings. The magnetic elements are configured to generate a magnetic field and the stator windings are configured to interact with the magnetic field to generate a voltage in the stator windings. A heat pipe assembly thermally engaging one of the stator and the rotor to dissipate heat generated in the stator or rotor.

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

LaSalle, F.R.; Golbeg, P.R.; Chenault, D.M.

For reactor and nuclear facilities, both Title 10, Code of Federal Regulations, Part 50, and US Department of Energy Order 6430.1A require assessments of the interaction of non-Safety Class 1 piping and equipment with Safety Class 1 piping and equipment during a seismic event to maintain the safety function. The safety class systems of nuclear reactors or nuclear facilities are designed to the applicable American Society of Mechanical Engineers standards and Seismic Category 1 criteria that require rigorous analysis, construction, and quality assurance. Because non-safety class systems are generally designed to lesser standards and seismic criteria, they may become missilesmore » during a safe shutdown earthquake. The resistance of piping, tubing, and equipment to seismically generated missiles is addressed in the paper. Gross plastic and local penetration failures are considered with applicable test verification. Missile types and seismic zones of influence are discussed. Field qualification data are also developed for missile evaluation.« less

Multiphoton laser ionization for energy conversion in barium vapor

NASA Astrophysics Data System (ADS)

Makdisi, Y.; Kokaj, J.; Afrousheh, K.; Mathew, J.; Nair, R.; Pichler, G.

2013-03-01

We have studied the ion detection of barium atoms in special heated ovens with a tungsten rod in the middle of the stainless steel tube. The tungsten rod was heated indirectly by the oven body heaters. A bias voltage between the cell body and the tungsten rod of 9 V was used to collect electrons, after the barium ions had been created. However, we could collect the electrons even without the bias voltage, although with ten times less efficiency. We studied the conditions for the successful bias-less thermionic signal detection using excimer/dye laser two-photon excitation of Rydberg states below and above the first ionization limit (two-photon wavelength at 475.79 nm). We employed a hot-pipe oven and heat-pipe oven (with inserted mesh) in order to generate different barium vapor distributions inside the oven. The thermionic signal increased by a factor of two under heat-pipe oven conditions.

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

Eperin, A.P.; Zakharzhevsky, Yu.O.; Arzhaev, A.I.

A two-year Finnish-Russian cooperation program has been initiated in 1995 to demonstrate the applicability of the leak-before-break concept (LBB) to the primary circuit piping of the Leningrad NPP. The program includes J-R curve testing of authentic pipe materials at full operating temperature, screening and computational LBB analyses complying with the USNRC Standard Review Plan 3.6.3, and exchange of LBB-related information with emphasis on NDE. Domestic computer codes are mainly used, and all tests and analyses are independently carried out by each party. The results are believed to apply generally to RBMK type plants of the first generation.

On the prediction of turbulent secondary flows

NASA Technical Reports Server (NTRS)

Speziale, C. G.; So, R. M. C.; Younis, B. A.

1992-01-01

The prediction of turbulent secondary flows, with Reynolds stress models, in circular pipes and non-circular ducts is reviewed. Turbulence-driven secondary flows in straight non-circular ducts are considered along with turbulent secondary flows in pipes and ducts that arise from curvature or a system rotation. The physical mechanisms that generate these different kinds of secondary flows are outlined and the level of turbulence closure required to properly compute each type is discussed in detail. Illustrative computations of a variety of different secondary flows obtained from two-equation turbulence models and second-order closures are provided to amplify these points.

Sparse reconstruction localization of multiple acoustic emissions in large diameter pipelines

NASA Astrophysics Data System (ADS)

Dubuc, Brennan; Ebrahimkhanlou, Arvin; Salamone, Salvatore

2017-04-01

A sparse reconstruction localization method is proposed, which is capable of localizing multiple acoustic emission events occurring closely in time. The events may be due to a number of sources, such as the growth of corrosion patches or cracks. Such acoustic emissions may yield localization failure if a triangulation method is used. The proposed method is implemented both theoretically and experimentally on large diameter thin-walled pipes. Experimental examples are presented, which demonstrate the failure of a triangulation method when multiple sources are present in this structure, while highlighting the capabilities of the proposed method. The examples are generated from experimental data of simulated acoustic emission events. The data corresponds to helical guided ultrasonic waves generated in a 3 m long large diameter pipe by pencil lead breaks on its outer surface. Acoustic emission waveforms are recorded by six sparsely distributed low-profile piezoelectric transducers instrumented on the outer surface of the pipe. The same array of transducers is used for both the proposed and the triangulation method. It is demonstrated that the proposed method is able to localize multiple events occurring closely in time. Furthermore, the matching pursuit algorithm and the basis pursuit densoising approach are each evaluated as potential numerical tools in the proposed sparse reconstruction method.

Effects of Faults on Petroleum Fluid Dynamics, Borderland Basins of Southern California

NASA Astrophysics Data System (ADS)

Jung, B.; Garven, G.; Boles, J. R.

2012-12-01

Multiphase flow modeling provides a useful quantitative tool for understanding crustal processes such as petroleum migration in geological systems, and also for characterizing subsurface environmental issues such as carbon sequestration in sedimentary basins. However, accurate modeling of multi-fluid behavior is often difficult because of the various coupled and nonlinear physics affecting multiphase fluid saturation and migration, including effects of capillarity and relative permeability, anisotropy and heterogeneity of the medium, and the effects of pore pressure, composition, and temperature on fluid properties. Regional fault structures also play a strong role in controlling fluid pathlines and mobility, so considering hydrogeologic effects of these structures is critical for testing exploration concepts, and for predicting the fate of injected fluids. To address these issues on spatially large and long temporal scales, we have developed a 2-D multiphase fluid flow model, coupled to heat flow, using a hybrid finite element and finite volume method. We have had good success in applying the multiphase flow model to fundamental issues of long-distance petroleum migration and accumulation in the Los Angeles basin, which is intensely faulted and disturbed by transpressional tectonic stresses, and host to the world's richest oil accumulation. To constrain the model, known subsurface geology and fault structures were rendered using geophysical logs from industry exploration boreholes and published seismic profiles. Plausible multiphase model parameters were estimated, either from known fault permeability measurements in similar strata in the Santa Barbara basin, and from known formation properties obtained from numerous oil fields in the Los Angeles basin. Our simulations show that a combination of continuous hydrocarbon generation and primary migration from upper Miocene source rocks in the central LA basin synclinal region, coupled with a subsiding basin fluid dynamics, favored the massive accumulation and alignment of hydrocarbon pools along the Newport-Inglewood fault zone (NIFZ). According to our multiphase flow calculations, the maximum formation water velocities within fault zones likely ranged between 1 ~ 2 m/yr during the middle Miocene to Pliocene (13 to 2.6 Ma). The estimated time for long-distance (~ 25 km) petroleum migration from source beds in the central basin to oil fields along the NIFZ is approximately 150,000 ~ 250,000 years, depending on the effective permeability assigned to the faults and adjacent interbedded sandstone and siltstone "petroleum aquifers". With an average long-distance flow rate (~ 0.6 m/yr) and fault permeability of 100 millidarcys (10-13 m2), the total petroleum oil of Inglewood oil field of 450 million barrels (~ 1.6 × 105 m3) would have accumulated rather quickly, likely over 25,000 years or less. The results also suggest that besides the thermal and structural history of the basin, the fault permeability, capillary pressure, and the configuration of aquifer and aquitard layers played an important role in controlling petroleum migration rates, patterns of flow, and the overall fluid mechanics of petroleum accumulation.

Simplified contaminant source depletion models as analogs of multiphase simulators

NASA Astrophysics Data System (ADS)

Basu, Nandita B.; Fure, Adrian D.; Jawitz, James W.

2008-04-01

Four simplified dense non-aqueous phase liquid (DNAPL) source depletion models recently introduced in the literature are evaluated for the prediction of long-term effects of source depletion under natural gradient flow. These models are simple in form (a power function equation is an example) but are shown here to serve as mathematical analogs to complex multiphase flow and transport simulators. The spill and subsequent dissolution of DNAPLs was simulated in domains having different hydrologic characteristics (variance of the log conductivity field = 0.2, 1 and 3) using the multiphase flow and transport simulator UTCHEM. The dissolution profiles were fitted using four analytical models: the equilibrium streamtube model (ESM), the advection dispersion model (ADM), the power law model (PLM) and the Damkohler number model (DaM). All four models, though very different in their conceptualization, include two basic parameters that describe the mean DNAPL mass and the joint variability in the velocity and DNAPL distributions. The variability parameter was observed to be strongly correlated with the variance of the log conductivity field in the ESM and ADM but weakly correlated in the PLM and DaM. The DaM also includes a third parameter that describes the effect of rate-limited dissolution, but here this parameter was held constant as the numerical simulations were found to be insensitive to local-scale mass transfer. All four models were able to emulate the characteristics of the dissolution profiles generated from the complex numerical simulator, but the one-parameter PLM fits were the poorest, especially for the low heterogeneity case.

Simplified contaminant source depletion models as analogs of multiphase simulators.

PubMed

Basu, Nandita B; Fure, Adrian D; Jawitz, James W

2008-04-28

Four simplified dense non-aqueous phase liquid (DNAPL) source depletion models recently introduced in the literature are evaluated for the prediction of long-term effects of source depletion under natural gradient flow. These models are simple in form (a power function equation is an example) but are shown here to serve as mathematical analogs to complex multiphase flow and transport simulators. The spill and subsequent dissolution of DNAPLs was simulated in domains having different hydrologic characteristics (variance of the log conductivity field=0.2, 1 and 3) using the multiphase flow and transport simulator UTCHEM. The dissolution profiles were fitted using four analytical models: the equilibrium streamtube model (ESM), the advection dispersion model (ADM), the power law model (PLM) and the Damkohler number model (DaM). All four models, though very different in their conceptualization, include two basic parameters that describe the mean DNAPL mass and the joint variability in the velocity and DNAPL distributions. The variability parameter was observed to be strongly correlated with the variance of the log conductivity field in the ESM and ADM but weakly correlated in the PLM and DaM. The DaM also includes a third parameter that describes the effect of rate-limited dissolution, but here this parameter was held constant as the numerical simulations were found to be insensitive to local-scale mass transfer. All four models were able to emulate the characteristics of the dissolution profiles generated from the complex numerical simulator, but the one-parameter PLM fits were the poorest, especially for the low heterogeneity case.

Storm Water Management Model Reference Manual Volume II ...

EPA Pesticide Factsheets

SWMM is a dynamic rainfall-runoff simulation model used for single event or long-term (continuous) simulation of runoff quantity and quality from primarily urban areas. The runoff component of SWMM operates on a collection of subcatchment areas that receive precipitation and generate runoff and pollutant loads. The routing portion of SWMM transports this runoff through a system of pipes, channels, storage/treatment devices, pumps, and regulators. SWMM tracks the quantity and quality of runoff generated within each subcatchment, and the flow rate, flow depth, and quality of water in each pipe and channel during a simulation period comprised of multiple time steps. The reference manual for this edition of SWMM is comprised of three volumes. Volume I describes SWMM’s hydrologic models, Volume II its hydraulic models, and Volume III its water quality and low impact development models. This document provides the underlying mathematics for the hydraulic calculations of the Storm Water Management Model (SWMM)

Lorentz force on sodium and chlorine ions in a salt water solution flow under a transverse magnetic field

NASA Astrophysics Data System (ADS)

DeLuca, R.

2009-05-01

It is shown that, by applying elementary concepts in electromagnetism and electrochemistry to a system consisting of salt water flowing in a thin rectangular pipe at an average velocity vA under the influence of a transverse magnetic field B0, an electromotive force generator can be conceived. In fact, the Lorentz force acting on the sodium and chlorine ions in a water solution gives rise to a so-called Faraday voltage across the two metal electrodes, positioned at the sides of the pipe. The effect is carried along the following chemical reactions at the electrodes: at the cathode, water is reduced (instead of sodium ions) and hydrogen gas is generated; at the anode, chlorine gas is produced. In college physics teaching, this interdisciplinary subject can be adopted to stress analogies and differences between the Hall voltage in conductors and the Faraday voltage in electrolyte solutions.

The recovery and analysis of mitochondrial DNA from exploded pipe bombs.

PubMed

Foran, David R; Gehring, Michael E; Stallworth, Shawn E

2009-01-01

Improvised explosive devices (IEDs) represent one of the most common modes of arbitrarily injuring or killing human beings. Because of the heat generated by, and destruction to, an IED postconflagration, most methods for identifying who assembled the device are ineffective. In the research presented, steel pipe bombs were mock-assembled by volunteers, and the bombs detonated under controlled conditions. The resultant shrapnel was collected and swabbed for residual cellular material. Mitochondrial DNA profiles were generated and compared blind to the pool of individuals who assembled the bombs. Assemblers were correctly identified 50% of the time, while another 19% could be placed into a group of three individuals with shared haplotypes. Only one bomb was assigned incorrectly. In some instances a contaminating profile (mixture) was also observed. Taken together, the results speak to the extreme sensitivity the methods have for identifying those who assemble IEDs, along with precautions needed when collecting and processing such evidence.

Compact acoustic refrigerator

DOEpatents

Bennett, Gloria A.

1992-01-01

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

A Longitudinal Mode Electromagnetic Acoustic Transducer (EMAT) Based on a Permanent Magnet Chain for Pipe Inspection.

PubMed

Cong, Ming; Wu, Xinjun; Qian, Chunqiao

2016-05-21

A new electromagnetic acoustic transducer (EMAT) design, employing a special structure of the permanent magnet chain, is proposed to generate and receive longitudinal guided waves for pipe inspection based on the magnetostriction mechanism. Firstly, a quantitative analysis of the excitation forces shows the influence of the radial component can be ignored. Furthermore, as the axial component of the static magnetic field is dominant, a method of solenoid testing coils connected in series is adopted to increase the signal amplitude. Then, two EMAT configurations are developed to generate and receive the L(0,2) guided wave mode. The experimental results show the circumferential notch can be identified and located successfully. Finally, a detailed investigation of the performance of the proposed EMATs is given. Compared to the conventional EMAT configuration, the proposed configurations have the advantages of small volume, light weight, easy installation and portability, which is helpful to improve inspection efficiency.

Advanced space solar dynamic receivers

NASA Technical Reports Server (NTRS)

Strumpf, Hal J.; Coombs, Murray G.; Lacy, Dovie E.

1988-01-01

A study has been conducted to generate and evaluate advanced solar heat receiver concepts suitable for orbital application with Brayton and Stirling engine cycles in the 7-kW size range. The generated receiver designs have thermal storage capability (to enable power production during the substantial eclipse period which accompanies typical orbits) and are lighter and smaller than state-of-the-art systems, such as the Brayton solar receiver being designed and developed by AiResearch for the NASA Space Station. Two receiver concepts have been developed in detail: a packed bed receiver and a heat pipe receiver. The packed bed receiver is appropriate for a Brayton engine; the heat pipe receiver is applicable for either a Brayton or Stirling engine. The thermal storage for both concepts is provided by the melting and freezing of a salt. Both receiver concepts offer substantial improvements in size and weight compared to baseline receivers.

A novel partitioning method for block-structured adaptive meshes

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

Fu, Lin, E-mail: lin.fu@tum.de; Litvinov, Sergej, E-mail: sergej.litvinov@aer.mw.tum.de; Hu, Xiangyu Y., E-mail: xiangyu.hu@tum.de

We propose a novel partitioning method for block-structured adaptive meshes utilizing the meshless Lagrangian particle concept. With the observation that an optimum partitioning has high analogy to the relaxation of a multi-phase fluid to steady state, physically motivated model equations are developed to characterize the background mesh topology and are solved by multi-phase smoothed-particle hydrodynamics. In contrast to well established partitioning approaches, all optimization objectives are implicitly incorporated and achieved during the particle relaxation to stationary state. Distinct partitioning sub-domains are represented by colored particles and separated by a sharp interface with a surface tension model. In order to obtainmore » the particle relaxation, special viscous and skin friction models, coupled with a tailored time integration algorithm are proposed. Numerical experiments show that the present method has several important properties: generation of approximately equal-sized partitions without dependence on the mesh-element type, optimized interface communication between distinct partitioning sub-domains, continuous domain decomposition which is physically localized and implicitly incremental. Therefore it is particularly suitable for load-balancing of high-performance CFD simulations.« less

Secondary organic aerosol formation through cloud processing of aromatic VOCs

NASA Astrophysics Data System (ADS)

Herckes, P.; Hutchings, J. W.; Ervens, B.

2010-12-01

Field observations have shown substantial concentrations (20-5,500 ng L-1) of aromatic volatile organic compounds (VOC) in cloud droplets. The potential generation of secondary organic aerosol mass through the processing of these anthropogenic VOCs was investigated through laboratory and modeling studies. Under simulated atmospheric laboratory conditions, in idealized solutions, benzene, toluene, ethylbenzene, and xylene (BTEX) degraded quickly in the aqueous phase. The degradation process yielded less volatile products which would contribute to new aerosol mass upon cloud evaporation. However, when realistic cloud solutions containing natural organic matter were used in the experiments, the reaction rates decreased with increasing organic carbon content. Kinetic data derived from these experiments were used as input to a multiphase box model in order to evaluate the secondary organic aerosol (SOA) mass formation potential of cloud processing of BTEX. Model results will be presented that quantify the SOA amounts from these aqueous phase pathways. The efficiency of this multiphase SOA source will be compared to SOA yields from the same aromatics as treated in traditional SOA models that are restricted to gas phase oxidation and subsequent condensation on particles.

A novel partitioning method for block-structured adaptive meshes

NASA Astrophysics Data System (ADS)

Fu, Lin; Litvinov, Sergej; Hu, Xiangyu Y.; Adams, Nikolaus A.

2017-07-01

We propose a novel partitioning method for block-structured adaptive meshes utilizing the meshless Lagrangian particle concept. With the observation that an optimum partitioning has high analogy to the relaxation of a multi-phase fluid to steady state, physically motivated model equations are developed to characterize the background mesh topology and are solved by multi-phase smoothed-particle hydrodynamics. In contrast to well established partitioning approaches, all optimization objectives are implicitly incorporated and achieved during the particle relaxation to stationary state. Distinct partitioning sub-domains are represented by colored particles and separated by a sharp interface with a surface tension model. In order to obtain the particle relaxation, special viscous and skin friction models, coupled with a tailored time integration algorithm are proposed. Numerical experiments show that the present method has several important properties: generation of approximately equal-sized partitions without dependence on the mesh-element type, optimized interface communication between distinct partitioning sub-domains, continuous domain decomposition which is physically localized and implicitly incremental. Therefore it is particularly suitable for load-balancing of high-performance CFD simulations.

Multiphase Modeling of Secondary Atomization in a Shock Environment

NASA Astrophysics Data System (ADS)

St. Clair, Jeffrey; McGrath, Thomas; Balachandar, Sivaramakrishnan

2017-06-01

Understanding and developing accurate modeling strategies for shock-particulate interaction remains a challenging and important topic, with application to energetic materials development, volcanic eruptions, and safety/risk assessment. This work presents computational modeling of compressible multiphase flows with shock-induced droplet atomization. Droplet size has a strong influence on the interphase momentum and heat transfer. A test case is presented that is sensitive to this, requiring the dynamic modeling of the secondary atomization process occurring when the shock impacts the droplets. An Eulerian-Eulerian computational model that treats all phases as compressible, is hyperbolic and satisfies the 2nd Law of Thermodynamics is applied. Four different breakup models are applied to the test case in which a planar shock wave encounters a cloud of water droplets. The numerical results are compared with both experimental and previously-generated modeling results. The effect of the drag relation used is also investigated. The computed results indicate the necessity of using a droplet breakup model for this application, and the relative accuracy of results obtained with the different droplet breakup and drag models is discussed.

Mechanical Extraction of Power From Ocean Currents and Tides

NASA Technical Reports Server (NTRS)

Jones, Jack; Chao, Yi

2010-01-01

A proposed scheme for generating electric power from rivers and from ocean currents, tides, and waves is intended to offer economic and environmental advantages over prior such schemes, some of which are at various stages of implementation, others of which have not yet advanced beyond the concept stage. This scheme would be less environmentally objectionable than are prior schemes that involve the use of dams to block rivers and tidal flows. This scheme would also not entail the high maintenance costs of other proposed schemes that call for submerged electric generators and cables, which would be subject to degradation by marine growth and corrosion. A basic power-generation system according to the scheme now proposed would not include any submerged electrical equipment. The submerged portion of the system would include an all-mechanical turbine/pump unit that would superficially resemble a large land-based wind turbine (see figure). The turbine axis would turn slowly as it captured energy from the local river flow, ocean current, tidal flow, or flow from an ocean-wave device. The turbine axis would drive a pump through a gearbox to generate an enclosed flow of water, hydraulic fluid, or other suitable fluid at a relatively high pressure [typically approx.500 psi (approx.3.4 MPa)]. The pressurized fluid could be piped to an onshore or offshore facility, above the ocean surface, where it would be used to drive a turbine that, in turn, would drive an electric generator. The fluid could be recirculated between the submerged unit and the power-generation facility in a closed flow system; alternatively, if the fluid were seawater, it could be taken in from the ocean at the submerged turbine/pump unit and discharged back into the ocean from the power-generation facility. Another alternative would be to use the pressurized flow to charge an elevated reservoir or other pumped-storage facility, from whence fluid could later be released to drive a turbine/generator unit at a time of high power demand. Multiple submerged turbine/pump units could be positioned across a channel to extract more power than could be extracted by a single unit. In that case, the pressurized flows in their output pipes would be combined, via check valves, into a wider pipe that would deliver the combined flow to a power-generating or pumped-storage facility.

Multi-phase SPH modelling of violent hydrodynamics on GPUs

NASA Astrophysics Data System (ADS)

Mokos, Athanasios; Rogers, Benedict D.; Stansby, Peter K.; Domínguez, José M.

2015-11-01

This paper presents the acceleration of multi-phase smoothed particle hydrodynamics (SPH) using a graphics processing unit (GPU) enabling large numbers of particles (10-20 million) to be simulated on just a single GPU card. With novel hardware architectures such as a GPU, the optimum approach to implement a multi-phase scheme presents some new challenges. Many more particles must be included in the calculation and there are very different speeds of sound in each phase with the largest speed of sound determining the time step. This requires efficient computation. To take full advantage of the hardware acceleration provided by a single GPU for a multi-phase simulation, four different algorithms are investigated: conditional statements, binary operators, separate particle lists and an intermediate global function. Runtime results show that the optimum approach needs to employ separate cell and neighbour lists for each phase. The profiler shows that this approach leads to a reduction in both memory transactions and arithmetic operations giving significant runtime gains. The four different algorithms are compared to the efficiency of the optimised single-phase GPU code, DualSPHysics, for 2-D and 3-D simulations which indicate that the multi-phase functionality has a significant computational overhead. A comparison with an optimised CPU code shows a speed up of an order of magnitude over an OpenMP simulation with 8 threads and two orders of magnitude over a single thread simulation. A demonstration of the multi-phase SPH GPU code is provided by a 3-D dam break case impacting an obstacle. This shows better agreement with experimental results than an equivalent single-phase code. The multi-phase GPU code enables a convergence study to be undertaken on a single GPU with a large number of particles that otherwise would have required large high performance computing resources.

The algorithm of verification of welding process for plastic pipes

NASA Astrophysics Data System (ADS)

Rzasinski, R.

2017-08-01

The study analyzes the process of butt welding of PE pipes in terms of proper selection of connector parameters. The process was oriented to the elements performed as a series of types of pipes. Polymeric materials commonly referred to as polymers or plastics, synthetic materials are produced from oil products in the polyreaction compounds of low molecular weight, called monomers. During the polyreactions monomers combine to build a macromolecule material monomer named with the prefix poly polypropylene, polyethylene or polyurethane, creating particles in solid state on the order of 0,2 to 0,4 mm. Finished products from polymers of virtually any shape and size are obtained by compression molding, injection molding, extrusion, laminating, centrifugal casting, etc. Weld can only be a thermoplastic that softens at an elevated temperature, and thus can be connected via a clamp. Depending on the source and method of supplying heat include the following welding processes: welding contact, radiant welding, friction welding, dielectric welding, ultrasonic welding. The analysis will be welding contact. In connection with the development of new generation of polyethylene, and the production of pipes with increasing dimensions (diameter, wall thickness) is important to select the correct process.

Turbulent spots and scalar flashes in pipe transition

NASA Astrophysics Data System (ADS)

Adrian, Ronald; Wu, Xiaohua; Moin, Parviz

2017-11-01

Recent study (Wu et al., PNAS, 1509451112, 2015) demonstrated the feasibility and accuracy of direct computation of the Osborne Reynolds' pipe transition experiment without the unphysical axially periodic boundary condition. Here we use this approach to address three questions: (1) What are the dynamics of turbulent spot generation in pipe transition? (2) How is the succession of scalar flashes, as observed and sketched by Osborne Reynolds, created? (3) What happens to the succession of flashes further downstream? In this study, the inlet disturbance is of radial-mode type imposed through a narrow, three-degree numerical wedge; and the simulation Reynolds number is 6500. Numerical dye is introduced at the inlet plane locally very close to the pipe axis, similar to the needle injection by O. Reynolds. Inception of infant turbulent spots occurs when normal, forward inclined hairpin packets form near the walls from the debris of the inlet perturbations. However, the young and mature turbulent spots consist almost exclusively of reverse, backward leaning hairpin vortices. Scalar flashes appear successively downstream and persist well into the fully-developed turbulent region. Their creation mechanism is addressed. RJA gratefully acknowledges support of the National Science Foundation with NSF Award CBET-0933848.

NORTH PORTAL-HOT WATER CIRCULATION PUMP CALCULATION-SHOP BUILDING #5006

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

R. Blackstone

1996-01-25

The purpose of this design analysis and calculation is to size a circulating pump for the service hot water system in the Shop Building 5006, in accordance with the Uniform Plumbing Code (Section 4.4.1) and U.S. Department of Energy Order 6430.1A-1540 (Section 4.4.2). The method used for the calculation is based on Reference 5.2. This consists of determining the total heat transfer from the service hot water system piping to the surrounding environment. The heat transfer is then used to define the total pumping capacity based on a given temperature change in the circulating hot water as it flows throughmore » the closed loop piping system. The total pumping capacity is used to select a pump model from manufacturer's literature. This established the head generation for that capacity and particular pump model. The total length of all hot water supply and return piping including fittings is then estimated from the plumbing drawings which defines the pipe friction losses that must fit within the available pump head. Several iterations may be required before a pump can be selected that satisfies the head-capacity requirements.« less

Viscous and gravitational fingering in multiphase compositional and compressible flow

NASA Astrophysics Data System (ADS)

Moortgat, Joachim

2016-03-01

Viscous and gravitational fingering refer to flow instabilities in porous media that are triggered by adverse mobility or density ratios, respectively. These instabilities have been studied extensively in the past for (1) single-phase flow (e.g., contaminant transport in groundwater, first-contact-miscible displacement of oil by gas in hydrocarbon production), and (2) multi-phase immiscible and incompressible flow (e.g., water-alternating-gas (WAG) injection in oil reservoirs). Fingering in multiphase compositional and compressible flow has received much less attention, perhaps due to its high computational complexity. However, many important subsurface processes involve multiple phases that exchange species. Examples are carbon sequestration in saline aquifers and enhanced oil recovery (EOR) by gas or WAG injection below the minimum miscibility pressure. In multiphase flow, relative permeabilities affect the mobility contrast for a given viscosity ratio. Phase behavior can also change local fluid properties, which can either enhance or mitigate viscous and gravitational instabilities. This work presents a detailed study of fingering behavior in compositional multiphase flow in two and three dimensions and considers the effects of (1) Fickian diffusion, (2) mechanical dispersion, (3) flow rates, (4) domain size and geometry, (5) formation heterogeneities, (6) gravity, and (7) relative permeabilities. Results show that fingering in compositional multiphase flow is profoundly different from miscible conditions and upscaling techniques used for the latter case are unlikely to be generalizable to the former.

Design and fabrication of biomimetic multiphased scaffolds for ligament-to-bone fixation.

PubMed

He, Jiankang; Zhang, Wenyou; Liu, Yaxiong; Li, Xiang; Li, Dichen; Jin, Zhongmin

2015-05-01

Conventional ligament grafts with single material composition cannot effectively integrate with the host bones due to mismatched properties and eventually affect their long-term function in vivo. Here we presented a multi-material strategy to design and fabricate composite scaffolds including ligament, interface and bone multiphased regions. The interface region consists of triphasic layers with varying material composition and porous structure to mimic native ligament-to-bone interface while the bone region contains polycaprolactone (PCL) anchor and microchanneled ceramic scaffolds to potentially provide combined mechanical and biological implant-bone fixation. Finite element analysis (FEA) demonstrated that the multiphased scaffolds with interference value smaller than 0.5 mm could avoid the fracture of ceramic scaffold during the implantation process, which was validated by in-vitro implanting the multiphased scaffolds into porcine joint bones. Pull-out experiment showed that the initial fixation between the multiphased scaffolds with 0.47 mm interference and the host bones could withstand the maximum force of 360.31±97.51 N, which can be improved by reinforcing the ceramic scaffolds with biopolymers. It is envisioned that the multiphased scaffold could potentially induce the regeneration of a new bone as well as interfacial tissue with the gradual degradation of the scaffold and subsequently realize long-term biological fixation of the implant with the host bone. Copyright © 2015 Elsevier B.V. All rights reserved.

Researchers Mine Information from Next-Generation Subsurface Flow Simulations

DOE PAGES

Gedenk, Eric D.

2015-12-01

A research team based at Virginia Tech University leveraged computing resources at the US Department of Energy's (DOE's) Oak Ridge National Laboratory to explore subsurface multiphase flow phenomena that can't be experimentally observed. Using the Cray XK7 Titan supercomputer at the Oak Ridge Leadership Computing Facility, the team took Micro-CT images of subsurface geologic systems and created two-phase flow simulations. The team's model development has implications for computational research pertaining to carbon sequestration, oil recovery, and contaminant transport.

Advances in Highly Constrained Multi-Phase Trajectory Generation using the General Pseudospectral Optimization Software (GPOPS)

DTIC Science & Technology

2013-08-01

release; distribution unlimited. PA Number 412-TW-PA-13395 f generic function g acceleration due to gravity h altitude L aerodynamic lift force L Lagrange...cost m vehicle mass M Mach number n number of coefficients in polynomial regression p highest order of polynomial regression Q dynamic pressure R...Method (RPM); the collocation points are defined by the roots of Legendre -Gauss- Radau (LGR) functions.9 GPOPS also automatically refines the “mesh” by

In-line stirling energy system

DOEpatents

Backhaus, Scott N [Espanola, NM; Keolian, Robert [State College, PA

2011-03-22

A high efficiency generator is provided using a Stirling engine to amplify an acoustic wave by heating the gas in the engine in a forward mode. The engine is coupled to an alternator to convert heat input to the engine into electricity. A plurality of the engines and respective alternators can be coupled to operate in a timed sequence to produce multi-phase electricity without the need for conversion. The engine system may be operated in a reverse mode as a refrigerator/heat pump.

A discontinuous Poisson-Boltzmann equation with interfacial jump: homogenisation and residual error estimate.

PubMed

Fellner, Klemens; Kovtunenko, Victor A

2016-01-01

A nonlinear Poisson-Boltzmann equation with inhomogeneous Robin type boundary conditions at the interface between two materials is investigated. The model describes the electrostatic potential generated by a vector of ion concentrations in a periodic multiphase medium with dilute solid particles. The key issue stems from interfacial jumps, which necessitate discontinuous solutions to the problem. Based on variational techniques, we derive the homogenisation of the discontinuous problem and establish a rigorous residual error estimate up to the first-order correction.

Parallel multiphase microflows: fundamental physics, stabilization methods and applications.

PubMed

Aota, Arata; Mawatari, Kazuma; Kitamori, Takehiko

2009-09-07

Parallel multiphase microflows, which can integrate unit operations in a microchip under continuous flow conditions, are discussed. Fundamental physics, stabilization methods and some applications are shown.

References and benchmarks for pore-scale flow simulated using micro-CT images of porous media and digital rocks

NASA Astrophysics Data System (ADS)

Saxena, Nishank; Hofmann, Ronny; Alpak, Faruk O.; Berg, Steffen; Dietderich, Jesse; Agarwal, Umang; Tandon, Kunj; Hunter, Sander; Freeman, Justin; Wilson, Ove Bjorn

2017-11-01

We generate a novel reference dataset to quantify the impact of numerical solvers, boundary conditions, and simulation platforms. We consider a variety of microstructures ranging from idealized pipes to digital rocks. Pore throats of the digital rocks considered are large enough to be well resolved with state-of-the-art micro-computerized tomography technology. Permeability is computed using multiple numerical engines, 12 in total, including, Lattice-Boltzmann, computational fluid dynamics, voxel based, fast semi-analytical, and known empirical models. Thus, we provide a measure of uncertainty associated with flow computations of digital media. Moreover, the reference and standards dataset generated is the first of its kind and can be used to test and improve new fluid flow algorithms. We find that there is an overall good agreement between solvers for idealized cross-section shape pipes. As expected, the disagreement increases with increase in complexity of the pore space. Numerical solutions for pipes with sinusoidal variation of cross section show larger variability compared to pipes of constant cross-section shapes. We notice relatively larger variability in computed permeability of digital rocks with coefficient of variation (of up to 25%) in computed values between various solvers. Still, these differences are small given other subsurface uncertainties. The observed differences between solvers can be attributed to several causes including, differences in boundary conditions, numerical convergence criteria, and parameterization of fundamental physics equations. Solvers that perform additional meshing of irregular pore shapes require an additional step in practical workflows which involves skill and can introduce further uncertainty. Computation times for digital rocks vary from minutes to several days depending on the algorithm and available computational resources. We find that more stringent convergence criteria can improve solver accuracy but at the expense of longer computation time.

Offshore multiphase meter nears acceptable accuracy level

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

Gaisford, S.; Amdal, J.; Berentsen, H.

1993-05-17

Companies worldwide are looking for new production methods for offshore oil fields. In many areas, undeveloped smaller fields cannot bear the cost of dedicated production facilities. Multiphase transportation to existing production facilities can extend the distance over which unseparated oil, water, and gas streams can be transported, from a limit of several kilometers today to perhaps 200 km in the future. An encouraging multiphase meter test was sponsored by Saga Petroleum AS and carried out by Den norske stats oljeselskap AS (Statoil) on the Gullfaks B platform, Norwegian sector of the North Sea. The complete multiphase meter has two separatemore » meters. One is the composition meter for measuring the instantaneous volume or mass fractions of oil, water, and gas in the sensor. The other is a velocity meter for determining the speed of the mixture through the sensor. An instantaneous volume or mass production rate for each component is calculated by combining the outputs from the two meters. The paper describes the multiphase meter; measurements; limitations; the test setup; calibration; test results for the composition meter, velocity meter, and production rates; and future plans.« less

Multiphase complete exchange on Paragon, SP2 and CS-2

NASA Technical Reports Server (NTRS)

Bokhari, Shahid H.

1995-01-01

The overhead of interprocessor communication is a major factor in limiting the performance of parallel computer systems. The complete exchange is the severest communication pattern in that it requires each processor to send a distinct message to every other processor. This pattern is at the heart of many important parallel applications. On hypercubes, multiphase complete exchange has been developed and shown to provide optimal performance over varying message sizes. Most commercial multicomputer systems do not have a hypercube interconnect. However, they use special purpose hardware and dedicated communication processors to achieve very high performance communication and can be made to emulate the hypercube quite well. Multiphase complete exchange has been implemented on three contemporary parallel architectures: the Intel Paragon, IBM SP2 and Meiko CS-2. The essential features of these machines are described and their basic interprocessor communication overheads are discussed. The performance of multiphase complete exchange is evaluated on each machine. It is shown that the theoretical ideas developed for hypercubes are also applicable in practice to these machines and that multiphase complete exchange can lead to major savings in execution time over traditional solutions.

Multiphase flow and transport in porous media

NASA Astrophysics Data System (ADS)

Parker, J. C.

1989-08-01

Multiphase flow and transport of compositionally complex fluids in geologic media is of importance in a number of applied problems which have major social and economic effects. In petroleum reservoir engineering, efficient recovery of energy reserves is the principal goal. Unfortunately, some of these hydrocarbons and other organic chemicals often find their way unwanted into the soils and groundwater supplies. Removal in the latter case is predicated on ensuring the public health and safety. In this paper, principles of modeling fluid flow in systems containing up to three fluid phases (namely, water, air, and organic liquid) are described. Solution of the governing equations for multiphase flow requires knowledge of functional relationships between fluid pressures, saturations, and permeabilities which may be formulated on the basis of conceptual models of fluid-porous media interactions. Mechanisms of transport in multicomponent multiphase systems in which species may partition between phases are also described, and the governing equations are presented for the case in which local phase equilibrium may be assumed. A number of hypothetical numerical problems are presented to illustrate the physical behavior of systems in which multiphase flow and transport arise.

Shock tube Multiphase Experiments

NASA Astrophysics Data System (ADS)

Middlebrooks, John; Allen, Roy; Paudel, Manoj; Young, Calvin; Musick, Ben; McFarland, Jacob

2017-11-01

Shock driven multiphase instabilities (SDMI) are unique physical phenomena that have far-reaching practical applications in engineering and science. The instability is present in high energy explosions, scramjet combustors, and supernovae events. The SDMI arises when a multiphase interface is impulsively accelerated by the passage of a shockwave. It is similar in development to the Richtmyer-Meshkov (RM) instability however, particle-to-gas coupling is the driving mechanism of the SDMI. As particle effects such as lag and phase change become more prominent, the SDMI's development begins to significantly deviate from the RM instability. We have developed an experiment for studying the SDMI in our shock tube facility. In our experiments, a multiphase interface is created using a laminar jet and flowed into the shock tube where it is accelerated by the passage of a planar shockwave. The interface development is captured using CCD cameras synchronized with planar laser illumination. This talk will give an overview of new experiments conducted to examine the development of a shocked cylindrical multiphase interface. The effects of Atwood number, particle size, and a second acceleration (reshock) of the interface will be discussed.

Multiphase magnetic systems: Measurement and simulation

NASA Astrophysics Data System (ADS)

Cao, Yue; Ahmadzadeh, Mostafa; Xu, Ke; Dodrill, Brad; McCloy, John S.

2018-01-01

Multiphase magnetic systems are common in nature and are increasingly being recognized in technical applications. One characterization method which has shown great promise for determining separate and collective effects of multiphase magnetic systems is first order reversal curves (FORCs). Several examples are given of FORC patterns which provide distinguishing evidence of multiple phases. In parallel, a visualization method for understanding multiphase magnetic interaction is given, which allocates Preisach magnetic elements as an input "Preisach hysteron distribution pattern" to enable simulation of different "wasp-waisted" magnetic behaviors. These simulated systems allow reproduction of different major hysteresis loops and FORC patterns of real systems and parameterized theoretical systems. The experimental FORC measurements and FORC diagrams of four commercially obtained magnetic materials, particularly those sold as nanopowders, show that these materials are often not phase pure. They exhibit complex hysteresis behaviors that are not predictable based on relative phase fraction obtained by characterization methods such as diffraction. These multiphase materials, consisting of various fractions of BaFe12O19, ɛ-Fe2O3, and γ-Fe2O3, are discussed.

Dynamic properties of interfaces in soft matter: Experiments and theory

NASA Astrophysics Data System (ADS)

Sagis, Leonard M. C.

2011-10-01

The dynamic properties of interfaces often play a crucial role in the macroscopic dynamics of multiphase soft condensed matter systems. These properties affect the dynamics of emulsions, of dispersions of vesicles, of biological fluids, of coatings, of free surface flows, of immiscible polymer blends, and of many other complex systems. The study of interfacial dynamic properties, surface rheology, is therefore a relevant discipline for many branches of physics, chemistry, engineering, and life sciences. In the past three to four decades a vast amount of literature has been produced dealing with the rheological properties of interfaces stabilized by low molecular weight surfactants, proteins, (bio)polymers, lipids, colloidal particles, and various mixtures of these surface active components. In this paper recent experiments are reviewed in the field of surface rheology, with particular emphasis on the models used to analyze surface rheological data. Most of the models currently used are straightforward generalizations of models developed for the analysis of rheological data of bulk phases. In general the limits on the validity of these generalizations are not discussed. Not much use is being made of recent advances in nonequilibrium thermodynamic formalisms for multiphase systems, to construct admissible models for the stress-deformation behavior of interfaces. These formalisms are ideally suited to construct thermodynamically admissible constitutive equations for rheological behavior that include the often relevant couplings to other fluxes in the interface (heat and mass), and couplings to the transfer of mass from the bulk phase to the interface. In this review recent advances in the application of classical irreversible thermodynamics, extended irreversible thermodynamics, rational thermodynamics, extended rational thermodynamics, and the general equation for the nonequilibrium reversible-irreversible coupling formalism to multiphase systems are also discussed, and shown how these formalisms can be used to generate a wide range of thermodynamically admissible constitutive models for the surface stress tensor. Some of the generalizations currently in use are shown to have only limited validity. The aim of this review is to stimulate new developments in the fields of experimental surface rheology and constitutive modeling of multiphase systems using nonequilibrium thermodynamic formalisms and to promote a closer integration of these disciplines.

Quaternary borocarbides: New class of intermetallic superconductors

NASA Technical Reports Server (NTRS)

Nagarajan, R.; Gupta, L. C.; Dhar, S. K.; Mazumdar, Chandan; Hossain, Zakir; Godart, C.; Levy-Clement, C.; Padalia, B. D.; Vijayaraghavan, R.

1995-01-01

Our recent discovery of superconductivity (SC) in the four-element multiphase Y-Ni-B-C system at an elevated temperature (TC approximately 12 K) has opened up great possibilities of identifying new superconducting materials and generating new physics. Superconductivity with Tc (greater than 20 K) higher than that known so far in bulk intermetallics has been observed in multiphase Y-Pd-B-C and Th-Pd-B-C systems and a family of single phase materials RENi2B2C (RE= Y, rare earth) have been found. Our investigations show YNi2B2C to be a strong coupling hard type-II SC. HC2(T) exhibits an unconventional temperature dependence. Specific heat and magnetization studies reveal coexistence of SC and magnetism in RNi2B2C (R = Ho, Er, Tm) with magnetic ordering temperatures (Tc approximately 8 K, 10.5 K, 11 K and Tm approximately 5 K, approximately 7K, approximately 4 K respectively) that are remarkably higher than those in known magnetic superconductors . Mu-SR studies suggest the possibility of Ni atoms carrying a moment in TmNi2B2C. Resistivity results suggests a double re-entrant transition (SC-normal-SC) in HoNi2B2C. RENi2B2C (RE = Ce, Nd, Gd) do not show SC down to 4.2 K. The Nd- and Gd-compounds order magnetically at approximately 4.5 K and approximately 19.5 K, respectively. Two SC transitions are observed in Y-Pd-B-C (Tc approximately 22 K, approximately 10 K) and in Th-Pd-B-C (Tc approximately 20 K, approximately 14 K) systems, which indicate that there are at least two structures which support SC in these borocarbides. In our multiphase ThNi2B2C we observe SC at approximately 6 K. No SC was seen in multiphase UNi2B2C, UPd2B2C, UOs2Ge2C and UPd5B3C(0.35) down to 4.2 K. Tc in YNi2B2C is depressed by substitutions (Gd, Th and U at Y-sites and Fe, Co at Ni-sites).

Post-injection Multiphase Flow Modeling and Risk Assessments for Subsurface CO2 Storage in Naturally Fractured Reservoirs

NASA Astrophysics Data System (ADS)

Jin, G.

2015-12-01

Subsurface storage of carbon dioxide in geological formations is widely regarded as a promising tool for reducing global atmospheric CO2 emissions. Successful geologic storage for sequestrated carbon dioxides must prove to be safe by means of risk assessments including post-injection analysis of injected CO2 plumes. Because fractured reservoirs exhibit a higher degree of heterogeneity, it is imperative to conduct such simulation studies in order to reliably predict the geometric evolution of plumes and risk assessment of post CO2injection. The research has addressed the pressure footprint of CO2 plumes through the development of new techniques which combine discrete fracture network and stochastic continuum modeling of multiphase flow in fractured geologic formations. A subsequent permeability tensor map in 3-D, derived from our preciously developed method, can accurately describe the heterogeneity of fracture reservoirs. A comprehensive workflow integrating the fracture permeability characterization and multiphase flow modeling has been developed to simulate the CO2plume migration and risk assessments. A simulated fractured reservoir model based on high-priority geological carbon sinks in central Alabama has been employed for preliminary study. Discrete fracture networks were generated with an NE-oriented regional fracture set and orthogonal NW-fractures. Fracture permeability characterization revealed high permeability heterogeneity with an order of magnitude of up to three. A multiphase flow model composed of supercritical CO2 and saline water was then applied to predict CO2 plume volume, geometry, pressure footprint, and containment during and post injection. Injection simulation reveals significant permeability anisotropy that favors development of northeast-elongate CO2 plumes, which are aligned with systematic fractures. The diffusive spreading front of the CO2 plume shows strong viscous fingering effects. Post-injection simulation indicates significant upward lateral spreading of CO2 resulting in accumulation of CO2 directly under the seal unit because of its buoyancy and strata-bound vertical fractures. Risk assessment shows that lateral movement of CO2 along interconnected fractures requires widespread seals with high integrity to confine the injected CO2.

Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} heterogeneous photocatalyst prepared by a facile hydrothermal synthesis with enhanced photocatalytic performance under visible light irradiation

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

Ran, Rong; McEvoy, Joanne Gamage; Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario, K1N 6N5

Highlights: • The photocatalyst was hydrothermally prepared by adjusting the ratio of Ag to V. • Multi-phase Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} obtained exhibited multi-morphological features. • The photocatalyst exhibited strong visible light driven photoactivity towards RhB. - Abstract: A novel Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} photocatalyst was synthesized by adjusting the molar ratio of silver–vanadium (Ag–V) in a facile hydrothermal method to obtain multi-phase Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} photocatalyst. The photocatalytic activity of the prepared samples was quantified by the degradation of Rhodamine B (RhB) model organic pollutant under visible light irradiation.more » Compared to pure Ag{sub 3}VO{sub 4}, Ag{sub 4}V{sub 2}O{sub 7} and P25 TiO{sub 2}, respectively, the as-synthesized multi-phase Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} powders gave rise to a significantly higher photocatalytic activity, achieving up to 99% degradation of RhB in 2 h under visible light. This enhanced photocatalytic performance was attributed to the effect of the multi-phase Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7} photocatalyst and the surface plasmon resonance (SPR) of the incorporated metallic silver (Ag{sup 0}) nanoparticles (NPs) generated during the photocatalysis, as evidenced by post-use characterization, resulting in improved visible light absorption and electron-hole (e{sup −}-h{sup +}) separation. A mechanism was proposed for the photocatalytic degradation of RhB on the surface of Ag{sub 2}O/Ag{sub 3}VO{sub 4}/Ag{sub 4}V{sub 2}O{sub 7}.« less

Investigation of free vibration characteristics for skew multiphase magneto-electro-elastic plate

NASA Astrophysics Data System (ADS)

Kiran, M. C.; Kattimani, S.

2018-04-01

This article presents the investigation of skew multiphase magneto-electro-elastic (MMEE) plate to assess its free vibration characteristics. A finite element (FE) model is formulated considering the different couplings involved via coupled constitutive equations. The transformation matrices are derived to transform local degrees of freedom into the global degrees of freedom for the nodes lying on the skew edges. Effect of different volume fraction (Vf) on the free vibration behavior is explicitly studied. In addition, influence of width to thickness ratio, the aspect ratio, and the stacking arrangement on natural frequencies of skew multiphase MEE plate investigated. Particular attention has been paid to investigate the effect of skew angle on the non-dimensional Eigen frequencies of multiphase MEE plate with simply supported edges.

Oil field management system

DOEpatents

Fincke, James R.

2003-09-23

Oil field management systems and methods for managing operation of one or more wells producing a high void fraction multiphase flow. The system includes a differential pressure flow meter which samples pressure readings at various points of interest throughout the system and uses pressure differentials derived from the pressure readings to determine gas and liquid phase mass flow rates of the high void fraction multiphase flow. One or both of the gas and liquid phase mass flow rates are then compared with predetermined criteria. In the event such mass flow rates satisfy the predetermined criteria, a well control system implements a correlating adjustment action respecting the multiphase flow. In this way, various parameters regarding the high void fraction multiphase flow are used as control inputs to the well control system and thus facilitate management of well operations.

Power Generator with Thermo-Differential Modules

NASA Technical Reports Server (NTRS)

Saiz, John R.; Nguyen, James

2010-01-01

A thermoelectric power generator consists of an oven box and a solar cooker/solar reflector unit. The solar reflector concentrates sunlight into heat and transfers the heat into the oven box via a heat pipe. The oven box unit is surrounded by five thermoelectric modules and is located at the bottom end of the solar reflector. When the heat is pumped into one side of the thermoelectric module and ejected from the opposite side at ambient temperatures, an electrical current is produced. Typical temperature accumulation in the solar reflector is approximately 200 C (392 F). The heat pipe then transfers heat into the oven box with a loss of about 40 percent. At the ambient temperature of about 20 C (68 F), the temperature differential is about 100 C (180 F) apart. Each thermoelectric module, generates about 6 watts of power. One oven box with five thermoelectric modules produces about 30 watts. The system provides power for unattended instruments in remote areas, such as space colonies and space vehicles, and in polar and other remote regions on Earth.

Adaptive reference voltage generator for firing angle control of line-commutated inverters

NASA Technical Reports Server (NTRS)

Dolland, C. R. (Inventor)

1983-01-01

A control system for a permanent-magnet motor driven by a multiphase line-commulated inverter is described. It is provided with integrators for integrating the back EMF of each phase of the motor for use in generating system control signals for an inverter gate logic using a sync and firing angle control generator connected to the outputs of the integrators. The firing angle control signals are produced by the control generator by means for combining 120 deg segments of the integrated back EMF signals symmetrical about their maxima into composite positive and negative waveforms, and means for sampling the maxima of each waveform every 120 deg. These samples are then used as positive and negative firing angle control signals. Whereby any change in amplitude of the integrated back EMF signals will not affect a change in the operating power factor of the motor and inverter.

Metallurgical causes for the occurrence of creep damage in longitudinally seam-welded Cr-Mo high-energy piping

NASA Astrophysics Data System (ADS)

Zhou, Gang

A continuous occurrence of catastrophic failures, leaks and cracks of the Cr-Mo steam piping has created widespread utility concern for the integrity and serviceability of the seam-welded piping systems in power plants across USA. Cr-Mo steels are the materials widely used for elevated temperature service in fossil-fired generating stations. A large percentage of the power plant units with the Cr-Mo seam-welded steam piping have been in operation for a long duration such that the critical components of the units have been employed beyond the design life (30 or 40 years). This percentage will increase even more significantly in the near future. There is a strong desire to extend and thus there is a need to assess the remaining life of these units. Thus, understanding of the metallurgical causes for the failures and damage in the Cr-Mo seam-welded piping plays a major role in estimating possible life-extension and decision making on whether to operate, repair or replace. In this study, an optical metallographic method and a Cryo-Crack fractographic method have been developed for characterization and quantification of the damage in seam-welded steam piping. More than 500 metallographic assessments, from more than 25 power plants, have been accomplished using the optical metallographic method, and more than 200 fractographic specimens from 10 power plants have been evaluated using the "Cryo-Crack" fractographic technique. For comparison, "virgin" SA welds were fabricated using the Mohave welding procedure with re-N&T Mohave base metal with both "acid" and "basic" fluxes. The damage mechanism, damage distribution pattern, damage classification, correlation of the damage with the microstructural features of these SA welds and the impurity segregation patterns have been determined. A physical model for cavitation (leading to failure) in Cr-Mo SA weld metals and evaluation methodologies for high energy piping are proposed.

Constitutive Relationships and Models in Continuum Theories of Multiphase Flows. [conferences

NASA Technical Reports Server (NTRS)

Decker, Rand (Editor)

1989-01-01

In April, 1989, a workshop on constitutive relationships and models in continuum theories of multiphase flows was held at NASA's Marshall Space Flight Center. Topics of constitutive relationships for the partial or per phase stresses, including the concept of solid phase pressure are discussed. Models used for the exchange of mass, momentum, and energy between the phases in a multiphase flow are also discussed. The program, abstracts, and texts of the presentations from the workshop are included.

Final Project Report CFA-14-6357: A New Paradigm for Understanding Multiphase Ceramic Waste Form Performance

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

Brinkman, Kyle; Bordia, Rajendra; Reifsnider, Kenneth

This project fabricated model multiphase ceramic waste forms with processing-controlled microstructures followed by advanced characterization with synchrotron and electron microscopy-based 3D tomography to provide elemental and chemical state-specific information resulting in compositional phase maps of ceramic composites. Details of 3D microstructural features were incorporated into computer-based simulations using durability data for individual constituent phases as inputs in order to predict the performance of multiphase waste forms with varying microstructure and phase connectivity.

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

Christon, Mark A.; Bakosi, Jozsef; Francois, Marianne M.

This talk presents an overview of the multiphase flow efforts with Hydra-TH. The presentation begins with a definition of the requirements and design principles for multiphase flow relevant to CASL-centric problems. A brief survey of existing codes and their solution algorithms is presented before turning the model formulation selected for Hydra-TH. The issues of hyperbolicity and wellposedness are outlined, and a three candidate solution algorithms are discussed. The development status of Hydra-TH for multiphase flow is then presented with a brief summary and discussion of future directions for this work.

Palaeomagnetic Emplacement Temperature Determinations of Pyroclastic and Volcaniclastic Deposits in Southern African Kimberlite Pipes

NASA Astrophysics Data System (ADS)

Fontana, G.; Mac Niocaill, C.; Brown, R.; Sparks, R. S.; Matthew, F.; Gernon, T. M.

2009-12-01

Kimberlites are complex, ultramafic and diamond-bearing volcanic rocks preserved in volcanic pipes, dykes and craters. The formation of kimberlite pipes is a strongly debated issue and two principal theories have been proposed to explain pipe formation: (1) the explosive degassing of magma, and (2) the interaction of rising magma with groundwater (phreatomagmatism). Progressive thermal demagnetization studies are a powerful tool for determining the emplacement temperatures of ancient volcanic deposits and we present the first application of such techniques to kimberlite deposits. Lithic clasts were sampled from a variety of lithofacies, from three pipes for which the internal geology is well constrained (A/K1 pipe, Orapa Mine, Botswana and the K1 and K2 pipes, Venetia Mine, South Africa). The sampled deposits included massive and layered vent-filling breccias with varying abundances of lithic inclusions and layered crater-filling pyroclastic deposits, talus breccias and volcaniclastic breccias. Lithic clasts sampled from layered and massive vent-filling pyroclastic deposits in A/K1 were emplaced at >590° C. Results from K1 and K2 provide a maximum emplacement temperature limit for vent-filling breccias of 420-460° C; and constrain equilibrium deposit temperatures at 300-340° C. Crater-filling volcaniclastic kimberlite breccias and talus deposits from A/K1 were emplaced at ambient temperatures, consistent with infilling of the pipe by post-eruption epiclastic processes. Identified within the epiclastic crater-fill succession is a laterally extensive 15-20 metre thick kimberlite pyroclastic flow deposit emplaced at temperatures of 220-440° C. It overlies the post-eruption epiclastic units and is considered an extraneous pyroclastic kimberlite deposit erupted from another kimberlite vent. The results provide important constraints on kimberlite emplacement mechanisms and eruption dynamics. Emplacement temperatures of >590°C for pipe-filling pyroclastic deposits are consistent with volatile-driven eruptions, and suggest phreatomagmatism did not play a major role in the generation of the deposits. The discovery of an extraneous pyroclastic flow deposit within the Orapa A/K1 epiclastic crater, which was erupted from another vent, suggests kimberlite eruptions are capable of producing sustained eruption columns and thick pyroclastic deposits involving significant transport away from source.

A mass-conserving multiphase lattice Boltzmann model for simulation of multiphase flows

NASA Astrophysics Data System (ADS)

Niu, Xiao-Dong; Li, You; Ma, Yi-Ren; Chen, Mu-Feng; Li, Xiang; Li, Qiao-Zhong

2018-01-01

In this study, a mass-conserving multiphase lattice Boltzmann (LB) model is proposed for simulating the multiphase flows. The proposed model developed in the present study is to improve the model of Shao et al. ["Free-energy-based lattice Boltzmann model for simulation of multiphase flows with density contrast," Phys. Rev. E 89, 033309 (2014)] by introducing a mass correction term in the lattice Boltzmann model for the interface. The model of Shao et al. [(the improved Zheng-Shu-Chew (Z-S-C model)] correctly considers the effect of the local density variation in momentum equation and has an obvious improvement over the Zheng-Shu-Chew (Z-S-C) model ["A lattice Boltzmann model for multiphase flows with large density ratio," J. Comput. Phys. 218(1), 353-371 (2006)] in terms of solution accuracy. However, due to the physical diffusion and numerical dissipation, the total mass of each fluid phase cannot be conserved correctly. To solve this problem, a mass correction term, which is similar to the one proposed by Wang et al. ["A mass-conserved diffuse interface method and its application for incompressible multiphase flows with large density ratio," J. Comput. Phys. 290, 336-351 (2015)], is introduced into the lattice Boltzmann equation for the interface to compensate the mass losses or offset the mass increase. Meanwhile, to implement the wetting boundary condition and the contact angle, a geometric formulation and a local force are incorporated into the present mass-conserving LB model. The proposed model is validated by verifying the Laplace law, simulating both one and two aligned droplets splashing onto a liquid film, droplets standing on an ideal wall, droplets with different wettability splashing onto smooth wax, and bubbles rising under buoyancy. Numerical results show that the proposed model can correctly simulate multiphase flows. It was found that the mass is well-conserved in all cases considered by the model developed in the present study. The developed model has been found to perform better than the improved Z-S-C model in this aspect.

Actively generated noise liquid flowmeter.

PubMed

Tanisawa, S; Hirose, H; Yoshihisa, N

1994-01-01

A new noise flowmeter with two transducers has been tested experimentally in water. It detects the noises generated by the interaction between artificially introduced air bubbles and a built-in obstacle with a downstream transducer, and differentiates them from the external noises detected by the upstream transducer in a pipe. The system includes processing instrumentation with functions such as averaging and difference-operating for reduction of external noise effects.

Hydrodynamic modeling of petroleum reservoirs using simulator MUFITS

NASA Astrophysics Data System (ADS)

Afanasyev, Andrey

2015-04-01

MUFITS is new noncommercial software for numerical modeling of subsurface processes in various applications (www.mufits.imec.msu.ru). To this point, the simulator was used for modeling nonisothermal flows in geothermal reservoirs and for modeling underground carbon dioxide storage. In this work, we present recent extension of the code to petroleum reservoirs. The simulator can be applied in conventional black oil modeling, but it also utilizes a more complicated models for volatile oil and gas condensate reservoirs as well as for oil rim fields. We give a brief overview of the code by providing the description of internal representation of reservoir models, which are constructed of grid blocks, interfaces, stock tanks as well as of pipe segments and pipe junctions for modeling wells and surface networks. For conventional black oil approach, we present the simulation results for SPE comparative tests. We propose an accelerated compositional modeling method for sub- and supercritical flows subjected to various phase equilibria, particularly to three-phase equilibria of vapour-liquid-liquid type. The method is based on the calculation of the thermodynamic potential of reservoir fluid as a function of pressure, total enthalpy and total composition and storing its values as a spline table, which is used in hydrodynamic simulation for accelerated PVT properties prediction. We provide the description of both the spline calculation procedure and the flashing algorithm. We evaluate the thermodynamic potential for a mixture of two pseudo-components modeling the heavy and light hydrocarbon fractions. We develop a technique for converting black oil PVT tables to the potential, which can be used for in-situ hydrocarbons multiphase equilibria prediction under sub- and supercritical conditions, particularly, in gas condensate and volatile oil reservoirs. We simulate recovery from a reservoir subject to near-critical initial conditions for hydrocarbon mixture. We acknowledge financial support by a Grant from the president of the Russian Federation (SP-2222.2012.5) and by Russian foundation for basic research (RFBR 15-31-20585).

Combined free and forced convection heat transfer in magneto fluid mechanic pipe flow

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

Gardner, R.A.; Lo, Y.T.

1977-01-01

A study is made of fully developed, laminar, free-and-forced convection heat transfer in an electrically conducting fluid flowing in an electrically insulated, horizontal, circular pipe in a vertical transverse magnetic field. The normalized magnetofluidmechanic and energy equations are reduced to three coupled partial differential equations by the introduction of a stream function of the secondary flow. A perturbation solution is generated in inverse powers of the Lykoudis number, Ly = M/sup 2//..sqrt..Gr, which yields the influence of the magnetic field on the stream function of the secondary flow, axial velocity profiles, temperature profiles, and Nusselt number. 6 figures, 1 table.

The influence on response of axial rotation of a six-group local-conductance probe in horizontal oil-water two-phase flow

NASA Astrophysics Data System (ADS)

Weihang, Kong; Lingfu, Kong; Lei, Li; Xingbin, Liu; Tao, Cui

2017-06-01

Water volume fraction is an important parameter of two-phase flow measurement, and it is an urgent task for accurate measurement in horizontal oil field development and optimization of oil production. The previous ring-shaped conductance water-cut meter cannot obtain the response values corresponding to the oil field water conductivity for oil-water two-phase flow in horizontal oil-producing wells characterized by low yield liquid, low velocity and high water cut. Hence, an inserted axisymmetric array structure sensor, i.e. a six-group local-conductance probe (SGLCP), is proposed in this paper. Firstly, the electric field distributions generated by the exciting electrodes of SGLCP are investigated by the finite element method (FEM), and the spatial sensitivity distributions of SGLCP are analyzed from the aspect of different separations between two electrodes and different axial rotation angles respectively. Secondly, the numerical simulation responses of SGLCP in horizontal segregated flow are calculated from the aspect of different water cut and heights of the water layer, respectively. Lastly, an SGLCP-based well logging instrument was developed, and experiments were carried out in a horizontal pipe with an inner diameter of 125 mm on the industrial-scale experimental multiphase flow setup in the Daqing Oilfield, China. In the experiments, the different oil-water two-phase flow, mineralization degree, temperature and pressure were tested. The results obtained from the simulation experiments and simulation well experiments demonstrate that the designed and developed SGLCP-based instrument still has a good response characteristic for measuring water conductivity under the different conditions mentioned above. The validity and reliability of obtaining the response values corresponding to the water conductivity through the designed and developed SGLCP-based instrument are verified by the experimental results. The significance of this work can provide an effective technology for measuring the water volume fraction of oil-water two-phase flow in horizontal oil-producing wells.

Methodology for Life Testing of Refractory Metal/Sodium Heat Pipes

NASA Technical Reports Server (NTRS)

Martin, James J.; Reid, Robert S.

2006-01-01

The focus of this work was to establish an approach to generate carefully controlled data that can conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. To accomplish this goal acceleration is required to compress 10 years of operational life into 3 years of laboratory testing through a combination of increased temperature and mass fluence. Specific test series have been identi3ed, based on American Society for Testing and Materials (ASTM) specifications, to investigate long term corrosion rates. The refractory metal selected for demonstration purposes is a Molybdenum-44.5%Rhenium alloy formed by powder metallurgy. The heat pipe makes use of an annular crescent wick design formed by hot isostatic pressing of Molybdenum-Rhenium wire mesh. The heat pipes are filled using vacuum distillation and purity sampling is considered. Testing of these units is round-the-clock with 6-month destructive and non-destructive inspection intervals to identify the onset and level of corrosion. Non-contact techniques are employed for providing power to the evaporator (radio frequency induction heating at I to 5 kW per unit) and calorimetry at the condenser (static gas gap coupled water cooled calorimeter). The planned operating temperature range would extend from 1123 to 1323 K. Accomplishments prior to project cancellation included successful demonstration of the heat pipe wick fabrication technique, establishment of all engineering designs, baselined operational test requirements and procurement/assembly of supporting test hardware systems.

Extension of the CAPRAM mechanism with the improved mechanism generator GECKO-A

NASA Astrophysics Data System (ADS)

Bräuer, Peter; Mouchel-Vallon, Camille; Tilgner, Andreas; Wolke, Ralf; Aumont, Bernard; Herrmann, Hartmut

2013-04-01

Organic compounds are an ubiquitous constituent of the tropospheric multiphase system. With either biogenic or anthropogenic sources, they have a major influence on the atmospheric multiphase system and thus have become a main research topic within the last decades. Modelling can provide a useful tool to explore the tropospheric multiphase chemistry. While in the gas phase several comprehensive near-explicit mechanisms exist, in the aqueous phase those mechanisms are very limited. The current study aims to advance the currently most comprehensive aqueous phase mechanism CAPRAM 3.0 by means of automated mechanism construction. Therefore, the mechanism generator GECKO-A (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere; see Aumont et al., 2005) has been advanced to the aqueous phase. A protocol has been designed for automated mechanism construction based on reviewed experimental data and evaluated prediction methods. The generator is able to describe the oxidation of aliphatic organic compounds by OH and NO3. For the mechanism construction, mainly structure-activity relationships are used, which are completed by Evans-Polanyi-type correlations and further suitable estimates. GECKO-A has been used to create new CAPRAM versions, where branching ratios are introduced and new chemical subsystems with species with up to 4 carbon atoms are added. The currently most comprehensive version, CAPRAM 3.7, includes about 2000 aqueous phase species and more than 3300 reactions in the aqueous phase. Box model studies have been performed using a meteorological scenario with non-permanent clouds. Besides the investigation of the concentration-time profiles, detailed time-resolved flux analyses have been performed. Several aqueous phase subsystems have been investigated, such as the formation of oxidised mono- and diacids in the aqueous phase, as well as interactions to inorganic cycles and the influence on the gas phase chemistry and composition. Results have been compared to results of previous versions and show a significant improvement in the new mechanism versions, when comparing the modelled data to field data from literature. For example, in CAPRAM 3.7 there is a malonic acid production of about 80 ng m-3 compared to a few ng m-3 in CAPRAM 3.0. The results in CAPRAM 3.7 confirm recent measurements by Bao et al. (2012), who measure up to 137 ng m-3. Moreover, several attempts have been undertaken to validate the mechanisms created by GECKO-A with own field experiments, such as the HCCT-2010 campaign and chamber experiments in the LEAK chamber. References Aumont, B., Szopa, S., Madronich, S.: Modelling the evolution of organic carbon during its gas-phase tropospheric oxidation: development of an explicit model based on a self generating approach. Atmos. Chem. Phys., 5, 2497-2517 (2005). Bao, L., Matsumoto, M., Kubota, T., Sekiguchi, K., Wang, Q., Sakamoto, K.: Gas/particle partitioning of low-molecular-weight dicarboxylic acids at a suburban site in Saitama, Japan. Atmos. Env., 47, 546 - 553 (2012).

Study on stress-strain response of multi-phase TRIP steel under cyclic loading

NASA Astrophysics Data System (ADS)

Dan, W. J.; Hu, Z. G.; Zhang, W. G.; Li, S. H.; Lin, Z. Q.

2013-12-01

The stress-strain response of multi-phase TRIP590 sheet steel is studied in cyclic loading condition at room temperature based on a cyclic phase transformation model and a multi-phase mixed kinematic hardening model. The cyclic martensite transformation model is proposed based on the shear-band intersection, where the repeat number, strain amplitude and cyclic frequency are used to control the phase transformation process. The multi-phase mixed kinematic hardening model is developed based on the non-linear kinematic hardening rule of per-phase. The parameters of transformation model are identified with the relationship between the austenite volume fraction and the repeat number. The parameters in Kinematic hardening model are confirmed by the experimental hysteresis loops in different strain amplitude conditions. The responses of hysteresis loop and stress amplitude are evaluated by tension-compression data.

Design and Activation of a LOX/GH Chemical Steam Generator

NASA Technical Reports Server (NTRS)

Saunders, G. P.; Mulkey, C. A.; Taylor, S. A.

2009-01-01

The purpose of this paper is to give a detailed description of the design and activation of the LOX/GH fueled chemical steam generator installed in Cell 2 of the E3 test facility at Stennis Space Center, MS (SSC). The steam generator uses a liquid oxygen oxidizer with gaseous hydrogen fuel. The combustion products are then quenched with water to create steam at pressures from 150 to 450 psig at temperatures from 350 to 750 deg F (from saturation to piping temperature limits).

Implementation of a Water Heat Pipe at CETIAT

NASA Astrophysics Data System (ADS)

Favreau, J. O.; Georgin, E.; Savanier, B.; Merlone, A.

2017-12-01

CETIAT's calibration laboratory, accredited by COFRAC, is a secondary thermometry laboratory. It uses overflow and stirred calibration baths (from - 80 {°}C up to + 215 {°}C), dry blocks and furnaces (from + 100 {°}C up to + 1050 {°}C) and thermostatic chambers (from - 30 {°}C up to + 160 {°}C). Typical calibration uncertainties that can be reached for platinum resistance thermometers in a thermostatic bath are between 0.03 {°}C and 0.06 {°}C. In order to improve its calibration capabilities, CETIAT is working on the implementation of a gas-controlled heat pipe (GCHP) temperature generator, used for industrial sensor calibrations. This article presents the results obtained during the characterization of water GCHP for industrial applications. This is a new approach to the use of a heat pipe as a temperature generator for industrial sensor calibrations. The objective of this work is to improve measurement uncertainties and daily productivity. Indeed, as has been shown in many studies (Dunn and Reay in Heat Pipes, Pergamon Press, Oxford, 1976; Merlone et al. 2012), the temperature of the system is pressure dependent and the response time, in temperature, follows the pressure accordingly. Thanks to this generator, it is possible to perform faster calibrations with smaller uncertainties. In collaboration with INRiM, the GCHP developed at CETIAT works with water and covers a temperature range from + 30 {°}C up to + 150 {°}C. This device includes some improvements such as a removable cover, which allows us to have different sets of thermometric wells adjustable according to the probe to be calibrated, and a pressure controller based on a temperature sensor. This article presents the metrological characterization in terms of homogeneity and stability in temperature. A rough investigation of the response time of the system is also presented in order to evaluate the time for reaching thermal equilibrium. The results obtained in this study concern stability and thermal homogeneity. The homogeneity on 200 mm is better than 5 mK and with a calibration uncertainty reduced by a factor of three.

Separation of emulsified crude oil in saline water by flotation with micro- and nanobubbles generated by a multiphase pump.

PubMed

Oliveira, H A; Azevedo, A C; Etchepare, R; Rubio, J

2017-11-01

The flocculation-column flotation with hydraulic loading (HL, >10 m h -1 ) was studied for the treatment of oil-in-water emulsions containing 70-400 mg L -1 (turbidity = 70-226 NTU) of oil and salinity (30 and 100 g L -1 ). A polyacrylamide (Dismulgan, 20 mg L -1 ) flocculated the oil droplets, using two floc generator reactors, with rapid and slow mixing stages (head loss = 0.9 to 3.5 bar). Flotation was conducted in two cells (1.5 and 2.5 m) with microbubbles (MBs, 5-80 μm) and nanobubbles (NBs, 50-300 nm diameter, concentration of 10 8 NBs mL -1 ). Bubbles were formed using a centrifugal multiphase pump, with optimized parameters and a needle valve. The results showed higher efficiency with the taller column reducing the residual oil content to 4 mg L -1 and turbidity to 7 NTU. At high HL (27.5 m h -1 ), the residual oil concentrations were below the standard emission (29 mg L -1 ), reaching 18 mg L -1 . The best results were obtained with high concentration of NBs (apart from the bigger bubbles). Mechanisms involved appear to be attachment and entrapment of the NBs onto and inside the flocs. Thus, the aggregates were readily captured, by bigger bubbles (mostly MBs) aiding shear withstanding. Advantages are the small footprint of the cells, low residence time and high processing rate.

Effects of bending-torsional duct-induced swirl distortion on aerodynamic performance of a centrifugal compressor

NASA Astrophysics Data System (ADS)

Hou, Hongjuan; Wang, Leilei; Wang, Rui; Yang, Yanzhao

2017-04-01

A turbocharger compressor working in commercial vehicles, especially in some passenger cars, often works together with some pipes with complicated geometry as an air intake system, due to limit of available space in internal combustion engine compartments. These pipes may generate various distortions of physical parameters of the air at the inlet of the compressor and therefore the compressor aerodynamic performance deteriorates. Sometimes, the turbocharging engine fails to work at some operation points. This paper investigates the effects of various swirl distortions induced by different bending-torsional intake ducts on the aerodynamic performance of a turbocharger compressor by both 3D numerical simulations and experimental measurements. It was found that at the outlet of the pipes the different inlet ducts can generate different swirl distortions, twin vortices and bulk-like vortices with different rotating directions. Among them, the bulk-like vortices not only affect seriously the pressure distribution in the impeller domain, but also significantly deteriorate the compressor performance, especially at high flow rate region. And the rotating direction of the bulk-like vortices is also closely associated with the efficiency penalty. Besides the efficiency, the transient flow rate through a single impeller channel, or the asymmetric mass flow crossing the whole impeller, can be influenced by two disturbances. One is from the upstream bending-torsional ducts; other one is from the downstream volute.

Liquid gating elastomeric porous system with dynamically controllable gas/liquid transport.

PubMed

Sheng, Zhizhi; Wang, Honglong; Tang, Yongliang; Wang, Miao; Huang, Lizhi; Min, Lingli; Meng, Haiqiang; Chen, Songyue; Jiang, Lei; Hou, Xu

2018-02-01

The development of membrane technology is central to fields ranging from resource harvesting to medicine, but the existing designs are unable to handle the complex sorting of multiphase substances required for many systems. Especially, the dynamic multiphase transport and separation under a steady-state applied pressure have great benefits for membrane science, but have not been realized at present. Moreover, the incorporation of precisely dynamic control with avoidance of contamination of membranes remains elusive. We show a versatile strategy for creating elastomeric microporous membrane-based systems that can finely control and dynamically modulate the sorting of a wide range of gases and liquids under a steady-state applied pressure, nearly eliminate fouling, and can be easily applied over many size scales, pressures, and environments. Experiments and theoretical calculation demonstrate the stability of our system and the tunability of the critical pressure. Dynamic transport of gas and liquid can be achieved through our gating interfacial design and the controllable pores' deformation without changing the applied pressure. Therefore, we believe that this system will bring new opportunities for many applications, such as gas-involved chemical reactions, fuel cells, multiphase separation, multiphase flow, multiphase microreactors, colloidal particle synthesis, and sizing nano/microparticles.

Pore-scale simulation of CO2-water-rock interactions

NASA Astrophysics Data System (ADS)

Deng, H.; Molins, S.; Steefel, C. I.; DePaolo, D. J.

2017-12-01

In Geologic Carbon Storage (GCS) systems, the migration of scCO2 versus CO2-acidifed brine ultimately determines the extent of mineral trapping and caprock integrity, i.e. the long-term storage efficiency and security. While continuum scale multiphase reactive transport models are valuable for large scale investigations, they typically (over-)simplify pore-scale dynamics and cannot capture local heterogeneities that may be important. Therefore, pore-scale models are needed in order to provide mechanistic understanding of how fine scale structural variations and heterogeneous processes influence the transport and geochemistry in the context of multiphase flow, and to inform parameterization of continuum scale modeling. In this study, we investigate the interplay of different processes at pore scale (e.g. diffusion, reactions, and multiphase flow) through the coupling of a well-developed multiphase flow simulator with a sophisticated reactive transport code. The objectives are to understand where brine displaced by scCO2 will reside in a rough pore/fracture, and how the CO2-water-rock interactions may affect the redistribution of different phases. In addition, the coupled code will provide a platform for model testing in pore-scale multiphase reactive transport problems.

A Multiphase Model for the Intracluster Medium

NASA Technical Reports Server (NTRS)

Nagai, Daisuke; Sulkanen, Martin E.; Evrard, August E.

1999-01-01

Constraints on the clustered mass density of the universe derived from the observed population mean intracluster gas fraction of x-ray clusters may be biased by reliance on a single-phase assumption for the thermodynamic structure of the intracluster medium (ICM). We propose a descriptive model for multiphase structure in which a spherically symmetric ICM contains isobaric density perturbations with a radially dependent variance. Fixing the x-ray emission and emission weighted temperature, we explore two independently observable signatures of the model in the parameter space. For bremsstrahlung dominated emission, the central Sunyaev-Zel'dovich (SZ) decrement in the multiphase case is increased over the single-phase case and multiphase x-ray spectra in the range 0.1-20 keV are flatter in the continuum and exhibit stronger low energy emission lines than their single-phase counterpart. We quantify these effects for a fiducial 10e8 K cluster and demonstrate how the combination of SZ and x-ray spectroscopy can be used to identify a preferred location in the plane of the model parameter space. From these parameters the correct value of mean intracluster gas fraction in the multiphase model results, allowing an unbiased estimate of clustered mass density to he recovered.

Liquid gating elastomeric porous system with dynamically controllable gas/liquid transport

PubMed Central

Sheng, Zhizhi; Wang, Honglong; Tang, Yongliang; Wang, Miao; Huang, Lizhi; Min, Lingli; Meng, Haiqiang; Chen, Songyue; Jiang, Lei; Hou, Xu

2018-01-01

The development of membrane technology is central to fields ranging from resource harvesting to medicine, but the existing designs are unable to handle the complex sorting of multiphase substances required for many systems. Especially, the dynamic multiphase transport and separation under a steady-state applied pressure have great benefits for membrane science, but have not been realized at present. Moreover, the incorporation of precisely dynamic control with avoidance of contamination of membranes remains elusive. We show a versatile strategy for creating elastomeric microporous membrane-based systems that can finely control and dynamically modulate the sorting of a wide range of gases and liquids under a steady-state applied pressure, nearly eliminate fouling, and can be easily applied over many size scales, pressures, and environments. Experiments and theoretical calculation demonstrate the stability of our system and the tunability of the critical pressure. Dynamic transport of gas and liquid can be achieved through our gating interfacial design and the controllable pores’ deformation without changing the applied pressure. Therefore, we believe that this system will bring new opportunities for many applications, such as gas-involved chemical reactions, fuel cells, multiphase separation, multiphase flow, multiphase microreactors, colloidal particle synthesis, and sizing nano/microparticles. PMID:29487906

Multi-Phase Extraction: State-of-the-Practice

EPA Pesticide Factsheets

This report describes the state-of-the-practice for multi-phase extraction (MPE) of contaminated soil and groundwater, focusing primarily on the application and use of MPE at sites with halogenated volatile organic compounds (VOCs).

A Conceptual Design Study on the Application of Liquid Metal Heat Transfer Technology to the Solar Thermal Power Plant

NASA Technical Reports Server (NTRS)

Zimmerman, W. F.; Robertson, C. S.; Ehde, C. L.; Divakaruni, S. M.; Stacy, L. E.

1979-01-01

Alkali metal heat transfer technology was used in the development of conceptual designs for the transport and storage of sensible and latent heat thermal energy in distributed concentrator, solar Stirling power conversion systems at a power level of 15 kWe per unit. Both liquid metal pumped loop and heat pipe thermal transport were considered; system configurations included: (1) an integrated, focal mounted sodium heat pipe solar receiver (HPSR) with latent heat thermal energy storage; (2) a liquid sodium pumped loop with the latent heat storage, Stirling engine-generator, pump and valves located on the back side of the concentrator; and (3) similar pumped loops serving several concentrators with more centralized power conversion and storage. The focus mounted HPSR was most efficient, lightest and lowest in estimated cost. Design confirmation testing indicated satisfactory performance at all angles of inclination of the primary heat pipes to be used in the solar receiver.

Low-cost high-quality Fe-based shape memory alloys suitable for pipe joints

NASA Astrophysics Data System (ADS)

Kajiwara, Setsuo; Baruj, Albert L.; Kikuchi, Takehiko; Shinya, Norio

2003-08-01

By addition of small amount of Nb and C to the conventional Fe-Mn-Si based shape memory alloys, shape memory properties are greatly improved in such an extent that the costly 'training' heat treatment is no more necessary. The key to this remarkable improvement of shape memory effect is to produce small NbC precipitates of about several nm in size in austenite. In order to generate such very small NbC particles, the sample is firstly rolled at 870 K and then aged at 1070 K. An example of Fe-28Mn-6Si-5Cr-0.53Nb-0.06C (mass %) alloy is shown; 95% shape recovery for initial strain of 4% is obtained and the shape recovery stress of about 300 MPa is attained for the sample pre-rolled 14%, which is well above the criterion for industry application of pipe jointing. A pipe jointing with this material is demonstrated.

A universal algorithm for an improved finite element mesh generation Mesh quality assessment in comparison to former automated mesh-generators and an analytic model.

PubMed

Kaminsky, Jan; Rodt, Thomas; Gharabaghi, Alireza; Forster, Jan; Brand, Gerd; Samii, Madjid

2005-06-01

The FE-modeling of complex anatomical structures is not solved satisfyingly so far. Voxel-based as opposed to contour-based algorithms allow an automated mesh generation based on the image data. Nonetheless their geometric precision is limited. We developed an automated mesh-generator that combines the advantages of voxel-based generation with improved representation of the geometry by displacement of nodes on the object-surface. Models of an artificial 3D-pipe-section and a skullbase were generated with different mesh-densities using the newly developed geometric, unsmoothed and smoothed voxel generators. Compared to the analytic calculation of the 3D-pipe-section model the normalized RMS error of the surface stress was 0.173-0.647 for the unsmoothed voxel models, 0.111-0.616 for the smoothed voxel models with small volume error and 0.126-0.273 for the geometric models. The highest element-energy error as a criterion for the mesh quality was 2.61x10(-2) N mm, 2.46x10(-2) N mm and 1.81x10(-2) N mm for unsmoothed, smoothed and geometric voxel models, respectively. The geometric model of the 3D-skullbase resulted in the lowest element-energy error and volume error. This algorithm also allowed the best representation of anatomical details. The presented geometric mesh-generator is universally applicable and allows an automated and accurate modeling by combining the advantages of the voxel-technique and of improved surface-modeling.

Recent developments in biocatalysis in multiphasic ionic liquid reaction systems.

PubMed

Meyer, Lars-Erik; von Langermann, Jan; Kragl, Udo

2018-06-01

Ionic liquids are well known and frequently used 'designer solvents' for biocatalytic reactions. This review highlights recent achievements in the field of multiphasic ionic liquid-based reaction concepts. It covers classical biphasic systems including supported ionic liquid phases, thermo-regulated multi-component solvent systems (TMS) and polymerized ionic liquids. These powerful concepts combine unique reaction conditions with a high potential for future applications on a laboratory and industrial scale. The presence of a multiphasic system simplifies downstream processing due to the distribution of the catalyst and reactants in different phases.

75 FR 29723 - Foreign-Trade Zone 29-Louisville, KY; Application for Expansion and Expansion of Manufacturing...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-27

..., plates, filters, bearings, air pumps/compressors, valves, switches, electric motors, tubes/pipes/profiles... electric motors, pinions, magnets, ignition parts, diodes, transistors, resistors, semiconductors, liquid..., starter motors, motor/generator units, alternators, distributors, other static converters, inverter...

PROCESS DESIGN MANUAL: SURFACE DISPOSAL OF SEWAGE SLUDGE AND DOMESTIC SEPTAGE

EPA Science Inventory

Human domestic activities generate wastewater that is piped into municipal sewer systems, underground septic tanks, or portable sanitation devices. Wastewater in municipal systems is treated before being discharged into the environment, as required under the Clean Water Act. This...

Multiphasic modeling of charged solute transport across articular cartilage: Application of multi-zone finite-bath model.

PubMed

Arbabi, Vahid; Pouran, Behdad; Weinans, Harrie; Zadpoor, Amir A

2016-06-14

Charged and uncharged solutes penetrate through cartilage to maintain the metabolic function of chondrocytes and to possibly restore or further breakdown the cartilage tissue in different stages of osteoarthritis. In this study the transport of charged solutes across the various zones of cartilage was quantified, taken into account the physicochemical interactions between the solute and the cartilage constituents. A multiphasic finite-bath finite element (FE) model was developed to simulate equine cartilage diffusion experiments that used a negatively charged contrast agent (ioxaglate) in combination with serial micro-computed tomography (micro-CT) to measure the diffusion. By comparing the FE model with the experimental data both the diffusion coefficient of ioxaglate and the fixed charge density (FCD) were obtained. In the multiphasic model, cartilage was divided into multiple (three) zones to help understand how diffusion coefficient and FCD vary across cartilage thickness. The direct effects of charged solute-FCD interaction on diffusion were investigated by comparing the diffusion coefficients derived from the multiphasic and biphasic-solute models. We found a relationship between the FCD obtained by the multiphasic model and ioxaglate partitioning obtained from micro-CT experiments. Using our multi-zone multiphasic model, diffusion coefficient of the superficial zone was up to ten-fold higher than that of the middle zone, while the FCD of the middle zone was up to almost two-fold higher than that of the superficial zone. In conclusion, the developed finite-bath multiphasic model provides us with a non-destructive method by which we could obtain both diffusion coefficient and FCD of different cartilage zones. The outcomes of the current work will also help understand how charge of the bath affects the diffusion of a charged molecule and also predict the diffusion behavior of a charged solute across articular cartilage. Copyright © 2016 Elsevier Ltd. All rights reserved.

System and method for monitoring and controlling stator winding temperature in a de-energized AC motor

DOEpatents

Lu, Bin [Kenosha, WI; Luebke, Charles John [Sussex, WI; Habetler, Thomas G [Snellville, GA; Zhang, Pinjia [Atlanta, GA; Becker, Scott K [Oak Creek, WI

2011-12-27

A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings.

Multiphase Microstructure in a Metastability-Assisted Medium Carbon Alloy Steel

NASA Astrophysics Data System (ADS)

Liu, Cheng; Cui, Xixi; Yang, Chen

2018-05-01

A medium carbon alloy steel is processed by austenizing at 900 °C for 30 min, then rapid quenching into a patented quenching liquid and holding at 170 °C for 5 min, finally isothermally holding at 250 °C for different times. The morphology and mechanical properties are performed by using optical microscopy and scanning electron microscopy. A multiphase microstructure characterized by a mixture of lenticular prior martensite (PM), fine needle bainitic ferrite and filmy retained austenite (RA) is obtained. It is found that the PM formed firstly upon quenching can accelerate the subsequent bainitic transformation and promote refinement of multiphase colonies. The results show that an optimum mechanical property of a 4000.9 MPa bending strength and a 2030 MPa tensile strength is achieved at 250 °C for 120 min, which is attributed to the multiphase microstructural characteristics and a high product of the volume fraction of RA and the carbon content of austenite.

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

Aeloiza, Eddy C.; Burgos, Rolando P.

A step-down AC/AC converter for use in an electric distribution system includes at least one chopper circuit for each one of a plurality of phases of the AC power, each chopper circuit including a four-quadrant switch coupled in series between primary and secondary sides of the chopper circuit and a current-bidirectional two-quadrant switch coupled between the secondary side of the chopper circuit and a common node. Each current-bidirectional two-quadrant switch is oriented in the same direction, with respect to the secondary side of the corresponding chopper circuit and the common node. The converter further includes a control circuit configured tomore » pulse-width-modulate control inputs of the switches, to convert a first multiphase AC voltage at the primary sides of the chopper circuits to a second multiphase AC voltage at the secondary sides of the chopper circuits, the second multiphase AC voltage being lower in voltage than the first multiphase AC voltage.« less

Near-Field Sound Localization Based on the Small Profile Monaural Structure

PubMed Central

Kim, Youngwoong; Kim, Keonwook

2015-01-01

The acoustic wave around a sound source in the near-field area presents unconventional properties in the temporal, spectral, and spatial domains due to the propagation mechanism. This paper investigates a near-field sound localizer in a small profile structure with a single microphone. The asymmetric structure around the microphone provides a distinctive spectral variation that can be recognized by the dedicated algorithm for directional localization. The physical structure consists of ten pipes of different lengths in a vertical fashion and rectangular wings positioned between the pipes in radial directions. The sound from an individual direction travels through the nearest open pipe, which generates the particular fundamental frequency according to the acoustic resonance. The Cepstral parameter is modified to evaluate the fundamental frequency. Once the system estimates the fundamental frequency of the received signal, the length of arrival and angle of arrival (AoA) are derived by the designed model. From an azimuthal distance of 3–15 cm from the outer body of the pipes, the extensive acoustic experiments with a 3D-printed structure show that the direct and side directions deliver average hit rates of 89% and 73%, respectively. The closer positions to the system demonstrate higher accuracy, and the overall hit rate performance is 78% up to 15 cm away from the structure body. PMID:26580618

Unitized Regenerative Fuel Cell System Gas Storage/Radiator Development

NASA Technical Reports Server (NTRS)

Jakupca, Ian; Burke, Kenneth A.

2003-01-01

The ancillary components for Unitized Regenerative Fuel Cell (URFC) Energy Storage System are being developed at the NASA Glenn Research Center. This URFC system is unique in that it uses the surface area of the hydrogen and oxygen storage tanks as radiating heat surfaces for overall thermal control of the system. The waste heat generated by the URFC stack during charging and discharging is transferred from the cell stack to the surface of each tank by loop heat pipes. The heat pipes are coiled around each tank and covered with a thin layer of thermally conductive layer of carbon composite. The thin layer of carbon composite acts as a fin structure that spreads the heat away from the heat pipe and across the entire tank surface. Two different sized commercial grade composite tanks were constructed with integral heat pipes and tested in a thermal vacuum chamber to examine the feasibility of using the storage tanks as system radiators. The storage radiators were subjected to different steady-state heat loads and varying heat load profiles. The surface emissivity and specific heat capacity of each tank were calculated. The results were incorporated into a model that simulates the performance of similar radiators using lightweight, space rated carbon composite tanks.

Heat Rejection Concepts for Lunar Fission Surface Power Applications

NASA Technical Reports Server (NTRS)

Siamidis, John

2006-01-01

This paper describes potential heat rejection design concepts for lunar surface Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for surface power applications. Surface reactors may be used for the moon to power human outposts enabling extended stays and closed loop life support. The Brayton Heat Rejection System (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Space Brayton conversion system designs tend to optimize at efficiencies of about 20 to 25 percent with radiator temperatures in the 400 K to 600 K range. A notional HRS was developed for a 100 kWe-class Brayton power system that uses a pumped water heat transport loop coupled to a water heat pipe radiator. The radiator panels employ a tube and fin construction consisting of regularly-spaced circular heat pipes contained within two composite facesheets. The water heat pipes interface to the coolant through curved sections partially contained within the cooling loop. The paper evaluates various design parameters including radiator panel orientation, coolant flow path, and facesheet thickness. Parameters were varied to compare design options on the basis of H2O pump pressure rise and required power, heat pipe unit power and radial flux, radiator area, radiator panel areal mass, and overall HRS mass.

Enhanced heat transfer with full circumferential ribs in helical pipe

NASA Astrophysics Data System (ADS)

Chang, S. W.; Su, L. M.; Yang, T. L.

2002-08-01

This paper describes an experimental study of heat transfers in the smooth-walled and rib-roughened helical pipes with reference to the design of enhanced cooling passages in the cylinder head and liner of a marine propulsive diesel engine. The manner in which the repeated ribs modify the forced heat convection in the helical pipe is considered for the case where the flow is turbulent upon entering the coil but laminar in further downstream. A selection of experimental results illustrates the individual and interactive effects of Dean vortices and rib-flows on heat transfer along the inner and outer helixes of coils. The experimental-based observations reveal that the centrifugal force modifies the heat transfer in a manner to generate circumferential heat transfer variation with better cooling performance on the outer edge relative to its inner counterpart even with the agitated flow field caused by the repeated ribs. Heat transfer augmentation factor in the range of 1.3 - 3 times of the smooth-walled level is achieved using the present ribbing geometry. A set of empirical correlations based on the experimental data has been developed to permit the evaluation of heat transfers along the inner and outer helixes of the smooth-walled and rib-roughened helical pipes.

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

Gerard, R.; Malekian, C.; Meessen, O.

The Leak Before Break (LBB) concept allows to eliminate from the design basis the double-ended guillotine break of the primary loop piping, provided it can be demonstrated by a fracture mechanics analysis that a through-wall flaw, of a size giving rise to a leakage still well detectable by the plant leak detection systems, remains stable even under accident conditions (including the Safe Shutdown Earthquake (SSE)). This concept was successfully applied to the primary loop piping of several Belgian Pressurized Water Reactor (PWR) units, operated by the Utility Electrabel. One of the main benefits is to permit justification of supports inmore » the primary loop and justification of the integrity of the reactor pressure vessel and internals in case of a Loss Of Coolant Accident (LOCA) in stretch-out conditions. For two of the Belgian PWR units, the LBB approach also made it possible to reduce the number of large hydraulic snubbers installed on the primary coolant pumps. Last but not least, the LBB concept also facilitates the steam generator replacement operations, by eliminating the need for some pipe whip restraints located close to the steam generator. In addition to the U.S. regulatory requirements, the Belgian safety authorities impose additional requirements which are described in details in a separate paper. An novel aspect of the studies performed in Belgium is the way in which residual loads in the primary loop are taken into account. Such loads may result from displacements imposed to close the primary loop in a steam generator replacement operation, especially when it is performed using the {open_quote}two cuts{close_quotes} technique. The influence of such residual loads on the LBB margins is discussed in details and typical results are presented.« less

How Galaxies Acquire their Gas: A Map of Multiphase Accretion and Feedback in Gaseous Galaxy Halos

NASA Astrophysics Data System (ADS)

Tumlinson, Jason

2009-07-01

We propose to address two of the biggest open questions in galaxy formation - how galaxies acquire their gas and how they return it to the IGM - with a concentrated COS survey of diffuse multiphase gas in the halos of SDSS galaxies at z = 0.15 - 0.35. Our chief science goal is to establish a basic set of observational facts about the physical state, metallicity, and kinematics of halo gas, including the sky covering fraction of hot and cold material, the metallicity of infall and outflow, and correlations with galaxy stellar mass, type, and color - all as a function of impact parameter from 10 - 150 kpc. Theory suggests that the bimodality of galaxy colors, the shape of the luminosity function, and the mass-metallicity relation are all influenced at a fundamental level by accretion and feedback, yet these gas processes are poorly understood and cannot be predicted robustly from first principles. We lack even a basic observational assessment of the multiphase gaseous content of galaxy halos on 100 kpc scales, and we do not know how these processes vary with galaxy properties. This ignorance is presently one of the key impediments to understanding galaxy formation in general. We propose to use the high-resolution gratings G130M and G160M on the Cosmic Origins Spectrograph to obtain sensitive column density measurements of a comprehensive suite of multiphase ions in the spectra of 43 z < 1 QSOs lying behind 43 galaxies selected from the Sloan Digital Sky Survey. In aggregate, these sightlines will constitute a statistically sound map of the physical state and metallicity of gaseous halos, and subsets of the data with cuts on galaxy mass, color, and SFR will seek out predicted variations of gas properties with galaxy properties. Our interpretation of these data will be aided by state-of-the-art hydrodynamic simulations of accretion and feedback, in turn providing information to refine and test such models. We will also use Keck, MMT, and Magellan {as needed} to obtain optical spectra of the QSOs to measure cold gas with Mg II, and optical spectra of the galaxies to measure SFRs and to look for outflows. In addition to our other science goals, these observations will help place the Milky Way's population of multiphase, accreting High Velocity Clouds {HVCs} into a global context by identifying analogous structures around other galaxies. Our program is designed to make optimal use of the unique capabilities of COS to address our science goals and also generate a rich dataset of other absorption-line systems along a significant total pathlength through the IGM {Delta z 20}.

36 CFR 14.70 - Statutory authority.

Code of Federal Regulations, 2010 CFR

2010-07-01

... electrical plants, poles, and lines for the generation and distribution of electrical power, and for telephone and telegraph purposes, and for pipe lines, canals, ditches, water plants, and other purposes to the extent of the ground occupied by such canals, ditches, water plants, or other works permitted...

36 CFR 14.70 - Statutory authority.

Code of Federal Regulations, 2011 CFR

2011-07-01

... electrical plants, poles, and lines for the generation and distribution of electrical power, and for telephone and telegraph purposes, and for pipe lines, canals, ditches, water plants, and other purposes to the extent of the ground occupied by such canals, ditches, water plants, or other works permitted...

A Longitudinal Mode Electromagnetic Acoustic Transducer (EMAT) Based on a Permanent Magnet Chain for Pipe Inspection

PubMed Central

Cong, Ming; Wu, Xinjun; Qian, Chunqiao

2016-01-01

A new electromagnetic acoustic transducer (EMAT) design, employing a special structure of the permanent magnet chain, is proposed to generate and receive longitudinal guided waves for pipe inspection based on the magnetostriction mechanism. Firstly, a quantitative analysis of the excitation forces shows the influence of the radial component can be ignored. Furthermore, as the axial component of the static magnetic field is dominant, a method of solenoid testing coils connected in series is adopted to increase the signal amplitude. Then, two EMAT configurations are developed to generate and receive the L(0,2) guided wave mode. The experimental results show the circumferential notch can be identified and located successfully. Finally, a detailed investigation of the performance of the proposed EMATs is given. Compared to the conventional EMAT configuration, the proposed configurations have the advantages of small volume, light weight, easy installation and portability, which is helpful to improve inspection efficiency. PMID:27213400

Incorporating Water Boiling in the Numerical Modelling of Thermal Remediation by Electrical Resistance Heating

NASA Astrophysics Data System (ADS)

Molnar, I. L.; Krol, M.; Mumford, K. G.

2017-12-01

Developing numerical models for subsurface thermal remediation techniques - such as Electrical Resistive Heating (ERH) - that include multiphase processes such as in-situ water boiling, gas production and recovery has remained a significant challenge. These subsurface gas generation and recovery processes are driven by physical phenomena such as discrete and unstable gas (bubble) flow as well as water-gas phase mass transfer rates during bubble flow. Traditional approaches to multiphase flow modeling soil remain unable to accurately describe these phenomena. However, it has been demonstrated that Macroscopic Invasion Percolation (MIP) can successfully simulate discrete and unstable gas transport1. This has lead to the development of a coupled Electro Thermal-MIP Model2 (ET-MIP) capable of simulating multiple key processes in the thermal remediation and gas recovery process including: electrical heating of soil and groundwater, water flow, geological heterogeneity, heating-induced buoyant flow, water boiling, gas bubble generation and mobilization, contaminant mass transport and removal, and additional mechanisms such as bubble collapse in cooler regions. This study presents the first rigorous validation of a coupled ET-MIP model against two-dimensional water boiling and water/NAPL co-boiling experiments3. Once validated, the model was used to explore the impact of water and co-boiling events and subsequent gas generation and mobilization on ERH's ability to 1) generate, expand and mobilize gas at boiling and NAPL co-boiling temperatures, 2) efficiently strip contaminants from soil during both boiling and co-boiling. In addition, a quantification of the energy losses arising from steam generation during subsurface water boiling was examined with respect to its impact on the efficacy of thermal remediation. While this study specifically targets ERH, the study's focus on examining the fundamental mechanisms driving thermal remediation (e.g., water boiling) renders these results applicable to a wide range of thermal and gas-based remediation techniques. 1. Mumford, K. G., et al. (2010), Adv. Water Resour. 2010, 33 (4), 504-513. 2. Krol, M. M., et al. (2011), Adv. Water Resour. 2011, 34 (4), 537-549. 3. Hegele, P. R. and Mumford, K. G. Journal of Contaminant Hydrology 2014, 165, 24-36.

Non-contact modal testing by the electromagnetic acoustic principle: Applications to bending and torsional vibrations of metallic pipes

NASA Astrophysics Data System (ADS)

Kim, Hongjin; Park, Chan Il; Lee, Sun Ho; Kim, Yoon Young

2013-02-01

This work aims to investigate a possibility of non-contact vibration modal testing for bending and torsional motions of cylindrical bodies such as pipes. Here, a transducer operated by the electromagnetic acoustic coupling principle is newly devised. Depending on vibration modes, bending or torsional, different magnetic circuit configurations are employed to fabricate the transducer. The main characteristic of the proposed transducer is non-contact vibration generation in a test specimen without any mechanical movement of the actuating unit. It can be also used as a non-contact sensing unit if necessary. The validity and the performance of the proposed non-contact modal testing method are checked with several experiments.

Credit BG. View west of Test Stand "D" complex, with ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Credit BG. View west of Test Stand "D" complex, with ends of Dd (left) and Dy (right) station ejectors in view. Steam piping from accumulator (sphere) to ejectors is apparent; long horizontal loops in the pipes permit expansion and contraction without special joints. The small platform straddling the Dd ejector (near the accumulator) was originally constructed for a "Hyprox" steam generator which supplied steam to the Dd ejector before the accumulator and Dy stand were built. Note ejectors on top of interstage condenser in Test Stand "D" tower. Metal shed in far right background is for storage - Jet Propulsion Laboratory Edwards Facility, Test Stand D, Edwards Air Force Base, Boron, Kern County, CA

Directional antennas for electromagnetic mapping in a borehole

DOEpatents

Reagor, David Wesley; Nguyen, Doan Ngoc; Ashworth, Stephen Paul

2017-05-02

A bottom hole assembly used for a field operation is disclosed herein. The bottom hole assembly can include at least one directional antenna disposed on an outer surface of a first tubing pipe of a tubing string, where the at least one directional antenna receives a first electric current from at least one power source, where the first electric current generates a first magnetic field that radiates from the at least one directional antenna into a formation. The bottom hole assembly can also include at least one receiver disposed on a second tubing pipe of the tubing string, where the at least one receiver receives the first magnetic field returning from the formation.

Free-piston Stirling Engine system considerations for various space power applications

NASA Technical Reports Server (NTRS)

Dochat, George R.; Dhar, Manmohan

1991-01-01

Free-Piston Stirling Engines (FPSE) have the potential to provide high reliability, long life, and efficient operation. Therefore, they are excellent candidates for the dynamic power conversion module of a space-based, power-generating system. FPSE can be coupled with many potential heat sources (radioisotope, solar, or nuclear reactor), various heat input systems (pumped loop, heat pipe), heat rejection (pumped loop or heat pipe), and various power management and distribution systems (ac, dc, high or low voltage, and fixed or variable load). This paper reviews potential space missions that can be met using free-piston Stirling engines and discusses options of various system integration approaches. This paper briefly outlines the program and recent progress.

Numerical simulation of two-phase slug flow with liquid carryover in different diameter ratio T-junction

NASA Astrophysics Data System (ADS)

Pao, W.; Hon, L.; Saieed, A.; Ban, S.

2017-10-01

A smaller diameter conduit pointing at 12 o’clock position is typically hot-tapped to a horizontal laying production header in offshore platform to tap produced gas for downstream process train. This geometric feature is commonly known as T-junction. The nature of multiphase fluid splitting at the T-junction is a major operational challenge due to unpredictable production environment. Often, excessive liquid carryover occurs in the T-junction, leading to complete platform trip and halt production. This is because the downstream process train is not designed to handle excessive liquid. The objective of this research is to quantify the effect of different diameter ratio on phase separation efficiency in T-junction. The liquid carryover is modelled as two-phase air-water flow using Eulerian Mixture Model coupled with Volume of Fluid Method to mimic the slug flow in the main pipe. The focus in this paper is 0.0254 m (1 inch) diameter horizontal main arm and vertical branch arm with diameter ratio of 1.0, 0.5 and 0.3. The present research narrowed the investigation to only slug flow regime using Baker’s map as reference. The investigation found that, contrary to common believe, smaller diameter ratio T-junction perform worse than larger diameter ratio T-junction.

Magnetohydrodynamic flow and heat transfer around a heated cylinder of arbitrary conductivity

NASA Astrophysics Data System (ADS)

Tassone, A.; Nobili, M.; Caruso, G.

2017-11-01

The interaction of the liquid metal with the plasma confinement magnetic field constitutes a challenge for the design of fusion reactor blankets, due to the arise of MHD effects: increased pressure drops, heat transfer suppression, etc. To overcome these issues, a dielectric fluid can be employed as coolant for the breeding zone. A typical configuration involves pipes transverse to the liquid metal flow direction. This numerical study is conducted to assess the influence of pipe conductivity on the MHD flow and heat transfer. The CFD code ANSYS CFX was employed for this purpose. The fluid is assumed to be bounded by rectangular walls with non-uniform thickness and subject to a skewed magnetic field with the main component aligned with the cylinder axis. The simulations were restricted to Re = (20; 40) and M = (10; 50). Three different scenarios for the obstacle were considered: perfectly insulating, finite conductivity and perfectly conducting. The electrical conductivity was found to affect the channel pressure penalty due to the obstacle insertion only for M = 10 and just for the two limiting cases. A general increment of the heat transfer with M was found due to the tendency of the magnetic field to equalize the flow rate between the sub-channels individuated by the pipe. The best results were obtained with the insulating pipe, due to the reduced electromagnetic drag. The generation of counter-rotating vortices close to the lateral duct walls was observed for M = 50 and perfectly conducting pipe as a result of the modified currents distribution.

Automated GMA welding of austenitic stainless steel pipe

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

Tahash, G.J.

1996-12-31

The study focused on reducing weld cycle times of rotatable subassemblies (spools) using automated welding equipment. A unique automatic Gas Metal Arc Welding (GMAW) system was used to produce a series of pipe to pipe welds on 141 mm (5 in.) schedule 80 seamless stainless steel pipe. After manual tack welding, the adaptive control system welded the root pass of the argon gas backed open vee groove circumferential butt joints in the IG rotated position with short circuiting transfer GMAW. The fill and cover passes were welded automatically with spray transfer GMAW. Automatic welding cycle times were found to bemore » 50--80 percent shorter than the current techniques of roll welding with Shielded Metal Arc Welding and manual Gas Tungsten Arc Welding. Weld costs ({Brit_pounds}/m), including amortization, for the various systems were compared. The cost of automated GMA welds was virtually equivalent to the most competitive methods while depositing 75% more filler metal per year. Also investigated were metallurgical effects generated by weld thermal cycling, and the associated effects on mechanical properties of the weld joint. Mechanical properties of the welds met or exceeded those of the base metal. Sensitization of the pipe did not occur in the heat affected zone (HAZ), based on the absence of evidence of intergranular attack in modified Strauss corrosion tests and despite the fact of interpass temperatures well above recommended maximums. Cooling rates of 3--5 C/s in the heat affected zone of the four pass welds were measured by thermocouple technique and found to be within the non-sensitizing range for this alloy.« less

Power generation by high head water in a building using micro hydro turbine-a greener approach.

PubMed

M M S R S, Bhargav; V, Ratna Kishore; S P, Anbuudayasankar; K, Balaji

2016-05-01

Demand for green energy production is arising all over the world. A lot of emphasis is laid in making the buildings green. Even a small amount of energy savings made contribute to saving the environment. In this study, an idea is proposed and studied to extract power from the high head water in the pipelines of a building. A building of height 15 m is considered for this study. Water flowing in the pipe has sufficient energy to run a micro hydro turbine. The feasibility of producing electrical energy from the energy of pipe water is found. The motivation is to find the feasibility of generating power using a low-cost turbine. The experimental setup consists of micro turbine of 135 mm diameter coupled to a 12-V DC generator; LEDs and resistors are employed to validate the results. The theoretical calculations were presented using the fundamental equations of fluid mechanics. The theoretical results are validated using experimental and numerical results using CFD simulation. In addition, exergy analysis has been carried out to quantify the irreversibilities during the process in the system.

A multiphase model for tissue construct growth in a perfusion bioreactor.

PubMed

O'Dea, R D; Waters, S L; Byrne, H M

2010-06-01

The growth of a cell population within a rigid porous scaffold in a perfusion bioreactor is studied, using a three-phase continuum model of the type presented by Lemon et al. (2006, Multiphase modelling of tissue growth using the theory of mixtures. J. Math. Biol., 52, 571-594) to represent the cell population (and attendant extracellular matrix), culture medium and porous scaffold. The bioreactor system is modelled as a 2D channel containing the cell-seeded rigid porous scaffold (tissue construct) which is perfused with culture medium. The study concentrates on (i) the cell-cell and cell-scaffold interactions and (ii) the impact of mechanotransduction mechanisms on construct composition. A numerical and analytical analysis of the model equations is presented and, depending upon the relative importance of cell aggregation and repulsion, markedly different cell movement is revealed. Additionally, mechanotransduction effects due to cell density, pressure and shear stress-mediated tissue growth are shown to generate qualitative differences in the composition of the resulting construct. The results of our simulations indicate that this model formulation (in conjunction with appropriate experimental data) has the potential to provide a means of identifying the dominant regulatory stimuli in a cell population.

Computer simulations of comet- and asteroidlike bodies passing through the Venusian atmosphere: Preliminary results on atmospheric and ground shock effects

NASA Technical Reports Server (NTRS)

Roddy, D.; Hatfield, D.; Hassig, P.; Rosenblatt, M.; Soderblom, L.; Dejong, E.

1992-01-01

We have completed computer simulations that model shock effects in the venusian atmosphere caused during the passage of two cometlike bodies 100 m and 1000 m in diameter and an asteroidlike body 10 km in diameter. Our objective is to examine hypervelocity-generated shock effects in the venusian atmosphere for bodies of different types and sizes in order to understand the following: (1) their deceleration and depth of penetration through the atmosphere; and (2) the onset of possible ground-surface shock effects such as splotches, craters, and ejecta formations. The three bodies were chosen to include both a range of general conditions applicable to Venus as well as three specific cases of current interest. These calculations use a new multiphase computer code (DICE-MAZ) designed by California Research & Technology for shock-dynamics simulations in complex environments. The code was tested and calibrated in large-scale explosion, cratering, and ejecta research. It treats a wide range of different multiphase conditions, including material types (vapor, melt, solid), particle-size distributions, and shock-induced dynamic changes in velocities, pressures, temperatures (internal energies), densities, and other related parameters, all of which were recorded in our calculations.

A Multi-Phase Based Fluid-Structure-Microfluidic interaction sensor for Aerodynamic Shear Stress

NASA Astrophysics Data System (ADS)

Hughes, Christopher; Dutta, Diganta; Bashirzadeh, Yashar; Ahmed, Kareem; Qian, Shizhi

2014-11-01

A novel innovative microfluidic shear stress sensor is developed for measuring shear stress through multi-phase fluid-structure-microfluidic interaction. The device is composed of a microfluidic cavity filled with an electrolyte liquid. Inside the cavity, two electrodes make electrochemical velocimetry measurements of the induced convection. The cavity is sealed with a flexible superhydrophobic membrane. The membrane will dynamically stretch and flex as a result of direct shear cross-flow interaction with the seal structure, forming instability wave modes and inducing fluid motion within the microfluidic cavity. The shear stress on the membrane is measured by sensing the induced convection generated by membrane deflections. The advantages of the sensor over current MEMS based shear stress sensor technology are: a simplified design with no moving parts, optimum relationship between size and sensitivity, no gaps such as those created by micromachining sensors in MEMS processes. We present the findings of a feasibility study of the proposed sensor including wind-tunnel tests, microPIV measurements, electrochemical velocimetry, and simulation data results. The study investigates the sensor in the supersonic and subsonic flow regimes. Supported by a NASA SBIR phase 1 contract.

Electromagnetic fields in small systems from a multiphase transport model

NASA Astrophysics Data System (ADS)

Zhao, Xin-Li; Ma, Yu-Gang; Ma, Guo-Liang

2018-02-01

We calculate the electromagnetic fields generated in small systems by using a multiphase transport (AMPT) model. Compared to A +A collisions, we find that the absolute electric and magnetic fields are not small in p +Au and d +Au collisions at energies available at the BNL Relativistic Heavy Ion Collider and in p +Pb collisions at energies available at the CERN Large Hadron Collider. We study the centrality dependencies and the spatial distributions of electromagnetic fields. We further investigate the azimuthal fluctuations of the magnetic field and its correlation with the fluctuating geometry using event-by-event simulations. We find that the azimuthal correlation 〈" close="〉cos(ϕα+ϕβ-2 ΨRP)〉">cos2 (ΨB-Ψ2) between the magnetic field direction and the second-harmonic participant plane is almost zero in small systems with high multiplicities, but not in those with low multiplicities. This indicates that the charge azimuthal correlation is not a valid probe to study the chiral magnetic effect (CME) in small systems with high multiplicities. However, we suggest searching for possible CME effects in small systems with low multiplicities.

An improved method for estimating capillary pressure from 3D microtomography images and its application to the study of disconnected nonwetting phase

NASA Astrophysics Data System (ADS)

Li, Tianyi; Schlüter, Steffen; Dragila, Maria Ines; Wildenschild, Dorthe

2018-04-01

We present an improved method for estimating interfacial curvatures from x-ray computed microtomography (CMT) data that significantly advances the potential for this tool to unravel the mechanisms and phenomena associated with multi-phase fluid motion in porous media. CMT data, used to analyze the spatial distribution and capillary pressure-saturation (Pc-S) relationships of liquid phases, requires accurate estimates of interfacial curvature. Our improved method for curvature estimation combines selective interface modification and distance weighting approaches. It was verified against synthetic (analytical computer-generated) and real image data sets, demonstrating a vast improvement over previous methods. Using this new tool on a previously published data set (multiphase flow) yielded important new insights regarding the pressure state of the disconnected nonwetting phase during drainage and imbibition. The trapped and disconnected non-wetting phase delimits its own hysteretic Pc-S curve that inhabits the space within the main hysteretic Pc-S loop of the connected wetting phase. Data suggests that the pressure of the disconnected, non-wetting phase is strongly modified by the pore geometry rather than solely by the bulk liquid phase that surrounds it.

Dual domain material point method for multiphase flows

NASA Astrophysics Data System (ADS)

Zhang, Duan

2017-11-01

Although the particle-in-cell method was first invented in the 60's for fluid computations, one of its later versions, the material point method, is mostly used for solid calculations. Recent development of the multi-velocity formulations for multiphase flows and fluid-structure interactions requires the Lagrangian capability of the method be combined with Eulerian calculations for fluids. Because of different numerical representations of the materials, additional numerical schemes are needed to ensure continuity of the materials. New applications of the method to compute fluid motions have revealed numerical difficulties in various versions of the method. To resolve these difficulties, the dual domain material point method is introduced and improved. Unlike other particle based methods, the material point method uses both Lagrangian particles and Eulerian mesh, therefore it avoids direct communication between particles. With this unique property and the Lagrangian capability of the method, it is shown that a multiscale numerical scheme can be efficiently built based on the dual domain material point method. In this talk, the theoretical foundation of the method will be introduced. Numerical examples will be shown. Work sponsored by the next generation code project of LANL.

MULTIPHASE FLOW AND TRANSPORT IN POROUS MEDIA

EPA Science Inventory

Multiphase flow and transport of compositionally complex fluids in geologic media is of importance in a number of applied problems which have major social and economic effects. n petroleum reservoir engineering efficient recovery of energy reserves is the principal goal. nfortuna...

FINITE-ELEMENT ANALYSIS OF MULTIPHASE IMMISCIBLE FLOW THROUGH SOILS

EPA Science Inventory

A finite-element model is developed for multiphase flow through soil involving three immiscible fluids: namely, air, water, and a nonaqueous phase liquid (NAPL). A variational method is employed for the finite-element formulation corresponding to the coupled differential equation...

Multiphase organic synthesis in microchannel reactors.

PubMed

Kobayashi, Juta; Mori, Yuichiro; Kobayashi, Shū

2006-07-17

"Miniaturization" is one of the most important aspects in today's technology. Organic chemistry is no exception. The search for highly effective, controllable, environmentally friendly methods for preparing products is of prime importance. The development of multiphase organic reactions in microchannel reactors has gained significant importance in recent years to allow novel reactivity, and has led to many fruitful results that are not attainable in conventional reactors. This Focus Review aims to shed light on how effectively multiphase organic reactions can be conducted with microchannel reactors by providing examples of recent remarkable studies, which have been grouped on the basis of the phases involved.

Continuum-Kinetic Models and Numerical Methods for Multiphase Applications

NASA Astrophysics Data System (ADS)

Nault, Isaac Michael

This thesis presents a continuum-kinetic approach for modeling general problems in multiphase solid mechanics. In this context, a continuum model refers to any model, typically on the macro-scale, in which continuous state variables are used to capture the most important physics: conservation of mass, momentum, and energy. A kinetic model refers to any model, typically on the meso-scale, which captures the statistical motion and evolution of microscopic entitites. Multiphase phenomena usually involve non-negligible micro or meso-scopic effects at the interfaces between phases. The approach developed in the thesis attempts to combine the computational performance benefits of a continuum model with the physical accuracy of a kinetic model when applied to a multiphase problem. The approach is applied to modeling a single particle impact in Cold Spray, an engineering process that intimately involves the interaction of crystal grains with high-magnitude elastic waves. Such a situation could be classified a multiphase application due to the discrete nature of grains on the spatial scale of the problem. For this application, a hyper elasto-plastic model is solved by a finite volume method with approximate Riemann solver. The results of this model are compared for two types of plastic closure: a phenomenological macro-scale constitutive law, and a physics-based meso-scale Crystal Plasticity model.

Sulfur and Metal Fertilization of the Lower Continental Crust

NASA Technical Reports Server (NTRS)

Locmelis, Marek; Fiorentini, Marco L.; Rushmer, Tracy; Arevalo, Ricardo, Jr.; Adam, John; Denyszyn, Steven W.

2015-01-01

Mantle-derived melts and metasomatic fluids are considered to be important in the transport and distribution of trace elements in the subcontinental lithospheric mantle. However, the mechanisms that facilitate sulfur and metal transfer from the upper mantle into the lower continental crust are poorly constrained. This study addresses this knowledge gap by examining a series of sulfide- and hydrous mineral-rich alkaline mafic-ultramafic pipes that intruded the lower continental crust of the Ivrea-Verbano Zone in the Italian Western Alps. The pipes are relatively small (<300 m diameter) and primarily composed of a matrix of subhedral to anhedral amphibole (pargasite), phlogopite and orthopyroxene that enclose sub-centimeter-sized grains of olivine. The 1 to 5 m wide rim portions of the pipes locally contain significant blebby and disseminated Fe-Ni-Cu-PGE sulfide mineralization.Stratigraphic relationships, mineral chemistry, geochemical modeling and phase equilibria suggest that the pipes represent open-ended conduits within a large magmatic plumbing system. The earliest formed pipe rocks were olivine-rich cumulates that reacted with hydrous melts to produce orthopyroxene, amphibole and phlogopite.Sulfides precipitated as immiscible liquid droplets that were retained within a matrix of silicate crystals and scavenged metals from the percolating hydrous melt. New high-precision chemical abrasion TIMS-UPb dating of zircons from one of the pipes indicates that these pipes were emplaced at 249.1+/-0.2 Ma, following partial melting of lithospheric mantle pods that were metasomatized during the Eo-Variscan oceanic to continental subduction (approx. 420-310 Ma). The thermal energy required to generate partial melting of the metasomatized mantle was most likely derived from crustal extension, lithospheric decompression and subsequent asthenospheric rise during the orogenic collapse of the Variscan belt (<300 Ma). Unlike previous models, outcomes from this study suggest a significant temporal gap between the occurrence of mantle metasomatism, subsequent partial melting and emplacement of the pipes.We argue that this multi-stage process is a very effective mechanism to fertilize the commonly dry and refractory lower continental crust in metals and volatiles. During the four-dimensional evolution of the thermo-tectonic architecture of any given terrain, metals and volatiles stored in the lower continental crust may become available as sources for subsequent ore-forming processes, thus enhancing the prospectivity of continental block margins for a wide range of mineral systems.

Partnership in Innovative Preparation for Educators and Students (PIPES)

DTIC Science & Technology

2013-12-23

it? Sign up for this workshop to find out! You will construct a working wind generator to find out which turbine generates the most electricity...program an advanced robot that will accomplish a greater number of amazing tasks using additional sensors and commands. Requires some previous NXT...tech wireless networks and cell phones to solve a cyber-bullying mystery . Learn ways to stay safe online. 19 Kitchen Chemistry – Science and

Passage of downstream migrant American eels through an airlift-assisted deep bypass

USGS Publications Warehouse

Haro, Alexander J.; Watten, Barnaby J.; Noreika, John

2016-01-01

Traditional downstream guidance and bypass facilities for anadromous fishes (i.e., surface bypasses, surface guidance structures, and behavioral barriers) have frequently been ineffective for anguillid eels. Because eels typically spend the majority of their time near the bottom in the vicinity of intake structures, deep bypass structures with entrances near the bottom hold promise for increased effectiveness, thereby aiding in the recovery of this important species. A new design of a deep bypass system that uses airlift technology (the Conte Airlift Bypass) to induce flow in a bypass pipe was tested in a simulated intake entrance environment under controlled laboratory conditions. Water velocities of 0.9–1.5 m s−1 could be generated at the bypass entrance (opening with 0.073 m2 area), with corresponding flows through the bypass pipe of 0.07–0.11 m3 s−1. Gas saturation and hydrostatic pressure within the bypass pipe did not vary appreciably from a control (no air) condition under tested airflows. Migratory silver-phase American eels (Anguilla rostrata) tested during dark conditions readily located, entered, and passed through the bypass; initial avoidance rates (eels approaching but not entering the bypass entrance) were lower at higher entrance velocities. Eels that investigated the bypass pipe entrance tended to enter headfirst, but those that then exited the pipe upstream did so more frequently at lower entrance velocities. Eels appeared to swim against the flow while being transported downstream through the pipe; median transit times through the bypass for each test velocity ranged from 5.8 to 12.2 s, with transit time decreasing with increasing entrance velocity. Eels did not show strong avoidance of the vertical section of the pipe which contained injected air. No mortality or injury of bypassed eels was observed, and individual eels repeatedly passed through the bypass at rates of up to 40 passes per hour, suggesting that individuals do not avoid repeated entrainment through the bypass. Airlift technology appears to be a viable method for increasing passage effectiveness for American eels through a deep bypass system.

41 CFR 50-204.66 - Acetylene.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... (b) The piped systems for the in-plant transfer and distribution of acetylene shall be designed..., Vapors, Fumes, Dusts, and Mists § 50-204.66 Acetylene. (a) The in-plant transfer, handling, storage, and...) Plants for the generation of acetylene and the charging (filling) of acetylene cylinders shall be...

Machinist's Mate 1 and C: Rate Training Manual.

ERIC Educational Resources Information Center

Naval Training Command, Pensacola, FL.

The rate training manual covers the duties required to efficiently operate and maintain ship propulsion machinery and associated equipment and to maintain applicable records and reports. Chapters cover: turbines; reduction gears; steam-driven generators; heat exchangers and air ejectors; pumps; piping and valves; distilling plants; refrigeration…

Biofilm-Growing Bacteria Involved in the Corrosion of Concrete Wastewater Pipes: Protocols for Comparative Metagenomic Analyses

EPA Science Inventory

Advances in high-throughput next-generation sequencing (NGS) technology for direct sequencing of environmental DNA (i.e. shotgun metagenomics) is transforming the field of microbiology. NGS technologies are now regularly being applied in comparative metagenomic studies, which pr...

Myocardial perfusion in patients with suspected coronary artery disease: comparison between 320-MDCT and rubidium-82 PET.

PubMed

Dantas, Roberto Nery; Assuncao, Antonildes Nascimento; Marques, Ismar Aguiar; Fahel, Mateus Guimaraes; Nomura, Cesar Higa; Avila, Luiz Francisco Rodrigues; Giorgi, Maria Clementina Pinto; Soares, Jose; Meneghetti, Jose Claudio; Parga, Jose Rodrigues

2018-06-01

Despite advances in non-invasive myocardial perfusion imaging (MPI) evaluation, computed tomography (CT) multiphase MPI protocols have not yet been compared with the highly accurate rubidium-82 positron emission tomography ( 82 RbPET) MPI. Thus, this study aimed to evaluate agreement between 82 RbPET and 320-detector row CT (320-CT) MPI using a multiphase protocol in suspected CAD patients. Forty-four patients referred for MPI evaluation were prospectively enrolled and underwent dipyridamole stress 82 RbPET and multiphase 320-CT MPI (five consecutive volumetric acquisitions during stress). Statistical analyses were performed using the R software. There was high agreement for recognizing summed stress scores ≥ 4 (kappa 0.77, 95% CI 0.55-0.98, p < 0.001) and moderate for detecting SDS ≥ 2 (kappa 0.51, 95% CI 0.23-0.80, p < 0.001). In a per segment analysis, agreement was high for the presence of perfusion defects during stress and rest (kappa 0.75 and 0.82, respectively) and was moderate for impairment severity (kappa 0.58 and 0.65, respectively). The 320-CT protocol was safe, with low radiation burden (9.3 ± 2.4 mSv). There was a significant agreement between dipyridamole stress 320-CT MPI and 82 RbPET MPI in the evaluation of suspected CAD patients of intermediate risk. The multiphase 320-CT MPI protocol was feasible, diagnostic and with relatively low radiation exposure. • Rubidium-82 PET and 320-MDCT can perform MPI studies for CAD investigation. • There is high agreement between rubidium-82 PET and 320-MDCT for MPI assessment. • Multiphase CT perfusion protocols are feasible and with low radiation. • Multiphase CT perfusion protocols can identify image artefacts.

From the Lab to the real world : sources of error in UF {sub 6} gas enrichment monitoring

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

Lombardi, Marcie L.

2012-03-01

Safeguarding uranium enrichment facilities is a serious concern for the International Atomic Energy Agency (IAEA). Safeguards methods have changed over the years, most recently switching to an improved safeguards model that calls for new technologies to help keep up with the increasing size and complexity of today’s gas centrifuge enrichment plants (GCEPs). One of the primary goals of the IAEA is to detect the production of uranium at levels greater than those an enrichment facility may have declared. In order to accomplish this goal, new enrichment monitors need to be as accurate as possible. This dissertation will look at themore » Advanced Enrichment Monitor (AEM), a new enrichment monitor designed at Los Alamos National Laboratory. Specifically explored are various factors that could potentially contribute to errors in a final enrichment determination delivered by the AEM. There are many factors that can cause errors in the determination of uranium hexafluoride (UF{sub 6}) gas enrichment, especially during the period when the enrichment is being measured in an operating GCEP. To measure enrichment using the AEM, a passive 186-keV (kiloelectronvolt) measurement is used to determine the {sup 235}U content in the gas, and a transmission measurement or a gas pressure reading is used to determine the total uranium content. A transmission spectrum is generated using an x-ray tube and a “notch” filter. In this dissertation, changes that could occur in the detection efficiency and the transmission errors that could result from variations in pipe-wall thickness will be explored. Additional factors that could contribute to errors in enrichment measurement will also be examined, including changes in the gas pressure, ambient and UF{sub 6} temperature, instrumental errors, and the effects of uranium deposits on the inside of the pipe walls will be considered. The sensitivity of the enrichment calculation to these various parameters will then be evaluated. Previously, UF{sub 6} gas enrichment monitors have required empty pipe measurements to accurately determine the pipe attenuation (the pipe attenuation is typically much larger than the attenuation in the gas). This dissertation reports on a method for determining the thickness of a pipe in a GCEP when obtaining an empty pipe measurement may not be feasible. This dissertation studies each of the components that may add to the final error in the enrichment measurement, and the factors that were taken into account to mitigate these issues are also detailed and tested. The use of an x-ray generator as a transmission source and the attending stability issues are addressed. Both analytical calculations and experimental measurements have been used. For completeness, some real-world analysis results from the URENCO Capenhurst enrichment plant have been included, where the final enrichment error has remained well below 1% for approximately two months.« less

Calculation of critical heat transfer in horizontal evaporator pipes in cooling systems of high-rise buildings

NASA Astrophysics Data System (ADS)

Aksenov, Andrey; Malysheva, Anna

2018-03-01

An exact calculation of the heat exchange of evaporative surfaces is possible only if the physical processes of hydrodynamics of two-phase flows are considered in detail. Especially this task is relevant for the design of refrigeration supply systems for high-rise buildings, where powerful refrigeration equipment and branched networks of refrigerants are used. On the basis of experimental studies and developed mathematical model of asymmetric dispersed-annular flow of steam-water flow in horizontal steam-generating pipes, a calculation formula has been obtained for determining the boundaries of the zone of improved heat transfer and the critical value of the heat flux density. A new theoretical approach to the solution of the problem of the flow structure of a two-phase flow is proposed. The applied method of dissipative characteristics of a two-phase flow in pipes and the principle of a minimum rate of entropy increase in stabilized flows made it possible to obtain formulas that directly reflect the influence of the viscous characteristics of the gas and liquid media on their distribution in the flow. The study showed a significant effect of gravitational forces on the nature of the phase distribution in the cross section of the evaporative tubes. At a mass velocity of a two-phase flow less than 700 kg / m2s, the volume content of the liquid phase near the upper outer generating lines of the tube is almost an order of magnitude lower than the lower one. The calculation of the heat transfer crisis in horizontal evaporative tubes is obtained. The calculated dependence is in good agreement with the experimental data of the author and a number of foreign researchers. The formula generalizes the experimental data for pipes with the diameter of 6-40 mm in the pressure of 2-7 MPa.

NGSPanPipe: A Pipeline for Pan-genome Identification in Microbial Strains from Experimental Reads.

PubMed

Kulsum, Umay; Kapil, Arti; Singh, Harpreet; Kaur, Punit

2018-01-01

Recent advancements in sequencing technologies have decreased both time span and cost for sequencing the whole bacterial genome. High-throughput Next-Generation Sequencing (NGS) technology has led to the generation of enormous data concerning microbial populations publically available across various repositories. As a consequence, it has become possible to study and compare the genomes of different bacterial strains within a species or genus in terms of evolution, ecology and diversity. Studying the pan-genome provides insights into deciphering microevolution, global composition and diversity in virulence and pathogenesis of a species. It can also assist in identifying drug targets and proposing vaccine candidates. The effective analysis of these large genome datasets necessitates the development of robust tools. Current methods to develop pan-genome do not support direct input of raw reads from the sequencer machine but require preprocessing of reads as an assembled protein/gene sequence file or the binary matrix of orthologous genes/proteins. We have designed an easy-to-use integrated pipeline, NGSPanPipe, which can directly identify the pan-genome from short reads. The output from the pipeline is compatible with other pan-genome analysis tools. We evaluated our pipeline with other methods for developing pan-genome, i.e. reference-based assembly and de novo assembly using simulated reads of Mycobacterium tuberculosis. The single script pipeline (pipeline.pl) is applicable for all bacterial strains. It integrates multiple in-house Perl scripts and is freely accessible from https://github.com/Biomedinformatics/NGSPanPipe .

Bacterial community changes in copper and PEX drinking water pipeline biofilms under extra disinfection and magnetic water treatment.

PubMed

Inkinen, J; Jayaprakash, B; Ahonen, M; Pitkänen, T; Mäkinen, R; Pursiainen, A; Santo Domingo, J W; Salonen, H; Elk, M; Keinänen-Toivola, M M

2018-02-01

To study the stability of biofilms and water quality in pilot scale drinking water copper and PEX pipes in changing conditions (extra disinfection, magnetic water treatment, MWT). Next-generation sequencing (NGS) of 16S ribosomal RNA genes (rDNA) to describe total bacterial community and ribosomal RNA (rRNA) to describe active bacterial members in addition to traditional microbiological methods were applied. Biofilms from control copper and PEX pipes shared same most abundant bacteria (Methylobacterium spp., Sphingomonas spp., Zymomonas spp.) and average species diversities (Shannon 3·8-4·2) in rDNA and rRNA libraries, whereas few of the taxa differed by their abundance such as lower total Mycobacterium spp. occurrence in copper (<0·02%) to PEX (<0·2%) pipes. Extra disinfection (total chlorine increase from c. 0·5 to 1 mg l -1 ) affected total and active population in biofilms seen as decrease in many bacterial species and diversity (Shannon 2·7, P < 0·01, rRNA) and increase in Sphingomonas spp. as compared to control samples. Furthermore, extra-disinfected copper and PEX samples formed separate clusters in unweighted non-metric multidimensional scaling plot (rRNA) similarly to MWT-treated biofilms of copper (but not PEX) pipes that instead showed higher species diversity (Shannon 4·8, P < 0·05 interaction). Minor chlorine dose addition increased selection pressure and many species were sensitive to chlorination. Pipe material seemed to affect mycobacteria occurrence, and bacterial communities with MWT in copper but not in PEX pipes. This study using rRNA showed that chlorination affects especially active fraction of bacterial communities. Copper and PEX differed by the occurrence of some bacterial members despite similar community profiles. © 2017 The Society for Applied Microbiology.

NaK Variable Conductance Heat Pipe for Radioisotope Stirling Systems

NASA Technical Reports Server (NTRS)

Tarau, Calin; Anderson, William G.; Walker, Kara

2008-01-01

In a Stirling radioisotope power system, heat must continually be removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides most of this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending use of that convertor for the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) was designed to allow multiple stops and restarts of the Stirling convertor. In the design of the VCHP for the Advanced Stirling Radioisotope Generator, the VCHP reservoir temperature can vary between 40 and 120 C. While sodium, potassium, or cesium could be used as the working fluid, their melting temperatures are above the minimum reservoir temperature, allowing working fluid to freeze in the reservoir. In contrast, the melting point of NaK is -12 C, so NaK can't freeze in the reservoir. One potential problem with NaK as a working fluid is that previous tests with NaK heat pipes have shown that NaK heat pipes can develop temperature non-uniformities in the evaporator due to NaK's binary composition. A NaK heat pipe was fabricated to measure the temperature non-uniformities in a scale model of the VCHP for the Stirling Radioisotope system. The temperature profiles in the evaporator and condenser were measured as a function of operating temperature and power. The largest delta T across the condenser was 2S C. However, the condenser delta T decreased to 16 C for the 775 C vapor temperature at the highest heat flux applied, 7.21 W/ square cm. This decrease with increasing heat flux was caused by the increased mixing of the sodium and potassium in the vapor. This temperature differential is similar to the temperature variation in this ASRG heat transfer interface without a heat pipe, so NaK can be used as the VCHP working fluid.

KINEMATIC MODELING OF MULTIPHASE SOLUTE TRANSPORT IN THE VADOSE ZONE

EPA Science Inventory

The goal of this research was the development of a computationally efficient simulation model for multiphase flow of organic hazardous waste constituents in the shallow soil environment. Such a model is appropriate for investigation of fate and transport of organic chemicals intr...

MODELING MULTIPHASE ORGANIC CHEMICAL TRANSPORT IN SOILS AND GROUND WATER

EPA Science Inventory

Subsurface contamination due to immiscible organic liquids is a widespread problem which poses a serious threat to ground-water resources. n order to understand the movement of such materials in the subsurface, a mathematical model was developed for multiphase flow and multicompo...

Minnesota Multiphasic Personality Inventory Differences between Terminators and Continuers in Youth Counseling

ERIC Educational Resources Information Center

Horton, Margaret; Kriauciunas, Romualdas

1970-01-01

Thirty-two terminators and 28 continuers in personal counseling were compared on three measures derived from precounseling Minnesota Multiphasic Personality Inventory (MMPI) data. It was concluded that poor adolescent prospects for counseling are those characterized by marked rebellion toward authority. (Author)

Onboard Inert Gas Generation System/Onboard Oxygen Gas Generation System (OBIGGS/OBOGS) Study. Part 1; Aircraft System Requirements

NASA Technical Reports Server (NTRS)

Reynolds, Thomas L.; Bailey, Delbert B.; Lewinski, Daniel F.; Roseburg, Conrad M.; Palaszewski, Bryan (Technical Monitor)

2001-01-01

The purpose of this technology assessment is to define a multiphase research study program investigating Onboard Inert Gas Generation Systems (OBIGGS) and Onboard Oxygen Generation Systems (OBOGS) that would identify current airplane systems design and certification requirements (Subtask 1); explore state-of-the-art technology (Subtask 2); develop systems specifications (Subtask 3); and develop an initial system design (Subtask 4). If feasible, consideration may be given to the development of a prototype laboratory test system that could potentially be used in commercial transport aircraft (Subtask 5). These systems should be capable of providing inert nitrogen gas for improved fire cargo compartment fire suppression and fuel tank inerting and emergency oxygen for crew and passenger use. Subtask I of this research study, presented herein, defines current production aircraft certification requirements and design objectives necessary to meet mandatory FAA certification requirements and Boeing design and performance specifications. These requirements will be utilized for baseline comparisons for subsequent OBIGGS/OBOGS application evaluations and assessments.

The validity of multiphase DNS initialized on the basis of single--point statistics

NASA Astrophysics Data System (ADS)

Subramaniam, Shankar

1999-11-01

A study of the point--process statistical representation of a spray reveals that single--point statistical information contained in the droplet distribution function (ddf) is related to a sequence of single surrogate--droplet pdf's, which are in general different from the physical single--droplet pdf's. The results of this study have important consequences for the initialization and evolution of direct numerical simulations (DNS) of multiphase flows, which are usually initialized on the basis of single--point statistics such as the average number density in physical space. If multiphase DNS are initialized in this way, this implies that even the initial representation contains certain implicit assumptions concerning the complete ensemble of realizations, which are invalid for general multiphase flows. Also the evolution of a DNS initialized in this manner is shown to be valid only if an as yet unproven commutation hypothesis holds true. Therefore, it is questionable to what extent DNS that are initialized in this manner constitute a direct simulation of the physical droplets.

Modelling the structure of Zr-rich Pb(Zr1-xTix)O3, x = 0.4 by a multiphase approach.

PubMed

Bogdanov, Alexander; Mysovsky, Andrey; Pickard, Chris J; Kimmel, Anna V

2016-10-12

Solid solution perovskite Pb(Zr 1-x Ti x )O 3 (PZT) is an industrially important material. Despite the long history of experimental and theoretical studies, the structure of this material is still under intensive discussion. In this work, we have applied structure searching coupled with density functional theory methods to provide a multiphase description of this material at x = 0.4. We demonstrate that the permutational freedom of B-site cations leads to the stabilisation of a variety of local phases reflecting a relatively flat energy landscape of PZT. Using a set of predicted local phases we reproduce the experimental pair distribution function (PDF) profile with high accuracy. We introduce a complex multiphase picture of the structure of PZT and show that additional monoclinic and rhombohedral phases account for a better description of the experimental PDF profile. We propose that such a multiphase picture reflects the entropy reached in the sample during the preparation process.

Consistent multiphase-field theory for interface driven multidomain dynamics

NASA Astrophysics Data System (ADS)

Tóth, Gyula I.; Pusztai, Tamás; Gránásy, László

2015-11-01

We present a multiphase-field theory for describing pattern formation in multidomain and/or multicomponent systems. The construction of the free energy functional and the dynamic equations is based on criteria that ensure mathematical and physical consistency. We first analyze previous multiphase-field theories and identify their advantageous and disadvantageous features. On the basis of this analysis, we introduce a way of constructing the free energy surface and derive a generalized multiphase description for arbitrary number of phases (or domains). The presented approach retains the variational formalism, reduces (or extends) naturally to lower (or higher) number of fields on the level of both the free energy functional and the dynamic equations, enables the use of arbitrary pairwise equilibrium interfacial properties, penalizes multiple junctions increasingly with the number of phases, ensures non-negative entropy production and the convergence of the dynamic solutions to the equilibrium solutions, and avoids the appearance of spurious phases on binary interfaces. The approach is tested for multicomponent phase separation and grain coarsening.

Smartphone application for multi-phasic interventional trials in psychiatry: Technical design of a smart server.

PubMed

Zhang, Melvyn W B; Ho, Roger C M

2017-01-01

Smartphones and their accompanying applications are currently widely utilized in various healthcare interventions. Prior to the deployment of these tools for healthcare intervention, typically, proof of concept feasibility studies, as well as randomized trials are conducted to determine that these tools are efficacious prior to their actual implementation. In the field of psychiatry, most of the current interventions seek to compare smartphone based intervention against conventional care. There remains a paucity of research evaluating different forms of interventions using a single smartphone application. In the field of nutrition, there has been recent pioneering research demonstrating how a multi-phasic randomized controlled trial could be conducted using a single smartphone application. Despite the innovativeness of the previous smartphone conceptualization, there remains a paucity of technical information underlying the conceptualization that would support a multi-phasic interventional trial. It is thus the aim of the current technical note to share insights into an innovative server design that would enable the delivery of multi-phasic trials.

Multiphase Interface Tracking with Fast Semi-Lagrangian Contouring.

PubMed

Li, Xiaosheng; He, Xiaowei; Liu, Xuehui; Zhang, Jian J; Liu, Baoquan; Wu, Enhua

2016-08-01

We propose a semi-Lagrangian method for multiphase interface tracking. In contrast to previous methods, our method maintains an explicit polygonal mesh, which is reconstructed from an unsigned distance function and an indicator function, to track the interface of arbitrary number of phases. The surface mesh is reconstructed at each step using an efficient multiphase polygonization procedure with precomputed stencils while the distance and indicator function are updated with an accurate semi-Lagrangian path tracing from the meshes of the last step. Furthermore, we provide an adaptive data structure, multiphase distance tree, to accelerate the updating of both the distance function and the indicator function. In addition, the adaptive structure also enables us to contour the distance tree accurately with simple bisection techniques. The major advantage of our method is that it can easily handle topological changes without ambiguities and preserve both the sharp features and the volume well. We will evaluate its efficiency, accuracy and robustness in the results part with several examples.

Using a mixed-methods design to examine nurse practitioner integration in British Columbia.

PubMed

Sangster-Gormley, Esther; Griffith, Janessa; Schreiber, Rita; Borycki, Elizabeth

2015-07-01

To discuss and provide examples of how mixed-methods research was used to evaluate the integration of nurse practitioners (NPs) into a Canadian province. Legislation enabling NPs to practise in British Columbia (BC) was enacted in 2005. This research evaluated the integration of NPs and their effect on the BC healthcare system. Data were collected using surveys, focus groups, participant interviews and case studies over three years. Data sources and methods were triangulated to determine how the findings addressed the research questions. The challenges and benefits of using the multiphase design are highlighted in the paper. The multiphase mixed-methods research design was selected because of its applicability to evaluation research. The design proved to be robust and flexible in answering research questions. As sub-studies within the multiphase design are often published separately, it can be difficult for researchers to find examples. This paper highlights ways that a multiphase mixed-methods design can be conducted for researchers unfamiliar with the process.

Statistical analysis on the signals monitoring multiphase flow patterns in pipeline-riser system

NASA Astrophysics Data System (ADS)

Ye, Jing; Guo, Liejin

2013-07-01

The signals monitoring petroleum transmission pipeline in offshore oil industry usually contain abundant information about the multiphase flow on flow assurance which includes the avoidance of most undesirable flow pattern. Therefore, extracting reliable features form these signals to analyze is an alternative way to examine the potential risks to oil platform. This paper is focused on characterizing multiphase flow patterns in pipeline-riser system that is often appeared in offshore oil industry and finding an objective criterion to describe the transition of flow patterns. Statistical analysis on pressure signal at the riser top is proposed, instead of normal prediction method based on inlet and outlet flow conditions which could not be easily determined during most situations. Besides, machine learning method (least square supported vector machine) is also performed to classify automatically the different flow patterns. The experiment results from a small-scale loop show that the proposed method is effective for analyzing the multiphase flow pattern.

A smoothed particle hydrodynamics framework for modelling multiphase interactions at meso-scale

NASA Astrophysics Data System (ADS)

Li, Ling; Shen, Luming; Nguyen, Giang D.; El-Zein, Abbas; Maggi, Federico

2018-01-01

A smoothed particle hydrodynamics (SPH) framework is developed for modelling multiphase interactions at meso-scale, including the liquid-solid interaction induced deformation of the solid phase. With an inter-particle force formulation that mimics the inter-atomic force in molecular dynamics, the proposed framework includes the long-range attractions between particles, and more importantly, the short-range repulsive forces to avoid particle clustering and instability problems. Three-dimensional numerical studies have been conducted to demonstrate the capabilities of the proposed framework to quantitatively replicate the surface tension of water, to model the interactions between immiscible liquids and solid, and more importantly, to simultaneously model the deformation of solid and liquid induced by the multiphase interaction. By varying inter-particle potential magnitude, the proposed SPH framework has successfully simulated various wetting properties ranging from hydrophobic to hydrophilic surfaces. The simulation results demonstrate the potential of the proposed framework to genuinely study complex multiphase interactions in wet granular media.

Multiphase Model of Semisolid Slurry Generation and Isothermal Holding During Cooling Slope Rheoprocessing of A356 Al Alloy

NASA Astrophysics Data System (ADS)

Das, Prosenjit; Samanta, Sudip K.; Mondal, Biswanath; Dutta, Pradip

2018-04-01

In the present paper, we present an experimentally validated 3D multiphase and multiscale solidification model to understand the transport processes involved during slurry generation with a cooling slope. In this process, superheated liquid alloy is poured at the top of the cooling slope and allowed to flow along the slope under the influence of gravity. As the melt flows down the slope, it progressively loses its superheat, starts solidifying at the melt/slope interface with formation of solid crystals, and eventually exits the slope as semisolid slurry. In the present simulation, the three phases considered are the parent melt as the primary phase, and the solid grains and air as secondary phases. The air phase forms a definable air/liquid melt interface as the free surface. After exiting the slope, the slurry fills an isothermal holding bath maintained at the slope exit temperature, which promotes further globularization of microstructure. The outcomes of the present model include prediction of volume fractions of the three different phases considered, grain evolution, grain growth, size, sphericity and distribution of solid grains, temperature field, velocity field, macrosegregation and microsegregation. In addition, the model is found to be capable of making predictions of morphological evolution of primary grains at the onset of isothermal coarsening. The results obtained from the present simulations are validated by performing quantitative image analysis of micrographs of the rapidly oil-quenched semisolid slurry samples, collected from strategic locations along the slope and from the isothermal slurry holding bath.

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

Qui, Songgang; Galbraith, Ross

This final report summarizes the final results of the Phase II Innovative Application of Maintenance-Free Phase-Change Thermal Energy Storage for Dish-Engine Solar Power Generation project being performed by Infinia Corporation for the U.S. Department of Energy under contract DE-FC36-08GO18157 during the project period of September 1, 2009 - August 30, 2012. The primary objective of this project is to demonstrate the practicality of integrating thermal energy storage (TES) modules, using a suitable thermal salt phase-change material (PCM) as its medium, with a dish/Stirling engine; enabling the system to operate during cloud transients and to provide dispatchable power for 4 tomore » 6 hours after sunset. A laboratory prototype designed to provide 3 kW-h of net electrical output was constructed and tested at Infinia's Ogden Headquarters. In the course of the testing, it was determined that the system's heat pipe network - used to transfer incoming heat from the solar receiver to both the Stirling generator heater head and to the phase change salt - did not perform to expectations. The heat pipes had limited capacity to deliver sufficient heat energy to the generator and salt mass while in a charging mode, which was highly dependent on the orientation of the device (vertical versus horizontal). In addition, the TES system was only able to extract about 30 to 40% of the expected amount of energy from the phase change salt once it was fully molten. However, the use of heat pipes to transfer heat energy to and from a thermal energy storage medium is a key technical innovation, and the project team feels that the limitations of the current device could be greatly improved with further development. A detailed study of manufacturing costs using the prototype TES module as a basis indicates that meeting DOE LCOE goals with this hardware requires significant efforts. Improvement can be made by implementing aggressive cost-down initiatives in design and materials, improving system performance by boosting efficiencies, and by refining cost estimates with vendor quotes in lieu of mass-based approaches. Although the prototype did not fully demonstrate performance and realize projected cost targets, the project team believes that these challenges can be overcome. The test data showed that the performance can be significantly improved by refining the heat pipe designs. However, the project objective for phase 3 is to design and test on sun the field ready systems, the project team feels that is necessary to further refine the prototype heat pipe design in the current prototype TES system before move on to field test units, Phase 3 continuation will not be pursued.« less

46 CFR 56.50-30 - Boiler feed piping.

Code of Federal Regulations, 2014 CFR

2014-10-01

... pump may be used for other purposes. (2) If two independently driven pumps are provided, each capable... requirements. (1) Steam vessels, and motor vessels fitted with steam driven electrical generators shall have at... the necessary connections for this purpose. The arrangement of feed pumps shall be in accordance with...

Fluid Flow through Pipes--Another Look at Fire Hoses and Garden Hoses.

ERIC Educational Resources Information Center

Brouwer, W.; Paranjape, B. V.

1991-01-01

The forward force of water on a hose is calculated using only the pressure gradient, the radius and length of the hose. The misconception about recoil on the nozzle is discussed. Dissipation energy and the consequent heat generation in a fluid flow are also described. (KR)

Computational Flow Modeling of Hydrodynamics in Multiphase Trickle-Bed Reactors

NASA Astrophysics Data System (ADS)

Lopes, Rodrigo J. G.; Quinta-Ferreira, Rosa M.

2008-05-01

This study aims to incorporate most recent multiphase models in order to investigate the hydrodynamic behavior of a TBR in terms of pressure drop and liquid holdup. Taking into account transport phenomena such as mass and heat transfer, an Eulerian k-fluid model was developed resulting from the volume averaging of the continuity and momentum equations and solved for a 3D representation of the catalytic bed. Computational fluid dynamics (CFD) model predicts hydrodynamic parameters quite well if good closures for fluid/fluid and fluid/particle interactions are incorporated in the multiphase model. Moreover, catalytic performance is investigated with the catalytic wet oxidation of a phenolic pollutant.

Multiphasic acute disseminated encephalomyelitis associated with atypical rubella virus infection.

PubMed

Shinoda, Koji; Asahara, Hideaki; Uehara, Taira; Miyoshi, Katsue; Suzuki, Satoshi O; Iwaki, Toru; Kira, Jun-ichi

2015-02-01

We report the first case of an occurrence of multiphasic acute disseminated encephalomyelitis (ADEM) associated with atypical rubella virus infection with no rash and long-term increased titers of serum anti-rubella IgM in a 17-year-old male who had no history of rubella vaccination. He suffered from at least six clinical exacerbations with disseminated hyperintense lesions on FLAIR MR images during the course of 18 months. Repeated methylprednisolone pulse therapy and intravenous immunoglobulin therapy resolved the exacerbations. In patients with multiphasic ADEM of unknown etiology, clinicians should also consider the possibility of preceding infection with rubella virus. © The Author(s), 2015.

Chemically and compositionally modified solid solution disordered multiphase nickel hydroxide positive electrode for alkaline rechargeable electrochemical cells

DOEpatents

Ovshinsky, Stanford R.; Corrigan, Dennis; Venkatesan, Srini; Young, Rosa; Fierro, Christian; Fetcenko, Michael A.

1994-01-01

A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.

3D CFD simulation of Multi-phase flow separators

NASA Astrophysics Data System (ADS)

Zhu, Zhiying

2017-10-01

During the exploitation of natural gas, some water and sands are contained. It will be better to separate water and sands from natural gas to insure favourable transportation and storage. In this study, we use CFD to analyse the effect of multi-phase flow separator, whose detailed geometrical parameters are designed in advanced. VOF model and DPM are used here. From the results of CFD, we can draw a conclusion that separated effect of multi-phase flow achieves better results. No solid and water is carried out from gas outlet. CFD simulation provides an economical and efficient approach to shed more light on details of the flow behaviour.

Particle clustering within a two-phase turbulent pipe jet

NASA Astrophysics Data System (ADS)

Lau, Timothy; Nathan, Graham

2016-11-01

A comprehensive study of the influence of Stokes number on the instantaneous distributions of particles within a well-characterised, two-phase, turbulent pipe jet in a weak co-flow was performed. The experiments utilised particles with a narrow size distribution, resulting in a truly mono-disperse particle-laden jet. The jet Reynolds number, based on the pipe diameter, was in the range 10000 <= ReD <= 40000 , while the exit Stokes number was in the range 0 . 3 <= SkD <= 22 . 4 . The particle mass loading was fixed at ϕ = 0 . 4 , resulting in a flow that was in the two-way coupling regime. Instantaneous particle distributions within a two-dimensional sheet was measured using planar nephelometry while particle clusters were identified and subsequently characterised using an in-house developed technique. The results show that particle clustering is significantly influenced by the exit Stokes number. Particle clustering was found to be significant for 0 . 3 <= SkD <= 5 . 6 , with the degree of clustering increasing as SkD is decreased. The clusters, which typically appeared as filament-like structures with high aspect ratio oriented at oblique angles to the flow, were measured right from the exit plane, suggesting that they were generated inside the pipe. The authors acknowledge the financial contributions by the Australian Research Council (Grant No. DP120102961) and the Australian Renewable Energy Agency (Grant No. USO034).

Augmentation of Performance of a Monogroove Heat Pipe with Electrohydrodynamic Conduction Pumping

NASA Astrophysics Data System (ADS)

Jeong, S. I.; Seyed-Yagoobi, J.

2002-11-01

The electrohydrodynamic (EHD) phenomena involve the interaction of electric fields and flow fields in a dielectric fluid medium. There are three types of EHD pumps; induction, ion-drag, and conduction. EHD conduction pump is a new concept which has been explored only recently. Net pumping is achieved by properly utilizing the heterocharge layers present in the vicinity of the electrodes. Several innovative electrode designs have been investigated. This paper presents an electrode design that generates pressure heads on the order of 600 Pa per one electrode pair at 20 kV with less than 0.08 W of electric power. The working fluid is the Refrigerant R-123. An EHD conduction pump consisting of six pairs of electrodes is installed in the liquid line of a mono-grove heat pipe. The heat transport capacity of the heat pipe is measured in the absence and presence of the EHD conduction pump. Significant enhancements in the heat transport capacity of the heat pipe is achieved with the EHD conduction pump operating. Furthermore, the EHD conduction pump provides immediate recovery from the dry-out condition. The EHD conduction pump has many advantages, especially in the micro-gravity environment. It is simple in design, non-mechanical, and lightweight. It provides a rapid control of heat transfer in single-phase and two-phase flows. The electric power consumption is minimal with the very low acoustic noise level.

Effect of pulsation on black liquor gasification. Final report

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

Zinn, B.T.; Jagoda, J.; Jeong, H.

1998-12-01

Pyrolysis is an endothermic process. The heat of reaction is provided either by partial combustion of the waste or by heat transfer from an external combustion process. In one proposed system black liquor is pyrolized in a fluidized bed to which heat is added through a series of pulse combustor tail pipes submerged in the bed material. This system appears promising because of the relatively high heat transfer in pulse combustors and in fluidized beds. Other advantages of pulse combustors are discussed elsewhere. The process is, however, only economically viable if a part of the pyrolysis products can be usedmore » to fire the pulse combustors. The overall goals of this study were to determine: (1) which is the limiting heat transfer rate in the process of transferring heat from the hot combustion products to the pipe, through the pipe, from the tail pipe to the bed and through the bed; i.e., whether increased heat transfer within the pulse combustor will significantly increase the overall heat transfer rate; (2) whether the heat transfer benefits of the pulse combustor can be utilized while maintaining the temperature in the bed within the narrow temperature range required by the process without generating hot spots in the bed; and (3) whether the fuel gas produced during the gasification process can be used to efficiently fire the pulse combustor.« less

Car companies look to generate power from waste heat

NASA Astrophysics Data System (ADS)

Schirber, Michael

2008-04-01

You might think that the steam engine is an outdated technology that had its heyday centuries ago, but in fact steam is once again a hot topic with vehicle manufacturers. Indeed, the next generation of hybrid cars and trucks may incorporate some form of steam power. Honda, for example, has just released details of a new prototype hybrid car that recharges its battery using a steam engine that exploits waste heat from the exhaust pipe.

Multiphase flow and phase change in microgravity: Fundamental research and strategic research for exploration of space

NASA Technical Reports Server (NTRS)

Singh, Bhim S.

2003-01-01

NASA is preparing to undertake science-driven exploration missions. The NASA Exploration Team's vision is a cascade of stepping stones. The stepping-stone will build the technical capabilities needed for each step with multi-use technologies and capabilities. An Agency-wide technology investment and development program is necessary to implement the vision. The NASA Exploration Team has identified a number of areas where significant advances are needed to overcome all engineering and medical barriers to the expansion of human space exploration beyond low-Earth orbit. Closed-loop life support systems and advanced propulsion and power technologies are among the areas requiring significant advances from the current state-of-the-art. Studies conducted by the National Academy of Science's National Research Council and Workshops organized by NASA have shown that multiphase flow and phase change play a crucial role in many of these advanced technology concepts. Lack of understanding of multiphase flow, phase change, and interfacial phenomena in the microgravity environment has been a major hurdle. An understanding of multiphase flow and phase change in microgravity is, therefore, critical to advancing many technologies needed. Recognizing this, the Office of Biological and Physical Research (OBPR) has initiated a strategic research thrust to augment the ongoing fundamental research in fluid physics and transport phenomena discipline with research especially aimed at understanding key multiphase flow related issues in propulsion, power, thermal control, and closed-loop advanced life support systems. A plan for integrated theoretical and experimental research that has the highest probability of providing data, predictive tools, and models needed by the systems developers to incorporate highly promising multiphase-based technologies is currently in preparation. This plan is being developed with inputs from scientific community, NASA mission planners and industry personnel. The fundamental research in multiphase flow and phase change in microgravity is aimed at developing better mechanistic understanding of pool boiling and ascertaining the effects of gravity on heat transfer and the critical heat flux. Space flight experiments conducted in space have shown that nucleate pool boiling can be sustained under certain conditions in the microgravity environment. New space flight experiments are being developed to provide more quantitative information on pool boiling in microgravity. Ground-based investigations are also being conducted to develop mechanistic models for flow and pool boiling. An overview of the research plan and roadmap for the strategic research in multiphase flow and phase change as well as research findings from the ongoing program will be presented.

Double wall vacuum tubing and method of manufacture

DOEpatents

Stahl, Charles R.; Gibson, Michael A.; Knudsen, Christian W.

1989-01-01

An evacuated double wall tubing is shown together with a method for the manufacture of such tubing which includes providing a first pipe of predetermined larger diameter and a second pipe having an O.D. substantially smaller than the I.D. of the first pipe. An evacuation opening is then in the first pipe. The second pipe is inserted inside the first pipe with an annular space therebetween. The pipes are welded together at one end. A stretching tool is secured to the other end of the second pipe after welding. The second pipe is then prestressed mechanically with the stretching tool an amount sufficient to prevent substantial buckling of the second pipe under normal operating conditions of the double wall pipe. The other ends of the first pipe and the prestressed second pipe are welded together, preferably by explosion welding, without the introduction of mechanical spacers between the pipes. The annulus between the pipes is evacuated through the evacuation opening, and the evacuation opening is finally sealed. The first pipe is preferably of steel and the second pipe is preferably of titanium. The pipes may be of a size and wall thickness sufficient for the double wall pipe to be structurally load bearing or may be of a size and wall thickness insufficient for the double wall pipe to be structurally load bearing, and the double wall pipe positioned with a sliding fit inside a third pipe of a load-bearing size.

Numerical modeling of experimental observations on gas formation and multi-phase flow of carbon dioxide in subsurface formations

NASA Astrophysics Data System (ADS)

Pawar, R.; Dash, Z.; Sakaki, T.; Plampin, M. R.; Lassen, R. N.; Illangasekare, T. H.; Zyvoloski, G.

2011-12-01

One of the concerns related to geologic CO2 sequestration is potential leakage of CO2 and its subsequent migration to shallow groundwater resources leading to geochemical impacts. Developing approaches to monitor CO2 migration in shallow aquifer and mitigate leakage impacts will require improving our understanding of gas phase formation and multi-phase flow subsequent to CO2 leakage in shallow aquifers. We are utilizing an integrated approach combining laboratory experiments and numerical simulations to characterize the multi-phase flow of CO2 in shallow aquifers. The laboratory experiments involve a series of highly controlled experiments in which CO2 dissolved water is injected in homogeneous and heterogeneous soil columns and tanks. The experimental results are used to study the effects of soil properties, temperature, pressure gradients and heterogeneities on gas formation and migration. We utilize the Finite Element Heat and Mass (FEHM) simulator (Zyvoloski et al, 2010) to numerically model the experimental results. The numerical models capture the physics of CO2 exsolution, multi-phase fluid flow as well as sand heterogeneity. Experimental observations of pressure, temperature and gas saturations are used to develop and constrain conceptual models for CO2 gas-phase formation and multi-phase CO2 flow in porous media. This talk will provide details of development of conceptual models based on experimental observation, development of numerical models for laboratory experiments and modelling results.

Benchmark of multi-phase method for the computation of fast ion distributions in a tokamak plasma in the presence of low-amplitude resonant MHD activity

NASA Astrophysics Data System (ADS)

Bierwage, A.; Todo, Y.

2017-11-01

The transport of fast ions in a beam-driven JT-60U tokamak plasma subject to resonant magnetohydrodynamic (MHD) mode activity is simulated using the so-called multi-phase method, where 4 ms intervals of classical Monte-Carlo simulations (without MHD) are interlaced with 1 ms intervals of hybrid simulations (with MHD). The multi-phase simulation results are compared to results obtained with continuous hybrid simulations, which were recently validated against experimental data (Bierwage et al., 2017). It is shown that the multi-phase method, in spite of causing significant overshoots in the MHD fluctuation amplitudes, accurately reproduces the frequencies and positions of the dominant resonant modes, as well as the spatial profile and velocity distribution of the fast ions, while consuming only a fraction of the computation time required by the continuous hybrid simulation. The present paper is limited to low-amplitude fluctuations consisting of a few long-wavelength modes that interact only weakly with each other. The success of this benchmark study paves the way for applying the multi-phase method to the simulation of Abrupt Large-amplitude Events (ALE), which were seen in the same JT-60U experiments but at larger time intervals. Possible implications for the construction of reduced models for fast ion transport are discussed.

Heat transfer in turbulent magneto-fluid-mechanic pipe flow

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

Andelman, M.P.

1975-12-01

The ability to predict heat transfer in Magneto-Fluid-Mechanic flow is of importance in light of the development of MHD generators and the proposed development of thermonuclear reactors. In both cases heat transfer from (or to) a conducting fluid in the presence of a magnetic field plays an important part in the overall economics of the system. A semi-empirical analytical method is given for obtaining heat transfer coefficients in turbulent liquid metal pipe flow in the presence of a magnetic field aligned to the flow. The analysis was based on the Lykoudis turbulent transport model with the influence of a longitudinalmore » magnetic field included. The results are shown to be in agreement with available experimental values. Experimental velocity profiles in mercury for pipe flow in a transverse magnetic field were made at a Reynolds number of 315,000; for Hartmann numbers of 0, 92, 184, 369, and 1198; and at orientations of 0 degrees, 45 degrees, and 90 degrees from the magnetic field. These results provide a basis for the determination of the effect of a transverse magnetic field on turbulent diffusivities.« less

Mars sample return power supply

NASA Technical Reports Server (NTRS)

Hoang, Don; Ludwigs, Sharon; Schmitz, Paul; Wright, John

1988-01-01

A power supply is designed for a vehicle able to operate on the surface of Mars for a period of 5 to 10 years. This vehicle will be used for sample and data collection. The design is based on the assumption that the vehicle will be unmanned. Also, there will be no means by which components could be repaired or replaced while on the Martian surface. A consequence of this is that all equipment must meet high standards of reliability and, if possible, redundancy. Power will be supplied to the vehicle by means of a General Purpose Heat Source capable of producing a minimum of 7 kW of thermal power. The heat generated from the General Purpose Heat Source will be transferred to a Stirling engine via hot side heat pipes. The Stirling engine will then convert this heat into 2 kW of electrical power. Cold side heat pipes will be used to carry away waste heat, which will be released to the Martian environment via radiators connected to the end of the cold side heat pipes.

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

NASA Astrophysics Data System (ADS)

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

2017-06-01

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

Neutron tomography of axially symmetric objects using 14 MeV neutrons from a portable neutron generator

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

Andersson, P., E-mail: peter.andersson@physics.uu.se; Andersson-Sunden, E.; Sjöstrand, H.

2014-08-01

In nuclear boiling water reactor cores, the distribution of water and steam (void) is essential for both safety and efficiency reasons. In order to enhance predictive capabilities, void distribution assessment is performed in two-phase test-loops under reactor-relevant conditions. This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to determine the time-averaged void distribution in these loops. Fast neutrons have the advantage of high transmission through the metallic structures and pipes typically concealing a thermal-hydraulic test loop, while still being fairly sensitive to the water/void content. However, commercially available fast-neutron generators also have the disadvantagemore » of a relatively low yield and fast-neutron detection also suffers from relatively low detection efficiency. Fortunately, some loops are axially symmetric, a property which can be exploited to reduce the amount of data needed for tomographic measurement, thus limiting the interrogation time needed. In this article, three axially symmetric test objects depicting a thermal-hydraulic test loop have been examined; steel pipes with outer diameter 24 mm, thickness 1.5 mm, and with three different distributions of the plastic material POM inside the pipes. Data recorded with the FANTOM fast-neutron tomography instrument have been used to perform tomographic reconstructions to assess their radial material distribution. Here, a dedicated tomographic algorithm that exploits the symmetry of these objects has been applied, which is described in the paper. Results are demonstrated in 20 rixel (radial pixel) reconstructions of the interior constitution and 2D visualization of the pipe interior is demonstrated. The local POM attenuation coefficients in the rixels were measured with errors (RMS) of 0.025, 0.020, and 0.022 cm{sup −1}, solid POM attenuation coefficient. The accuracy and precision is high enough to provide a useful indication on the flow mode, and a visualization of the radial material distribution can be obtained. A benefit of this system is its potential to be mounted at any axial height of a two-phase test section without requirements for pre-fabricated entrances or windows. This could mean a significant increase in flexibility of the void distribution assessment capability at many existing two-phase test loops.« less

Neutron tomography of axially symmetric objects using 14 MeV neutrons from a portable neutron generator.

PubMed

Andersson, P; Andersson-Sunden, E; Sjöstrand, H; Jacobsson-Svärd, S

2014-08-01

In nuclear boiling water reactor cores, the distribution of water and steam (void) is essential for both safety and efficiency reasons. In order to enhance predictive capabilities, void distribution assessment is performed in two-phase test-loops under reactor-relevant conditions. This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to determine the time-averaged void distribution in these loops. Fast neutrons have the advantage of high transmission through the metallic structures and pipes typically concealing a thermal-hydraulic test loop, while still being fairly sensitive to the water/void content. However, commercially available fast-neutron generators also have the disadvantage of a relatively low yield and fast-neutron detection also suffers from relatively low detection efficiency. Fortunately, some loops are axially symmetric, a property which can be exploited to reduce the amount of data needed for tomographic measurement, thus limiting the interrogation time needed. In this article, three axially symmetric test objects depicting a thermal-hydraulic test loop have been examined; steel pipes with outer diameter 24 mm, thickness 1.5 mm, and with three different distributions of the plastic material POM inside the pipes. Data recorded with the FANTOM fast-neutron tomography instrument have been used to perform tomographic reconstructions to assess their radial material distribution. Here, a dedicated tomographic algorithm that exploits the symmetry of these objects has been applied, which is described in the paper. Results are demonstrated in 20 rixel (radial pixel) reconstructions of the interior constitution and 2D visualization of the pipe interior is demonstrated. The local POM attenuation coefficients in the rixels were measured with errors (RMS) of 0.025, 0.020, and 0.022 cm(-1), solid POM attenuation coefficient. The accuracy and precision is high enough to provide a useful indication on the flow mode, and a visualization of the radial material distribution can be obtained. A benefit of this system is its potential to be mounted at any axial height of a two-phase test section without requirements for pre-fabricated entrances or windows. This could mean a significant increase in flexibility of the void distribution assessment capability at many existing two-phase test loops.

A multi-phase network situational awareness cognitive task analysis

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

Erbacher, Robert; Frincke, Deborah A.; Wong, Pak C.

Abstract The goal of our project is to create a set of next-generation cyber situational-awareness capabilities with applications to other domains in the long term. The objective is to improve the decision-making process to enable decision makers to choose better actions. To this end, we put extensive effort into making certain that we had feedback from network analysts and managers and understand what their genuine needs are. This article discusses the cognitive task-analysis methodology that we followed to acquire feedback from the analysts. This article also provides the details we acquired from the analysts on their processes, goals, concerns, themore » data and metadata that they analyze. Finally, we describe the generation of a novel task-flow diagram representing the activities of the target user base.« less

Adaptive control system for line-commutated inverters

NASA Technical Reports Server (NTRS)

Dolland, C. R.; Bailey, D. A. (Inventor)

1983-01-01

A control system for a permanent magnet motor driven by a multiphase line commutated inverter is provided with integration for integrating the back EMF of each phase of the motor. This is used in generating system control signals for an inverter gate logic using a sync and firing angle (alpha) control generator connected to the outputs of the integrators. A precision full wave rectifier provides a speed control feedback signal to a phase delay rectifier via a gain and loop compensation circuit and to the integrators for adaptive control of the attenuation of low frequencies by the integrators as a function of motor speed. As the motor speed increases, the attenuation of low frequency components by the integrators is increased to offset the gain of the integrators to spurious low frequencies.

Computation and analysis of cavitating flow in Francis-class hydraulic turbines

NASA Astrophysics Data System (ADS)

Leonard, Daniel J.

Hydropower is the most proven renewable energy technology, supplying the world with 16% of its electricity. Conventional hydropower generates a vast majority of that percentage. Although a mature technology, hydroelectric generation shows great promise for expansion through new dams and plants in developing hydro countries. Moreover, in developed hydro countries, such as the United States, installing generating units in existing dams and the modern refurbishment of existing plants can greatly expand generating capabilities with little to no further impact on the environment. In addition, modern computational technology and fluid dynamics expertise has led to substantial improvements in modern turbine design and performance. Cavitation has always presented a problem in hydroturbines, causing performance breakdown, erosion, damage, vibration, and noise. While modern turbines are usually designed to be cavitation-free at their best efficiency point, due to the variable demand of the energy market it is fairly common to operate at off-design conditions. Here, cavitation and its deleterious effects are unavoidable, and hence, cavitation is a limiting factor on the design and operation of these turbines. Multiphase Computational Fluid Dynamics (CFD) has been used in recent years to model cavitating flow for a large range of problems, including turbomachinery. However, CFD of cavitating flow in hydroturbines is still in its infancy. This dissertation presents steady-periodic Reynolds-averaged Navier-Stokes simulations of a cavitating Francis-class hydroturbine at model and prototype scales. Computational results of the reduced-scale model and full-scale prototype, undergoing performance breakdown, are compared with empirical model data and prototype performance estimations based on standard industry scalings from the model data. Mesh convergence of the simulations is also displayed. Comparisons are made between the scales to display that cavitation performance breakdown can occur more abruptly in the model than the prototype, due to lack of Froude similitude between the two. When severe cavitation occurs, clear differences are observed in vapor content between the scales. A stage-by-stage performance decomposition is conducted to analyze the losses within individual components of each scale of the machine. As cavitation becomes more severe, the losses in the draft tube account for an increasing amount of the total losses in the machine. More losses occur in the model draft tube as cavitation formation in the prototype draft tube is prevented by the larger hydrostatic pressure gradient across the machine. Additionally, unsteady Detached Eddy Simulations of the fully-coupled cavitating hydroturbine are performed for both scales. Both mesh and temporal convergence studies are provided. The temporal and spectral content of fluctuations in torque and pressure are monitored and compared between single-phase, cavitating, model, and prototype cases. A shallow draft tube induced runner imbalance results in an asymmetric vapor distribution about the runner, leading to more extensive growth and collapse of vapor on any individual blade as it undergoes a revolution. Unique frequency components manifest and persist through the entire machine only when cavitation is present in the hub vortex. Large maximum pressure spikes, which result from vapor collapse, are observed on the blade surfaces in the multiphase simulations, and these may be a potential source of cavitation damage and erosion. Multiphase CFD is shown to be an accurate and effective technique for simulating and analyzing cavitating flow in Francis-class hydraulic turbines. It is recommended that it be used as an industrial tool to supplement model cavitation experiments for all types of hydraulic turbines. Moreover, multiphase CFD can be equally effective as a research tool, to investigate mechanisms of cavitating hydraulic turbines that are not understood, and to uncover unique new phenomena which are currently unknown.

Translational velocity oscillations of piston generated vortex rings

NASA Astrophysics Data System (ADS)

Kumar, Manoj; Arakeri, J. H.; Shankar, P. N.

1995-11-01

Experimental results are presented that show that the translational velocities of piston generated vortex rings often undergo oscillations, similar to those recently discovered for drop generated rings. An attempt has been made to minimize uncertainties by utilizing both dye and hydrogen bubbles for visualization and carefully repeating measurements on the same ring and on different realizations under the same nominal piston conditions. The results unambiguously show that under most conditions, both for laminar and turbulent rings and for rings generated from pipes and orifices, the oscillations are present. The present results, together with the earlier results on drop generated rings, give support to the view that translational velocity oscillations are probably an inherent feature of translating vortex ring fields.

Embedded fiber optic ultrasonic sensors and generators

NASA Astrophysics Data System (ADS)

Dorighi, John F.; Krishnaswamy, Sridhar; Achenbach, Jan D.

1995-04-01

Ultrasonic sensors and generators based on fiber-optic systems are described. It is shown that intrinsic fiber optic Fabry-Perot ultrasound sensors that are embedded in a structure can be stabilized by actively tuning the laser frequency. The need for this method of stabilization is demonstrated by detecting piezoelectric transducer-generated ultrasonic pulses in the presence of low frequency dynamic strains that are intentionally induced to cause sensor drift. The actively stabilized embedded fiber optic Fabry-Perot sensor is also shown to have sufficient sensitivity to detect ultrasound that is generated in the interior of a structure by means of a high-power optical fiber that pipes energy from a pulsed laser to an embedded generator of ultrasound.

The technology improvement and development of the new design-engineering principles of pilot bore directional drilling

NASA Astrophysics Data System (ADS)

Shadrina, A.; Saruev, L.; Vasenin, S.

2016-09-01

This paper addresses the effectiveness of impact energy use in pilot bore directional drilling at pipe driving. We establish and develop new design-engineering principles for this method. These principles are based on a drill string construction with a new nipple thread connection and a generator construction of strain waves transferred through the drill string. The experiment was conducted on a test bench. Strain measurement is used to estimate compression, tensile, shear and bending stresses in the drill string during the propagation of elastic waves. Finally, the main directions of pilot bore directional drilling improvement during pipe driving are determinated. The new engineering design, as components of the pilot bore directional drilling technology are presented.

Downhole tool

DOEpatents

Hall, David R.; Muradov, Andrei; Pixton, David S.; Dahlgren, Scott Steven; Briscoe, Michael A.

2007-03-20

A double shouldered downhole tool connection comprises box and pin connections having mating threads intermediate mating primary and secondary shoulders. The connection further comprises a secondary shoulder component retained in the box connection intermediate a floating component and the primary shoulders. The secondary shoulder component and the pin connection cooperate to transfer a portion of makeup load to the box connection. The downhole tool may be selected from the group consisting of drill pipe, drill collars, production pipe, and reamers. The floating component may be selected from the group consisting of electronics modules, generators, gyroscopes, power sources, and stators. The secondary shoulder component may comprises an interface to the box connection selected from the group consisting of radial grooves, axial grooves, tapered grooves, radial protrusions, axial protrusions, tapered protrusions, shoulders, and threads.

Minimization of the negative influence on the biosphere in heavy oil extraction and ecologically clean technology for the injection of the steam with supercritical parameters in oil strata on the basis of new ecologically clean tubing pipes with heat-resistant coatings

NASA Astrophysics Data System (ADS)

Komkov, M. A.; Moiseev, V. A.; Tarasov, V. A.; Timofeev, M. P.

2015-12-01

Some ecological problems related to heavy-oil extraction and ways for minimizing the negative impacts of this process on the biosphere are discussed. The ecological hazard of, for example, frequently used multistage hydraulic fracturing of formation is noted and the advantages and perspectives of superheated steam injection are considered. Steam generators of a new type and ecologically clean and costeffective insulating for tubing pipes (TPs) are necessary to develop the superheated steam injection method. The article is devoted to solving one of the most important and urgent tasks, i.e., the development and usage of lightweight, nonflammable, environmentally safe, and cost-effective insulating materials. It is shown that, for tubing shielding operating at temperatures up to 420°C, the most effective thermal insulation is a highly porous material based on basalt fiber. The process of filtration deposition of short basalt fibers with a bunch of alumina thermal insulation tubing pipe coatings in the form of cylinders and cylindrical shells from liquid pulp is substantiated. Based on the thermophysical characteristics of basalt fibers and on the technological features of manufacturing highly porous coating insulation, the thickness of a tubing pipe is determined. During the prolonged pumping of the air at an operating temperature of 400°C in the model sample of tubing pipes with insulation and a protective layer, we find that the surface temperature of the thermal barrier coating does not exceed 60°C. Introducing the described technology will considerably reduce the negative impact of heavy-oil extraction on the biosphere.

Water Leak Detection by Using Ground Penetrating Radar, Synthetic Simulation and Four-Dimensional Visualization

NASA Astrophysics Data System (ADS)

Al-Shukri, H.; Eyuboglu, S.; Mahdi, H.

2005-12-01

Many geophysical techniques have been suggested as candidates for detecting water leakage in water distribution system, including ground penetrating radar (GPR), acoustic devices, and gas sampling devices. A series of laboratory experiments were conducted to determine the validity and effectiveness of GPR in detecting water leakage in metal and plastic PVC pipes. The goal was to derive a practical and robust procedure for detecting such leakage. Initially, prototype laboratory experiments were designed to simulate leaks in both PVC and metal pipe. The experiments were very well controlled and results obtained indicate that GPR is effective in detecting subsurface water leaks. This was followed by an outdoor life size experiments. 50 feet by 30 feet by 5 feet test bed was constructed using local soil and commercial water distribution pipes. A 400 MHz antenna was used to collect three-dimensional GPR data as a function of time for a number of experiments using different type of pipes. Advanced imaging and visualization technology was used to further analyze the data. The UALR Virtual Reality Center CAVE facilities were utilized to accomplish this test. Results obtained indicate that GPR is effective in detecting subsurface water leaks in both pipes. Synthetic models of the GPR signals based on Finite Difference Time Domain Method (FDTD) were built to help select an appropriate equipment configuration (frequency band, type of antenna, and real-time imaging software) prior to data acquisition. The simulation software was used to determine the near-field radiation characteristics of the GPR antenna. Different experimental models were adapted for which observational GPR data was previously collected. Matlab regression analysis was used to generate the incident waves for each model to ensure highly accurate and controlled experiments.

Smart Pipe System for a Shipyard 4.0

PubMed Central

Fraga-Lamas, Paula; Noceda-Davila, Diego; Fernández-Caramés, Tiago M.; Díaz-Bouza, Manuel A.; Vilar-Montesinos, Miguel

2016-01-01

As a result of the progressive implantation of the Industry 4.0 paradigm, many industries are experimenting a revolution that shipyards cannot ignore. Therefore, the application of the principles of Industry 4.0 to shipyards are leading to the creation of Shipyards 4.0. Due to this, Navantia, one of the 10 largest shipbuilders in the world, is updating its whole inner workings to keep up with the near-future challenges that a Shipyard 4.0 will have to face. Such challenges can be divided into three groups: the vertical integration of production systems, the horizontal integration of a new generation of value creation networks, and the re-engineering of the entire production chain, making changes that affect the entire life cycle of each piece of a ship. Pipes, which exist in a huge number and varied typology on a ship, are one of the key pieces, and its monitoring constitutes a prospective cyber-physical system. Their improved identification, traceability, and indoor location, from production and through their life, can enhance shipyard productivity and safety. In order to perform such tasks, this article first conducts a thorough analysis of the shipyard environment. From this analysis, the essential hardware and software technical requirements are determined. Next, the concept of smart pipe is presented and defined as an object able to transmit signals periodically that allows for providing enhanced services in a shipyard. In order to build a smart pipe system, different technologies are selected and evaluated, concluding that passive and active RFID (Radio Frequency Identification) are currently the most appropriate technologies to create it. Furthermore, some promising indoor positioning results obtained in a pipe workshop are presented, showing that multi-antenna algorithms and Kalman filtering can help to stabilize Received Signal Strength (RSS) and improve the overall accuracy of the system. PMID:27999392

Framework for Structural Online Health Monitoring of Aging and Degradation of Secondary Systems due to some Aspects of Erosion

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

Gribok, Andrei; Patnaik, Sobhan; Williams, Christian

This report describes the current state of research related to critical aspects of erosion and selected aspects of degradation of secondary components in nuclear power plants. The report also proposes a framework for online health monitoring of aging and degradation of secondary components. The framework consists of an integrated multi-sensor modality system which can be used to monitor different piping configurations under different degradation conditions. The report analyses the currently known degradation mechanisms and available predictive models. Based on this analysis, the structural health monitoring framework is proposed. The Light Water Reactor Sustainability Program began to evaluate technologies that couldmore » be used to perform online monitoring of piping and other secondary system structural components in commercial NPPs. These online monitoring systems have the potential to identify when a more detailed inspection is needed using real-time measurements, rather than at a pre-determined inspection interval. This transition to condition-based, risk informed automated maintenance will contribute to a significant reduction of operations and maintenance costs that account for the majority of nuclear power generation costs. There is unanimous agreement between industry experts and academic researchers that identifying and prioritizing inspection locations in secondary piping systems (for example, in raw water piping or diesel piping) would eliminate many excessive in-service inspections. The proposed structural health monitoring framework takes aim at answering this challenge by combining long-range guided wave technologies with other monitoring techniques, which can significantly increase the inspection length and pinpoint the locations that degraded the most. More widely, the report suggests research efforts aimed at developing, validating, and deploying online corrosion monitoring techniques for complex geometries, which are pervasive in NPPs.« less

Smart Pipe System for a Shipyard 4.0.

PubMed

Fraga-Lamas, Paula; Noceda-Davila, Diego; Fernández-Caramés, Tiago M; Díaz-Bouza, Manuel A; Vilar-Montesinos, Miguel

2016-12-20

As a result of the progressive implantation of the Industry 4.0 paradigm, many industries are experimenting a revolution that shipyards cannot ignore. Therefore, the application of the principles of Industry 4.0 to shipyards are leading to the creation of Shipyards 4.0. Due to this, Navantia, one of the 10 largest shipbuilders in the world, is updating its whole inner workings to keep up with the near-future challenges that a Shipyard 4.0 will have to face. Such challenges can be divided into three groups: the vertical integration of production systems, the horizontal integration of a new generation of value creation networks, and the re-engineering of the entire production chain, making changes that affect the entire life cycle of each piece of a ship. Pipes, which exist in a huge number and varied typology on a ship, are one of the key pieces, and its monitoring constitutes a prospective cyber-physical system. Their improved identification, traceability, and indoor location, from production and through their life, can enhance shipyard productivity and safety. In order to perform such tasks, this article first conducts a thorough analysis of the shipyard environment. From this analysis, the essential hardware and software technical requirements are determined. Next, the concept of smart pipe is presented and defined as an object able to transmit signals periodically that allows for providing enhanced services in a shipyard. In order to build a smart pipe system, different technologies are selected and evaluated, concluding that passive and active RFID (Radio Frequency Identification) are currently the most appropriate technologies to create it. Furthermore, some promising indoor positioning results obtained in a pipe workshop are presented, showing that multi-antenna algorithms and Kalman filtering can help to stabilize Received Signal Strength (RSS) and improve the overall accuracy of the system.

Structural Dynamic Assessment of the GN2 Piping System for NASA's New and Powerful Reverberant Acoustic Test Facility

NASA Technical Reports Server (NTRS)

McNelis, Mark E.; Staab, Lucas D.; Akers, James C.; Hughes, William O.; Chang, Li C.; Hozman, Aron D.; Henry, Michael W.

2012-01-01

The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has led the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA from 2007 to 2011. SAIC-Benham has completed construction of a new reverberant acoustic test facility to support the future testing needs of NASA's space exploration program and commercial customers. The large Reverberant Acoustic Test Facility (RATF) is approximately 101,000 cubic feet in volume and was designed to operate at a maximum empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. Initial checkout acoustic testing was performed on March 2011 by SAIC-Benham at test levels up to 161 dB OASPL. During testing, several branches of the gaseous nitrogen (GN2) piping system, which supply the fluid to the noise generating acoustic modulators, failed at their T-junctions connecting the 12 in. supply line to their respective 4 in. branch lines. The problem was initially detected when the oxygen sensors in the horn room indicated a lower than expected oxygen level from which was inferred GN2 leaks in the piping system. In subsequent follow up inspections, cracks were identified in the failed T-junction connections through non-destructive evaluation testing. Through structural dynamic modeling of the piping system, the root cause of the T-junction connection failures was determined. The structural dynamic assessment identified several possible corrective design improvements to the horn room piping system. The effectiveness of the chosen design repairs were subsequently evaluated in September 2011 during acoustic verification testing to 161 dB OASPL.

Structural Dynamic Assessment of the GN2 Piping System for NASA's New and Powerful Reverberant Acoustic Test Facility

NASA Technical Reports Server (NTRS)

McNelis, Mark E.; Staab, Lucas D.; Akers, James C.; Hughes, WIlliam O.; Chang, Li, C.; Hozman, Aron D.; Henry, Michael W.

2012-01-01

The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has led the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA from 2007-2011. SAIC-Benham has completed construction of a new reverberant acoustic test facility to support the future testing needs of NASA's space exploration program and commercial customers. The large Reverberant Acoustic Test Facility (RATF) is approximately 101,000 cu ft in volume and was designed to operate at a maximum empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world's known active reverberant acoustic test facilities. Initial checkout acoustic testing was performed on March 2011 by SAIC-Benham at test levels up to 161 dB OASPL. During testing, several branches of the gaseous nitrogen (GN2) piping system, which supply the fluid to the noise generating acoustic modulators, failed at their "t-junctions" connecting the 12 inch supply line to their respective 4 inch branch lines. The problem was initially detected when the oxygen sensors in the horn room indicated a lower than expected oxygen level from which was inferred GN2 leaks in the piping system. In subsequent follow up inspections, cracks were identified in the failed "t-junction" connections through non-destructive evaluation testing . Through structural dynamic modeling of the piping system, the root cause of the "t-junction" connection failures was determined. The structural dynamic assessment identified several possible corrective design improvements to the horn room piping system. The effectiveness of the chosen design repairs were subsequently evaluated in September 2011 during acoustic verification testing to 161 dB OASPL.

Influence of hydraulic regimes on bacterial community structure and composition in an experimental drinking water distribution system.

PubMed

Douterelo, I; Sharpe, R L; Boxall, J B

2013-02-01

Microbial biofilms formed on the inner-pipe surfaces of drinking water distribution systems (DWDS) can alter drinking water quality, particularly if they are mechanically detached from the pipe wall to the bulk water, such as due to changes in hydraulic conditions. Results are presented here from applying 454 pyrosequencing of the 16S ribosomal RNA (rRNA) gene to investigate the influence of different hydrological regimes on bacterial community structure and to study the potential mobilisation of material from the pipe walls to the network using a full scale, temperature-controlled experimental pipeline facility accurately representative of live DWDS. Analysis of pyrosequencing and water physico-chemical data showed that habitat type (water vs. biofilm) and hydraulic conditions influenced bacterial community structure and composition in our experimental DWDS. Bacterial community composition clearly differed between biofilms and bulk water samples. Gammaproteobacteria and Betaproteobacteria were the most abundant phyla in biofilms while Alphaproteobacteria was predominant in bulk water samples. This suggests that bacteria inhabiting biofilms, predominantly species belonging to genera Pseudomonas, Zooglea and Janthinobacterium, have an enhanced ability to express extracellular polymeric substances to adhere to surfaces and to favour co-aggregation between cells than those found in the bulk water. Highest species richness and diversity were detected in 28 days old biofilms with this being accentuated at highly varied flow conditions. Flushing altered the pipe-wall bacterial community structure but did not completely remove bacteria from the pipe walls, particularly under highly varied flow conditions, suggesting that under these conditions more compact biofilms were generated. This research brings new knowledge regarding the influence of different hydraulic regimes on the composition and structure of bacterial communities within DWDS and the implication that this might have on drinking water quality. Copyright © 2012 Elsevier Ltd. All rights reserved.