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Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Scoping heat transfer analysis of a completely-blocked Type-Q septifoil  

SciTech Connect (OSTI)

Heat removal mechanisms for a completely-blocked Type-Q (new design) septifoil situated in an otherwise normally operating K-reactor are investigated in this report. The best-estimate maximum septifoil heat generation rate for a 26.2{degrees}C cooling water inlet temperature is 119 to 141 kW depending on the counter-current flow limitation correlation chosen. The corresponding reactor powers are 648 and 768 MW or 27 and 32% of 2400 MW (historical annual averaged full power). These estimates are based on a steady-state scoping analysis and have a large uncertainty.

Flach, G.P.

1991-12-01T23:59:59.000Z

2

HEAT TRANSFER FLUIDS  

E-Print Network [OSTI]

The choice of heat transfer fluids has significant effects on the performance, cost, and reliability of solar thermal systems. In this chapter, we evaluate existing heat transfer fluids such as oils and molten salts based ...

Lenert, Andrej

2012-01-01T23:59:59.000Z

3

Heat transfer system  

DOE Patents [OSTI]

A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

McGuire, Joseph C. (Richland, WA)

1982-01-01T23:59:59.000Z

4

Heat transfer system  

DOE Patents [OSTI]

A heat transfer system for a nuclear reactor is described. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

Not Available

1980-03-07T23:59:59.000Z

5

Heat Transfer Guest Editorial  

E-Print Network [OSTI]

Journal of Heat Transfer Guest Editorial We are indeed delighted in bringing out this special issue was showcased in diverse areas such as traditional heat and mass transfer, lab-on-chip, sensors, biomedical applica- tions, micromixers, fuel cells, and microdevices. Selected papers in the field of heat transfer

Kandlikar, Satish

6

Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference  

E-Print Network [OSTI]

Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference Las Vegas, Nevada, USA July 21-23, 2003 HT2003-47449 HEAT TRANSFER FROM A MOVING AND EVAPORATING MENISCUS ON A HEATED SURFACE meniscus with complete evaporation of water without any meniscus break-up. The experimental heat transfer

Kandlikar, Satish

7

Faculty Positions Heat Transfer and  

E-Print Network [OSTI]

Faculty Positions Heat Transfer and Thermal/Energy Sciences Naval Postgraduate School Monterey-track faculty position at the assistant professor level in the areas of Heat Transfer and Thermal/Fluid Sciences

8

5. Heat transfer Ron Zevenhoven  

E-Print Network [OSTI]

1/120 5. Heat transfer Ron Zevenhoven �bo Akademi University Thermal and Flow Engineering / Värme Three heat transfer mechanisms Conduction Convection Radiation 2/120 Pic: B�88 �bo Akademi University | Thermal and Flow Engineering | 20500 Turku | Finland #12;3/120 5.1 Conductive heat transfer �bo Akademi

Zevenhoven, Ron

9

Building Blocks of Tropical Diabatic Heating  

SciTech Connect (OSTI)

Rotated EOF analyses are used to study the composition and variability of large-scale tropical diabatic heating profiles estimated from eight field campaigns. The results show that the profiles are composed of a pair of building blocks. These are the stratiform heating with peak heating near 400hpa and a cooling peak near 700hPa and convective heating with a heating maximum near 700hPa. Variations in the contributions of these building blocks account for the evolution of the large-scale heating profile. Instantaneous top (bottom) heavy large scale heating profiles associated with excess of stratiform (convective) heating evolve towards a stationary mean profile due to exponential decay of the excess stratiform (convective) heating.

Hagos, Samson M.

2010-07-01T23:59:59.000Z

10

Project Profile: Heat Transfer and Latent Heat Storage in Inorganic...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for CSP Plants Project Profile: Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for CSP Plants...

11

Urban Sewage Delivery Heat Transfer System (2): Heat Transfer  

E-Print Network [OSTI]

The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Using the efficiency-number of transfer units method ( ), the heat-transfer efficiencies of the parallel-flow and reverse-flow TDTH...

Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.

2006-01-01T23:59:59.000Z

12

Heat transfer probe  

DOE Patents [OSTI]

Apparatuses, systems, methods, and computer code for, among other things, monitoring the health of samples such as the brain while providing local cooling or heating. A representative device is a heat transfer probe, which includes an inner channel, a tip, a concentric outer channel, a first temperature sensor, and a second temperature sensor. The inner channel is configured to transport working fluid from an inner inlet to an inner outlet. The tip is configured to receive at least a portion of the working fluid from the inner outlet. The concentric outer channel is configured to transport the working fluid from the inner outlet to an outer outlet. The first temperature sensor is coupled to the tip, and the second temperature sensor spaced apart from the first temperature sensor.

Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff

2006-10-10T23:59:59.000Z

13

Spring 2014 Heat Transfer -2  

E-Print Network [OSTI]

Spring 2014 Heat Transfer - 2 A thin electronic chip is in the shape of a square wafer, b = 1 cm surface of the chip with a heat transfer coefficient of h = 100 W/m2 -K. Assume the chip has a uniform per side with a mass of m = 0.3 grams and specific heat of C = 103 J/kg-K. The chip is mounted

Virginia Tech

14

Spring 2014 Heat Transfer -1  

E-Print Network [OSTI]

Spring 2014 1 Heat Transfer - 1 Consider a cylindrical nuclear fuel rod of length L and diameter df and the tube at a rate m , and the outer surface of the tube is well insulated. Heat generation occurs within. The specific heat of water pc , and the thermal conductivity of the fuel rod fk are constants. The system

Virginia Tech

15

Electrohydrodynamically enhanced condensation heat transfer  

E-Print Network [OSTI]

In a condenser the thickness of the liquid condensate film covering the cooled surface constitutes a resistance to the heat transfer. By establishing a non uniform electric field in the vicinity of the condensation surface the extraction of liquid...

Wawzyniak, Markus

2012-06-07T23:59:59.000Z

16

MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER  

E-Print Network [OSTI]

MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts

Lahey, Richard T.

17

Enhanced heat transfer using nanofluids  

DOE Patents [OSTI]

This invention is directed to a method of and apparatus for enhancing heat transfer in fluids such as deionized water. ethylene glycol, or oil by dispersing nanocrystalline particles of substances such as copper, copper oxide, aluminum oxide, or the like in the fluids. Nanocrystalline particles are produced and dispersed in the fluid by heating the substance to be dispersed in a vacuum while passing a thin film of the fluid near the heated substance. The fluid is cooled to control its vapor pressure.

Choi, Stephen U. S. (Lisle, IL); Eastman, Jeffrey A. (Naperville, IL)

2001-01-01T23:59:59.000Z

18

Nanoscale heat transfer - from computation to experiment  

E-Print Network [OSTI]

Heat transfer can differ distinctly at the nanoscale from that at the macroscale. Recent advancement in

Luo, Tengfei

2013-04-09T23:59:59.000Z

19

Journal of Heat Transfer1999 JHT Heat Transfer Gallery Department of Mechanical 8. Aerospace Engineering  

E-Print Network [OSTI]

Journal of Heat Transfer1999 JHT Heat Transfer Gallery S. M. You Department of Mechanical 8 Transfer Visualization Committee organized two photo gallery sessions in 1998. The International Heat Transfer Photo Gallery was held at the l la' International Heat Transfer Conference (IHTC) in Kyongju

Kihm, IconKenneth David

20

ME 519: THEORY OF HEAT TRANSFER Instructor  

E-Print Network [OSTI]

ME 519: THEORY OF HEAT TRANSFER Fall 2014 Instructor: Class time: Classroom: Office Hours: Prof Tuesday 4­5pm or by appointment Class description This course will cover the fundamentals of heat transfer. An introductory course in heat transfer (ME 419 or equivalent) is pre-requisite. Grading 20% Homework 25% Exam 1

Lin, Xi

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Heat transfer via dropwise condensation on hydrophobic microstructured surfaces  

E-Print Network [OSTI]

Dropwise condensation has the potential to greatly increase heat transfer rates. Heat transfer coefficients by dropwise condensation and film condensation on microstructured silicon chips were compared. Heat transfer ...

Ruleman, Karlen E. (Karlen Elizabeth)

2009-01-01T23:59:59.000Z

22

Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass  

E-Print Network [OSTI]

Kaviany and B.P. Singh, “Radiative heat transfer in porousmedia”, Advances in Heat Transfer, vol. 23, no. 23, pp. 133–Thermal radiation heat transfer, Hemisphere Publishing Co. ,

Kitamura, Rei; Pilon, Laurent

2009-01-01T23:59:59.000Z

23

Acoustically Enhanced Boiling Heat Transfer  

E-Print Network [OSTI]

An acoustic field is used to increase the critical heat flux (CHF) of a flat-boiling-heat-transfer surface. The increase is a result of the acoustic effects on the vapor bubbles. Experiments are performed to explore the effects of an acoustic field on vapor bubbles in the vicinity of a rigid-heated wall. Work includes the construction of a novel heater used to produce a single vapor bubble of a prescribed size and at a prescribed location on a flatboiling surface for better study of an individual vapor bubble's reaction to the acoustic field. Work also includes application of the results from the single-bubble heater to a calibrated-copper heater used for quantifying the improvements in CHF.

Z. W. Douglas; M. K. Smith; A. Glezer

2008-01-07T23:59:59.000Z

24

Heat Transfer Research, 2010, Vol. 41, No. 6 Turbine Aero-Heat Transfer Studies  

E-Print Network [OSTI]

AU TH O R PR O O F Heat Transfer Research, 2010, Vol. 41, No. 6 Turbine Aero-Heat Transfer Studies in Rotating Research Facilities CENGIZ CAMCI Turbomachinery Aero-Heat Transfer Laboratory, Department The present paper deals with the experimental aero-heat transfer studies performed in rotating turbine

Camci, Cengiz

25

Heat exchanger device and method for heat removal or transfer  

DOE Patents [OSTI]

Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

Koplow, Jeffrey P. (San Ramon, CA)

2012-07-24T23:59:59.000Z

26

Heat exchanger device and method for heat removal or transfer  

DOE Patents [OSTI]

Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

Koplow, Jeffrey P

2013-12-10T23:59:59.000Z

27

Heat-Traced Fluid Transfer Lines  

E-Print Network [OSTI]

HEAT-TRACED FLUID TRANSFER LINES Robert E. Schilling, P.E. Eaton Corporation Aurora, Ohio This paper discusses basic considerations in designing a heat tracing system using either steam or electrical tracing. Four basic reasons to heat...

Schilling, R. E.

1984-01-01T23:59:59.000Z

28

Nuclear reactor safety heat transfer  

SciTech Connect (OSTI)

Reviewed is a book which has 5 parts: Overview, Fundamental Concepts, Design Basis Accident-Light Water Reactors (LWRs), Design Basis Accident-Liquid-Metal Fast Breeder Reactors (LMFBRs), and Special Topics. It combines a historical overview, textbook material, handbook information, and the editor's personal philosophy on safety of nuclear power plants. Topics include thermal-hydraulic considerations; transient response of LWRs and LMFBRs following initiating events; various accident scenarios; single- and two-phase flow; single- and two-phase heat transfer; nuclear systems safety modeling; startup and shutdown; transient response during normal and upset conditions; vapor explosions, natural convection cooling; blockages in LMFBR subassemblies; sodium boiling; and Three Mile Island.

Jones, O.C.

1982-07-01T23:59:59.000Z

29

Heat-transfer coefficients in agitated vessels. Latent heat models  

SciTech Connect (OSTI)

Latent heat models were developed to calculate heat-transfer coefficients in agitated vessels for two cases: (1) heating with a condensable fluid flowing through coils and jackets; (2) vacuum reflux cooling with an overhead condenser. In either case the mathematical treatment, based on macroscopic balances, requires no iterative schemes. In addition to providing heat-transfer coefficients, the models predict flow rates of service fluid through the coils and jackets, estimate the percentage of heat transfer due to latent heat, and compute reflux rates.

Kumpinsky, E. [Ashland Chemical Co., Columbus, OH (United States)] [Ashland Chemical Co., Columbus, OH (United States)

1996-03-01T23:59:59.000Z

30

Enhanced heat transfer for thermionic power modules  

SciTech Connect (OSTI)

The thermionic power module is capable of operating at very high heat fluxes, which in turn serve to reduce capital costs. The most efficient operation also requires uniform heat fluxes. The development of enhanced heat transfer systems is required to meet the demand for high heat fluxes (>20 w/cm/sup 2/) at high temperatures (>1500K) which advanced thermionic power modules place upon combustion systems. Energy transfer from the hot combustion gases may take place by convection, radiation, or a combination of radiation and convection. Enhanced convective heat transfer with a jet impingement system has been demonstrated in a thermionic converter. The recently-developed cellular ceramic radiative heat transfer system has also been applied to a thermionic converter. By comparing the jet impingement and cellular ceramic radiative heat transfer systems, an appropriate system may be selected for utilization in advanced thermionic power modules. Results are reported.

Johnson, D.C.

1981-07-01T23:59:59.000Z

31

Radiative heat transfer in porous uranium dioxide  

SciTech Connect (OSTI)

Due to low thermal conductivity and high emissivity of UO{sub 2}, it has been suggested that radiative heat transfer may play a significant role in heat transfer through pores of UO{sub 2} fuel. This possibility was computationally investigated and contribution of radiative heat transfer within pores to overall heat transport in porous UO{sub 2} quantified. A repeating unit cell was developed to model approximately a porous UO{sub 2} fuel system, and the heat transfer through unit cells representing a wide variety of fuel conditions was calculated using a finite element computer program. Conduction through solid fuel matrix as wekk as pore gas, and radiative exchange at pore surface was incorporated. A variety of pore compositions were investigated: porosity, pore size, shape and orientation, temperature, and temperature gradient. Calculations were made in which pore surface radiation was both modeled and neglected. The difference between yielding the integral contribution of radiative heat transfer mechanism to overall heat transport. Results indicate that radiative component of heat transfer within pores is small for conditions representative of light water reactor fuel, typically less than 1% of total heat transport. It is much larger, however, for conditions present in liquid metal fast breeder reactor fuel; during restructuring of this fuel type early in life, the radiative heat transfer mode was shown to contribute as much as 10-20% of total heat transport in hottest regions of fuel.

Hayes, S.L. [Texas A and M Univ., College Station, TX (United States)] [Texas A and M Univ., College Station, TX (United States)

1992-12-01T23:59:59.000Z

32

Development of a Heat Transfer Model for the Integrated Facade Heating  

E-Print Network [OSTI]

the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts...

Gong, X.; Archer, D. H.; Claridge, D. E.

2007-01-01T23:59:59.000Z

33

Heat Transfer in Complex Fluids  

SciTech Connect (OSTI)

Amongst the most important constitutive relations in Mechanics, when characterizing the behavior of complex materials, one can identify the stress tensor T, the heat flux vector q (related to heat conduction) and the radiant heating (related to the radiation term in the energy equation). Of course, the expression 'complex materials' is not new. In fact, at least since the publication of the paper by Rivlin & Ericksen (1955), who discussed fluids of complexity (Truesdell & Noll, 1992), to the recently published books (Deshpande et al., 2010), the term complex fluids refers in general to fluid-like materials whose response, namely the stress tensor, is 'non-linear' in some fashion. This non-linearity can manifest itself in variety of forms such as memory effects, yield stress, creep or relaxation, normal-stress differences, etc. The emphasis in this chapter, while focusing on the constitutive modeling of complex fluids, is on granular materials (such as coal) and non-linear fluids (such as coal-slurries). One of the main areas of interest in energy related processes, such as power plants, atomization, alternative fuels, etc., is the use of slurries, specifically coal-water or coal-oil slurries, as the primary fuel. Some studies indicate that the viscosity of coal-water mixtures depends not only on the volume fraction of solids, and the mean size and the size distribution of the coal, but also on the shear rate, since the slurry behaves as shear-rate dependent fluid. There are also studies which indicate that preheating the fuel results in better performance, and as a result of such heating, the viscosity changes. Constitutive modeling of these non-linear fluids, commonly referred to as non-Newtonian fluids, has received much attention. Most of the naturally occurring and synthetic fluids are non-linear fluids, for example, polymer melts, suspensions, blood, coal-water slurries, drilling fluids, mud, etc. It should be noted that sometimes these fluids show Newtonian (linear) behavior for a given range of parameters or geometries; there are many empirical or semi-empirical constitutive equations suggested for these fluids. There have also been many non-linear constitutive relations which have been derived based on the techniques of continuum mechanics. The non-linearities oftentimes appear due to higher gradient terms or time derivatives. When thermal and or chemical effects are also important, the (coupled) momentum and energy equations can give rise to a variety of interesting problems, such as instability, for example the phenomenon of double-diffusive convection in a fluid layer. In Conclusion, we have studied the flow of a compressible (density gradient type) non-linear fluid down an inclined plane, subject to radiation boundary condition. The heat transfer is also considered where a source term, similar to the Arrhenius type reaction, is included. The non-dimensional forms of the equations are solved numerically and the competing effects of conduction, dissipation, heat generation and radiation are discussed. It is observed that the velocity increases rapidly in the region near the inclined surface and is slower in the region near the free surface. Since R{sub 7} is a measure of the heat generation due to chemical reaction, when the reaction is frozen (R{sub 7}=0.0) the temperature distributions would depend only on R{sub 1}, and R{sub 2}, representing the effects of the pressure force developed in the material due to the distribution, R{sub 3} and R{sub 4} viscous dissipation, R{sub 5} the normal stress coefficient, R{sub 6} the measure of the emissivity of the particles to the thermal conductivity, etc. When the flow is not frozen (RP{sub 7} > 0) the temperature inside the flow domain is much higher than those at the inclined and free surfaces. As a result, heat is transferred away from the flow toward both the inclined surface and the free surface with a rate that increases as R{sub 7} increases. For a given temperature, an increase in {zeta} implies that the activation energy is smaller and thus, the reaction ra

Mehrdad Massoudi

2012-01-01T23:59:59.000Z

34

Radiative heat transfer between dielectric bodies  

E-Print Network [OSTI]

The recent development of a scanning thermal microscope (SThM) has led to measurements of radiative heat transfer between a heated sensor and a cooled sample down to the nanometer range. This allows for comparision of the known theoretical description of radiative heat transfer, which is based on fluctuating electrodynamics, with experiment. The theory itself is a macroscopic theory, which can be expected to break down at distances much smaller than 10-8m. Against this background it seems to be reasonable to revisit the known macroscopic theory of fluctuating electrodynamics and of radiative heat transfer.

Svend-Age Biehs

2011-03-16T23:59:59.000Z

35

"Nanotechnology Enabled Advanced Industrial Heat Transfer Fluids"  

SciTech Connect (OSTI)

ABSTRACT Nanotechnology Enabled Advanced industrial Heat Transfer Fluids” Improving the efficiency of Industrial Heat Exchangers offers a great opportunity to improve overall process efficiencies in diverse industries such as pharmaceutical, materials manufacturing and food processing. The higher efficiencies can come in part from improved heat transfer during both cooling and heating of the material being processed. Additionally, there is great interest in enhancing the performance and reducing the weight of heat exchangers used in automotives in order to increase fuel efficiency. The goal of the Phase I program was to develop nanoparticle containing heat transfer fluids (e.g., antifreeze, water, silicone and hydrocarbon-based oils) that are used in transportation and in the chemical industry for heating, cooling and recovering waste heat. Much work has been done to date at investigating the potential use of nanoparticle-enhanced thermal fluids to improve heat transfer in heat exchangers. In most cases the effect in a commercial heat transfer fluid has been marginal at best. In the Phase I work, we demonstrated that the thermal conductivity, and hence heat transfer, of a fluid containing nanoparticles can be dramatically increased when subjected to an external influence. The increase in thermal conductivity was significantly larger than what is predicted by commonly used thermal models for two-phase materials. Additionally, the surface of the nanoparticles was engineered so as to have a minimal influence on the viscosity of the fluid. As a result, a nanoparticle-laden fluid was successfully developed that can lead to enhanced heat transfer in both industrial and automotive heat exchangers

Dr. Ganesh Skandan; Dr. Amit Singhal; Mr. Kenneth Eberts; Mr. Damian Sobrevilla; Prof. Jerry Shan; Stephen Tse; Toby Rossmann

2008-06-12T23:59:59.000Z

36

Heat and mass transfer considerations in advanced heat pump systems  

SciTech Connect (OSTI)

Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.

Panchal, C.B.; Bell, K.J.

1992-08-01T23:59:59.000Z

37

Heat and mass transfer considerations in advanced heat pump systems  

SciTech Connect (OSTI)

Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.

Panchal, C.B.; Bell, K.J.

1992-01-01T23:59:59.000Z

38

Heat Transfer Derivation of differential equations for heat transfer conduction  

E-Print Network [OSTI]

) or kW *h or Btu. U is the change in stored energy, in units of kW *h (kWh) or Btu. qx is the heat conducted (heat flux) into the control volume at surface edge x, in units of kW/m2 or Btu/(h-ft2). qx volume is positive), in kW/m3 or Btu/(h-ft3) (a heat sink, heat drawn out of the volume, is negative

Veress, Alexander

39

Heat-transfer coefficients in agitated vessels. Sensible heat models  

SciTech Connect (OSTI)

Transient models for sensible heat were developed to assess the thermal performance of agitated vessels with coils and jackets. Performance is quantified with the computation of heat-transfer coefficients by introducing vessel heating and cooling data into model equations. Of the two model categories studied, differential and macroscopic, the latter is preferred due to mathematical simplicity and lower sensitivity to experimental data variability.

Kumpinsky, E. [Ashland Chemical Co., Columbus, OH (United States). Research and Development Dept.

1995-12-01T23:59:59.000Z

40

Dynamics of heat transfer between nano systems  

E-Print Network [OSTI]

We develop a dynamical theory of heat transfer between two nano systems. In particular, we consider the resonant heat transfer between two nanoparticles due to the coupling of localized surface modes having a finite spectral width. We model the coupled nanosystem by two coupled quantum mechanical oscillators, each interacting with its own heat bath, and obtain a master equation for the dynamics of heat transfer. The damping rates in the master equation are related to the lifetimes of localized plasmons in the nanoparticles. We study the dynamics towards the steady state and establish connection with the standard theory of heat transfer in steady state. For strongly coupled nano particles we predict Rabi oscillations in the mean occupation number of surface plasmons in each nano particle.

Svend-Age Biehs; Girish S. Agarwal

2012-10-18T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Heat transfer pathways in underfloor air distribution (UFAD) systems  

E-Print Network [OSTI]

permission. QC-06-053 Heat Transfer Pathways in Underfloorchange the dynamics of heat transfer within a room as wellchange the dynamics of heat transfer within a room as well

Bauman, F.; Jin, H.; Webster, T.

2006-01-01T23:59:59.000Z

42

Optimization of Phase Change Heat Transfer in Biporous Media  

E-Print Network [OSTI]

in Compressed Open- Celled Foams”. Numerical Heat Transfer,open the need to effectively estimate the heat transfer inopen porosities for different packed bed of spheres arrangements. The scaled heat transfer

Reilly, Sean

2013-01-01T23:59:59.000Z

43

Passive heat transfer means for nuclear reactors  

DOE Patents [OSTI]

An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. Means such as shrouding normally isolated the secondary condensing section from effective heat transfer with the heat sink, but a sensor responds to overheat conditions of the reactor to open the shrouding, which thereby increases the cooling capacity of the heat pipe. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.

Burelbach, James P. (Glen Ellyn, IL)

1984-01-01T23:59:59.000Z

44

Modelling Heat Transfer of Carbon Nanotubes  

E-Print Network [OSTI]

Modelling heat transfer of carbon nanotubes is important for the thermal management of nanotube-based composites and nanoelectronic device. By using a finite element method for three-dimensional anisotropic heat transfer, we have simulated the heat conduction and temperature variations of a single nanotube, a nanotube array and a part of nanotube-based composite surface with heat generation. The thermal conductivity used is obtained from the upscaled value from the molecular simulations or experiments. Simulations show that nanotube arrays have unique cooling characteristics due to its anisotropic thermal conductivity.

Yang, Xin-She

2010-01-01T23:59:59.000Z

45

Clean Boiler Waterside Heat Transfer Surfaces  

SciTech Connect (OSTI)

This revised ITP tip sheet on cleaning boiler water-side heat transfer surfaces provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

Not Available

2006-01-01T23:59:59.000Z

46

Analysis of Heat Transfer in Metal Hydride Based Hydrogen Separation  

SciTech Connect (OSTI)

This thesis presents a transient heat transfer analysis to model the heat transfer in the Pd/k packed column, and the impact of adding metallic foam.

Fleming, W.H. Jr.

1999-10-20T23:59:59.000Z

47

ME 339 Heat Transfer ABET EC2000 syllabus  

E-Print Network [OSTI]

ME 339­ Heat Transfer Page 1 ABET EC2000 syllabus ME 339 ­ Heat Transfer Spring 2010 Required convection; radiation; introduction to phase change heat transfer and to heat exchangers. Prerequisite(s): ME, Fundamentals of Heat and Mass Transfer, 6th ed., Wiley Other Required Material: NA Course Objectives

Ben-Yakar, Adela

48

Nanoparticle enhanced ionic liquid heat transfer fluids  

DOE Patents [OSTI]

A heat transfer fluid created from nanoparticles that are dispersed into an ionic liquid is provided. Small volumes of nanoparticles are created from e.g., metals or metal oxides and/or alloys of such materials are dispersed into ionic liquids to create a heat transfer fluid. The nanoparticles can be dispersed directly into the ionic liquid during nanoparticle formation or the nanoparticles can be formed and then, in a subsequent step, dispersed into the ionic liquid using e.g., agitation.

Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.; Gray, Joshua R.; Garcia-Diaz, Brenda L.

2014-08-12T23:59:59.000Z

49

Examination of Liquid Fluoride Salt Heat Transfer  

SciTech Connect (OSTI)

The need for high efficiency power conversion and energy transport systems is increasing as world energy use continues to increase, petroleum supplies decrease, and global warming concerns become more prevalent. There are few heat transport fluids capable of operating above about 600oC that do not require operation at extremely high pressures. Liquid fluoride salts are an exception to that limitation. Fluoride salts have very high boiling points, can operate at high temperatures and low pressures and have very good heat transfer properties. They have been proposed as coolants for next generation fission reactor systems, as coolants for fusion reactor blankets, and as thermal storage media for solar power systems. In each case, these salts are used to either extract or deliver heat through heat exchange equipment, and in order to design this equipment, liquid salt heat transfer must be predicted. This paper discusses the heat transfer characteristics of liquid fluoride salts. Historically, heat transfer in fluoride salts has been assumed to be consistent with that of conventional fluids (air, water, etc.), and correlations used for predicting heat transfer performance of all fluoride salts have been the same or similar to those used for water conventional fluids an, water, etc). A review of existing liquid salt heat transfer data is presented, summarized, and evaluated on a consistent basis. Less than 10 experimental data sets have been found in the literature, with varying degrees of experimental detail and measured parameters provided. The data has been digitized and a limited database has been assembled and compared to existing heat transfer correlations. Results vary as well, with some data sets following traditional correlations; in others the comparisons are less conclusive. This is especially the case for less common salt/materials combinations, and suggests that additional heat transfer data may be needed when using specific salt eutectics in heat transfer equipment designs. All of the data discussed above were taken under forced convective conditions (both laminar and turbulent). Some recent data taken at ORNL under free convection conditions are also presented and results discussed. This data was taken using a simple crucible experiment with an instrumented nickel heater inserted in the salt to induce natural circulation within the crucible. The data was taken over a temperature range of 550oC to 650oC in FLiNaK salt. This data covers both laminar and turbulent natural convection conditions, and is compared to existing forms of natural circulation correlations.

Yoder Jr, Graydon L [ORNL] [ORNL

2014-01-01T23:59:59.000Z

50

Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger  

E-Print Network [OSTI]

The concept of a "Divided-flow" heat exchanger is generalized by locating the shell inlet (or outlet) nozzle off-center such that the two shell sub-streams are unequal and traverse unequal flow paths. The governing equations for heat transfer...

Singh, K. P.

1979-01-01T23:59:59.000Z

51

Heat Transfer in Underground Rail Tunnels  

E-Print Network [OSTI]

The transfer of heat between the air and surrounding soil in underground tunnels ins investigated, as part of the analysis of environmental conditions in underground rail systems. Using standard turbulent modelling assumptions, flow profiles are obtained in both open tunnels and in the annulus between a tunnel wall and a moving train, from which the heat transfer coefficient between the air and tunnel wall is computed. The radial conduction of heat through the surrounding soil resulting from changes in the temperature of air in the tunnel are determined. An impulse change and an oscillating tunnel air temperature are considered separately. The correlations between fluctuations in heat transfer coefficient and air temperature are found to increase the mean soil temperature. Finally, a model for the coupled evolution of the air and surrounding soil temperature along a tunnel of finite length is given.

Sadokierski, Stefan

2007-01-01T23:59:59.000Z

52

Numerical methods in heat transfer  

SciTech Connect (OSTI)

This book contains nine papers. Some of the titles are: Numerical calculation of bubble growth in nucleate boiling from inception through departure; An evaluation of a translator for finite element data to resistor/capacitor data for the heat diffusion; Thermophoretic deposition due to jet impingement on an inclined plane; and A three-dimensional boundary-fitted coordinate system.

Emery, A.F.; Douglass, R.W.

1988-01-01T23:59:59.000Z

53

Analysis of heat transfer in unlooped and looped pulsating  

E-Print Network [OSTI]

Analysis of heat transfer in unlooped and looped pulsating heat pipes M.B. Sha®i and A. Faghri of Mechnical Engineering, New Mexico State University, Las Cruces, USA Keywords Heat transfer, Condensation, Tubing Abstract An advanced heat transfer model for both unlooped and looped Pulsating Heat Pipes (PHPs

Zhang, Yuwen

54

Radiative Heat Transfer between Neighboring Particles  

E-Print Network [OSTI]

The near-field interaction between two neighboring particles is known to produce enhanced radiative heat transfer. We advance in the understanding of this phenomenon by including the full electromagnetic particle response, heat exchange with the environment, and important radiative corrections both in the distance dependence of the fields and in the particle absorption coefficients. We find that crossed terms of electric and magnetic interactions dominate the transfer rate between gold and SiC particles, whereas radiative corrections reduce it by several orders of magnitude even at small separations. Radiation away from the dimer can be strongly suppressed or enhanced at low and high temperatures, respectively. These effects must be taken into account for an accurate description of radiative heat transfer in nanostructured environments.

Alejandro Manjavacas; F. Javier Garcia de Abajo

2012-01-26T23:59:59.000Z

55

Heat transfer analysis in Stirling engine heat input system  

SciTech Connect (OSTI)

One of the major factor in commercialization of Stirling engine is mass productivity, and the heat input system including tubular heater is one of the obstacles to mass production because of its complexity in shape and difficulty in manufacturing, which resulted from using oxidation-resistant, low-creep alloys which are not easy to machine and weld. Therefore a heater heat exchanger which is very simple in shape and easy to make has been devised, and a burner system appropriate to this heater also has been developed. In this paper specially devised heat input system which includes a heater shell shaped like U-cup and a flame tube located in the heater shell is analyzed in point of heat transfer processes to find optimum heat transfer. To enhance the heat transfer from the flame tube to the heater shell wall, it is required that the flame tube diameter be enlarged as close to the heater shell diameter as possible, and the flame tube temperature be raised as high as possible. But the enlargement of the flame tube diameter should be restricted by the state of combustion affected by hydraulic resistance of combustion gas, and the boost of the flame tube temperature should be considered carefully in the aspects of the flame tube`s service life.

Chung, W.; Kim, S. [LG Electronics Inc., Seoul (Korea, Republic of). Living System Lab.

1995-12-31T23:59:59.000Z

56

Self supporting heat transfer element  

DOE Patents [OSTI]

The present invention provides an improved internal heat exchange element arranged so as to traverse the inside diameter of a container vessel such that it makes good mechanical contact with the interior wall of that vessel. The mechanical element is fabricated from a material having a coefficient of thermal conductivity above about 0.8 W cm.sup.-1.degree. K.sup.-1 and is designed to function as a simple spring member when that member has been cooled to reduce its diameter to just below that of a cylindrical container or vessel into which it is placed and then allowed to warm to room temperature. A particularly important application of this invention is directed to a providing a simple compartmented storage container for accommodating a hydrogen absorbing alloy.

Story, Grosvenor Cook (Livermore, CA); Baldonado, Ray Orico (Livermore, CA)

2002-01-01T23:59:59.000Z

57

Cooperative heat transfer and ground coupled storage system  

DOE Patents [OSTI]

A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.

Metz, Philip D. (Rocky Point, NY)

1982-01-01T23:59:59.000Z

58

Convective heat transfer in rotating, circular channels  

E-Print Network [OSTI]

Nusselt number values for flow in a rotating reference frame are obtained through computational fluid dynamic (CFD) analysis for Rossby numbers Ro ~1-4 and Reynolds numbers Re ~1,000-2,000. The heat-transfer model is first ...

Hogan, Brenna Elizabeth

2012-01-01T23:59:59.000Z

59

Heat Transfer between Graphene and Amorphous SiO2  

E-Print Network [OSTI]

We study the heat transfer between graphene and amorphous SiO2. We include both the heat transfer from the area of real contact, and between the surfaces in the non-contact region. We consider the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies, and the heat transfer by the gas in the non-contact region. We find that the dominant contribution to the heat transfer result from the area of real contact, and the calculated value of the heat transfer coefficient is in good agreement with the value deduced from experimental data.

B. N. J. Persson; H. Ueba

2010-07-22T23:59:59.000Z

60

CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER  

E-Print Network [OSTI]

1 CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER for evaporation heat transfer coefficient of refrigerant R-134a flowing in a plate heat exchanger. Correlation schemes proposed by Yan and Lin (1999b) for modeling the heat transfer coefficient in both a single- phase

Kandlikar, Satish

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Boiling heat transfer in a hydrofoil-based micro pin fin heat sink  

E-Print Network [OSTI]

Boiling heat transfer in a hydrofoil-based micro pin fin heat sink Ali KosĂ?ar, Yoav Peles-based micro pin fin heat sink was investigated. Average two-phase heat transfer coefficients were obtained intermittent and spray-annular flows. Heat transfer coefficient trends and flow morphologies were used to infer

Peles, Yoav

62

INVESTIGATING THE EFFECT OF HEATING METHOD ON POOL BOILING HEAT TRANSFER  

E-Print Network [OSTI]

INVESTIGATING THE EFFECT OF HEATING METHOD ON POOL BOILING HEAT TRANSFER Satish G. Kandlikar surfaces in laboratories to obtain the heat transfer coefficient data. In many process applications however, a fluid stream is employed as the heating medium. The heat transfer data generated with the electrically

Kandlikar, Satish

63

Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Systems Lehigh University: Novel Thermal Storage Technologies for Concentrating Solar Power Generation Terrafore: Heat Transfer and Latent Heat Storage in Inorganic Molten...

64

Nanofluid heat transfer enhancement for nuclear reactor applications  

E-Print Network [OSTI]

Colloidal dispersions of nanoparticles are known as `nanofluids'. Such engineered fluids offer the potential for enhancing heat transfer, particularly boiling heat transfer, while avoiding the drawbacks (i.e., erosion, ...

Buongiorno, Jacopo

65

Hydrodynamics, heat transfer and flow boiling instabilities in microchannels   

E-Print Network [OSTI]

Boiling in microchannels is a very efficient mode of heat transfer with high heat and mass transfer coefficients achieved. Less pumping power is required for two-phase flows than for single-phase liquid flows to achieve ...

Barber, Jacqueline Claire

2010-01-01T23:59:59.000Z

66

Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet)  

SciTech Connect (OSTI)

Fact sheet describing NREL CSP Program capabilities in the area of thermal storage and advanced heat transfer fluids: measuring thermophysical properties, measuring fluid flow and heat transfer, and simulating flow of thermal energy and fluid.

Not Available

2010-08-01T23:59:59.000Z

67

Experimental evaluation of heat transfer characteristics of silica nanofluid  

E-Print Network [OSTI]

The laminar convective heat transfer characteristics were investigated for silica nanofluid. An experimental loop was built to obtain heat transfer coefficients for single-phase nanofluids in a circular conduit in laminar ...

Zhang, Zihao, S.B. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

68

Low-melting point heat transfer fluid  

DOE Patents [OSTI]

A low-melting point, heat transfer fluid made of a mixture of five inorganic salts including about 29.1-33.5 mol % LiNO.sub.3, 0-3.9 mol % NaNO.sub.3, 2.4-8.2 mol % KNO.sub.3, 18.6-19.9 mol % NaNO.sub.2, and 40-45.6 mol % KNO.sub.2. These compositions can have liquidus temperatures below 80.degree. C. for some compositions.

Cordaro, Joseph Gabriel (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)

2010-11-09T23:59:59.000Z

69

Molten Salt Heat Transfer Fluid (HTF)  

Energy Innovation Portal (Marketing Summaries) [EERE]

Sandia has developed a heat transfer fluid (HTF) for use at elevated temperatures that has a lower freezing point than any molten salt mixture available commercially. This allows the HTF to be used in applications in which the expensive parasitic energy costs necessary for freeze protection can be significantly reduced. The higher operating temperature limit significantly increases power cycle efficiency and overall power plan sun-to-net electric efficiency....

2013-03-12T23:59:59.000Z

70

High flux heat transfer in a target environment  

E-Print Network [OSTI]

High flux heat transfer in a target environment T. Davenne High Power Targets Group Rutherford Valid for: Consider turbulent heat transfer in a 1.5mm diameter pipe ­ Dittus Boelter correlation Achenbach correlation for heat transfer in a packed bed of spheres Max power density for a sphere

McDonald, Kirk

71

Proceeding of the 1st International Forum on Heat Transfer  

E-Print Network [OSTI]

Proceeding of the 1st International Forum on Heat Transfer November 24-26, 2004, Kyoto, Japan Paper No. HEAT TRANSFER PROBLEMS RELATED WITH CARBON NANOTUBES BY MOLECULAR DYNAMICS-BASED SIMULATIONS Dynamics Simulation, Thermal Conductance ABSTRACT Several heat transfer problems related to single

Maruyama, Shigeo

72

Heat transfer from nanoparticles: a corresponding state analysis  

E-Print Network [OSTI]

Heat transfer from nanoparticles: a corresponding state analysis Samy Merabia , Sergei Shenogin that inhibits the formation of an insulating vapor film. heat transfer | nanoparticles | liquids | phase transitions Introduction Sub-micron scale heat transfer is attracting a growing inter- est, motivated by both

Paris-Sud XI, Université de

73

STEADY STATE LIQUID CRYSTAL THERMOGRAPHY AND HEAT TRANSFER MEASUREMENTS ON  

E-Print Network [OSTI]

Chapter V STEADY STATE LIQUID CRYSTAL THERMOGRAPHY AND HEAT TRANSFER MEASUREMENTS ON SURFACES Composite Heat Transfer Surface Liquid Crystal Image Processing Technique V . 4 Experimental Results and Discussion Test Conditions and Data Analysis Application to Endwall Heat Transfer Problem Further Application

Camci, Cengiz

74

16 Heat Transfer and Air Flow in a Domestic Refrigerator  

E-Print Network [OSTI]

445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR GĂ©nie Industriel........................................................................447 16.2.2 Heat Transfer and Airflow Near a Vertical Plate..................................................448 16.2.3 Heat Transfer and Airflow in Empty Closed Cavity

Paris-Sud XI, Université de

75

RADIATIVE HEAT TRANSFER WITH QUASI-MONTE CARLO METHODS  

E-Print Network [OSTI]

RADIATIVE HEAT TRANSFER WITH QUASI-MONTE CARLO METHODS A. Kersch1 W. Moroko2 A. Schuster1 1Siemens of Quasi-Monte Carlo to this problem. 1.1 Radiative Heat Transfer Reactors In the manufacturing of the problems which can be solved by such a simulation is high accuracy modeling of the radiative heat transfer

76

Dt2boool2> Nora Heat Transfer Correlations  

E-Print Network [OSTI]

Dt2boool2> Nora Heat Transfer Correlations in Nuclear Reactor Safety Calculations VW �Aiiatt�aii #12;fcflison cufiMiMltt lor yhdyiifci aomicantfgy RIS0-M-25O4 6«.*). HEAT TRANSFER of work 26 3. PRESENT KNOWLEDGE 27 3.1. General considerations 27 3.2. Heat transfer in different flow

77

Proceedings of NHTC'00: 34 th National Heat Transfer Conference  

E-Print Network [OSTI]

Proceedings of NHTC'00: 34 th National Heat Transfer Conference Pittsburgh, Pennsylvania, August 20 ON SINGLE- AND TWO-PHASE HEAT TRANSFER CHARACTERISTICS IN A MICROCHANNEL Michael S June Graduate Student study investigates the heat transfer characteristics of single and two-phase flows in a 200 m wide

Kandlikar, Satish

78

Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference  

E-Print Network [OSTI]

Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference July 19-23, 2009, San Francisco, CA, USA HT2009-88261 SIMULATION OF FOCUSED RADIATION PROPAGATION AND TRANSIENT HEAT TRANSFER IN TURBID-dependent radiation and conduction bio-heat transfer model. Ultrashort pulsed radiation transport in the cylindrical

Guo, Zhixiong "James"

79

innovati nAdvanced Heat Transfer Technologies Increase Vehicle  

E-Print Network [OSTI]

innovati nAdvanced Heat Transfer Technologies Increase Vehicle Performance and Reliability Keeping with industry to develop and demonstrate advanced heat transfer technologies such as jet impingement cooling for thermal grease and significantly enhances direct heat transfer from the electronics. A series of nozzles

80

RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1  

E-Print Network [OSTI]

509 RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1 C. JOHANNES Service de Recherches Appliquées, L boiling, forced convection heat transfer. Relations between critical nucleate flux and some parameters confronted with the problem of calculating the heat transfer from the helium to the superconducting material

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION  

E-Print Network [OSTI]

Forced Convection Heat Transfer in Curved RectangularInfluence of Curvature on Heat Transfer to IncompressibleT. , "Forced Convective Heat Transfer in a Curved Channel

Yee, G.

2010-01-01T23:59:59.000Z

82

Heat Transfer Operators Associated with Quantum Operations  

E-Print Network [OSTI]

Any quantum operation applied on a physical system is performed as a unitary transformation on a larger extended system. If the extension used is a heat bath in thermal equilibrium, the concomitant change in the state of the bath necessarily implies a heat exchange with it. The dependence of the average heat transferred to the bath on the initial state of the system can then be found from the expectation value of a hermitian operator, which is named as the heat transfer operator (HTO). The purpose of this article is the investigation of the relation between the HTOs and the associated quantum operations. Since, any given quantum operation on a system can be realized by different baths and unitaries, many different HTOs are possible for each quantum operation. On the other hand, there are also strong restrictions on the HTOs which arise from the unitarity of the transformations. The most important of these is the Landauer erasure principle. This article is concerned with the question of finding a complete set of restrictions on the HTOs that are associated with a given quantum operation. An answer to this question has been found only for a subset of quantum operations. For erasure operations, these characterizations are equivalent to the generalized Landauer erasure principle. For the case of generic quantum operations however, it appears that the HTOs obey further restrictions which cannot be obtained from the entropic restrictions of the generalized Landauer erasure principle.

Ç. Aksak; S. Turgut

2011-04-14T23:59:59.000Z

83

A comparison of the heat transfer capabilities of two manufacturing methods for high heat flux water-cooled devices  

SciTech Connect (OSTI)

An experimental program was undertaken to compare the heat transfer characteristics of water-cooled copper devices manufactured via conventional drilled passage construction and via a technique whereby molten copper is cast over a network of preformed cooling tubes. Two similar test blocks were constructed; one using the drilled passage technique, the other via casting copper over Monel pipe. Each test block was mounted in a vacuum system and heated uniformly on the top surface using a swept electron beam. From the measured absorbed powers and resultant temperatures, an overall heat transfer coefficient was calculated. The maximum heat transfer coefficient calculated for the case of the drilled passage test block was 2534 Btu/hr/ft/sup 2///sup 0/F. This corresponded to an absorbed power density of 320 w/cm/sup 2/ and resulted in a maximum recorded copper temperature of 346/sup 0/C. Corresponding figures for the cast test block were 363 Btu/hr/ft/sup 2///sup 0/F, 91 w/cm/sup 2/, and 453/sup 0/C.

McKoon, R.H.

1986-10-01T23:59:59.000Z

84

Analysis of roll gap heat transfers in hot steel strip rolling through roll temperature sensors and heat transfer models  

E-Print Network [OSTI]

Analysis of roll gap heat transfers in hot steel strip rolling through roll temperature sensors and heat transfer models N. Legrand1,a , N. Labbe1,b D. Weisz-Patrault2,c , A. Ehrlacher2,d , T. Luks3,e heat transfers during pilot hot steel strip rolling. Two types of temperature sensors (drilled and slot

Paris-Sud XI, Université de

85

Numerical study of high heat ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b  

E-Print Network [OSTI]

Numerical study of high heat ÂŻux pool boiling heat transfer Ying He a,*, Masahiro Shoji b , Shigeo simulation model of boiling heat transfer is proposed based on a numerical macrolayer model [S. Maruyama, M. Shoji, S. Shimizu, A numerical simulation of transition boiling heat transfer, in: Proceedings

Maruyama, Shigeo

86

Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers  

E-Print Network [OSTI]

Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers Paul A transfer along the tube wall of the compact heat exchanger through the use of winglets placed of attack, aspect ratio, direction, and shape, were all evaluated based on heat transfer augmentation

Thole, Karen A.

87

Journal of Enhanced Heat Transfer, 19 (5): 457476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT  

E-Print Network [OSTI]

Journal of Enhanced Heat Transfer, 19 (5): 457­476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT microfin tubes, most of the heat transfer and friction factor studies were focused on the turbulent region. However, there is a lack of information about the heat transfer and friction factor behavior of microfin

Ghajar, Afshin J.

88

MERLOT: a model for flow and heat transfer through porous media for high heat flux applications  

E-Print Network [OSTI]

MERLOT: a model for flow and heat transfer through porous media for high heat flux applications A Abstract Fusion power plant studies have found helium to be an attractive coolant based on its safety tend to provide modest heat transfer performance due to their inherently low heat capacity and heat

Raffray, A. René

89

Radial heat transfer from a moving plasma  

E-Print Network [OSTI]

. The plasma temperature is assumed constant axially and rad'ally and equal to the value at the exit of tl. e arc. chamber. This temperature was used in the determ'r. a- tion of the Nusselt number a, d the Reynolds number used in the above correlatior... and measured values and estimated the accuracy of the heat flux data to be within Measurements of the total continuum radiatior. or simply the energy transferred by radiation from a wall stabilized argon plasma arc were made by Barzelay (14), Comparisons...

Johnson, James Randall

1966-01-01T23:59:59.000Z

90

Thermal conductivity and heat transfer in superlattices  

SciTech Connect (OSTI)

Understanding the thermal conductivity and heat transfer processes in superlattice structures is critical for the development of thermoelectric materials and devices based on quantum structures. This work reports progress on the modeling of thermal conductivity of superlattice structures. Results from the models established based on the Boltzmann transport equation could explain existing experimental results on the thermal conductivity of semiconductor superlattices in both in plane and cross-plane directions. These results suggest the possibility of engineering the interfaces to further reduce thermal conductivity of superlattice structures.

Chen, G.; Neagu, M.; Borca-Tasciuc, T.

1997-07-01T23:59:59.000Z

91

Heat Transfer Laboratory | Argonne National Laboratory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr FlickrGuidedCH2M HILL SecretaryHazmat work opensHeat Transfer

92

Outside heat transfer coefficients for atmospheric coolers  

E-Print Network [OSTI]

for the same conditions of operation is given by Robinson ()i. 9). TABLE I Comparison of various authors' values of outside heat transfer coefficients Btugour x square foot x F ~ ) Adams (1 ) 1001 1041 915 74, 6 1021 981 910 Clarke 945 997 841... ozeventing any recycling of the wet air. "M~4~ 1 f jc, : 1 C. X L, w 38 Cooled water fro~ the tower is centrifugally pmnoed through a 2 inch pipe to a rotameter and a I and operated control valve, Figure 8, before entering a 1 1/g inch by 5 foot...

George, David Mark

1950-01-01T23:59:59.000Z

93

Summary Weusedthreemethodstomeasureboundarylayer conductance to heat transfer (gbH) and water vapor transfer  

E-Print Network [OSTI]

Summary Weusedthreemethodstomeasureboundarylayer conductance to heat transfer (gbH) and water vapor of transpiration). The boundary layer conductance to heat transfer is small enough that leaf temperature can become diffusion, the boundary layer around a leaf also provides resistance to the transfer of heat between a leaf

Martin, Timothy

94

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures  

E-Print Network [OSTI]

using boiling heat transfer, it opens up a new direction forusing boiling heat transfer. This opens up a new direction

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

95

Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools  

E-Print Network [OSTI]

Goss. (1998). “Local heat transfer in open frame cavities ofthe local heat transfer in cavities open to the exterior

Gustavsen, Arild

2009-01-01T23:59:59.000Z

96

Heat transfer to impacting drops and post critical heat flux dispersed flow  

E-Print Network [OSTI]

Heat transfer to drops impacting on a hot surface is examined in context of dispersions of flowing, boiling fluids. The liquid contribution to heat transfer from a hot tube to a two-phase dispersion is formulated in terms ...

Kendall, Gail E.

1978-01-01T23:59:59.000Z

97

FLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS  

E-Print Network [OSTI]

= heat, f = LO-mode, g = LO, h = LA-mode, i = negligible, j = remote heat sink 7/ 70 #12;Heat conductionFLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS Mihir Sen Department · Shallow water analogy · Vorticity dynamics · Linear stability analysis · Numerical simulations of heat

Sen, Mihir

98

Heat transfer assembly for a fluorescent lamp and fixture  

DOE Patents [OSTI]

In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure.

Siminovitch, Michael J. (Richmond, CA); Rubenstein, Francis M. (Berkeley, CA); Whitman, Richard E. (Richmond, CA)

1992-01-01T23:59:59.000Z

99

Heat transfer assembly for a fluorescent lamp and fixture  

DOE Patents [OSTI]

In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure. 11 figs.

Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.

1992-12-29T23:59:59.000Z

100

RADIATIVE HEAT TRANSFER WITH QUASIMONTE CARLO METHODS \\Lambda  

E-Print Network [OSTI]

RADIATIVE HEAT TRANSFER WITH QUASI­MONTE CARLO METHODS \\Lambda A. Kersch 1 W. Morokoff 2 A accuracy modeling of the radiative heat transfer from the heater to the wafer. Figure 1 shows the draft Carlo simulation is often used to solve radiative transfer problems where complex physical phenomena

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

CONDUCTION HEAT TRANSFER Dr. Ruhul Amin Fall 2011  

E-Print Network [OSTI]

ME 525 CONDUCTION HEAT TRANSFER Dr. Ruhul Amin Fall 2011 Office: 201C Roberts Hall Lecture Room of conduction heat transfer. Important results which are useful for engineering application will also: 121 Roberts Hall Phone: 994-6295 Lecture Periods: 12:45- 2:00, TR TEXT: Heat Conduction, M. N. Ozisik

Dyer, Bill

102

Proceedings of NHTC'00 34th National Heat Transfer Conference  

E-Print Network [OSTI]

Proceedings of NHTC'00 34th National Heat Transfer Conference Pittsburgh, Pennsylvania, August 20­22, 2000 NHTC2000-12151 HEAT TRANSFER IN A FUEL CELL ENGINE J. Musser and C.Y. Wang Department-4848 E-mail: cxw31@psu.edu KEYWORDS: PEM, Fuel Cell Engine, Heat Generation, Current Density, System

Wang, Chao-Yang

103

Transient critical heat flux and blowdown heat-transfer studies  

SciTech Connect (OSTI)

Objective of this study is to give a best-estimate prediction of transient critical heat flux (CHF) during reactor transients and hypothetical accidents. To accomplish this task, a predictional method has been developed. Basically it involves the thermal-hydraulic calculation of the heated core with boundary conditions supplied from experimental measurements. CHF predictions were based on the instantaneous ''local-conditions'' hypothesis, and eight correlations (consisting of round-tube, rod-bundle, and transient correlations) were tested against most recent blowdown heat-transfer test data obtained in major US facilities. The prediction results are summarized in a table in which both CISE and Biasi correlations are found to be capable of predicting the early CHF of approx. 1 s. The Griffith-Zuber correlation is credited for its prediction of the delay CHF that occurs in a more tranquil state with slowly decaying mass velocity. In many instances, the early CHF can be well correlated by the x = 1.0 criterion; this is certainly indicative of an annular-flow dryout-type crisis. The delay CHF occurred at near or above 80% void fraction, and the success of the modified Zuber pool-boiling correlation suggests that this CHF is caused by flooding and pool-boiling type hydrodynamic crisis.

Leung, J.C.

1980-05-01T23:59:59.000Z

104

Sensitivity Analysis of the Gap Heat Transfer Model in BISON.  

SciTech Connect (OSTI)

This report summarizes the result of a NEAMS project focused on sensitivity analysis of the heat transfer model in the gap between the fuel rod and the cladding used in the BISON fuel performance code of Idaho National Laboratory. Using the gap heat transfer models in BISON, the sensitivity of the modeling parameters and the associated responses is investigated. The study results in a quantitative assessment of the role of various parameters in the analysis of gap heat transfer in nuclear fuel.

Swiler, Laura Painton; Schmidt, Rodney C.; Williamson, Richard (INL); Perez, Danielle (INL)

2014-10-01T23:59:59.000Z

105

IntroductiontoProcessEngineering(PTG) 5. Heat transfer  

E-Print Network [OSTI]

#5/6 IntroductiontoProcessEngineering(PTG) VST rz13 1/114 5. Heat transfer Ron Zevenhoven Ă?boProcessEngineering(PTG) VST rz13 Three heat transfer mechanisms Conduction Convection Radiation 2/114 Pic: BĂ?88 #12;#5/6 IntroductiontoProcessEngineering(PTG) VST rz13 3/114 5.1 Conductive heat transfer #5/6 Introductionto

Zevenhoven, Ron

106

Effects of solar photovoltaic panels on roof heat transfer  

E-Print Network [OSTI]

the energy performance of  photovoltaic roofs, ASHRAE Trans A thermal model for photovoltaic systems, Solar Energy, Effects of Solar Photovoltaic Panels on Roof Heat Transfer 

Dominguez, Anthony; Kleissl, Jan; Luvall, Jeffrey C

2011-01-01T23:59:59.000Z

107

Heat Transfer Interface for Thermo-Solar Energy - Energy Innovation...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Energy Efficiency Building Energy Efficiency Find More Like This Return to Search Heat Transfer Interface for Thermo-Solar Energy Lawrence Berkeley National Laboratory...

108

Characterization and Development of Advanced Heat Transfer Technologies (Presentation)  

SciTech Connect (OSTI)

This presentation gives an overview of the status and FY09 accomplishments for the NREL thermal management research project 'Characterization and Development of Advanced Heat Transfer Technologies'.

Kelly, K.

2009-05-01T23:59:59.000Z

109

Low-melting point heat transfer fluid  

DOE Patents [OSTI]

A low-melting point, heat transfer fluid comprising a mixture of LiNO.sub.3, NaNO.sub.3, KNO.sub.3, NaNO.sub.2 and KNO.sub.2 salts where the Li, Na and K cations are present in amounts of about 20-33.5 mol % Li, about 18.6-40 mol % Na, and about 40-50.3 mol % K and where the nitrate and nitrite anions are present in amounts of about 36-50 mol % NO.sub.3, and about 50-62.5 mol % NO.sub.2. These compositions can have liquidus temperatures between 70.degree. C. and 80.degree. C. for some compositions.

Cordaro, Joseph G. (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)

2011-04-12T23:59:59.000Z

110

Submersible pumping system with heat transfer mechanism  

DOE Patents [OSTI]

A submersible pumping system for downhole use in extracting fluids containing hydrocarbons from a well. In one embodiment, the pumping system comprises a rotary induction motor, a motor casing, one or more pump stages, and a cooling system. The rotary induction motor rotates a shaft about a longitudinal axis of rotation. The motor casing houses the rotary induction motor such that the rotary induction motor is held in fluid isolation from the fluid being extracted. The pump stages are attached to the shaft outside of the motor casing, and are configured to impart fluid being extracted from the well with an increased pressure. The cooling system is disposed at least partially within the motor casing, and transfers heat generated by operation of the rotary induction motor out of the motor casing.

Hunt, Daniel Francis Alan; Prenger, F. Coyne; Hill, Dallas D; Jankowski, Todd Andrew

2014-04-15T23:59:59.000Z

111

Heat transfer and pressure drop in tape generated swirl flow  

E-Print Network [OSTI]

The heat transfer and pressure drop characteristics of water in tape generated swirl flow were investigated. The test sections were electrically heated small diameter nickel tubes with tight fitting full length Inconel ...

Lopina, Robert F.

1967-01-01T23:59:59.000Z

112

2.51 Intermediate Heat and Mass Transfer, Fall 2001  

E-Print Network [OSTI]

Analysis, modeling, and design of heat and mass transfer processes with application to common technologies. Unsteady heat conduction in one or more dimensions, steady conduction in multidimensional configurations, numerical ...

Lienhard, John H., 1961-

113

Proceedings of HT'03 2003 Summer Heat Transfer Conference  

E-Print Network [OSTI]

Proceedings of HT'03 2003 Summer Heat Transfer Conference July 21­23, 2003, Las Vegas, Nevada, USA HT2003-47016 A NEW TECHNIQUE FOR HEAT FLUX DETERMINATION D.G. Walker Department of Mechanical@vt.edu ABSTRACT A new method for estimating heat fluxes from heating rate measurements and an approach to measure

Walker, D. Greg

114

Neutron behavior, reactor control, and reactor heat transfer. Volume four  

SciTech Connect (OSTI)

Volume four covers neutron behavior (neutron absorption, how big are nuclei, neutron slowing down, neutron losses, the self-sustaining reactor), reactor control (what is controlled in a reactor, controlling neutron population, is it easy to control a reactor, range of reactor control, what happens when the fuel burns up, controlling a PWR, controlling a BWR, inherent safety of reactors), and reactor heat transfer (heat generation in a nuclear reactor, how is heat removed from a reactor core, heat transfer rate, heat transfer properties of the reactor coolant).

Not Available

1986-01-01T23:59:59.000Z

115

E-Print Network 3.0 - advanced heat transfer Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Performance Evaluations Alternate... and Diagnostic Center (EADC) Ground Coupled Heat Pumps Heat and Mass Transfer in Attic Systems Industrial... and Heat Transfer...

116

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

DOE Patents [OSTI]

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

Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

1996-12-03T23:59:59.000Z

117

Internal Heat Transfer Coefficient Determination in a Packed Bed From the Transient Response Due to Solid Phase Induction Heating  

E-Print Network [OSTI]

the Hydraulic Drag and Heat Transfer Coefficients in PorousT. E. W. , 1929, “Heat Transfer: A Liquid Flowing Through a5] Locke, G. L. , 1950, “Heat Transfer and Flow Friction

Geb, David; Zhou, Feng; Catton, Ivan

2012-01-01T23:59:59.000Z

118

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

DOE Patents [OSTI]

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

Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI); Marsala, Joseph (Glen Ellyn, IL)

1994-11-29T23:59:59.000Z

119

Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel  

E-Print Network [OSTI]

Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel July 2008 Keywords: Boiling Microchannels Visualisation Flow boiling instabilities Heat transfer a b intensification heat removal. Flow boiling heat transfer in microchannel geometry and the associated flow

Aussillous, Pascale

120

Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools  

E-Print Network [OSTI]

860. Batchelor, G.K. 1954. Heat transfer by free convectionfree convection. In: Heat Transfer and Turbulent BuoyantHEAT2, A PC-program for heat transfer in two dimensions.

Gustavsen, Arild

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Measurement and analysis of gas turbine blade endwall heat transfer  

E-Print Network [OSTI]

the aerodynamic flow and external heat transfer distribution around the airfoils and end-wall surfaces. A stationary 5 vane linear cascade is designed and developed to investigate gas turbine blade endwall heat transfer and flow. The test cascade is instrumented...

Lee, Joon Ho

2001-01-01T23:59:59.000Z

122

Enhanced surfaces lead to increased heat transfer and power density.  

E-Print Network [OSTI]

Enhanced surfaces lead to increased heat transfer and power density. Inverters are used in hybrid researchers are using the coating to improve heat transfer in automotive power electron- ics devices. Photo electric vehicles (HEVs) and electric vehicles (EVs) to con- vert DC battery power into a form that can

123

Heat transfer in proteinwater interfaces Anders Lervik,ab  

E-Print Network [OSTI]

Heat transfer in protein­water interfaces Anders Lervik,ab Fernando Bresme,*ac Signe Kjelstrup of the heat diffusion equation we compute the thermal conductivity and thermal diffusivity of the proteins by about 4 nm.4 It is expected that the energy transfer between these sites may involve the concerted

Kjelstrup, Signe

124

Enhanced radiative heat transfer between nanostructured gold plates  

E-Print Network [OSTI]

We compute the radiative heat transfer between nanostructured gold plates in the framework of the scattering theory. We predict an enhancement of the heat transfer as we increase the depth of the corrugations while keeping the distance of closest approach fixed. We interpret this effect in terms of the evolution of plasmonic and guided modes as a function of the grating's geometry.

R. Guérout; J. Lussange; F. S. S. Rosa; J. -P. Hugonin; D. A. R. Dalvit; J. -J. Greffet; A. Lambrecht; S. Reynaud

2012-03-07T23:59:59.000Z

125

Gas heat transfer in a heated vertical channel under deteriorated turbulent heat transfer regime  

E-Print Network [OSTI]

Passive cooling via natural circulation of gas after a loss of coolant (LOCA) accident is one of the major goals of the Gas-cooled Fast Reactor (GFR). Due to its high surface heat flux and low coolant velocities under ...

Lee, Jeongik

2007-01-01T23:59:59.000Z

126

Gas Heat Transfer in a Heated Vertical Channel under Deteriorated Turbulent Heat Transfer Regime  

E-Print Network [OSTI]

Passive cooling via natural circulation of gas after a loss of coolant (LOCA) accident is one of the major goals of the Gas-cooled Fast Reactor (GFR). Due to its high surface heat flux and low coolant velocities under ...

Lee, Jeongik

127

Heat transfer between elastic solids with randomly rough surfaces  

E-Print Network [OSTI]

We study the heat transfer between elastic solids with randomly rough surfaces. We include both the heat transfer from the area of real contact, and the heat transfer between the surfaces in the noncontact regions. We apply a recently developed contact mechanics theory, which accounts for the hierarchical nature of the contact between solids with roughness on many different length scales. For elastic contact, at the highest (atomic) resolution the area of real contact typically consists of atomic (nanometer) sized regions, and we discuss the implications of this for the heat transfer. For solids with very smooth surfaces, as is typical in many modern engineering applications, the interfacial separation in the non-contact regions will be very small, and for this case we show the importance of the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies.

B. N. J. Persson; B. Lorenz; A. I. Volokitin

2009-08-27T23:59:59.000Z

128

Dual circuit embossed sheet heat transfer panel  

DOE Patents [OSTI]

A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed to form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet. 6 figs.

Morgan, G.D.

1984-02-21T23:59:59.000Z

129

The Advantages of Sealless Pumps in Heat Transfer Fluid Services  

E-Print Network [OSTI]

THE ADV ANTAGES OF SEALLESS PUMPS IN HEAT TRANSFER FLUID SERVICES Michael D. Smith Engineering Manager Sundstrand Fluid Handling Arvada, CO ABSTRACT The expectations for heat transfer fluid (HTF) system safety and reliability... of the issues which challenge mechanical seals. In addition, one type of sealless pump, the canned motor pump, raises the thermal efficiency of HTF systems. Waste heat from the drive motors of m'ost pumps is dissipated to the air. A shaft driven fan wastes...

Smith, M. D.

130

Enhanced two phase flow in heat transfer systems  

DOE Patents [OSTI]

A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.

Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D

2013-12-03T23:59:59.000Z

131

Nano-engineering the boiling surface for optimal heat transfer rate and critical heat flux  

E-Print Network [OSTI]

The effects on pool boiling characteristics such as critical heat flux and the heat transfer coefficient of different surface characteristics such as surface wettability, roughness, morphology, and porosity are not well ...

Phillips, Bren Andrew

2011-01-01T23:59:59.000Z

132

Heat Transfer of a Multiple Helical Coil Heat Exchanger Using a Microencapsulated Phase Change Material Slurry  

E-Print Network [OSTI]

The present study has focused on the use of coil heat exchangers (CHEs) with microencapsulated phase change material (MPCM) slurries to understand if CHEs can yield greater rates of heat transfer. An experimental study was conducted using a...

Gaskill, Travis

2012-02-14T23:59:59.000Z

133

The deterioration in heat transfer to fluids at supercritical pressure and high heat fluxes  

E-Print Network [OSTI]

At slightly supercritical pressure and in the neighborhood of the pseudo-critical temperature (defined as the temperature corresponding to the peak in specific heat at the operating pressure), the heat transfer coefficient ...

Shiralkar, B. S.

1968-01-01T23:59:59.000Z

134

Joule heating and heat transfer in poly(dimethylsiloxane) microfluidic systems  

E-Print Network [OSTI]

Joule heating and heat transfer in poly(dimethylsiloxane) microfluidic systems David Erickson microfluidic/biochip systems must have the ability to rapidly reject this heat to the surroundings. Generally it is the ability to dissipate this heat that limits the strength of the applied electric field and thus the maximum

Erickson, David

135

Heat Transfer and Cooling Techniques at Low Temperature  

E-Print Network [OSTI]

The first part of this chapter gives an introduction to heat transfer and cooling techniques at low temperature. We review the fundamental laws of heat transfer (conduction, convection and radiation) and give useful data specific to cryogenic conditions (thermal contact resistance, total emissivity of materials and heat transfer correlation in forced or boiling flow for example) used in the design of cooling systems. In the second part, we review the main cooling techniques at low temperature, with or without cryogen, from the simplest ones (bath cooling) to the ones involving the use of cryocoolers without forgetting the cooling flow techniques.

Baudouy, B

2014-01-01T23:59:59.000Z

136

AndreiG.Fedorov Title: George W. Woodruff Professorship in Heat Transfer, Combustion and  

E-Print Network [OSTI]

AndreiG.Fedorov Title: George W. Woodruff Professorship in Heat Transfer, Combustion and Energy Research Areas of Interest Heat Transfer, combustion, and energy systems Bioengineering, lab ionization and imaging for bioanalytical mass spectrometry Thermal radiation heat transfer Thermal

Garmestani, Hamid

137

HEAT TRANSFER DURING THE SHOCK-INDUCED IGNITION OF AN EXPOLSIVE GAS  

E-Print Network [OSTI]

11 Stagnation Point Heat Transfer Measurements in Air atR.M. , and Kemp, N.H. , Heat Transfer from High TemperatureProceedings of the 1963 Heat Transfer and Fluid Mechanics

Heperkan, H.

2013-01-01T23:59:59.000Z

138

Rheology and Convective Heat Transfer of Colloidal Gas Aphrons in Horizontal Minichannels  

E-Print Network [OSTI]

Single-phase convective heat transfer in microchannels: aand Newell, M. E. , 1967. Heat transfer in fully developed3 /s at 130 W. Water CGA Heat Transfer Coefficient, h (W/m 2

Tseng, H.; Pilon, L.; Warrier, G.

2006-01-01T23:59:59.000Z

139

Research on Heat Resisting Character of Hollow Building Blocks in Energy Saving Wall  

E-Print Network [OSTI]

By establishing a mathematical model with the finite difference method, the three-dimensional temperature fields of a new type of asymmetrical hollow building blocks in an energy saving wall are solved in this paper. The three forms of heat...

Zhang, Y.; He, J.; Gao, S.

2006-01-01T23:59:59.000Z

140

Experimental and numerical study of pressure drop and heat transfer in a single-phase micro-channel heat sink  

E-Print Network [OSTI]

Experimental and numerical study of pressure drop and heat transfer in a single-phase micro Received 6 July 2001; received in revised form 26 October 2001 Abstract The pressure drop and heat transfer-dimensional heat transfer characteristics of the heat sink were analyzed numerically by solving the conjugate heat

Qu, Weilin

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Fourier analysis of conductive heat transfer for glazed roofing materials  

SciTech Connect (OSTI)

For low-rise buildings, roof is the most exposed surface to solar radiation. The main mode of heat transfer from outdoor via the roof is conduction. The rate of heat transfer and the thermal impact is dependent on the thermophysical properties of roofing materials. Thus, it is important to analyze the heat distribution for the various types of roofing materials. The objectives of this paper are to obtain the Fourier series for the conductive heat transfer for two types of glazed roofing materials, namely polycarbonate and polyfilled, and also to determine the relationship between the ambient temperature and the conductive heat transfer for these materials. Ambient and surface temperature data were collected from an empirical field investigation in the campus of Universiti Teknologi MARA Shah Alam. The roofing materials were installed on free-standing structures in natural ventilation. Since the temperature data are generally periodic, Fourier series and numerical harmonic analysis are applied. Based on the 24-point harmonic analysis, the eleventh order harmonics is found to generate an adequate Fourier series expansion for both glazed roofing materials. In addition, there exists a linear relationship between the ambient temperature and the conductive heat transfer for both glazed roofing materials. Based on the gradient of the graphs, lower heat transfer is indicated through polyfilled. Thus polyfilled would have a lower thermal impact compared to polycarbonate.

Roslan, Nurhana Lyana; Bahaman, Nurfaradila; Almanan, Raja Noorliyana Raja; Ismail, Razidah [Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Zakaria, Nor Zaini [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

2014-07-10T23:59:59.000Z

142

Heat transfer during film condensation of a liquid metal vapor  

E-Print Network [OSTI]

The object of this investigation is to resolve the discrepancy between theory and experiment for the case of heat transfer durirnfilm condensation of liquid metal vapors. Experiments by previous investigators have yielded ...

Sukhatme, S. P.

1964-01-01T23:59:59.000Z

143

Survey and evaluation of techniques to augment convective heat transfer  

E-Print Network [OSTI]

This report presents a survey and evaluation of the numerous techniques which have been shown to augment convective heat transfer. These techniques are: surface promoters, including roughness and treatment; displaced ...

Bergles A. E.

1965-01-01T23:59:59.000Z

144

Effects of operating conditions on a heat transfer fluid aerosol  

E-Print Network [OSTI]

of heat transfer fluid aerosols from process leaks. To simulate industrial leaks, aerosol formation from a plain orifice into ambient air is studied by measuring liquid drop sizes and size distributions at various distances from an orifice. Measurements...

Sukmarg, Passaporn

2000-01-01T23:59:59.000Z

145

Transient Heat Transfer in TCAP Coils  

SciTech Connect (OSTI)

The Thermal Cycling Absorption Process (TCAP) is used to separate isotopes of hydrogen. TCAP involves passing a stream of mixed hydrogen isotopes through palladium deposited on kieselguhr (Pd/k) while cycling the temperature of the Pd/k. Kieselguhr is a silica mineral also called diatomite. To aid in the design of a full scale facility, the Thermal Fluids Laboratory was used by the Chemical and Hydrogen Technology Section to compare the heat transfer properties of three different configurations of stainless steel coils containing kieselguhr and helium. Testing of coils containing Pd/k and hydrogen isotopes would have been more prototypical but would have been too expensive. Three stainless steel coils filled with kieselguhr were tested; one made from 2.0 inch diameter tubing, one made from 2.0 inch diameter tubing with foam copper embedded in the kieselguhr and one made from 1.25 inch diameter tubing. It was known prior to testing that increasing the tubing diameter from 1.25 inch to 2.0 inch would slow the rate of temperature change. The primary purpose of the testing was to measure to what extent the presence of copper foam in a 2.0" tubing coil would compensate for the effect of larger diameter. Each coil was connected to a pressure gage and the coil was evacuated and backfilled with helium gas. Helium was used instead of a mixture of hydrogen isotopes for reasons of safety. Each coil was quickly immersed in a stirred bath of ethylene glycol at a temperature of approximately 100 degrees Celsius. The coil pressure increased, reflecting the increase in average temperature of its contents. The pressure transient was recored as a function of time after immersion. Because of the actual process will use Pd/k instead of kieselguhr, additional tests were run to determine the differences in thermal properties between the two materials. The method was to position a thermocouple at the center of a hollow sphere and pack the sphere with Pd/k. The sphere was sealed, quickly submerged in a bath of boiling water and the temperature transient was recorded. There sphere was then opened, the Pd/k was replaced with kieselguhr and the transient was repeated. The response was a factor of 1.4 faster for Pd/k than for kieselguhr, implying a thermal diffusivity approximately 40 percent higher than for kieselguhr. Another implication is that the transient tests with the coils would have proceeded faster if the coils had been filled with Pd/k rather than kieselguhr.

Steimke, J.L.

1999-03-09T23:59:59.000Z

146

Using Solid Particles as Heat Transfer Fluid for use in Concentrating...  

Broader source: Energy.gov (indexed) [DOE]

Using Solid Particles as Heat Transfer Fluid for use in Concentrating Solar Power (CSP) Plants Using Solid Particles as Heat Transfer Fluid for use in Concentrating Solar Power...

147

Heat transfer between anisotropic nanopartricles: Enhancement and switching  

E-Print Network [OSTI]

We theoretically study heat transfer between two anisotropic nanoparticles in vacuum, and derive closed expressions in terms of the anisotropic dipole polarizabilities. We show that transfer between two small spheroids can be many times as large as the one for two spheres of same volumes. Such increase with anisotropy is also found for the heat emission of an isolated small spheroid. Furthermore, we observe a strong dependence of transfer on the relative orientation, yielding the interpretation as a heat transfer switch. The switch quality, given as the ratio of transfer in the ``on'' and ``off'' positions, is observed to be as large as $10^3$ in the near field and even larger in the far field.

Roberta Incardone; Thorsten Emig; Matthias Krüger

2014-02-21T23:59:59.000Z

148

Heat transfer characteristics of a two-pass trapezoidal channel and a novel heat pipe  

E-Print Network [OSTI]

large variation of the local heat (mass) transfer distribution in the turn and downstream of the turn. The local heat (mass) transfer was high near the end wall and the downstream outer wall in the turn and was relatively low in two regions near...

Lee, Sang Won

2009-06-02T23:59:59.000Z

149

Heat Transfer Research 44(1), 130 (2013) ENTROPY GENERATION ANALYSIS  

E-Print Network [OSTI]

Heat Transfer Research 44(1), 1­30 (2013) ENTROPY GENERATION ANALYSIS FOR A PULSATING HEAT­vapor phase 2 Kim, Zhang, & Choi Heat Transfer Research NOMENCLATURE A area, m2 Qin,s,l sensible heat transfer into cp specific heat at constant liquid slug, W pressure, Qout,s,l sensible heat transfer out cv specific

Zhang, Yuwen

150

Heat transfer enhancement resulting from induction electrohydrodynamic pumping  

E-Print Network [OSTI]

HEAT TRANSFER ENHANCEMENT RESULTING FROM INDUCTION ELECTROHYDRODYNAMIC PUMPING A Thesis by BRYAN DAVID MARGO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1992 Major Subject: Mechanical Engineering HEAT TRANSFER ENHANCEMENT RESULTING FROM INDUCTION ELECTROHYDRODYNAMIC PUMPING A Thesis by BRYAN DAVID MARGO Approved as to style and content by: Jamal Seyed- Yagoobi (Chair...

Margo, Bryan David

1992-01-01T23:59:59.000Z

151

Mpemba effect, Newton cooling law and heat transfer equation  

E-Print Network [OSTI]

In this work we suggest a simple theoretical solution of the Mpemba effect in full agreement with known experimental data. This solution follows simply as an especial approximation (linearization) of the usual heat (transfer) equation, precisely linearization of the second derivation of the space part of the temperature function (as it is well-known Newton cooling law can be considered as the effective approximation of the heat (transfer) equation for constant space part of the temperature function).

Vladan Pankovic; Darko V. Kapor

2012-12-11T23:59:59.000Z

152

High thermal power density heat transfer apparatus providing electrical isolation at high temperature using heat pipes  

SciTech Connect (OSTI)

This invention is directed to transferring heat from an extremely high temperature source to an electrically isolated lower temperature receiver. The invention is particularly concerned with supplying thermal power to a thermionic converter from a nuclear reactor with electric isolation. Heat from a high temperature heat pipe is transferred through a vacuum or a gap filled with electrically nonconducting gas to a cooler heat pipe. The heat pipe is used to cool the nuclear reactor while the heat pipe is connected thermally and electrically to a thermionic converter. If the receiver requires greater thermal power density, geometries are used with larger heat pipe areas for transmitting and receiving energy than the area for conducting the heat to the thermionic converter. In this way the heat pipe capability for increasing thermal power densities compensates for the comparatively low thermal power densities through the electrically nonconducting gap between the two heat pipes.

Morris, J. F.

1985-03-19T23:59:59.000Z

153

Literature survey of heat transfer enhancement techniques in refrigeration applications  

SciTech Connect (OSTI)

A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.

Jensen, M.K.; Shome, B. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Mechanical Engineering, Aeronautical Engineering and Mechanics

1994-05-01T23:59:59.000Z

154

Technical Note Theoretical analysis of film condensation heat transfer  

E-Print Network [OSTI]

transfer coefficient of steam condensing inside an equilateral triangular channel is found. They divided the condensation area on the micro-fin surface into the flooded and the unflooded areasTechnical Note Theoretical analysis of film condensation heat transfer inside vertical mini

Zhao, Tianshou

155

Modeling of Heat Transfer in Geothermal Heat Exchangers  

E-Print Network [OSTI]

, University of Lund, Sweden, [7] Fang, Z., Diao, N., and Cui, P., Discontinuous operation of geothermal heat exchangers [J], Tsinghua Science and Technology. , 2002, 7 194?197. [8] Hellstrom, G., Ground heat storage -- Thermal analysis of duct storage... systems [D], Department of Mathem Sweden, 1991. [9] Mei, V. C. and Baxter, V. D., Performance of a ground-coupled heat pump with multiple dissimilar U-tu Transactions, 1986, 92 Part 2, 22-25. [10] Yavuzturk, C., Spitler, J. D. and Rees, S. J., A...

Cui, P.; Man, Y.; Fang, Z.

2006-01-01T23:59:59.000Z

156

Heat transfer in the plate heat exchanger of an ammonia-synthesis column  

SciTech Connect (OSTI)

The planning and construction of high-capacity synthetic ammonia plants requires the development and fabrication of unique, high unit-power equipment with high technical and economic characteristics. In foreign and domestic practice, tubular heat exchangers with relatively low heat-transfer coefficients are used. Plate heat exchangers are a promising alternative. They are compact and have a high heat energy efficiency and a relatively small metal content. To make an experimental check of the operating capability of a plate heat exchanger under ammonia production conditions, a welded plate heat exchanger was designed for an ammonia synthesis column 800mm in diameter. On prolonged testing (four years), the device provided an autothermal operating mode in the column and the heat transfer coefficient was practically constant for fixed space velocities. Consequently, the heat exchange surface was not contaminated significantly with catalyst dust, confirmed by visual observation of the heat exchanger after disassembly.

Obolentsev, Y.G.; Chus', M.S.; Norobchanskii, O.A.; Teplitshi, Y.S.; Tovazhnyanskii, L.L.

1983-01-01T23:59:59.000Z

157

Rod Bundle Heat Transfer: Steady-State Steam Cooling Experiments  

SciTech Connect (OSTI)

Through the joint efforts of the Pennsylvania State University and the United States Nuclear Regulatory Commission, an experimental rod bundle heat transfer (RBHT) facility was designed and built. The rod bundle consists of a 7 x 7 square pitch array with spacer grids and geometry similar to that found in a modern pressurized water reactor. From this facility, a series of steady-state steam cooling experiments were performed. The bundle inlet Reynolds number was varied from 1 400 to 30 000 over a pressure range from 1.36 to 4 bars (20 to 60 psia). The bundle inlet steam temperature was controlled to be at saturation for the specified pressure and the fluid exit temperature exceeded 550 deg. C in the highest power tests. One important quantity of interest is the local convective heat transfer coefficient defined in terms of the local bulk mean temperature of the flow, local wall temperature, and heat flux. Steam temperatures were measured at the center of selected subchannels along the length of the bundle by traversing miniaturized thermocouples. Using an analogy between momentum and energy transport, a method was developed for relating the local subchannel centerline temperature measurement to the local bulk mean temperature. Wall temperatures were measured using internal thermocouples strategically placed along the length of each rod and the local wall heat flux was obtained from an inverse conduction program. The local heat transfer coefficient was calculated from the data at each rod thermocouple location. The local heat transfer coefficients calculated for locations where the flow was fully developed were compared against several published correlations. The Weisman and El-Genk correlations were found to agree best with the RBHT steam cooling data, especially over the range of turbulent Reynolds numbers. The effect of spacer grids on the heat transfer enhancement was also determined from instrumentation placed downstream of the spacer grid locations. The local heat transfer was found to be greatest at locations immediately downstream of the grid, and as the flow moved further downstream from the grid it became more developed, thus causing the heat transfer to diminish. The amount of heat transfer enhancement was found to depend not only on the spacer grid design, but also on the local Reynolds number. It was seen that decreasing Reynolds number leads to greater heat transfer enhancement. (authors)

Spring, J.P.; McLaughlin, D.M. [The Pennsylvania State University, 201 Shields Building University Park, PA 16802 (United States)

2006-07-01T23:59:59.000Z

158

Error Analysis of Heat Transfer for Finned-Tube Heat-Exchanger Text-Board  

E-Print Network [OSTI]

In order to reduce the measurement error of heat transfer in water and air side for finned-tube heat-exchanger as little as possible, and design a heat-exchanger test-board measurement system economically, based on the principle of test-board system...

Chen, Y.; Zhang, J.

2006-01-01T23:59:59.000Z

159

Active heat transfer enhancement in integrated fan heat sinks  

E-Print Network [OSTI]

Modern computer processors require significant cooling to achieve their full performance. The "efficiency" of heat sinks is also becoming more important: cooling of electronics consumes 1% of worldwide electricity use by ...

Staats, Wayne Lawrence

2012-01-01T23:59:59.000Z

160

Pool boiling heat transfer characteristics of nanofluids  

E-Print Network [OSTI]

Nanofluids are engineered colloidal suspensions of nanoparticles in water, and exhibit a very significant enhancement (up to 200%) of the boiling Critical Heat Flux (CHF) at modest nanoparticle concentrations (50.1% by ...

Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Heat transfer in a thermoelectric generator for diesel engines  

SciTech Connect (OSTI)

This paper discusses the design and test results obtained for a 1kW thermoelectric generator used to convert the waste thermal energy in the exhaust of a Diesel engine directly to electric energy. The paper focuses on the heat transfer within the generator and shows what had to be done to overcome the heat transfer problems encountered in the initial generator testing to achieve the output goal of 1kW electrical. The 1kW generator uses Bismuth-Telluride thermoelectric modules for the energy conversion process. These modules are also being evaluated for other waste heat applications. Some of these applications are briefly addressed.

Bass, J.C. [Hi-Z Technology, Inc., San Diego, CA (United States)

1995-12-31T23:59:59.000Z

162

Heat Transfer Enhancement for Finned-Tube Heat Exchangers with Vortex Generators: Experimental and Numerical Results  

SciTech Connect (OSTI)

A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numerical modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.

O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert

2002-08-01T23:59:59.000Z

163

Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers  

E-Print Network [OSTI]

Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers Abstract The dominant thermal resistance used to increase heat transfer by initiating new boundary layer growth and increasing surface area

Thole, Karen A.

164

Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical delta winglets  

E-Print Network [OSTI]

Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical the formation of streamwise vortices and increase heat transfer between a working fluid and the surface on which the winglets are placed. This study investigates the use of delta winglets to augment heat transfer on the tube

Thole, Karen A.

165

Numerical model of mixed convection heat transfer between a series of vertical parallel plates with planar heat sources  

E-Print Network [OSTI]

Heat transfer between a series of vertical parallel plates with planar heat sources has been studied numerically. The series of plates formed a series of channels, or cooling passages, in which fluid could flow. Heat dissipation from the heat...

Watson, James Christopher

2012-06-07T23:59:59.000Z

166

Block Copolymer Solid Battery Electrolyte with High Li-Ion Transference Number  

E-Print Network [OSTI]

Block Copolymer Solid Battery Electrolyte with High Li-Ion Transference Number Ayan Ghosh number TLi+ value of 0.9 at room temperature 21­23°C . The solid-state flexible, translucent polymer of withstanding such high voltage conditions. Unlike traditional liquid electrolytes, solid-state polymer electro

Rubloff, Gary W.

167

A comparison of two heat transfer models for estimating thermal drawdown in Hot Dry Rock reservoirs  

SciTech Connect (OSTI)

Estimates of thermal drawdown in Hot Dry Rock geothermal systems have been made with two different models of heat transfer from hydraulically fractured reservoir rock blocks to water circulated through the fracture permeability. One model is based on deconvolution of experimental tracer response curves into a network of flowpaths connected in parallel with heat transfer calculated individually in each flowpath. The second model is based on one-dimensional flow through the rock with a block size distribution described as a group of equivalent-radius spheres for which the heat transfer equations can be solved analytically. The two models were applied to the planned Phase II long-term thermal drawdown experiment at Fenton Hill, NM. The results show good agreement between the two models, with estimates of temperature cooldown from 240şC to 150şC in a few years depending on selected operation parameters, but with somewhat differing cooldown curve characteristic shapes. Data from the long-term experiment will be helpful in improving the two models.

Robinson, Bruce A.; Kruger, Paul

1988-01-01T23:59:59.000Z

168

ME 544 Advanced Heat Transfer Spring 2013 Time: 2pm-3pm MWF  

E-Print Network [OSTI]

1 ME 544 Advanced Heat Transfer Spring 2013 Time: 2pm-3pm MWF Location: B4 Instructor: Dr. Allan and engineering applications of heat transfer including conduction, convection, and radiation. Course Learning, convection, and radiation heat transfer modes. 2. Determine the dominant modes of heat transfer, and apply

169

Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal Thermography  

E-Print Network [OSTI]

62 TC02-007 Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal-tube and 1000m micro-tube. In the single-phase heat transfer experiments, the fully-developed flow heat transfer were also measured using thermocouples (TC). The results showed that the heat transfer coefficient

Ghajar, Afshin J.

170

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

DOE Patents [OSTI]

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

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

1998-07-21T23:59:59.000Z

171

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

DOE Patents [OSTI]

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

Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

1998-07-21T23:59:59.000Z

172

Research on Convective Heat Transfer and Mass Transfer of the Evaporator in Micro/Mini-Channel  

E-Print Network [OSTI]

on the reviewers on the present household air conditioners, the potential requirements for new heat transfer enhancement used for household air conditioners are discussed. Investigations on condensation and boiling of refrigerants in mini/micro channels have...

Su, J.; Li, J.

2006-01-01T23:59:59.000Z

173

"Developing novel heat transfer diagnostics for nanosystems."  

E-Print Network [OSTI]

and development of electronic devices, power generation modules, and waste energy harvesting techniques alloys. Thermal conductivity of bismuth-doped III-V alloys Thermoelectric power generation (TPG) has become an increasingly popular technology for waste heat recovery in the last few years. The efficiency

Acton, Scott

174

Heat transfer coefficients in three phase fluidized beds  

SciTech Connect (OSTI)

In order to obtain a semitheoretical correlation for the heat transfer coefficients in three phase fluidized beds, Deckwer's semitheoretical correlation for the heat transfer coefficients in the bubble column, which was derived from Higbie's surface renewal theory of interphase mass transfer with the concept of isotropic turbulence, has been extended to three phase fluidized beds with the modification of the energy dissipation rate. One of the desirable characteristics of three phase fluidized beds is the uniformity of temperature in the bed. The intense longitudinal and transverse turbulent mixing in a fluidized bed may induce the uniform fields of temperature and solids concentration. For highly exothermic reactions, the uniform temperature in the bed is essential to avoid the local hot spots. In order to control the uniform temperature of three phase fluidized beds, the addition or removal of heat in the bed is required and the information on heat transfer surface and the bed is essential to designing the heat exchanger. Recently, Chiu and Ziegler (1983) determined wall-to-bed heat transfer coefficients in three phase fluidized bed (5.08 cm ID) of glass beads and cylindrical gamma alumina particles which were fluidized by cocurrent flow of air and water. Their data were correlated in terms of the modified Colburn j factor. Kato et al. (1981) measured wall-to-bed heat transfer coefficients in three phase fluidized beds of 5.2 and 12.0 cm internal diameter. Four different sizes of glass beads (0.42-2.2 mm) were fluidized by air and aqueous carboxymethyl cellulose solutions. The coefficients increased with decrease in liquid viscosity and with increase in gas and liquid velocity.

Suh, I.S.; Jin, G.T.; Kim, S.D.

1985-03-01T23:59:59.000Z

175

Thermodynamics of enhanced heat transfer: a model study  

E-Print Network [OSTI]

Situations where a spontaneous process of energy or matter transfer is enhanced by an external device are widespread in nature (human sweating system, enzyme catalysis, facilitated diffusion across bio-membranes, industrial heat exchangers). The thermodynamics of such processes remains however open. Here we study enhanced heat transfer by a model junction immersed between two thermal baths at different temperatures $T_h$ and $T_c$ ($T_h>T_c$). The transferred heat power is enhanced via controlling the junction by means of external time-dependent fields. Provided that the spontaneous heat flow process is optimized over the junction Hamiltonian, any enhancement of this spontaneous process does demand consumption and subsequent dissipation of work. The efficiency of enhancement is defined via the increment in the heat power divided over the amount of consumed work. We show that this efficiency is bounded from above by $T_c/(T_h-T_c)$. Formally this is identical to the Carnot bound for the efficiency of ordinary refrigerators which transfer heat from cold to hot. It also shares some (but not all) physical features of the Carnot bound.

Karen Hovhannisyan; Armen E. Allahverdyan

2010-07-20T23:59:59.000Z

176

heat transfer | OpenEI Community  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentrating SolarElectric Coop,SaveWhiskey Flats GeothermalElectricsecretaryguidanceheat transfer

177

Heat transfer and fluid flow characteristics in various micro devices for the development of micro absorption heat pump systems.  

E-Print Network [OSTI]

??This thesis presents a series of studies on heat transfer and fluid flow characteristics in various micro devices for the development of micro absorption heat… (more)

Hu, Jinshan

2007-01-01T23:59:59.000Z

178

Heat Transfer Enhancement for Finned-tube Heat Exchangers with Winglets  

SciTech Connect (OSTI)

This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with a circular tube and/or a delta-winglet pair. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.51 x 10-3 to 14.0 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 670 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of a circular tube, a delta-winglet pair, and a combination of a circular tube and a delta-winglet pair. Comparisons of local and average heat transfer distributions for the circular tube with and without winglets are provided. Overall mean finsurface Nusselt-number results indicate a significant level of heat transfer enhancement associated with the deployment of the winglets with the circular cylinder. At the lowest Reynolds numbers (which correspond to the laminar operating conditions of existing geothermal air-cooled condensers), the enhancement level is nearly a factor of two. At higher Reynolds numbers, the enhancement level is close to 50%.

O'Brien, James Edward; Sohal, Manohar Singh

2000-11-01T23:59:59.000Z

179

Convective heat transfer inside passive solar buildings  

SciTech Connect (OSTI)

Natural convection between spaces in a building can play a major role in energy transfer. Two situations are investigated: convection through a single doorway into a remote room, and a convective loop in a two-story house with a south sunspace where a north stairway serves as the return path. A doorway-sizing equation is given for the single-door case. Detailed data are given from the monitoring of airflow in one two-story house and summary data are given for five others. Observations on the nature of the airflow and design guidelines are presented.

Jones, R.W.; Balcomb, J.D.; Yamaguchi, K.

1983-01-01T23:59:59.000Z

180

Convective heat transfer inside passive solar buildings  

SciTech Connect (OSTI)

Natural convection between spaces in a building which play a major role in energy transfer are discussed. Two situations are investigated: Convection through a single doorway into a remote room, and a convective loop in a two story house with a south sunspace where a north stairway serves as the return path. A doorway sizing equation is given for the single door case. Data from airflow monitoring in one two-story house and summary data for five others are presented. The nature of the airflow and design guidelines are presented.

Jones, R.W.; Balcomb, J.D.; Yamaguchi, K.

1983-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Enhanced heat transfer using wire-coil inserts for high-heat-load applications.  

SciTech Connect (OSTI)

Enhanced heat-transfer techniques, used to significantly reduce temperatures and thermally induced stresses on beam-strike surfaces, are routinely used at the APS in all critical high-heat-load components. A new heat-transfer enhancement technique being evaluated at the APS involving the use of wire-coil inserts proves to be superior to previously employed techniques. Wire coils, similar in appearance to a common spring, are fabricated from solid wire to precise tolerances to mechanically fit inside standard 0.375-in-diameter cooling channels. In this study, a matrix of wire coils, fabricated with a series of different pitches from several different wire diameters, has been tested for heat-transfer performance and resulting pressure loss. This paper reviews the experimental data and the analytical calculations, compares the data with existing correlations, and interprets the results for APS front-end high-heat-load components.

Collins, J. T.; Conley, C. M.; Attig, J. N.; Baehl, M. M.

2002-09-20T23:59:59.000Z

182

Heat transfer education : Keeping it relevant and vibrant.  

SciTech Connect (OSTI)

The motivation for a fresh look at heat transfer education, both in content and in methodology, is generated by a number of trends in engineering practice. These include the increasing demand for engineers with interdisciplinary skills, rapid integration of technology, emergence of computerized and interactive problem-solving tools, shortening time of concept-to-market, availability of new technologies, and an increasing number of new or redesigned products and processes in which heat transfer plays a part. Examination of heat transfer education in this context can be aided by considering the changes, both qualitatively and quantitatively, in the student, educator, and researcher populations, employment opportunities, in the needs of corporations, government, industry, and universities, and in the relevant technical problems and issues of the day. Such an overview provides the necessary background for charting a response to the difficult question of how to maintain excellence and continuity in heat transfer education in the face of rapid, widespread, and complex changes. The present paper addresses how to make heat transfer education more relevant and stimulating. This paper represents a written summary of a 1996 panel discussion at the 1996 International Mechanical Engineering Conference and Exhibition (IMECE) of the American Society of Mechanical Engineers (ASME) in Atlanta, Georgia, on ''Heat Transfer Education: Keeping it Relevant and Vibrant,'' with significant expansion and amplification by the authors and the panelists in the 1997-98 period. The consensus of the participants is that the steps necessary to ensure the desired outcome in heat transfer education should include: (1) a better understanding of the interaction between the student, course content, and market needs; (2) an appreciation of the need in multidisciplinary industrial environments for engineers trained with a broad background: (3) a revision of the introductory heat transfer course to incorporate illustrative and insightful industrial examples and case studies reducible to order-of-magnitude analyses; (4) a reinforcement of real-world problem-solving abilities in students by introducing them to examples that emphasize multidisciplinary issues in modern thermal management problems and finally (5) industrial collaboration that would provide the educator with meaningful thermal management case studies (and possible funding), the student with an appreciation of industrial practices, and the industrial sponsor with access to academia for assistance in problem solving. Also suggested is an effective regular review program to provide assessment, feedback, and suggestions for quality control to interested institutions on their teaching methodology and materials.

Khounsary, A. M.

1998-08-14T23:59:59.000Z

183

Radiative heat transfer in 2D Dirac materials  

E-Print Network [OSTI]

We compute the radiative heat transfer between two sheets of 2D Dirac materials, including topological Chern insulators and graphene, within the framework of the local approximation for the optical response of these materials. In this approximation, which neglects spatial dispersion, we derive both numerically and analytically the short-distance asymptotic of the near-field heat transfer in these systems, and show that it scales as the inverse of the distance between the two sheets. Finally, we discuss the limitations to the validity of this scaling law imposed by spatial dispersion in 2D Dirac materials.

Pablo Rodriguez-Lopez; Wang-Kong Tse; Diego A. R. Dalvit

2015-02-02T23:59:59.000Z

184

Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas-  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformation Earth's Heat Jump to:Photon Place:NetHealth Division |Hays,Community CollegeFeatures

185

Combined heat and mass transfer device for improving separation process  

DOE Patents [OSTI]

A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area.

Tran, Thanh Nhon (Flossmoor, IL)

1999-01-01T23:59:59.000Z

186

Combined heat and mass transfer device for improving separation process  

DOE Patents [OSTI]

A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area. 12 figs.

Tran, T.N.

1999-08-24T23:59:59.000Z

187

Effect of turbulent heat transfer on continuous ingot solidification  

SciTech Connect (OSTI)

For many continuous ingot casting processes, turbulent heat transfer in the molten pool plays a critical role which, along with buoyancy and surface tension, is responsible for the quality of the end products. Based on a modified low Reynolds number K-[epsilon] two-equation closure, accounting for the phase change and mushy zone formation, the effect of turbulent heat transfer on the solidification characteristics during titanium alloy ingot casting in an electron beam melting process is investigated. The overall heat transfer rate is enhanced by turbulent transport via two sources, one through the correlated velocity and temperature fluctuations present for both single- and multi-phase flows, and the other through the correlated velocity and release of latent heat fluctuations which are unique to the flows with phase change. The roles played by both mechanisms are identified and assessed. The present turbulence model predicts that although the mushy zone defined by the mean temperature field is generally of substantial thickness as a result of the convection effect, the actual instantaneous zone thickness varies substantially due to turbulence effect. This finding is in contrast to the traditionally held viewpoint, based on the conduction analysis, of a generally thin mushy zone. The impact of turbulent heat transfer on local dendrite formation and remelting is illustrated and the issues involved in model development highlighted.

Shyy, W.; Chen, M.H. (Univ. of Florida, Gainesville, FL (United States). Dept. of Aerospace Engineering); Pang, Y.; Wei, D.Y. (GE Aircraft Engines, Engineering Materials Technology Labs., Lynn, MA (United States)); Hunter, G.B. (GE Aircraft Engines, Engineering Materials Technology Labs., Cincinnati, OH (United States))

1993-01-01T23:59:59.000Z

188

Enhanced boiling heat transfer in horizontal test bundles  

SciTech Connect (OSTI)

Two-phase flow boiling from bundles of horizontal tubes with smooth and enhanced surfaces has been investigated. Experiments were conducted in pure refrigerant R-113, pure R-11, and mixtures of R-11 and R-113 of approximately 25, 50, and 75% of R-113 by mass. Tests were conducted in two staggered tube bundles consisting of fifteen rows and five columns laid out in equilateral triangular arrays with pitch-to-diameter ratios of 1.17 and 1.5. The enhanced surfaces tested included a knurled surface (Wolverine`s Turbo-B) and a porous surface (Linde`s High Flux). Pool boiling tests were conducted for each surface so that reference values of the heat transfer coefficient could be obtained. Boiling heat transfer experiments in the tube bundles were conducted at pressures of 2 and 6 bar, heat flux values from 5 to 80 kW/m{sup 2}s, and qualities from 0% to 80%, Values of the heat transfer coefficients for the enhanced surfaces were significantly larger than for the smooth tubes and were comparable to the values obtained in pool boiling. It was found that the performance of the enhanced tubes could be predicted using the pool boiling results. The degradation in the smooth tube heat transfer coefficients obtained in fluid mixtures was found to depend on the difference between the molar concentration in the liquid and vapor.

Trewin, R.R.; Jensen, M.K.; Bergles, A.E.

1994-08-01T23:59:59.000Z

189

Heat transfer and film cooling with steam injection  

E-Print Network [OSTI]

for both coolants was determined for similar blowing rates and was used as a basis for comparisons. Heat transfer coefficients were calcula- ted from the experimental data using a transient analysis. DEDICATION To my wife and family. ACKNOWLEDGEMENTS... LIST OF TABLES PAGE TABLE 1 Variation in the Blowing Rate ------------ 55 TABLE 2 TABLE 3 Typical Air Film Cooling Effectiveness Data Typical Steam Film Cooling Effectiveness Data 62 62 1X LIST OF FIGURES PAGE Figure 1 Comparison of Heat...

Conklin, Gary Eugene

1982-01-01T23:59:59.000Z

190

Trace formulae for non-equilibrium Casimir interactions, heat radiation and heat transfer for arbitrary objects  

E-Print Network [OSTI]

We present a detailed derivation of heat radiation, heat transfer and (Casimir) interactions for N arbitrary objects in the framework of fluctuational electrodynamics in thermal non-equilibrium. The results can be expressed as basis-independent trace formulae in terms of the scattering operators of the individual objects. We prove that heat radiation of a single object is positive, and that heat transfer (for two arbitrary passive objects) is from the hotter to a colder body. The heat transferred is also symmetric, exactly reversed if the two temperatures are exchanged. Introducing partial wave-expansions, we transform the results for radiation, transfer and forces into traces of matrices that can be evaluated in any basis, analogous to the equilibrium Casimir force. The method is illustrated by (re)deriving the heat radiation of a plate, a sphere and a cylinder. We analyze the radiation of a sphere for different materials, emphasizing that a simplification often employed for metallic nano-spheres is typically invalid. We derive asymptotic formulae for heat transfer and non-equilibrium interactions for the cases of a sphere in front a plate and for two spheres, extending previous results. As an example, we show that a hot nano-sphere can levitate above a plate with the repulsive non-equilibrium force overcoming gravity -- an effect that is not due to radiation pressure.

Matthias Krüger; Giuseppe Bimonte; Thorsten Emig; Mehran Kardar

2012-07-16T23:59:59.000Z

191

A simplistic model of cyclic heat transfer phenomena in closed spaces  

SciTech Connect (OSTI)

Cyclic heat transfer inside closed spaces is investigated analytically using a simple heat transfer model. The model consists of a gas layer exchanging heat with two bounding parallel walls that pulsate against each other in the transverse direction. Correlations for the magnitude and the phase lag of the heat transfer are obtained. Also, an expression for the power loss due to the cyclic heat transfer is presented. It is shown that the loss approaches zero as the heat transfer process approaches either isothermal or adiabatic conditions. The power loss is shown to be a strong function of the phase angle between the bulk gas temperature and the heat transfer.

Lee, K.

1983-08-01T23:59:59.000Z

192

Enhanced heat transfer surface for cast-in-bump-covered cooling surfaces and methods of enhancing heat transfer  

DOE Patents [OSTI]

An annular turbine shroud separates a hot gas path from a cooling plenum containing a cooling medium. Bumps are cast in the surface on the cooling side of the shroud. A surface coating overlies the cooling side surface of the shroud, including the bumps, and contains cooling enhancement material. The surface area ratio of the cooling side of the shroud with the bumps and coating is in excess of a surface area ratio of the cooling side surface with bumps without the coating to afford increased heat transfer across the element relative to the heat transfer across the element without the coating.

Chiu, Rong-Shi Paul (Glenmont, NY); Hasz, Wayne Charles (Pownal, VT); Johnson, Robert Alan (Simpsonville, SC); Lee, Ching-Pang (Cincinnati, OH); Abuaf, Nesim (Lincoln City, OR)

2002-01-01T23:59:59.000Z

193

EFFECT OF REACTOR HEAT TRANSFER LIMITATIONS ON CO PREFERENTIAL OXIDATION  

E-Print Network [OSTI]

and conventional packed-bed lab reactors (m-PBR's). Strong evidence has suggested that the reverse water-gas transport limitations of conventional lab reactors [3,4,5,6]: the fast surface chemistry of the exothermic1 EFFECT OF REACTOR HEAT TRANSFER LIMITATIONS ON CO PREFERENTIAL OXIDATION X. Ouyang, R.S. Besser

Besser, Ronald S.

194

Heat transfer through a water spray curtain under the effect of a strong radiative source  

E-Print Network [OSTI]

Heat transfer through a water spray curtain under the effect of a strong radiative source P. Boulet - mail Pascal.Boulet@lemta.uhp-nancy.fr Keywords : heat transfer, radiative transfer, vaporization, convection, water spray Abstract Heat transfer inside a participating medium, made of droplets flowing in gas

Paris-Sud XI, Université de

195

Thermodynamics of enhanced heat transfer: a model study  

E-Print Network [OSTI]

Situations where a spontaneous process of energy or matter transfer is enhanced by an external device are widespread in nature (human sweating system, enzyme catalysis, facilitated diffusion across bio-membranes, industrial heat exchangers). The thermodynamics of such processes remains however open. Here we study enhanced heat transfer by a model junction immersed between two thermal baths at different temperatures $T_h$ and $T_c$ ($T_h>T_c$). The transferred heat power is enhanced via controlling the junction by means of external time-dependent fields. Provided that the spontaneous heat flow process is optimized over the junction Hamiltonian, any enhancement of this spontaneous process does demand consumption and subsequent dissipation of work. The efficiency of enhancement is defined via the increment in the heat power divided over the amount of consumed work. We show that this efficiency is bounded from above by $T_c/(T_h-T_c)$. Formally this is identical to the Carnot bound for the efficiency of ordinary ...

Hovhannisyan, Karen; 10.1088/1742-5468/2010/06/P06010

2010-01-01T23:59:59.000Z

196

Radiative heat transfer in a hydrous mantle transition zone Sylvia-Monique Thomas a,n  

E-Print Network [OSTI]

Radiative heat transfer in a hydrous mantle transition zone Sylvia-Monique Thomas a,n , Craig R contribute significantly to heat transfer in the mantle and demonstrate the importance of radiative heat, radiative heat transfer was considered relatively unimportant in the mantle. Earlier experimental work

Jacobsen, Steven D.

197

Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with  

E-Print Network [OSTI]

Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial-Newtonian boundary layer flow and heat transfer over an exponentially stretch- ing sheet with partial slip boundary. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed sur

Paris-Sud XI, Université de

198

Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants  

SciTech Connect (OSTI)

A key technological issue facing the success of future Concentrating Solar Thermal Power (CSP) plants is creating an economical Thermal Energy Storage (TES) system. Current TES systems use either sensible heat in fluids such as oil, or molten salts, or use thermal stratification in a dual-media consisting of a solid and a heat-transfer fluid. However, utilizing the heat of fusion in inorganic molten salt mixtures in addition to sensible heat , as in a Phase change material (PCM)-based TES, can significantly increase the energy density of storage requiring less salt and smaller containers. A major issue that is preventing the commercial use of PCM-based TES is that it is difficult to discharge the latent heat stored in the PCM melt. This is because when heat is extracted, the melt solidifies onto the heat exchanger surface decreasing the heat transfer. Even a few millimeters of thickness of solid material on heat transfer surface results in a large drop in heat transfer due to the low thermal conductivity of solid PCM. Thus, to maintain the desired heat rate, the heat exchange area must be large which increases cost. This project demonstrated that the heat transfer coefficient can be increase ten-fold by using forced convection by pumping a hyper-eutectic salt mixture over specially coated heat exchanger tubes. However,only 15% of the latent heat is used against a goal of 40% resulting in a projected cost savings of only 17% against a goal of 30%. Based on the failure mode effect analysis and experience with pumping salt at near freezing point significant care must be used during operation which can increase the operating costs. Therefore, we conclude the savings are marginal to justify using this concept for PCM-TES over a two-tank TES. The report documents the specialty coatings, the composition and morphology of hypereutectic salt mixtures and the results from the experiment conducted with the active heat exchanger along with the lessons learnt during experimentation.

Mathur, Anoop [Terrafore Inc.] [Terrafore Inc.

2013-08-14T23:59:59.000Z

199

Castor-1C spent fuel storage cask decay heat, heat transfer, and shielding analyses  

SciTech Connect (OSTI)

This report documents the decay heat, heat transfer, and shielding analyses of the Gesellschaft fuer Nuklear Services (GNS) CASTOR-1C cask used in a spent fuel storage demonstration performed at Preussen Elektra's Wurgassen nuclear power plant. The demonstration was performed between March 1982 and January 1984, and resulted in cask and fuel temperature data and cask exterior surface gamma-ray and neutron radiation dose rate measurements. The purpose of the analyses reported here was to evaluate decay heat, heat transfer, and shielding computer codes. The analyses consisted of (1) performing pre-look predictions (predictions performed before the analysts were provided the test data), (2) comparing ORIGEN2 (decay heat), COBRA-SFS and HYDRA (heat transfer), and QAD and DOT (shielding) results to data, and (3) performing post-test analyses if appropriate. Even though two heat transfer codes were used to predict CASTOR-1C cask test data, no attempt was made to compare the two codes. The codes are being evaluated with other test data (single-assembly data and other cask data), and to compare the codes based on one set of data may be premature and lead to erroneous conclusions.

Rector, D.R.; McCann, R.A.; Jenquin, U.P.; Heeb, C.M.; Creer, J.M.; Wheeler, C.L.

1986-12-01T23:59:59.000Z

200

MHD Effects on Heat Transfer in a Molten Salt Blanket  

SciTech Connect (OSTI)

Heat transfer in closed channel flows of molten salts (MS)s, such as FLiBe or FLiNaBe, has been considered under specific reactor conditions. MHD effects have been accessed for two blanket concepts: self-cooled MS blanket, and dual-coolant MS blanket. The effect of heat transfer degradation due to turbulence reduction by a magnetic field in the First Wall channels of the self-cooled blanket was analyzed with the K-{epsilon} model of turbulence. In the dual-coolant blanket, the MS flow is laminar. A 2-D MHD code was used to calculate the laminar velocity profile first. Then, the temperature field was calculated using a 3-D temperature code. Reasonable interface temperatures below the material limit of 550 deg. C, and low heat escape from the breeder zone have been demonstrated. Model limitations and the ways of their improvement are also discussed.

Smolentsev, Sergey; Miraghaie, Reza; Abdou, Mohamed [University of California (United States)

2005-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids  

SciTech Connect (OSTI)

Concentrating solar power (CSP) facilities are comprised of many miles of fluid-filled pipes arranged in large grids with reflective mirrors used to capture radiation from the sun. Solar radiation heats the fluid which is used to produce steam necessary to power large electricity generation turbines. Currently, organic, oil-based fluid in the pipes has a maximum temperature threshold of 400 °C, allowing for the production of electricity at approximately 15 cents per kilowatt hour. The DOE hopes to foster the development of an advanced heat transfer fluid that can operate within higher temperature ranges. The new heat transfer fluid, when used with other advanced technologies, could significantly decrease solar electricity cost. Lower costs would make solar thermal electricity competitive with gas and coal and would offer a clean, renewable source of energy. Molten salts exhibit many desirable heat transfer qualities within the range of the project objectives. Halotechnics developed advanced heat transfer fluids (HTFs) for application in solar thermal power generation. This project focused on complex mixtures of inorganic salts that exhibited a high thermal stability, a low melting point, and other favorable characteristics. A high-throughput combinatorial research and development program was conducted in order to achieve the project objective. Over 19,000 candidate formulations were screened. The workflow developed to screen various chemical systems to discover salt formulations led to mixtures suitable for use as HTFs in both parabolic trough and heliostat CSP plants. Furthermore, salt mixtures which will not interfere with fertilizer based nitrates were discovered. In addition for use in CSP, the discovered salt mixtures can be applied to electricity storage, heat treatment of alloys and other industrial processes.

Raade, Justin; Roark, Thomas; Vaughn, John; Bradshaw, Robert

2013-07-22T23:59:59.000Z

202

Local Heat Transfer for Finned-Tube Heat Exchangers using Oval Tubes  

SciTech Connect (OSTI)

This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with either a circular tube or an elliptical tube in crossflow. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.56 x 10-3 to 15.6 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 630 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. The elliptical tube had an aspect ratio of 3:1 and a/H equal to 4.33. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of circular and oval tubes and their relationship to the complex horseshoe vortex system that forms in the flow stagnation region. Fin surface stagnation-region Nusselt numbers are shown to be proportional to the square-root of Reynolds number.

O'Brien, James Edward; Sohal, Manohar Singh

2000-08-01T23:59:59.000Z

203

E-Print Network 3.0 - accurate heat transfer Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Pennsylvania State University Collection: Engineering 11 Boiling heat transfer in a hydrofoil-based micro pin fin heat sink Summary: in large scatter and were not able to...

204

MODELING HEAT TRANSFER IN SPENT FUEL TRANSFER CASK NEUTRON SHIELDS – A CHALLENGING PROBLEM IN NATURAL CONVECTION  

SciTech Connect (OSTI)

In the United States, commercial spent nuclear fuel is typically moved from spent fuel pools to outdoor dry storage pads within a transfer cask system that provides radiation shielding to protect personnel and the surrounding environment. The transfer casks are cylindrical steel enclosures with integral gamma and neutron radiation shields. Since the transfer cask system must be passively cooled, decay heat removal from spent nuclear fuel canister is limited by the rate of heat transfer through the cask components, and natural convection from the transfer cask surface. The primary mode of heat transfer within the transfer cask system is conduction, but some cask designs incorporate a liquid neutron shield tank surrounding the transfer cask structural shell. In these systems, accurate prediction of natural convection within the neutron shield tank is an important part of assessing the overall thermal performance of the transfer cask system. The large-scale geometry of the neutron shield tank, which is typically an annulus approximately 2 meters in diameter but only 10-15 cm in thickness, and the relatively small scale velocities (typically less than 5 cm/s) represent a wide range of spatial and temporal scales that contribute to making this a challenging problem for computational fluid dynamics (CFD) modeling. Relevant experimental data at these scales are not available in the literature, but some recent modeling studies offer insights into numerical issues and solutions; however, the geometries in these studies, and for the experimental data in the literature at smaller scales, all have large annular gaps that are not prototypic of the transfer cask neutron shield. This paper proposes that there may be reliable CFD approaches to the transfer cask problem, specifically coupled steady-state solvers or unsteady simulations; however, both of these solutions take significant computational effort. Segregated (uncoupled) steady state solvers that were tested did not accurately capture the flow field and heat transfer distribution in this application. Mesh resolution, turbulence modeling, and the tradeoff between steady state and transient solutions are addressed. Because of the critical nature of this application, the need for new experiments at representative scales is clearly demonstrated.

Fort, James A.; Cuta, Judith M.; Bajwa, C.; Baglietto, E.

2010-07-18T23:59:59.000Z

205

A visualization comparison of convective flow boiling heat transfer augmentation devices  

E-Print Network [OSTI]

The qualitative effects of inset-table heat transfer phics. augmentation devices on vertical in-tube convective flow boiling flow regimes, transition mechanisms, and heat transfer are presented in this study. Three twisted tapes with twist ratios...

Lundy, Brian Franklin

1998-01-01T23:59:59.000Z

206

Heat transfer rates for filmwise, dropwise, and superhydrophobic condensation on silicon substrates  

E-Print Network [OSTI]

Condensation, a two-phase heat transfer processes, is commonly utilized in industrial systems. Condensation heat transfer can be optimized by using surfaces in which dropwise condensation (DWC) occurs, and even further ...

Hery, Travis M

2011-01-01T23:59:59.000Z

207

FALL 2011 EMEC 326 DR. RUHUL AMIN HEAT TRANSFER 201 C Roberts Hall  

E-Print Network [OSTI]

FALL 2011 EMEC 326 DR. RUHUL AMIN HEAT TRANSFER 201 C Roberts Hall Phone: 994-6295 POLICY STATEMENT, convection, and radiation formulations. Introduction to heat transfer equipment. Course credit: 4

Dyer, Bill

208

Modeling of fuel-to-steel heat transfer in core disruptive accidents  

E-Print Network [OSTI]

A mathematical model for direct-contact boiling heat transfer between immiscible fluids was developed and tested experimentally. The model describes heat transfer from a hot fluid bath to an ensemble of droplets of a cooler ...

Smith, Russell Charles

1980-01-01T23:59:59.000Z

209

Heat transfer during film condensation of potassium vapor on a horizontal plate  

E-Print Network [OSTI]

The object of the investigation is to analyze the following two features of heat transfer during condensation of potassium vapor: a. Heat transfer during film condensation of a pure saturated potassium vapor on a horizontal ...

Meyrial, Paul M.

1968-01-01T23:59:59.000Z

210

Remote administration and user experience evaluation of the iLab Heat Transfer Project site  

E-Print Network [OSTI]

The iLab Heat Transfer Project provides a means for students to remotely execute, via a web interface, experiments related to the topic of heat transfer. The website associated with this project provides instructors with ...

Graham, Rodney K

2006-01-01T23:59:59.000Z

211

FLOW AND HEAT TRANSFER IN MICROFLUIDIC DEVICES WITH APPLICATION TO OPTOTHERMAL  

E-Print Network [OSTI]

FLOW AND HEAT TRANSFER IN MICROFLUIDIC DEVICES WITH APPLICATION TO OPTOTHERMAL ANALYTE transfer in microfluidic devices with applica- tion to optothermal analyte preconcentration and manipula the local fluid temperature in microfluidics. Thermal characteristics of the heating system have been

Bahrami, Majid

212

Including radiative heat transfer and reaction quenching in modeling a Claus plant waste heat boiler  

SciTech Connect (OSTI)

Due to increasingly stringent sulfur emission regulations, improvements are necessary in the modified Claus process. A recently proposed model by Nasato et al. for the Claus plant waste heat boiler (WHB) is improved by including radiative heat transfer, which yields significant changes in the predicted heat flux and the temperature profile along the WHB tube, leading to a faster quenching of chemical reactions. For the WHB considered, radiation accounts for approximately 20% of the heat transferred by convection alone. More importantly, operating the WHB at a higher gas mass flux is shown to enhance reaction quenching, resulting in a doubling of the predicted hydrogen flow rate. This increase in hydrogen flow rate is sufficient to completely meet the hydrogen requirement of the H[sub 2]S recovery process considered, which would eliminate the need for a hydrogen plant.

Karan, K.; Mehrotra, A.K.; Behie, L.A. (Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering)

1994-11-01T23:59:59.000Z

213

An experimental investigation of turbine blade heat transfer and turbine blade trailing edge cooling  

E-Print Network [OSTI]

studies have investigated the fluid flow and heat transfer behavior in high Reynolds number flows. Blair [7,8] investigated the effect of grid generated turbulence on flat plate heat transfer. He showed that turbulent heat transfer coefficient in flow... AN EXPERIMENTAL INVESTIGATION OF TURBINE BLADE HEAT TRANSFER AND TURBINE BLADE TRAILING EDGE COOLING A Dissertation by JUNGHO CHOI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

Choi, Jungho

2005-02-17T23:59:59.000Z

214

Heat transfer enhancement in a channel with porous baffles  

E-Print Network [OSTI]

with staggered positioned porous baffles. A numerical procedure was implemented, in conjunction with a commercially available Navier-Stokes solver, to model the turbulent flow in porous media. The Brinkman-Forchheimer-Extended Darcy model was used for modeling... fluid flow through the porous baffles. Conventional, one- equation, and two-equation models were used for heat transfer modeling. The accuracy and characteristics of each model were investigated and discussed. The results were compared...

Ko, Kang-Hoon

2005-02-17T23:59:59.000Z

215

Situ soil sampling probe system with heated transfer line  

DOE Patents [OSTI]

The present invention is directed both to an improved in situ penetrometer probe and to a heated, flexible transfer line. The line and probe may be implemented together in a penetrometer system in which the transfer line is used to connect the probe to a collector/analyzer at the surface. The probe comprises a heater that controls a temperature of a geologic medium surrounding the probe. At least one carrier gas port and vapor collection port are located on an external side wall of the probe. The carrier gas port provides a carrier gas into the geologic medium, and the collection port captures vapors from the geologic medium for analysis. In the transfer line, a flexible collection line that conveys a collected fluid, i.e., vapor, sample to a collector/analyzer. A flexible carrier gas line conveys a carrier gas to facilitate the collection of the sample. A system heating the collection line is also provided. Preferably the collection line is electrically conductive so that an electrical power source can generate a current through it so that the internal resistance generates heat.

Robbat, Jr., Albert (Andover, MA)

2002-01-01T23:59:59.000Z

216

Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin Finite Element Method  

E-Print Network [OSTI]

Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin;Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin Finite used to predict heat transfer to a cylinder in a hypersonic flow. The strong shock is captured

Peraire, Jaime

217

Heat Transfer on a Hypersonic Sphere with Gas Injection Vladimir V. Riabov  

E-Print Network [OSTI]

Heat Transfer on a Hypersonic Sphere with Gas Injection Vladimir V. Riabov Department be considered as an effective way of the reduction of heat transfer to the surface in this area [1 the viscous layer is blown completely off the surface, and heat transfer is zero. The effect of injecting

Riabov, Vladimir V.

218

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow  

E-Print Network [OSTI]

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. [2]. Our results

Boyer, Edmond

219

Numerical computation of 3D heat transfer in complex parallel convective exchangers using generalized Graetz modes  

E-Print Network [OSTI]

Numerical computation of 3D heat transfer in complex parallel convective exchangers using insights into the most con- tributing structure to exchanges and transfers. Several examples of heat, whilst many other can be found in a recent review [12]. As quoted in [12] conjugate heat transfer

Paris-Sud XI, Université de

220

Heat Transfer Engineering, 29(9):793804, 2008 Copyright C Taylor and Francis Group, LLC  

E-Print Network [OSTI]

Heat Transfer Engineering, 29(9):793­804, 2008 Copyright C Taylor and Francis Group, LLC ISSN: 0145 for Laminar and Turbulent Flow Convection Heat Transfer in a Horizontal Tube Using Artificial Neural Network was used to develop empirical correlations for laminar and turbulent heat transfer in a horizontal tube

Ghajar, Afshin J.

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Surface-Phonon Polariton Contribution to Nanoscale Radiative Heat Transfer. Emmanuel Rousseau  

E-Print Network [OSTI]

Surface-Phonon Polariton Contribution to Nanoscale Radiative Heat Transfer. Emmanuel Rousseau-sud Campus Polytechnique RD 128 91127 Palaiseau cedex, France Heat transfer between two plates of polar far-field value. In this article, we show that nanoscale heat transfer is dominated by the coupling

Paris-Sud XI, Université de

222

SINGLE-PHASE LIQUID HEAT TRANSFER IN PLAIN AND ENHANCED MICROCHANNELS Mark E. Steinke  

E-Print Network [OSTI]

SINGLE-PHASE LIQUID HEAT TRANSFER IN PLAIN AND ENHANCED MICROCHANNELS Mark E. Steinke Systems upon the understanding of the fundamental heat transfer processes that occur in these systems. There have been great advancements in our understanding of the heat transfer and fluid flow mechanisms

Kandlikar, Satish

223

A Scaleless Snake: Tests of the Role of Reptilian Scales in Water Loss and Heat Transfer  

E-Print Network [OSTI]

A Scaleless Snake: Tests of the Role of Reptilian Scales in Water Loss and Heat Transfer Reprinted: Tests of the Role of Reptilian Scales in Water Loss and Heat Transfer A unique specimen of gopher snake of pulmocutaneous water loss and heat transfer, no difference was observed between the scale- less animal

Bennett, Albert F.

224

Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based  

E-Print Network [OSTI]

Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based Continuous is dedicated to under- standing the fluid flow and heat transfer mechanisms occurring in continuous flow PCR are discussed in detail. The importance of each heat transfer mechanism for different situations is also

Le Roy, Robert J.

225

Assignment 6: Heat Transfer Page 1 of 8 600.112: Introduction to Programming  

E-Print Network [OSTI]

Assignment 6: Heat Transfer Page 1 of 8 600.112: Introduction to Programming for Scientists and Engineers Assignment 6: Heat Transfer Peter H. Fr¨ohlich phf@cs.jhu.edu Joanne Selinski joanne to Programming for Scientists and Engineers is all about heat transfer and how to simulate it. There are three

Fröhlich, Peter

226

Heat transfer in soft nanoscale interfaces: the influence of interface curvature  

E-Print Network [OSTI]

Heat transfer in soft nanoscale interfaces: the influence of interface curvature Anders Lervik transient non-equilibrium molecular-dynamics simulations, heat-transfer through nanometer-scale interfaces processes. We show that the modeling of heat transfer across a nanodroplet/fluid interface requires

Kjelstrup, Signe

227

Convective heat transfer as a function of wavelength: Implications for the cooling of the Earth  

E-Print Network [OSTI]

Convective heat transfer as a function of wavelength: Implications for the cooling of the Earth C, in particular, on its variation with the wavelength of convection. The heat transfer strongly depends in Earth's mantle can significantly reduce the efficiency of heat transfer. The likely variations

228

Proceedings of HT2007 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference  

E-Print Network [OSTI]

Proceedings of HT2007 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference July 8-12, 2007, Vancouver, British Columbia, CANADA HT2007-32219 VALIDATION OF A GENERAL HEAT TRANSFER, Stillwater, OK 74078, USA E-mail: ghajar@ceat.okstate.edu ABSTRACT A general heat transfer correlation

Ghajar, Afshin J.

229

MHD EFFECTS ON HEAT TRANSFER IN A MOLTEN SALT BLANKET Sergey Smolentsev, Reza Miraghaie, Mohamed Abdou  

E-Print Network [OSTI]

MHD EFFECTS ON HEAT TRANSFER IN A MOLTEN SALT BLANKET Sergey Smolentsev, Reza Miraghaie, Mohamed-mail (Sergey Smolentsev): Sergey@fusion.ucla.edu Heat transfer in closed channel flows of molten salts (MS of the concept is that the flows in the FW channels are turbulent to provide a high heat transfer coefficient

Abdou, Mohamed

230

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation  

E-Print Network [OSTI]

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation the results of finite element analysis of a heat transfer problem of flowing polymer melts in a tube­Nusselt problem 1. Introduction Heat transfer to incompressible viscous non-Newto- nian fluids is a problem

Wei, Dongming

231

FliHy experimental facilities for studying open channel turbulent flows and heat transfer  

E-Print Network [OSTI]

FliHy experimental facilities for studying open channel turbulent flows and heat transfer B. Freeze) facility was constructed at UCLA to study open channel turbulent flow and heat transfer of low supercritical flow regimes (Fr /1), in which the surface waves are amplified and heat transfer is enhanced due

Abdou, Mohamed

232

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow  

E-Print Network [OSTI]

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis

Boyer, Edmond

233

Convective heat transfer characteristics of China RP-3 aviation kerosene at supercritical pressure  

E-Print Network [OSTI]

Convective heat transfer characteristics of China RP-3 aviation kerosene at supercritical pressure Keywords: Supercritical pressure Aviation kerosene Convective heat transfer Numerical study a b s t r a c convective in kerosene pipe flow is complicated. Here the convective heat transfer characteristics of China

Guo, Zhixiong "James"

234

Heat Transfer Engineering, 27(5):2338, 2006 Copyright C Taylor and Francis Group, LLC  

E-Print Network [OSTI]

Heat Transfer Engineering, 27(5):23­38, 2006 Copyright C Taylor and Francis Group, LLC ISSN: 0145-7632 print / 1521-0537 online DOI: 10.1080/01457630600559538 Transitional Heat Transfer in Plain Horizontal, Oklahoma, USA In this study, the heat transfer behavior in the transition region for plain horizontal tubes

Ghajar, Afshin J.

235

Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow  

E-Print Network [OSTI]

Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE M@niu.edu * www.kostic.niu.edu Abstract: - An apparatus for exploring friction and heat transfer characteristics flow. Initial turbulent friction and heat transfer measurements for silica and carbon nanotube (CNT

Kostic, Milivoje M.

236

Heat Transfer Engineering, 28(6):525540, 2007 Copyright C Taylor and Francis Group, LLC  

E-Print Network [OSTI]

Heat Transfer Engineering, 28(6):525­540, 2007 Copyright C Taylor and Francis Group, LLC ISSN: 0145-7632 print / 1521-0537 online DOI: 10.1080/01457630701193906 Heat Transfer Measurements, Flow Pattern Maps, Stillwater, Oklahoma, USA Local heat transfer coefficients and flow parameters were measured for air

Ghajar, Afshin J.

237

FLIHY EXPERIMENTAL FACILITIES FOR STUDYING OPEN CHANNEL TURBULENT FLOWS AND HEAT TRANSFER  

E-Print Network [OSTI]

1 FLIHY EXPERIMENTAL FACILITIES FOR STUDYING OPEN CHANNEL TURBULENT FLOWS AND HEAT TRANSFER B was constructed at UCLA to study open channel turbulent flow and heat transfer of low-thermal and low supercritical flow regimes (Fr>1), in which the surface waves are amplified and heat transfer is enhanced due

California at Los Angeles, University of

238

Scaling of Heat Transfer Coefficients Along Louvered Fins A. C. Lyman1  

E-Print Network [OSTI]

1 Scaling of Heat Transfer Coefficients Along Louvered Fins A. C. Lyman1 , R. A. Stephan2 , and K 23681-2199 #12;2 Abstract Louvered fins provide a method for improving the heat transfer performance for evaluating the spatially-resolved louver heat transfer coefficients using various reference temperatures

Thole, Karen A.

239

On the Effect of Porous Layers on Melting Heat Transfer in an Enclosure  

E-Print Network [OSTI]

On the Effect of Porous Layers on Melting Heat Transfer in an Enclosure E. A. Ellinger* and C. To enhance heat transfer, the porous layers are located in regions where the melting rates for a pure the porous layer and the pure fluid layer cause strong variations in heat transfer, melt convection

Beckermann, Christoph

240

Flow Boiling Heat Transfer Coefficient In Minichannels Correlation and Trends Satish G. Kandlikar  

E-Print Network [OSTI]

Flow Boiling Heat Transfer Coefficient In Minichannels ­ Correlation and Trends Satish G. Kandlikar York 14623, USA The flow boiling heat transfer in small diameter passages is being applied in many boiling heat transfer coefficient with the correlations developed for conventional channels. It is found

Kandlikar, Satish

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Nanoscale Heat Transfer at Contact Between a Hot Tip and a Substrate Stphane Lefvre  

E-Print Network [OSTI]

Nanoscale Heat Transfer at Contact Between a Hot Tip and a Substrate Stéphane Lefèvre Laboratoire d three heat transfer modes with experimental data and modeling. We conclude that the three modes in "International Journal of Heat and Mass Transfer 49, 1-2 (2006) 251-258" DOI : 10.1016/j.ijheatmasstransfer.2005

Boyer, Edmond

242

Heat transfer from multiple row arrays of low aspect ratio pin fins Seth A. Lawson a,  

E-Print Network [OSTI]

Heat transfer from multiple row arrays of low aspect ratio pin fins Seth A. Lawson a, , Alan A 18 March 2011 Available online 5 May 2011 Keywords: Pin fins Heat transfer augmentation Array to enhance heat transfer. In modern gas turbines, for exam- ple, airfoils are designed with sophisticated

Thole, Karen A.

243

The Influence of Heat Transfer Irreversibilities on the Optimal Performance of Diabatic  

E-Print Network [OSTI]

The Influence of Heat Transfer Irreversibilities on the Optimal Performance of Diabatic is only slightly dependent on the heat transfer law considered. In the limit of an infinite number of trays even this column with resistance to transfer of heat becomes reversible. 1 #12;Keywords Diabatic

Salamon, Peter

244

Accepted Manuscript A wall heat transfer correlation for the baffled-rotary kilns with secondary air  

E-Print Network [OSTI]

Accepted Manuscript A wall heat transfer correlation for the baffled-rotary kilns with secondary;1 A wall heat transfer correlation for the baffled- rotary kilns with secondary air flow and recycled industrial applications suggests examining the heat transfer phenomena in order to improve the multi

Boyer, Edmond

245

HEAT TRANSFER ON A HYPERSONIC SPHERE WITH DIFFUSE RAREFIED-GAS INJECTION  

E-Print Network [OSTI]

HEAT TRANSFER ON A HYPERSONIC SPHERE WITH DIFFUSE RAREFIED-GAS INJECTION Vladimir V. Riabov* Rivier numbers Re0,R.3-7 Mass injection can be considered as an effective way of the reduction of heat transfer in the case of small Reynolds numbers. Moss12 found that mass injection dramatically reduces heat transfer

Riabov, Vladimir V.

246

HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME  

E-Print Network [OSTI]

1 HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME P. H or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers-dimensional numerical simulation of the heat transfers through the double skin reveals the most important parameters

Boyer, Edmond

247

Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a  

E-Print Network [OSTI]

Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a , Rafik ABSI 2 abenzaoui@gmail.com Keywords: turbulent flows, heat transfer, forced convection, low Reynolds number model data for Re = 150. Introduction Turbulent flow with heat transfer mechanism is of great importance from

Paris-Sud XI, Université de

248

Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a,  

E-Print Network [OSTI]

Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a, , Chia September 2011 Keywords: Microtube Heat transfer Liquid Crystal Thermography a b s t r a c t Several researches dealing with the single-phase forced convection heat transfer inside microchannels have been

Kandlikar, Satish

249

Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer in Window Frames  

E-Print Network [OSTI]

1 Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer Arasteh and Dragan Curcija ABSTRACT Accurately analyzing heat transfer in window frame cavities radiation heat-transfer effects.) We examine three representative complex cavity cross-section profiles

250

Int. Symp. on Heat Transfer in Gas Turbine Systems 9 14 August, 2009, Antalya, Turkey  

E-Print Network [OSTI]

Int. Symp. on Heat Transfer in Gas Turbine Systems 9 ­ 14 August, 2009, Antalya, Turkey EXPERIMENTAL TURBINE AERO-HEAT TRANSFER STUDIES IN ROTATING RESEARCH FACILITIES Cengiz Camci Turbomachinery Aero-Heat Transfer Laboratory Department of Aerospace Engineering The Pennsylvania State University 233

Camci, Cengiz

251

Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law  

E-Print Network [OSTI]

Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law F transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat-Cattaneo law, heat transfer, magnetic field, magnetization AMS subject classifications: 76N10, 35Q35. 1

Boyer, Edmond

252

Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped Emmanuel Rousseau  

E-Print Network [OSTI]

Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped silicon the role of surface plasmons for nanoscale radiative heat transfer between doped silicon surfaces. We derive a new accurate and closed-form expression of the radiative near- field heat transfer. We also

Paris-Sud XI, Université de

253

Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application  

E-Print Network [OSTI]

Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application to Crystal University of New York at Stony Brook Stony Brook N.Y. 11794 ABSTRACT Radiative heat transfer plays simulating radiative heat transfer in the crystal and in the region above the melt containing gas under

New York at Stoney Brook, State University of

254

The effects of topology upon fluid-flow and heat-transfer within cellular copper structures  

E-Print Network [OSTI]

and packed beds, but also a function of orientation (open area ratio). The overall heat transfer dependsThe effects of topology upon fluid-flow and heat-transfer within cellular copper structures J. Tian February 2004 Available online 20 March 2004 Abstract The fluid-flow and heat-transfer features of cellular

Wadley, Haydn

255

A FAST MULTILEVEL ALGORITHM FOR THE SOLUTION OF NONLINEAR SYSTEMS OF CONDUCTIVERADIATIVE HEAT TRANSFER EQUATIONS \\Lambda  

E-Print Network [OSTI]

­differential equations that model steady­state combined conductive­radiative heat transfer. This system of equations­Brakhage algorithm. Key words. conductive­radiative heat transfer, multilevel algorithm, compact fixed point problems integro­differential equations that model steady­state combined conductive­radiative heat transfer

256

Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure, Part I: Experimental results  

E-Print Network [OSTI]

Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure online 4 May 2013 Keywords: Pool boiling Heat transfer enhancement Open microchannels Cylindrical tube boiling heat transfer over enhanced cylindrical microchannel test surfaces with water at atmospheric

Kandlikar, Satish

257

Convective heat transfer on leeward building walls in an urban environment: Measurements in an outdoor scale model  

E-Print Network [OSTI]

surface, Proc. 5 th Int. Heat Transfer Conf. 3 (1974) 129-a vertical plate, J. Heat Transfer 109(1) [13] K. Patel,Experimental study of heat transfer in turbulent flows over

Nottrott, A.; Onomura, S.; Inagaki, A.; Kanda, M.; Kleissl, J.

2011-01-01T23:59:59.000Z

258

Modeling of Heat and Mass Transfer in Fusion Welding  

SciTech Connect (OSTI)

In fusion welding, parts are joined together by melting and subsequent solidification. Although this principle is simple, complex transport phenomena take place during fusion welding, and they determine the final weld quality and performance. The heat and mass transfer in the weld pool directly affect the size and shape of the pool, the solidification microstructure, the formation of weld defects such as porosity and humping, and the temperature distribution in the fusion zone and heat-affected zone (HAZ). Furthermore, the temperature evolution affects the kinetics and extent of various solid-state phase transformations, which in turn determine the final weld microstructure and mechanical properties. The formation of residual stresses and distortion originates from the thermal expansion and contraction during welding heating and cooling, respectively.

Zhang, Wei [ORNL

2011-01-01T23:59:59.000Z

259

Molten salt as a heat transfer fluid for heating a subsurface formation  

DOE Patents [OSTI]

A heating system for a subsurface formation includes a conduit located in an opening in the subsurface formation. An insulated conductor is located in the conduit. A material is in the conduit between a portion of the insulated conductor and a portion of the conduit. The material may be a salt. The material is a fluid at operating temperature of the heating system. Heat transfers from the insulated conductor to the fluid, from the fluid to the conduit, and from the conduit to the subsurface formation.

Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)

2010-11-16T23:59:59.000Z

260

Indirect Heat Transfer Technology For Waste Heat Recovery Can Save You Money  

E-Print Network [OSTI]

-drllt fIn lb. FI~-to_heot-roccvery .ylt8m Stoek gl' ..---::-----'1 _._.__.@_.; -+ Farcod?drall fan le. Air-prohe8ting syotem UBing I ....Hransfer ayltem Three typical arrangements for recovering waste heat from furnace flue gas Fig. 1 *Trademark... heat transfer fluid and thence to selected heat "user" sites (Figure 1C). This basic method often offers an attractive investment return, particu larly in applications where stack gas exit tempera tures exceed 316?C (600?F) and the furnace duty...

Beyrau, J. A.; Bogel, N. G.; Seifert, W. F.; Wuelpern, L. E.

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Thermo-mechanical simulations in double-sided heat transfer power assemblies.  

E-Print Network [OSTI]

Thermo-mechanical simulations in double-sided heat transfer power assemblies. E. Woirgard; I. Favre In power assemblies, heat transfer due to the die self- heating is one of the most important point on time life assemblies. Heat has to be evacuated toward the base- plate not to weaken the solder joint under

Boyer, Edmond

262

An early warning indicator for atmospheric blocking events using transfer operators  

E-Print Network [OSTI]

The existence of persistent midlatitude atmospheric flow regimes with time-scales larger than 5-10 days and indications of preferred transitions between them motivates to develop early warning indicators for such regime transitions. In this paper, we use a hemispheric barotropic model together with estimates of transfer operators on a reduced phase space to develop an early warning indicator of the zonal to blocked flow transition in this model. It is shown that, the spectrum of the transfer operators can be used to study the slow dynamics of the flow as well as the non-Markovian character of the reduction. The slowest motions are thereby found to have time scales of three to six weeks and to be associated with meta-stable regimes (and their transitions) which can be detected as almost-invariant sets of the transfer operator. From the energy budget of the model, we are able to explain the meta-stability of the regimes and the existence of preferred transition paths. Even though the model is highly simplified, the skill of the early warning indicator is promising, suggesting that the transfer operator approach can be used in parallel to an operational deterministic model for stochastic prediction or to assess forecast uncertainty.

Alexis Tantet; Fiona R. van der Burgt; Henk A. Dijkstra

2015-02-03T23:59:59.000Z

263

An early warning indicator for atmospheric blocking events using transfer operators  

E-Print Network [OSTI]

The existence of persistent midlatitude atmospheric flow regimes with time-scales larger than 5-10 days and indications of preferred transitions between them motivates to develop early warning indicators for such regime transitions. In this paper, we use a hemispheric barotropic model together with estimates of transfer operators on a reduced phase space to develop an early warning indicator of the zonal to blocked flow transition in this model. It is shown that, the spectrum of the transfer operators can be used to study the slow dynamics of the flow as well as the non-Markovian character of the reduction. The slowest motions are thereby found to have time scales of three to six weeks and to be associated with meta-stable regimes (and their transitions) which can be detected as almost-invariant sets of the transfer operator. From the energy budget of the model, we are able to explain the meta-stability of the regimes and the existence of preferred transition paths. Even though the model is highly simplified, the skill of the early warning indicator is promising, suggesting that the transfer operator approach can be used in parallel to an operational deterministic model for stochastic prediction or to assess forecast uncertainty.

Alexis Tantet; Fiona R. van der Burgt; Henk A. Dijkstra

2015-03-14T23:59:59.000Z

264

Barr and Showman: Heat Transfer in Europa's Icy Shell 405 Heat Transfer in Europa's Icy Shell  

E-Print Network [OSTI]

Europa's ice shell controls the thermal evolution of its interior and provides a source of energy surface features with steady-state thermal convection is challeng- ing, even with tidal heating, because convects, can the ocean be thermodynamically stable? What role might compositional heterogeneity play

265

Natural convection heat transfer for a staggered array of heated, horizontal cylinders within a rectangular enclosure  

SciTech Connect (OSTI)

This thesis presents the results of an experimental investigation of natural convection heat transfer in a staggered array of heated cylinders, oriented horizontally within a rectangular enclosure. The main purpose of this research was to extend the knowledge of heat transfer within enclosed bundles of spent nuclear fuel rods sealed within a shipping or storage container. This research extends Canaan`s investigation of an aligned array of heated cylinders that thermally simulated a boiling water reactor (BWR) spent fuel assembly sealed within a shipping or storage cask. The results are presented in terms of piecewise Nusselt-Rayleigh number correlations of the form Nu = C(Ra){sup n}, where C and n are constants. Correlations are presented both for individual rods within the array and for the array as a whole. The correlations are based only on the convective component of the heat transfer. The radiative component was calculated with a finite-element code that used measured surface temperatures, rod array geometry, and measured surface emissivities as inputs. The correlation results are compared to Canaan`s aligned array results and to other studies of natural convection in horizontal tube arrays.

Triplett, C.E.

1996-12-01T23:59:59.000Z

266

Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger  

DOE Patents [OSTI]

A radiative heat transfer mechanism in a furnace having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits.

Im, Kwan H. (Naperville, IL); Ahluwalia, Rajesh K. (Burr Ridge, IL)

1994-01-01T23:59:59.000Z

267

Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger  

DOE Patents [OSTI]

A radiative heat transfer mechanism in a furnace is described having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits. 7 figs.

Im, K.H.; Ahluwalia, R.K.

1994-10-18T23:59:59.000Z

268

Effect of combined nanoparticle and polymeric dispersions on critical heat flux, nucleate boiling heat transfer coefficient, and coating adhesion  

E-Print Network [OSTI]

An experimental study was performed to determine thermal performance and adhesion effects of a combined nanoparticle and polymeric dispersion coating. The critical heat flux (CHF) values and nucleate boiling heat transfer ...

Edwards, Bronwyn K

2009-01-01T23:59:59.000Z

269

PTG exam 9 April 2014 short answers 123. Heat given off = surface * heat transfer coefficient * temperature = A * h * T  

E-Print Network [OSTI]

= Q34 = h4 ­ h3 = 2173,3 kJ/kg d. Heat input = Q15 = h1 ­ h5 = h1 ­ h4 + 4 (pump power) = 2831,0 kPTG exam 9 April 2014 short answers 123. Heat given off = surface * heat transfer coefficient * temperature = A * h * T Heat transfer coefficient from Nunumber, which for natural convection

Zevenhoven, Ron

270

Couette flow regimes with heat transfer in rarefied gas  

SciTech Connect (OSTI)

Based on numerical solution of the Boltzmann equation by direct statistic simulation, the Couette flow with heat transfer is studied in a broad range of ratios of plate temperatures and Mach numbers of a moving plate. Flow regime classification by the form of the dependences of the energy flux and friction stress on the Knudsen number Kn is proposed. These dependences can be simultaneously monotonic and nonmonotonic and have maxima. Situations are possible in which the dependence of the energy flux transferred to a plate on Kn has a minimum, while the dependence of the friction stress is monotonic or even has a maximum. Also, regimes exist in which the dependence of the energy flux on Kn has a maximum, while the dependence of the friction stress is monotonic, and vice versa.

Abramov, A. A., E-mail: alabr54@mail.ru; Butkovskii, A. V., E-mail: albutkov@mail.ru [Zhukovski Central Aerohydrodynamics Institute (Russian Federation)

2013-06-15T23:59:59.000Z

271

Flexible profile approach to the conjugate heat transfer problem  

E-Print Network [OSTI]

The flexible profile approach proposed earlier to create CTM (compact or reduced order thermal models) is extended to cover the area of conjugate heat transfer. The flexible profile approach is a methodology that allows building a highly boundary conditions independent CTM, with any desired degree of accuracy, that may adequately replace detailed 3D models for the whole spectrum of applications in which the modeled object may be used. The extension to conjugate problems radically solves the problem of interfacing two different domains. Each domain, fluid or solid, can be "compacted" independently creating two CTM that can be joined together to produce reliable results for any arbitrary set of external boundary conditions.

M. -N. Sabry

2008-01-07T23:59:59.000Z

272

Grid-independent Issue in Numerical Heat Transfer  

E-Print Network [OSTI]

Grid independent is associated with the accuracy or even rationality of numerical results. This paper takes two-dimensional steady heat transfer for example to reveal the effect of grid resolution on numerical results. The law of grid dependence is obtained and a simple mathematical formula is presented. The production acquired here can be used as the guidance in choosing grid density in numerical simulation and get exact grid independent value without using infinite fine grid. Through analyzing grid independent, we can find the minimum number of grid cells that is needed to get grid-independent results. Such strategy can save computational resource while ensure a rational computational result.

Yao Wei; Wang Jian; Liao Guangxuan

2006-09-26T23:59:59.000Z

273

Heat Transfer in GE Jet Engines | GE Global Research  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Bigfront.jpgcommunity200cellHeat Transfer in GE Jet Engines Click to

274

TOPAZ3D. 3-D Finite Element Heat Transfer  

SciTech Connect (OSTI)

TOPAZ3D is a three-dimensional implicit finite element computer code for heat transfer analysis. TOPAZ3D can be used to solve for the steady-state or transient temperature field on three-dimensional geometries. Material properties may be temperature-dependent and either isotropic or orthotropic. A variety of time-dependent and temperature-dependent boundary conditions can be specified including temperature, flux, convection, and radiation. By implementing the user subroutine feature, users can model chemical reaction kinetics and allow for any type of functional representation of boundary conditions and internal heat generation. TOPAZ3D can solve problems of diffuse and specular band radiation in an enclosure coupled with conduction in the material surrounding the enclosure. Additional features include thermal contact resistance across an interface, bulk fluids, phase change, and energy balances.

Shapiro, A.B. [Lawrence Livermore National Lab., CA (United States)

1992-02-24T23:59:59.000Z

275

Effects of slitted fins on the heat transfer and pressure drop characteristics of a compact heat exchanger  

SciTech Connect (OSTI)

A compact heat exchanger which consists of air-cooled aluminum fins and copper tubes circulating refrigerant has been used in a cooling system for a long time. There are two key parameters to be seriously considered for a design of the heat exchanger and its performance improvement. These are the heat transfer rate and pressure drop coefficient which varies with the change of the tube size, its arrangement and the fin configuration. In here, a numerical study was carried to understand the effect of the fin configuration on the heat transfer and pressure drop of the heat exchanger. The diameter and the arrangement of tubes were fixed but three different types of the fin configuration were used to see its effect on the heat transfer capacity and the static pressure drop. The calculation results were compared with that of a flat plate fin. From the comparison, it was found that the slitted fins have higher pressure drop; however, they have higher heat transfer rate. It means that the simpler of the fin configuration, the lower pressure drop and heat transfer coefficients are obtained. It is mainly due to the discretisation of the thermal boundary layer on the fin surface to maximize the heat transfer to air. The slitted sides of fins act like obstacles in the airflow path. From the experimental result, it was found that the same trend in the variation of the heat transfer rate and the pressure drop with the change of the fin configuration was obtained.

Kim, C.H.; Yun, J.Y. [LG Electronics Living System Research Lab., Seoul (Korea, Republic of)

1996-12-31T23:59:59.000Z

276

Enhanced convective and film boiling heat transfer by surface gas injection  

SciTech Connect (OSTI)

Heat transfer measurements were made for stable film boiling of water over a horizontal, flat stainless steel plate from the minimum film boiling point temperature, T{sub SURFACE} {approximately}500K, to T{sub SURFACE} {approximately}950K. The pressure at the plate was approximately 1 atmosphere and the temperature of the water pool was maintained at saturation. The data were compared to the Berenson film-boiling model, which was developed for minimum film-boiling-point conditions. The model accurately represented the data near the minimum film-boiling point and at the highest temperatures measured, as long it was corrected for the heat transferred by radiation. On the average, the experimental data lay within {plus_minus}7% of the model. Measurements of heat transfer were made without film boiling for nitrogen jetting into an overlying pool of water from nine 1-mm- diameter holes, drilled in the heat transfer plate. The heat flux was maintained constant at approximately 26.4 kW/m{sup 2}. For water-pool heights of less than 6cm the heat transfer coefficient deceased linearly with a decrease in heights. Above 6cm the heat transfer coefficient was unaffected. For the entire range of gas velocities measured [0 to 8.5 cm/s], the magnitude of the magnitude of the heat transfer coefficient only changed by approximately 20%. The heat transfer data bound the Konsetov model for turbulent pool heat transfer which was developed for vertical heat transfer surfaces. This agreement suggests that surface orientation may not be important when the gas jets do not locally affect the surface heat transfer. Finally, a database was developed for heat transfer from the plate with both film boiling and gas jetting occurring simultaneously, in a pool of water maintained at its saturation temperature. The effect of passing nitrogen through established film boiling is to increase the heat transfer from that surface. 60 refs.

Duignan, M.R.; Greene, G.A. [Brookhaven National Lab., Upton, NY (United States); Irvine, T.F., Jr. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Mechanical Engineering

1992-04-01T23:59:59.000Z

277

Enhanced convective and film boiling heat transfer by surface gas injection  

SciTech Connect (OSTI)

Heat transfer measurements were made for stable film boiling of water over a horizontal, flat stainless steel plate from the minimum film boiling point temperature, T{sub SURFACE} {approximately}500K, to T{sub SURFACE} {approximately}950K. The pressure at the plate was approximately 1 atmosphere and the temperature of the water pool was maintained at saturation. The data were compared to the Berenson film-boiling model, which was developed for minimum film-boiling-point conditions. The model accurately represented the data near the minimum film-boiling point and at the highest temperatures measured, as long it was corrected for the heat transferred by radiation. On the average, the experimental data lay within {plus minus}7% of the model. Measurements of heat transfer were made without film boiling for nitrogen jetting into an overlying pool of water from nine 1-mm- diameter holes, drilled in the heat transfer plate. The heat flux was maintained constant at approximately 26.4 kW/m{sup 2}. For water-pool heights of less than 6cm the heat transfer coefficient deceased linearly with a decrease in heights. Above 6cm the heat transfer coefficient was unaffected. For the entire range of gas velocities measured (0 to 8.5 cm/s), the magnitude of the magnitude of the heat transfer coefficient only changed by approximately 20%. The heat transfer data bound the Konsetov model for turbulent pool heat transfer which was developed for vertical heat transfer surfaces. This agreement suggests that surface orientation may not be important when the gas jets do not locally affect the surface heat transfer. Finally, a database was developed for heat transfer from the plate with both film boiling and gas jetting occurring simultaneously, in a pool of water maintained at its saturation temperature. The effect of passing nitrogen through established film boiling is to increase the heat transfer from that surface. 60 refs.

Duignan, M.R.; Greene, G.A. (Brookhaven National Lab., Upton, NY (United States)); Irvine, T.F., Jr. (State Univ. of New York, Stony Brook, NY (United States). Dept. of Mechanical Engineering)

1992-04-01T23:59:59.000Z

278

Experimental and numerical study of laminar forced convection heat transfer for a dimpled heat sink  

E-Print Network [OSTI]

characteristics in a laminar and a turbulent airflow condition. A relative dimple depth in the range of 0.06 to 0.24 and a SIMPLEC (Semi-Implicit Method for Pressure-Linked Equations) method with multiblock grids were used to evaluate the flow change and heat....3) 4.3 Computation Procedure The computations of the fluid flow field and heat transfer were performed using CFD by Fluent software, version Fluent 6.2.16. Gambit 2.2.30 was used for the development of the computational grid. 4.3.1 Computational...

Park, Do Seo

2009-05-15T23:59:59.000Z

279

Study of natural convection heat transfer above a horizontal heated plate using a laser specklegram technique  

E-Print Network [OSTI]

flow from the horizontal isothermal plate. 15. Study of the effect of aspect ratio (AR) of the heated surface on the global Nusselt number for Ra = 104 50 NOMENCLATURE a distance between the test section and the second parabolic mirror (mm) b... plane of a CCD-camera (mm) h heat transfer coefficient. K Gladstone ? Dale constant for air ( m'/kg) . K, thermal conductivity of air ((tj)/m-'C) L Length of the test section measured along the optical axis m magnification of the second (parabolic...

Cheeti, Satish K.R.

1993-01-01T23:59:59.000Z

280

Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland  

E-Print Network [OSTI]

Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland M. de Graaf #12;Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland Martin de is used to calculate surface heat fluxes over glaciers. As determination of surface fluxes still

Graaf, Martin de

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 14, No. 4, OctoberDecember 2000  

E-Print Network [OSTI]

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 14, No. 4, October­December 2000 Multidimensional are optical tomographyof tissue, remote sensing of oceansand atmospheres, laser material processing radiative heat transfer in participat- ing media in recent years. However, the analysis of radiative heat

Guo, Zhixiong "James"

282

Characterization of the effect of Froude number on surface waves and heat transfer in inclined turbulent  

E-Print Network [OSTI]

describes wave/heat transfer phenomena in inclined turbulent open surface water flows. The experiments wereCharacterization of the effect of Froude number on surface waves and heat transfer in inclined Abstract Interfacial heat transport in open channel turbulent flows is strongly dependent on surface waves

Abdou, Mohamed

283

Heat Transfer in Buildings: Application to Solar Air Collector and Trombe Wall Design  

E-Print Network [OSTI]

11 Heat Transfer in Buildings: Application to Solar Air Collector and Trombe Wall Design H. Boyer focuses on the modeling of Trombe solar walls. In each case, detailed modeling of heat transfer allows with same thermal behaviour). For heat conduction in walls, it results from electrical analogy

Paris-Sud XI, Université de

284

2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 Molecular dynamics methods in  

E-Print Network [OSTI]

2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 2.13.7 Molecular dynamics methods in microscale heat transfer Shigeo Maruyama A. Introduction In normal heat transfer and fluid flow calculations of molecules. This situation is approached in microscale heat transfer and fluid flow. Molecular level

Maruyama, Shigeo

285

Taylor bubble-train flows and heat transfer in the context of Pulsating Balkrishna Mehta, Sameer Khandekar  

E-Print Network [OSTI]

Taylor bubble-train flows and heat transfer in the context of Pulsating Heat Pipes Balkrishna Mehta Nusselt number Heat transfer enhancement a b s t r a c t Understanding the performance of Pulsating Heat Pipes (PHPs) requires spatio-temporally coupled, flow and heat transfer information during the self

Khandekar, Sameer

286

Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated by Joule effect  

E-Print Network [OSTI]

)" #12;1. Introduction Brazed aluminium heat exchangers are composed of flat tubes on the refrigerant exchangers with round tube, such as charge reduction and higher heat transfer coefficient. But, according are thus not suitable to small-channel heat exchangers. As a consequence, the refrigerant distribution

Boyer, Edmond

287

A method of correlating heat transfer data for surface boiling of liquids  

E-Print Network [OSTI]

A method based an a logical uxplanation of the meani of beat transfer associated with the boiling process is presented for correlating heat transfer data for nucleate boiling of liquids for the case of pool boiling. Tbe ...

Rohsenow, Warren M.

1951-01-01T23:59:59.000Z

288

Constructal multi-scale package of vertical channels with natural convection and maximal heat transfer density. CONSTRUCTAL DESIGN: THE GENERATION OF MULTI-SCALE HEAT  

E-Print Network [OSTI]

transfer density. CONSTRUCTAL DESIGN: THE GENERATION OF MULTI-SCALE HEAT AND FLUID FLOW STRUCTURES-scale structures in natural convection with the objective of maximizing the heat transfer density, or the heat transfer rate per unit of volume§ . The flow volume is filled with vertical equidistant heated blades

Kihm, IconKenneth David

289

Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime Using Controlled Calorimetry  

SciTech Connect (OSTI)

A comprehensive description of the accomplishments of the DOE grant titled, ''Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime using Controlled Calorimetry''.

Don W. Miller; Andrew Kauffmann; Eric Kreidler; Dongxu Li; Hanying Liu; Daniel Mills; Thomas D. Radcliff; Joseph Talnagi

2001-12-31T23:59:59.000Z

290

Application Of A Spherical-Radial Heat Transfer Model To Calculate...  

Open Energy Info (EERE)

Spherical-Radial Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Jump to: navigation, search OpenEI Reference LibraryAdd to library...

291

A phase-field method for 3D simulation of two-phase heat transfer  

E-Print Network [OSTI]

stationary grids, different modes of heat transfer (e.g. convection/conduction), as well as its ... flow systems with sharp-interface models, moving-grid methods.

X. Zheng

2014-12-04T23:59:59.000Z

292

E-Print Network 3.0 - accident heat transfer Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

accident situations involving hundreds of kilograms... of the expansion, heat transfer is small and therefore fuel-coolant mixing and hydro- dynamics must be considered... from the...

293

RELAP5 MODEL OF THE DIVERTOR PRIMARY HEAT TRANSFER SYSTEM  

SciTech Connect (OSTI)

This report describes the RELAP5 model that has been developed for the divertor primary heat transfer system (PHTS). The model is intended to be used to examine the transient performance of the divertor PHTS and evaluate control schemes necessary to maintain parameters within acceptable limits during transients. Some preliminary results are presented to show the maturity of the model and examine general divertor PHTS transient behavior. The model can be used as a starting point for developing transient modeling capability, including control system modeling, safety evaluations, etc., and is not intended to represent the final divertor PHTS design. Preliminary calculations using the models indicate that during normal pulsed operation, present pressurizer controls may not be sufficient to keep system pressures within their desired range. Additional divertor PHTS and control system design efforts may be required to ensure system pressure fluctuation during normal operation remains within specified limits.

Popov, Emilian L [ORNL; Yoder Jr, Graydon L [ORNL; Kim, Seokho H [ORNL

2010-08-01T23:59:59.000Z

294

Extensions and enhancements to the iLab heat transfer project site  

E-Print Network [OSTI]

The iLab Heat Transfer Project website started four years ago to enable web access to experiments related to movement of heat through transport processes. This thesis details improvements made to the site which extend and ...

Saylor, David P. (David Patrick)

2005-01-01T23:59:59.000Z

295

A cut-cell method for adaptive high-order discretizations of conjugate heat transfer problems  

E-Print Network [OSTI]

Heat transfer between a conductive solid and an adjacent convective fluid is prevalent in many aerospace systems. The ability to achieve accurate predictions of the coupled heat interaction is critical in advancing ...

Ojeda, Steven Matthew

2014-01-01T23:59:59.000Z

296

Micro- and Nanoscale Measurement Methods for Phase Change Heat Transfer on Planar and Structured Surfaces  

E-Print Network [OSTI]

In this opinion piece, we discuss recent advances in experimental methods for characterizing phase change heat transfer. We begin with a survey of techniques for high-resolution measurements of temperature and heat flux ...

Buongiorno, Jacopo

297

Natural convection heat transfer within horizontal spent nuclear fuel assemblies  

SciTech Connect (OSTI)

Natural convection heat transfer is experimentally investigated in an enclosed horizontal rod bundle, which characterizes a spent nuclear fuel assembly during dry storage and/or transport conditions. The basic test section consists of a square array of sixty-four stainless steel tubular heaters enclosed within a water-cooled rectangular copper heat exchanger. The heaters are supplied with a uniform power generation per unit length while the surrounding enclosure is maintained at a uniform temperature. The test section resides within a vacuum/pressure chamber in order to subject the assembly to a range of pressure statepoints and various backfill gases. The objective of this experimental study is to obtain convection correlations which can be used in order to easily incorporate convective effects into analytical models of horizontal spent fuel systems, and also to investigate the physical nature of natural convection in enclosed horizontal rod bundles in general. The resulting data consist of: (1) measured temperatures within the assembly as a function of power, pressure, and backfill gas; (2) the relative radiative contribution for the range of observed temperatures; (3) correlations of convective Nusselt number and Rayleigh number for the rod bundle as a whole; and (4) correlations of convective Nusselt number as a function of Rayleigh number for individual rods within the array.

Canaan, R.E.

1995-12-01T23:59:59.000Z

298

USING LIGA BASED MICROFABRICATION TO IMPROVE OVERALL HEAT TRANSFER EFFICIENCY OF PRESSURIZED WATER REACTOR: I. Effects of Different Micro Pattern on Overall Heat Transfer.  

SciTech Connect (OSTI)

The Pressurized Water Reactors (PWRs in Figure 1) were originally developed for naval propulsion purposes, and then adapted to land-based applications. It has three parts: the reactor coolant system, the steam generator and the condenser. The Steam generator (a yellow area in Figure 1) is a shell and tube heat exchanger with high-pressure primary water passing through the tube side and lower pressure secondary feed water as well as steam passing through the shell side. Therefore, a key issue in increasing the efficiency of heat exchanger is to improve the design of steam generator, which is directly translated into economic benefits. The past research works show that the presence of a pin-fin array in a channel enhances the heat transfer significantly. Hence, using microfabrication techniques, such as LIGA, micro-molding or electroplating, some special microstructures can be fabricated around the tubes in the heat exchanger to increase the heat-exchanging efficiency and reduce the overall size of the heat-exchanger for the given heat transfer rates. In this paper, micro-pin fins of different densities made of SU-8 photoresist are fabricated and studied to evaluate overall heat transfer efficiency. The results show that there is an optimized micro pin-fin configuration that has the best overall heat transfer effects.

Zhang, M.; Ibekwe, S.; Li, G.; Pang, S.S.; and Lian, K.

2006-07-01T23:59:59.000Z

299

Abstract--The use of structured porous media is a proposed technique to achieve higher heat transfer coefficients by  

E-Print Network [OSTI]

transfer coefficients by increasing the specific surface area for heat transfer while aiming to maintain pressure drop for a given heat transfer performance. A comprehensive thermo-fluid model called MERLOT [1] was used to assess the use of porous heat transfer media for fusion plasma facing component applications

Pulsifer, John

300

Abstract. Tailored porous media is a proposed method of achieving higher heat transfer coefficients while seeking to  

E-Print Network [OSTI]

Abstract. Tailored porous media is a proposed method of achieving higher heat transfer coefficients general porous flow model (MERLOT [1]). The Model of Energy- transfer Rate for fLow in Open transfer performance. The low heat capacities and low heat transfer coefficients, h, of gas coolants

Raffray, A. René

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS  

E-Print Network [OSTI]

RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS Kyunghan Kim to incorporate transient radiation heat transfer in tissue welding and soldering with use of ultrafast lasers are performed between laser welding and laser soldering. The use of solder is found to substantially enhance

Guo, Zhixiong "James"

302

Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater  

E-Print Network [OSTI]

. It is found that the integrated characteristics of heat transfer and flow friction increase with the hole's diameter at the same hole density (which is equal to the ratio of the hole's total area to the baffle's area), and the heat transfer rate increases...

Zheng, H.; Fan, X.; Li, A.

2006-01-01T23:59:59.000Z

303

Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide plates  

E-Print Network [OSTI]

Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide://jap.aip.org/authors #12;Rectification of evanescent heat transfer between dielectric-coated and uncoated silicon carbide-infinite bodies of the dielectric-coated silicon carbide and uncoated silicon carbide. The permittivity

Fan, Shanhui

304

Bibliography of US patents on augmentation of convective heat and mass transfer-II  

SciTech Connect (OSTI)

Patents are an important source of information on the potential commercialization of augmented heat transfer technology. This report presents a bibliography of US patents pertinent to that technology. The total number of patents cited is 454. They are presented in three separate lists: by patent number, alphabetically by first inventor, and by augmentation technique (with secondary arrangement according to mode of heat transfer).

Webb, R.L.; Bergles, A.E.; Junkhan, G.H.

1983-12-01T23:59:59.000Z

305

1 Copyright 2012 by ASME Proceedings of the ASME 2012 Summer Heat Transfer Conference  

E-Print Network [OSTI]

1 Copyright © 2012 by ASME Proceedings of the ASME 2012 Summer Heat Transfer Conference HT2012 July. INTRODUCTION Passive cooling is a widely preferred method for electronic and power electronic devices since, #12;2 Copyright © 2012 by ASME is convective heat transfer coefficient and is thermal conductivity

Bahrami, Majid

306

Adaptive higher order numerical simulation of heat and mass transfer in fluidized beds  

E-Print Network [OSTI]

Adaptive higher order numerical simulation of heat and mass transfer in fluidized beds Ch. Nagaiah1 adaptive numerical results of heat and mass transfer in fluidized beds using higher order time stepping injection. The numerical results are tested with different time stepping methods for different spatial grid

Magdeburg, Universität

307

Radiative Heat Transfer Analysis of Fibrous Insulation Materials Using the ZonalGEF Method  

E-Print Network [OSTI]

Radiative Heat Transfer Analysis of Fibrous Insulation Materials Using the Zonal­GEF Method Walter to analyze radiative heat transfer in high porosity insulation materials which have a large scattering for LI900, a material used in the insulation tile for the space shuttle. Comparisons are presented

Yuen, Walter W.

308

MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA "BUILDINGS" LIBRARY  

E-Print Network [OSTI]

MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA "BUILDINGS" LIBRARY Michael Wetter, Wangda Zuo describes the implementation of the room heat transfer model in the free open-source Modelica "Buildings National Lab- oratory started the development of the free open- source Modelica "Buildings" library

309

Effect of surface conditions on boiling heat transfer of refrigerants in shell-and-tube evaporators  

SciTech Connect (OSTI)

Experimental results are presented for the boiling heat transfer performance of R 22 and R 717 on surfaces with porous metallized coatings. A calculational-theoretical model is given for predicting the heat transfer of refrigerants boiling on a bundle of finned tubes.

Danilova, G.N.; Dyundin, V.A.; Borishanskaya, A.V.; Soloviyov, A.G.; Vol'nykh, Y.A.; Kozyrev, A.A.

1990-01-01T23:59:59.000Z

310

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 19, No. 1, JanuaryMarch 2005  

E-Print Network [OSTI]

developed turbulent nonrotating tube flow Dh, D = hydraulic diameter, m h = heat transfer coefficient, W/m2 Program, Department of Civil Engineer- ing. Senior Member AIAA. Professor, Turbine Heat Transfer thermal efficiency, gas-turbine stages are being de- signed to operate at increasingly high inlet

Al-Qahtani, Mohammad

311

Glass foams: formation, transport properties, and heat, mass, and radiation transfer  

E-Print Network [OSTI]

Glass foams: formation, transport properties, and heat, mass, and radiation transfer Andrei G depend, to a large extent, on foams formed on the surface of the molten glass and of the batch due models for thermophysical and transport properties and heat, mass, and radiation transfer in glass foams

Pilon, Laurent

312

A vectorized heat transfer model for solid reactor cores  

SciTech Connect (OSTI)

The new generation of nuclear reactors includes designs that are significantly different from light water reactors. Among these new reactor designs is the Modular High-Temperature Gas-Cooled Reactor (MHTGR). In addition, nuclear thermal rockets share a number of similarities with terrestrial HTGRs and would be amenable to similar types of analyses. In these reactors, the heat transfer in the solid core mass is of primary interest in design and safety assessment. One significant safety feature of these reactors is the capability to withstand a loss of pressure and forced cooling in the primary system and still maintain peak fuel temperatures below the safe threshold for retaining the fission products. To accurately assess the performance of gas-cooled reactors during these types of transients, a Helium/Hydrogen Cooled Reactor Analysis (HERA) computer code has been developed. HERA has the ability to model arbitrary geometries in three dimensions, which allows the user to easily analyze reactor cores constructed of prismatic graphite elements. The code accounts for heat generation in the fuel, control rods and other structures; conduction and radiation across gaps; convection to the coolant; and a variety of boundary conditions. The numerical solution scheme has been optimized for vector computers, making long transient analyses economical. Time integration is either explicit or implicit, which allows the use of the model to accurately calculate both short- or long-term transients with an efficient use of computer time. Both the basic spatial and temporal integration schemes have been benchmarked against analytical solutions. Also, HERA has been used to analyze a depressurized loss of forced cooling transient in a HTGR with a very detailed three-dimensional input model. The results compare favorably with other means of analysis and provide further validation of the models and methods. 18 refs., 11 figs.

Rider, W.J.; Cappiello, M.W.; Liles, D.R.

1990-01-01T23:59:59.000Z

313

Thulium-170 heat source  

DOE Patents [OSTI]

An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

1992-01-01T23:59:59.000Z

314

Exact microscopic theory of electromagnetic heat transfer between a dielectric sphere and plate  

E-Print Network [OSTI]

Near-field electromagnetic heat transfer holds great potential for the advancement of nanotechnology. Whereas far-field electromagnetic heat transfer is constrained by Planck's blackbody limit, the increased density of states in the near-field enhances heat transfer rates by orders of magnitude relative to the conventional limit. Such enhancement opens new possibilities in numerous applications, including thermal-photo-voltaics, nano-patterning, and imaging. The advancement in this area, however, has been hampered by the lack of rigorous theoretical treatment, especially for geometries that are of direct experimental relevance. Here we introduce an efficient computational strategy, and present the first rigorous calculation of electromagnetic heat transfer in a sphere-plate geometry, the only geometry where transfer rate beyond blackbody limit has been quantitatively probed at room temperature. Our approach results in a definitive picture unifying various approximations previously used to treat this problem, and provides new physical insights for designing experiments aiming to explore enhanced thermal transfer.

Clayton Otey; Shanhui Fan

2011-10-10T23:59:59.000Z

315

Heat transfer in the trailing edge cooling channels of turbine blades  

E-Print Network [OSTI]

Foundation and from the funded research contract (RF5810) through Dr. Han. NOMENCLATURE A area of heat transfer in the pin fin channel AI, area of heat transfer in the long ejection segments Az cross-sectional area, of trailing edge ejection holes A..., ?minimum flow cross-sectional area in the pin fin channel C'~ discharge coefficient Cp specific heat of air 1 diameter of trailing edge ejection holes D diameter of pins f overall friction factor h?heat transfer coefficient in the n th segment...

Kumaran, T. K.

1989-01-01T23:59:59.000Z

316

Development of a UF{sub 6} cylinder transient heat transfer/stress analysis model  

SciTech Connect (OSTI)

A heat transfer/stress analysis model is being developed to simulate the heating to a point of rupture of a cylinder containing UF{sub 6} when it is exposed to a fire. The assumptions underlying the heat transfer portion of the model, which has been the focus of work to date, will be discussed. A key aspect of this model is a lumped parameter approach to modeling heat transfer. Preliminary results and future efforts to develop an integrated thermal/stress model will be outlined.

Williams, W.R. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

1991-12-31T23:59:59.000Z

317

Micro and nanostructured surfaces for enhanced phase change heat transfer  

E-Print Network [OSTI]

Two-phase microchannel heat sinks are of significant interest for thermal management applications, where the latent heat of vaporization offers an efficient method to dissipate large heat fluxes in a compact device. However, ...

Chu, Kuang-Han, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

318

Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass  

E-Print Network [OSTI]

by a heating lamp emitting in the visible and near infraredwith heating in a furnace at 400 o C. The infrared lamp was

Kitamura, Rei; Pilon, Laurent

2009-01-01T23:59:59.000Z

319

Downflow heat transfer in a heated ribbed vertical annulus with a cosine power profile  

SciTech Connect (OSTI)

Experiments designed to investigate downflow heat transfer in a heated, ribbed annulus test section simulating one of the annular coolant channels of a Savannah River Plant production reactor Mark 22 fuel assembly have been conducted at the Idaho National Engineering Laboratory. The inner surface of the annulus was constructed of aluminum and was electrically heated to provide an axial cosine power profile and a flat azimuthal power shape. Data presented in this report are from the ECS-2c series, which was a follow on series to the ECS-2b series, conducted specifically to provide additional data on the effect of different powers at the same test conditions, for use in evaluation of possible power effects on the aluminum temperature measurements. Electrical powers at 90%, 100%, and 110% of the power required to result in the maximum aluminum temperature at fluid saturation temperature were used at each set of test conditions previously used in the ECS-2b series. The ECS-2b series was conducted in the same test rig as the previous ECS-2b series. Data and experimental description for the ECS-2b series is provided in a previous report. 18 refs., 25 figs., 3 tabs.

Anderson, J.L.; Condie, K.G.; Larson, T.K.

1991-10-01T23:59:59.000Z

320

Vibration damping and heat transfer using material phase changes  

DOE Patents [OSTI]

A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.

Kloucek, Petr (Houston, TX); Reynolds, Daniel R. (Oakland, CA)

2009-03-24T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Dual-circuit embossed-sheet heat-transfer panel  

DOE Patents [OSTI]

A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed for form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet.

Morgan, G.D.

1982-08-23T23:59:59.000Z

322

Determination of heat transfer and friction characteristics of an adapted inclined louvered fin  

SciTech Connect (OSTI)

An experimental study of a fin-and-tube heat exchanger was performed. To this end a test rig was constructed to measure the heat transfer rate on the air and waterside of the heat exchanger. A wide range of Reynolds numbers on the airside was investigated. The resulting data was used to determine the convective heat transfer correlation (expressed using the Colburn factor) and the friction factor on the airside. The fin type used in the heat exchanger of this research is an adaptation of the standard inclined louvered type. A thorough error analysis was performed, to validate the results. (author)

T'Joen, C.; Steeman, H.-J.; Willockx, A.; De Paepe, M. [Department of Flow, Heat and Combustion Mechanics, Ghent University-UGent, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium)

2006-03-01T23:59:59.000Z

323

Condensation heat transfer in square, triangular, and semi-circular mini-channels Melanie Derby a  

E-Print Network [OSTI]

, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, United States b Department was the coolant. The heat transfer rate was obtained through a coolant-side energy balance. To obtain condensation. An energy balance on the fluid-to-fluid heat exchanger measured heat duty while sensors in two obstructed

Peles, Yoav

324

Numerical simulation of the heat transfer in amorphous silicon nitride membrane-based microcalorimeters  

E-Print Network [OSTI]

Numerical simulation of the heat transfer in amorphous silicon nitride membrane July 2003 Numerical simulations of the two-dimensional 2D heat flow in a membrane-based microcalorimeter have been performed. The steady-state isotherms and time-dependent heat flow have been calculated

Hellman, Frances

325

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

DOE Patents [OSTI]

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

Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

1996-11-05T23:59:59.000Z

326

A FULL SCALE ROOM FOR THE EXPERIMENTAL STUDY OF INTERIOR BUILDING CONVECTIVE HEAT TRANSFER  

E-Print Network [OSTI]

air flow measurement. A water source heat pump provided chilled water to a fan-coil unit which in turn on volumetric air flow measurement and an overall room heat balance. Analysis was directed at results fromA FULL SCALE ROOM FOR THE EXPERIMENTAL STUDY OF INTERIOR BUILDING CONVECTIVE HEAT TRANSFER: DESIGN

327

ThermalEngineeringLaboratory,VanderbiltUniversity Convection Heat Transfer of Nanofluids in Commercial  

E-Print Network [OSTI]

EngineeringLaboratory,VanderbiltUniversity Experimental Setup Straight Tube Setup Constant Temperature Bath Parastaltic Pump Nanofluid Reservoir Heated.91 od di Commercial System Setup Heater Insulation Water block 4/10 #12;Thermal gain across the heated tube for the DI-water and the 0.5% nanofluid · Greater temperature gain in the 1

Walker, D. Greg

328

Exact microscopic theory of electromagnetic heat transfer between a dielectric sphere and plate  

E-Print Network [OSTI]

Near-field electromagnetic heat transfer holds great potential for the advancement of nanotechnology. Whereas far-field electromagnetic heat transfer is constrained by Planck's blackbody limit, the increased density of states in the near-field enhances heat transfer rates by orders of magnitude relative to the conventional limit. Such enhancement opens new possibilities in numerous applications, including thermal-photo-voltaics, nano-patterning, and imaging. The advancement in this area, however, has been hampered by the lack of rigorous theoretical treatment, especially for geometries that are of direct experimental relevance. Here we introduce an efficient computational strategy, and present the first rigorous calculation of electromagnetic heat transfer in a sphere-plate geometry, the only geometry where transfer rate beyond blackbody limit has been quantitatively probed at room temperature. Our approach results in a definitive picture unifying various approximations previously used to treat this problem, ...

Otey, Clayton

2011-01-01T23:59:59.000Z

329

Eurotherm Seminar N81 Reactive Heat Transfer in Porous Media, Ecole des Mines d'Albi, France June 4-6, 2007 ET81-1 HEAT TRANSFER BY SIMULTANEOUS RADIATION-CONDUCTION  

E-Print Network [OSTI]

Eurotherm Seminar N°81 Reactive Heat Transfer in Porous Media, Ecole des Mines d'Albi, France June 4-6, 2007 ET81- 1 HEAT TRANSFER BY SIMULTANEOUS RADIATION-CONDUCTION AND CONVECTION IN A HIGH for the packed bed. The comparison between the radiative heat transfer and the exchanges by conduction and forced

Boyer, Edmond

330

Heat Transfer Boundary Conditions in the RELAP5-3D Code  

SciTech Connect (OSTI)

The heat transfer boundary conditions used in the RELAP5-3D computer program have evolved over the years. Currently, RELAP5-3D has the following options for the heat transfer boundary conditions: (a) heat transfer correlation package option, (b) non-convective option (from radiation/conduction enclosure model or symmetry/insulated conditions), and (c) other options (setting the surface temperature to a volume fraction averaged fluid temperature of the boundary volume, obtaining the surface temperature from a control variable, obtaining the surface temperature from a time-dependent general table, obtaining the heat flux from a time-dependent general table, or obtaining heat transfer coefficients from either a time- or temperature-dependent general table). These options will be discussed, including the more recent ones.

Richard A. Riemke; Cliff B. Davis; Richard R. Schultz

2008-05-01T23:59:59.000Z

331

Flow-Induced Deformation of a Flexible Thin Structure as Manifestation of Heat Transfer Enhancement  

E-Print Network [OSTI]

Flow-induced deformation of thin structures coupled with convective heat transfer has potential applications in energy harvesting and is important for understanding functioning of several biological systems. We numerically demonstrate large-scale flow-induced deformation as an effective passive heat transfer enhancement technique. An in-house, strongly-coupled fluid-structure interaction (FSI) solver is employed in which flow and structure solvers are based on sharp-interface immersed boundary and finite element method, respectively. In the present work, we validate convective heat transfer module of the in-house FSI solver against several benchmark examples of conduction and convective heat transfer including moving structure boundaries. The thermal augmentation is investigated as well as quantified for the flow-induced deformation of an elastic thin plate attached to lee side of a rigid cylinder in a heated channel laminar flow. We show that the wake vortices past the plate sweep higher sources of vorticity...

Soti, Atul Kumar; Sheridan, John

2015-01-01T23:59:59.000Z

332

Grid-region heat transfer in a gas solid fluidized bed  

SciTech Connect (OSTI)

The grid region heat transfer to a horizontal tube in a gas-solid fluidized bed was studied experimentally and theoretically. A preliminary experimental study was first conducted to investigate semi-quantitatively the heat transfer characteristics in the grid region as well as in the bubbling region of the gas-solid fluidized bed using a simple hot water circulation system. Experimental parameters included particle size, static bed height, superficial gas velocity, distributor open area, distributor hole sizes, distributor hole numbers, and vertical locations of the heating tube. An additional experimental study was then carried out to study quantitatively the heat transfer coefficient in each grid region phase, i.e., jet phase, emulsion phase and dead phase using an artificial jet and an electrically heated tube. The observed heat transfer coefficients for each phase were correlated as a function of experimental parameters. The observed results are also compared with results estimated from a heat transfer model, which is based on plausible heat transfer mechanisms in the grid region of a gas-solid fluidized bed.

Wang, R.C.

1986-01-01T23:59:59.000Z

333

CORQUENCH: A model for gas sparging-enhanced, melt-water, film-boiling heat transfer  

SciTech Connect (OSTI)

In evaluation of severe-accident sequences for water-cooled nuclear reactors, molten core materials may be postulated to be released into the containment and accumulate on concrete. The heatup and decomposition of concrete is accompanied by the release of water vapor and carbon dioxide gases. Gases flowing through the melt upper surface can influence the rates of heat transfer to water overlying the melt. In particular, the gas flow through the interface can be envisioned to enhance the heat removal from the melt. A mechanistic model (CORQUENCH) has been developed to describe film-boiling heat transfer between a molten pool and an overlying coolant layer in the presence of sparging gas. The model favorably predicts the lead-Feron 11 data of Greene and Greene et al. for which the calculations indicate that area enhancement in the conduction heat transfer across the film is the predominant mechanism leading to augmentation in the heat flux as the gas velocity increases. Predictions for oxidic corium indicate a rapid increase in film-boiling heat flux as the gas velocity rises. The predominant mode of heat transfer for this case is radiation, and the increase in heat flux with gas velocity is primarily a result of interfacial area enhancement of the radiation component of the overall heat transfer coefficient. The CORQUENCH model has been incorporated into the MELTSPREAD-1 computer code{sup 6} for the analysis of transient spreading in containments.

Farmer, M.T.; Sienicki, J.J.; Spencer, B.W.

1990-01-01T23:59:59.000Z

334

Heat transfer coefficients in two-dimensional Yukawa systems (numerical simulations)  

SciTech Connect (OSTI)

New data on heat transfer in two-dimensional Yukawa systems have been obtained. The results of a numerical study of the thermal conductivity for equilibrium systems with parameters close to the conditions of laboratory experiments in dusty plasma are presented. The Green-Kubo relations are used to calculate the heat transfer coefficients. The influence of dissipation (internal friction) on the heat transfer processes in nonideal systems is studied. New approximations are proposed for the thermal conductivity and diffusivity for nonideal dissipative systems. The results obtained are compared with the existing experimental and numerical data.

Khrustalyov, Yu. V., E-mail: yuri.khrustalyov@gmail.com; Vaulina, O. S. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2013-05-15T23:59:59.000Z

335

The influence of a magnetic field on turbulent heat transfer of a high Prandtl number fluid  

SciTech Connect (OSTI)

The influence of a transverse magnetic field on the local and average heat transfer of an electrically conducting, turbulent fluid flow with high Prandtl number was studied experimentally. The mechanism of heat transfer modification due to magnetic field is considered with aid of available numerical simulation data for turbulent flow field. The influence of the transverse magnetic field on the heat transfer was to suppress the temperature fluctuation and to steepen the mean temperature gradient in near-wall region in the direction parallel to the magnetic field. The mean temperature gradient is not influenced compared to the temperature fluctuation in the direction vertical to the magnetic field. (author)

Nakaharai, H. [Department of Advanced Energy Engineering Science, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-kouen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Takeuchi, J.; Morley, N.B.; Abdou, M.A. [Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA 90095-1597 (United States); Yokomine, T. [Faculty of Energy Engineering Science, Kyushu University, Kasuga-kouen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Kunugi, T. [Department of Nuclear Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8501 (Japan); Satake, S. [Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)

2007-10-15T23:59:59.000Z

336

International Conference on Heat Transfer, Fluid Mechanics, and Thermodynamics 8-10 April 2002, Kruger Park, South Africa  

E-Print Network [OSTI]

HEFAT2002 1st International Conference on Heat Transfer, Fluid Mechanics, and Thermodynamics 8 topic in heat transfer. The power dissipation of the computer chips is rapidly increasing. The thermal management of these high power systems provides a complex challenge. Unfortunately, the heat transfer area

Kandlikar, Satish

337

A new predictive dynamic model describing the effect of1 the ambient temperature and the convective heat transfer2  

E-Print Network [OSTI]

and the convective heat transfer2 coefficient on bacterial growth3 4 H. Ben Yaghlenea,b* , I. Leguerinela , M. Hamdib Ratkowsky "square root" model and a simplified two-parameter20 heat transfer model regarding an infinite air temperature, the convective heat transfer22 coefficient and the growth parameters of the micro

Paris-Sud XI, Université de

338

Molecular Dynamics Simulation of Heat Transfer Issues of Nanotubes. > Yasuhiro Igarashi, Yuki Taniguchi, Yasushi Shibuta and Shigeo Maruyama  

E-Print Network [OSTI]

Molecular Dynamics Simulation of Heat Transfer Issues of Nanotubes. ·> Yasuhiro Igarashi, Yuki 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan Heat transfer between single-walled carbon nanotubes, which was 0.105 µm. In other words, when the length of SWNT is 0.105 µm, the radial heat transfer

Maruyama, Shigeo

339

Fusion Engineering and Design 81 (2006) 549553 Numerical analysis of MHD flow and heat transfer in a  

E-Print Network [OSTI]

Fusion Engineering and Design 81 (2006) 549­553 Numerical analysis of MHD flow and heat transfer January 2006 Abstract MHD flow and heat transfer have been analyzed for a front poloidal channel blanket; Magnetohydrodynamics; Heat transfer 1. Introduction Using flow channel inserts (FCIs) made

Abdou, Mohamed

340

EUROTHERM Seminar 74 Proceedings Heat transfer in unsteady and transitional flows March 23-26, 2003 Eindhoven (The Netherlands)  

E-Print Network [OSTI]

EUROTHERM Seminar 74 Proceedings Heat transfer in unsteady and transitional flows March 23-26, 2003 to be governed by heat transfer and time microscales of turbulence through the inner sublayer. Physical interpreta- tions are given to relate the observed heat transfer correlation and these turbulence transition

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

PIV flow measurements for heat transfer characterization in two-pass square channels with smooth and 90 ribbed walls  

E-Print Network [OSTI]

PIV flow measurements for heat transfer characterization in two-pass square channels with smooth the correlation between the high- Reynolds number turbulent flow and wall heat transfer characteristics in a two number (Re) of 30,000. The PIV measurement results were compared with the heat transfer experimental data

Kihm, IconKenneth David

342

Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non intrusive method  

E-Print Network [OSTI]

Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non the results of experimental and numerical studies concerning boiling heat transfer inside vertical in minichannels for several gravity levels (µg, 1g, 2g). To fully understand the high heat transfer potential

343

Conclusions Observed enhancement in convection heat transfer coefficient in  

E-Print Network [OSTI]

in de-ionized water Commercial System Heater Insulation Water block · The water block replaces/min) di-water 1% nanofluid 0.5% nanofluid Results: Calculated Thermal Conductivity 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0 0.5 1 1.5 2 thermalconductivity(W/mK) volume loading (%) calculated di-water

Walker, D. Greg

344

Augmentation of condensation heat transfer with electrohydrodynamics on vertical enhanced tubes  

E-Print Network [OSTI]

for various heat loads . 48 . 49 . 58 NOMENCLATURE cr D ha k Nu qual Re V area, m', or current, A specific heat at constant pressure, J/kgK diameter, m electric field strength, V/m gravity, (9. 81 m/s') heat transfer coefficient, W... fluorocarbon or a hydrocarbon, the temperature of heat addition from the primary fluid to the secondary working fluid tends to be lower, thereby increasing the amount of heat rejected. In many cases the waste heat can be rejected through a condensation...

Motte, Edouard

1994-01-01T23:59:59.000Z

345

Passive heat-transfer means for nuclear reactors. [LMFBR  

DOE Patents [OSTI]

An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.

Burelbach, J.P.

1982-06-10T23:59:59.000Z

346

Dependency of Heat Transfer Rate on the Brinkman Number in Microchannels  

E-Print Network [OSTI]

Heat generation from electronics increases with the advent of high-density integrated circuit technology. To come up with the heat generation, microscale cooling has been thought as a promising technology. Prediction of heat transfer rate is crucial in design of microscale cooling device but is not clearly understood yet. This work proposes a new correlation between heat transfer rate and Brinkman number which is nondimensional number of viscosity, flow velocity and temperature. It is expected that the equation proposed by this work can be useful to design microchannel cooling device.

H. S. Park

2008-01-07T23:59:59.000Z

347

Heat transfer from combustion gases to a single row of closely spaced tubes in a swirl crossflow Stirling engine heater  

SciTech Connect (OSTI)

This paper describes an experimental program to determine the heat-transfer characteristics of a combustor and heat-exchange system in a hybrid solar receiver which utilizes a Stirling engine. The system consists of a swirl conbustor with a crossflow heat exchanger composed of a single row of 48 closely spaced curved tubes. In the present study, heat-transfer characteristics of the combustor/heat-exchanger system without a Stirling engine have been studied over a range of operating conditions and output levels using water as the working fluid. Non-dimensional heat-transfer coefficients based on total heat transfer have been obtained and are compared with available literature data. The results show significantly enhanced heat transfer for the present geometry and test conditions. Also, heat transfer along the length of the tubes is found to vary, the effect depending upon test condition.

Bankston, C.P.; Back, L.H.

1982-02-01T23:59:59.000Z

348

Investigation of boiling heat transfer at a surface with a system of cylindrical cavities under conditions of free motion  

SciTech Connect (OSTI)

The authors propose a mathematical model for the intensification of boiling heat transfer and the subsequent increase in thermal efficiency of the cylindrical heat transfer surfaces in an evaporative cooling system. The boiling curves for water, ethanol, and freon 113 are calculated for a surface with artificial nucleation sites. The model incorporates such coolant properties as surface tension, specific heat, and vaporization heat.

Danilova, G.N.; Reznikov, V.I.

1988-01-01T23:59:59.000Z

349

Heat transfer in sunspot penumbrae. Origin of dark-cored penumbral filaments  

E-Print Network [OSTI]

Context: Observations at 0.1" have revealed the existence of dark cores in the bright filaments of sunspot penumbrae. Expectations are high that such dark-cored filaments are the basic building blocks of the penumbra, but their nature remains unknown. Aims: We investigate the origin of dark cores in penumbral filaments and the surplus brightness of the penumbra. To that end we use an uncombed penumbral model. Methods: The 2D stationary heat transfer equation is solved in a stratified atmosphere consisting of nearly horizontal magnetic flux tubes embedded in a stronger and more vertical field. The tubes carry an Evershed flow of hot plasma. Results: This model produces bright filaments with dark cores as a consequence of the higher density of the plasma inside the tubes, which shifts the surface of optical depth unity toward higher (cooler) layers. Our calculations suggest that the surplus brightness of the penumbra is a natural consequence of the Evershed flow, and that magnetic flux tubes about 250 km in diameter can explain the morphology of sunspot penumbrae.

B. Ruiz Cobo; L. R. Bellot Rubio

2008-10-07T23:59:59.000Z

350

Local heat transfer distribution in a triangular channel with smooth walls and staggered ejection holes  

E-Print Network [OSTI]

Transient liquid crystal experiments have been conducted to determine the distribution of the local heat transfer coefficient in a triangular channel with smooth wails and ejection holes along one or two of the wails. The end of the test channel...

Moon, Sung-Won

1999-01-01T23:59:59.000Z

351

Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis  

E-Print Network [OSTI]

The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Given the schematic diagram of TDHT system, introducing the definition of equivalent fouling roughness height, and using the Niklaus...

Zhang, C.; Wu, R.; Li, G.; Li, X.; Huang, L.; Sun, D.

2006-01-01T23:59:59.000Z

352

Residential Slab-On-Grade Heat Transfer in Hot Humid Climates  

E-Print Network [OSTI]

Heat transfer through an uninsulated slab on grade is calculated using a simple method developed by Kusuda. The seasonal and annual slab loads are graphed as a function of annual average soil temperature, Tm, for a variety of floor system...

Clark, E.; Ascolese, M.; Collins, W.

1989-01-01T23:59:59.000Z

353

Numerical simulation of three-dimensional combined convective radiative heat transfer in rectangular channels  

E-Print Network [OSTI]

This dissertation presents a numerical simulation of three-dimensional flow and heat transfer in a channel with a backward-facing step. Flow was considered to be steady, incompressible, and laminar. The flow medium was treated to be radiatively...

Ko, Min Seok

2009-05-15T23:59:59.000Z

354

Estimating Heat and Mass Transfer Processes in Green Roof Systems: Current Modeling Capabilities and Limitations (Presentation)  

SciTech Connect (OSTI)

This presentation discusses estimating heat and mass transfer processes in green roof systems: current modeling capabilities and limitations. Green roofs are 'specialized roofing systems that support vegetation growth on rooftops.'

Tabares Velasco, P. C.

2011-04-01T23:59:59.000Z

355

L3:THM.CLS.P7.03 Bubble Condensation Heat Transfer in Subcooled...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

phase CFD codes requires the use of a closure relation that describes energy (heat) transfer from the vapor to liquid phase. In this study, seven correlations found in the...

356

Some aspects of the computer simulation of conduction heat transfer and phase change processes  

SciTech Connect (OSTI)

Various aspects of phase change processes in materials are discussd including computer modeling, validation of results and sensitivity. In addition, the possible incorporation of cognitive activities in computational heat transfer is examined.

Solomon, A. D.

1982-04-01T23:59:59.000Z

357

Mechanism and behavior of nucleate boiling heat transfer to the alkalai liquid metals  

E-Print Network [OSTI]

A model of boiling heat transfer to the alkali liquid metals is postulated from an examination of the events and phases of the nucleate boiling cycle. The model includes the important effect of microlayer evaporation which ...

Deane, Charles William

1969-01-01T23:59:59.000Z

358

Immersion Condensation on Oil-Infused Heterogeneous Surfaces for Enhanced Heat Transfer  

E-Print Network [OSTI]

Enhancing condensation heat transfer is important for broad applications from power generation to water harvesting systems. Significant efforts have focused on easy removal of the condensate, yet the other desired properties ...

Xiao, Rong

359

Wetting and phase-change phenomena on micro/nanostructures for enhanced heat transfer  

E-Print Network [OSTI]

Micro/nanostructures have been extensively studied to amplify the intrinsic wettability of materials to create superhydrophilic or superhydrophobic surfaces. Such extreme wetting properties can influence the heat transfer ...

Xiao, Rong, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

360

Convective Heat Transfer Enhancement in Nanofluids: Real Anomaly or Analysis Artifact?  

E-Print Network [OSTI]

The nanofluid literature contains many claims of anomalous convective heat transfer enhancement in both turbulent and laminar flow. To put such claims to the test, we have performed a critical detailed analysis of the ...

Prabhat, Naveen

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

The influence of return bends on the downstream pressure drop and condensation heat transfer in tubes  

E-Print Network [OSTI]

The influence of return bends on the downstream pressure drop and heat transfer coefficient of condensing refrigerant R-12 was studied experimentally. Flow patterns in glass return bends of 1/2 to 1 in. radius and 0.315 ...

Traviss, Donald P.

1971-01-01T23:59:59.000Z

362

Heat and mass transfer in bubble column dehumidifiers for HDH desalination  

E-Print Network [OSTI]

Heat and mass transfer processes governing the performance of bubble dehumidifier trays are studied in order to develop a predictive model and design rules for efficient and economical design of bubble column dehumidifiers ...

Tow, Emily W

2014-01-01T23:59:59.000Z

363

Numerical study of flow and heat transfer in 3D serpentine channels using colocated grids  

E-Print Network [OSTI]

and average Nusselt number. The numerical code developed was validated by solving for fully developed flow and heat transfer in a square straight channel. Grid-independent solution was established for a reference case of serpentine channel with the highest...

Chintada, Sailesh Raju

1998-01-01T23:59:59.000Z

364

6th World Conference on Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics  

E-Print Network [OSTI]

6th World Conference on Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics April 17-through open-system, therefore the reaction field is close to atmospheric pressure. Our experiments consisted

Maruyama, Shigeo

365

ASME 2008 Summer Heat transfer Conference August 10-14, 2008, Jacksonville, FL., USA  

E-Print Network [OSTI]

ASME 2008 Summer Heat transfer Conference August 10-14, 2008, Jacksonville, FL., USA HT2008, University of Victoria Victoria, BC , V8W 2Y2, Canada ABSTRACT Accurate information on the temperature eld

Bahrami, Majid

366

Orthogonal Decomposition Methods for Turbulent Heat Transfer Analysis with Application to Gas Turbines  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . 46 C. Computational procedure . . . . . . . . . . . . . . . . . . . 48 1. Solver settings and grid for URANS study . . . . . . . 48 2. LES study . . . . . . . . . . . . . . . . . . . . . . . . 52 D. Results... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 1. Orthogonal decomposition URANS . . . . . . . . . . . 59 2. Orthogonal decomposition LES . . . . . . . . . . . . . 62 E. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 V OPTIMIZING TURBULENT HEAT TRANSFER USING...

Schwaenen, Markus

2012-07-16T23:59:59.000Z

367

Forced-convection surface-boiling heat transfer and burnout in tubes of small diameters  

E-Print Network [OSTI]

A basic heat-transfer apparatus was designed and constructed for the study of forced-convection boiling in small channels. The various regions of forced-convection surface boiling were studied experimentally and analytically. ...

Bergles A. E.

1962-01-01T23:59:59.000Z

368

Numerical and analytical modeling of heat transfer between fluid and fractured rocks  

E-Print Network [OSTI]

Modeling of heat transfer between fluid and fractured rocks is of particular importance for energy extraction analysis in EGS, and therefore represents a critical component of EGS design and performance evaluation. In ...

Li, Wei, S.M. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

369

Linear Kinetic Heat Transfer: Moment Equations, Boundary Conditions, and Knudsen  

E-Print Network [OSTI]

] and phonons [6], and the radiative transfer equation [7]. The solution of any kinetic equation is usually][25], radiative transfer [7][26], and phonon transport in crystals [6]. Despite the long history, and success method, and the methods employed in [18][19][20], are based solely on the transport equations in the bulk, and

Struchtrup, Henning

370

Numerical analysis of turbulent heat transfer in a nuclear reactor coolant channel  

E-Print Network [OSTI]

NUMERICAL ANALYSIS OF TURBULENT HEAT TRANSFER IN A NUCLEAR REACTOR COOLANT CHANNEL A Thesis Clarence William Garrard, Jr. Submitted to the Graduate College of the Texas A&M University in partial fulfillment of' the requirements for the degree... of' MASTER OF SC1ENCE May, 1965 Ma)or Subject Nuclear Engineering NUMERICAL ANALYSIS OF TURBULENT HEAT TRANSFER 1N A NUCLEAR REACTOR COOLANT CHANNEL A Thesis By Clarence William Garrard, Jr. Approved as to style and content by; Head...

Garrard, Clarence William

1965-01-01T23:59:59.000Z

371

A PC simulation of heat transfer and temperature distribution in a circulating wellbore  

E-Print Network [OSTI]

A PC SIMULATION OF HEAT TRANSFER AND TEMPERATURE DISTRIBUTION IN A CIRCULATING WELLBORE A Thesis by ROBERT DUANE PIERCE Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1987 Major Subject: Petroleum Engineering A PC SIMULATION OF HEAT TRANSFER AND TEMPERATURE DISTRIBUTION IN A CIRCULATING WELLBORE A Thesis by ROBERT DUANE PIERCE Approved as to style and content by; Hans C . Juvkam...

Pierce, Robert Duane

1987-01-01T23:59:59.000Z

372

AN EXPERIMENTAL AND THEORETICAL STUDY OF HEAT TRANSFER WITH COMBUSTION  

E-Print Network [OSTI]

specific heat of ceramic thermal conductivity of ceramic kwthermal penetration depth is much smaller than the characterlstic dimensions of the gauge. The ceramic

Heperkan, Hasan A.

2013-01-01T23:59:59.000Z

373

Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass  

E-Print Network [OSTI]

samples are exposed to an incandescent lamp. Acknowledgmentin a furnace or by an incandescent lamp. It was observedwhen heated by an incandescent lamp than within furnace.

Kitamura, Rei; Pilon, Laurent

2009-01-01T23:59:59.000Z

374

ON CONVECTIVE HEAT TRANSFER IN BUILDING ENERGY ANALYSIS  

E-Print Network [OSTI]

Tien; Int. J. Heat Mass Trans Balcomb 1 s Weber and Wray; ininsulation-filled wall. Balcomb's group at LASL has carried

Gadgil, Ashok Jagannath

2013-01-01T23:59:59.000Z

375

Intra-channel mass and heat-transfer modeling in diesel oxidation catalysts  

E-Print Network [OSTI]

02FCC-140 Intra-channel mass and heat-transfer modeling in diesel oxidation catalysts Kalyana transfer in modeling the performance of diesel oxidation catalysts. Many modeling studies have assumed experimental measurements of CO and hydrocarbon oxidation in diesel exhaust re- veal that actual mass

Tennessee, University of

376

An experimental, theoretical and numerical investigation of corona wind heat transfer enhancement  

E-Print Network [OSTI]

Corona wind heat transfer enhancement is a non-mechanical means of augmenting transfer coefficients in free and low-velocity convection flow fields. Ions formed near the surface of a high-voltage electrode are forced along the electric field lines...

Owsenek, Brian Leonard

1993-01-01T23:59:59.000Z

377

Heat transfer in porous media with fluid phase changes  

SciTech Connect (OSTI)

A one-dimensional experimental apparatus was built to study the heat pipe phenomenon. Basically, it consists of a 25 cm long, 2.5 cm I.D. Lexane tube packed with Ottawa sand. The two ends of the tube were subjected to different tempratures, i.e., one above the boiling temperature and the other below. The tube was well insulated so that a uniform one-dimensional heat flux could pass through the sand pack. Presence of the heat pipe phenomenon was confirmed by the temperature and saturation profiles of the sand pack at the final steady state condition. A one-dimensional steady state theory to describe the experiment has been developed which shows the functional dependence of the heat pipe phenomenon on liquid saturation gradient, capillary pressure, permeability, fluid viscosity, latent heat, heat flux and gravity. Influence of the heat pipe phenomenon on wellbore heat losses was studied by use of a two-phase two-dimensional cylindrical coordinate computer model.

Su, H.J.

1981-06-01T23:59:59.000Z

378

Author's personal copy Radiative heat transfer in enhanced hydrogen  

E-Print Network [OSTI]

tube and heated in a furnace or by an incandescent lamp. It was observed that hydrogen release from the glass sample was faster and stronger when heated by an incandescent lamp than within a furnace. Here and the glass samples. In brief, the radiation emitted by the incandescent lamp is concentrated between 0

Pilon, Laurent

379

Heat Transfer Applications for the Stimulated Reservoir Volume  

E-Print Network [OSTI]

from oil shale. Thermal decomposition of kerogen to oil and gas requires heating the oil shale to 700 degrees F. High quality saturated steam generated using a small scale nuclear plant was used for heating the formation to the necessary temperature...

Thoram, Srikanth

2011-10-21T23:59:59.000Z

380

Resonant behavior in heat transfer across weak molecular interfaces  

SciTech Connect (OSTI)

Molecular dynamics (MD) simulations are used to study, in detail, the transfer of thermal (vibrational) energy between objects with discrete vibrational spectra to those with a semi-continuum of spectra. The transfer of energy is stochastic and strongly dependent on the instantaneous separation between the bodies. The insight from the MD simulations can be captured with a simple classical model that agrees well with quantum models. This model can be used to optimize systems for efficient frequency selective energy transfer, which can be used in designing a chemical sensor through nanomechanical resonance spectroscopy.

Sklan, Sophia R. [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Alex Greaney, P. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvalis, Oregon 97331 (United States); Grossman, Jeffrey C., E-mail: jcg@mit.edu [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2013-12-21T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Calculation of unsteady-state heat and mass transfer in steam injection wells  

E-Print Network [OSTI]

and mass transfer computation. Results obtained from this study were compared to field data and re- sults obtained from a semi-unsteady-state heat transfer and steady-state mass transfer model. As actual downhole steam quality measurements were...- hole pressure, temperature, and quality data from steam injection wells is virtually nonexistent in the literature. One limitation is that no downhole tool has been developed to reliably measure steam quality. Be- cause of the lack of field data from...

Ruddy, Kenneth Edward

1986-01-01T23:59:59.000Z

382

Heat and Mass Transfer Wrme-und Stoffbertragung  

E-Print Network [OSTI]

transfer coefficient (W m-2 K-1 ) Greek symbols a Thermal diffusivity (m2 s-1 ) e Surface emissivity q article is protected by copyright and all rights are held exclusively by Springer- Verlag Berlin

Guo, Zhixiong "James"

383

Numerical Modelling of Combined Heat Transfers in a Double Skin Faade -Full Scale Laboratory  

E-Print Network [OSTI]

, thermal comfort, visual comfort or energy gain [1]. In the current context of global warming, depletion heat transfers are also taken into account to obtain a global coupling between the different phenomena on two levels: during the winter period, the solar energy is used to heat the air in the façade [2], and

384

NUMERICAL STUDY OF FLUID FLOW AND HEAT TRANSFER OVER A SERIES OF IN-LINE NONCIRCULAR  

E-Print Network [OSTI]

NUMERICAL STUDY OF FLUID FLOW AND HEAT TRANSFER OVER A SERIES OF IN-LINE NONCIRCULAR TUBES CONFINED, Texas A&M University, College Station, Texas, USA Two-dimensional steady developing fluid flow and heat-volume technique. Grid independence study was carried out by running the developed code for several different grid

Bahaidarah, Haitham M.

385

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 16, No. 3, JulySeptember 2002  

E-Print Network [OSTI]

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 16, No. 3, July­September 2002 Three against the sizes of time increment and grid cell and angular discrete order are examined. The false order in SN approximation n = number of angular discretization Q = radiative heat ux R = re ectance r

Guo, Zhixiong "James"

386

Characterization and Development of Advanced Heat Transfer Technologie...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. ape11kelly.pdf More Documents & Publications Characterization and Development of Advanced Heat...

387

Heat Transfer to the Structure during the Fire   

E-Print Network [OSTI]

The post-flashover Fire Test One of a furnished room in Dalmarnock provides a wealth of information including measurements in both the gas phase and on compartment boundaries (Chapter 3). Total heat fluxes at a number ...

Jowsey, Allan; Torero, Jose L; Lane, Barbara

2007-11-14T23:59:59.000Z

388

Influence of Infrared Radiation on Attic Heat Transfer  

E-Print Network [OSTI]

roof temperatures. It was found that a radiant barrier such as aluminum foil can reduce the heat flux significantly. Experimental results were compared to a Three-Region approximate solution developed at Oak Ridge National Laboratories (ORNL). The model...

Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.

1985-01-01T23:59:59.000Z

389

Bibliography on augmentation of convective heat and mass transfer-II  

SciTech Connect (OSTI)

Heat transfer augmentation has developed into a major specialty area in heat transfer research and development. This report presents and updated bibliography of world literature on augmentation. The literature is classified into passive augmentation techniques, which require no external power, and active techniques, which do require external power. The fifteen techniques are grouped in terms of their applications to the various modes of heat transfer. Mass transfer is included for completeness. Key words are included with each citation for technique/mode identification. The total number of publications cited is 3045, including 135 surveys of various techniques and 86 papers on performance evaluation of passive techniques. Patents are not included, as they are the subject of a separate bibliographic report.

Bergles, A.E.; Nirmalan, V.; Junkhan, G.H.; Webb, R.L.

1983-12-01T23:59:59.000Z

390

Separate effects of surface roughness, wettability and porosity on boiling heat transfer and critical heat flux and optimization of boiling surfaces  

E-Print Network [OSTI]

The separate effects of surface wettability, porosity, and roughness on critical heat flux (CHF) and heat transfer coefficient (HTC) were examined using carefully-engineered surfaces. All test surfaces were prepared on ...

O'Hanley, Harrison Fagan

2012-01-01T23:59:59.000Z

391

Nanoscale modification of key surface parameters to augment pool boiling heat transfer and critical heat flux in water and dielectric fluids  

E-Print Network [OSTI]

Surface effects on pool boiling heat transfer and the critical heat flux are well documented but poorly understood. This study investigates the pool boiling characteristics of various fluids, and demonstrates that surface ...

Forrest, Eric Christopher

2009-01-01T23:59:59.000Z

392

A 2-D Test Problem for CFD Modeling Heat Transfer in Spent Fuel Transfer Cask Neutron Shields  

SciTech Connect (OSTI)

In the United States, commercial spent nuclear fuel is typically moved from spent fuel pools to outdoor dry storage pads within a transfer cask system that provides radiation shielding to protect personnel and the surrounding environment. The transfer casks are cylindrical steel enclosures with integral gamma and neutron radiation shields. Since the transfer cask system must be passively cooled, decay heat removal from spent nuclear fuel canister is limited by the rate of heat transfer through the cask components, and natural convection from the transfer cask surface. The primary mode of heat transfer within the transfer cask system is conduction, but some cask designs incorporate a liquid neutron shield tank surrounding the transfer cask structural shell. In these systems, accurate prediction of natural convection within the neutron shield tank is an important part of assessing the overall thermal performance of the transfer cask system. The large-scale geometry of the neutron shield tank, which is typically an annulus approximately 2 meters in diameter but only 5-10 cm in thickness, and the relatively small scale velocities (typically less than 5 cm/s) represent a wide range of spatial and temporal scales that contribute to making this a challenging problem for computational fluid dynamics (CFD) modeling. Relevant experimental data at these scales are not available in the literature, but some recent modeling studies offer insights into numerical issues and solutions; however, the geometries in these studies, and for the experimental data in the literature at smaller scales, all have large annular gaps that are not prototypic of the transfer cask neutron shield. This paper presents results for a simple 2-D problem that is an effective numerical analog for the neutron shield application. Because it is 2-D, solutions can be obtained relatively quickly allowing a comparison and assessment of sensitivity to model parameter changes. Turbulence models are considered as well as the tradeoff between steady state and transient solutions. Solutions are compared for two commercial CFD codes, FLUENT and STAR-CCM+. The results can be used to provide input to the CFD Best Practices for this application. Following study results for the 2-D test problem, a comparison of simulation results is provided for a high Rayleigh number experiment with large annular gap. Because the geometry of this validation is significantly different from the neutron shield, and due to the critical nature of this application, the argument is made for new experiments at representative scales

Zigh, Ghani; Solis, Jorge; Fort, James A.

2011-01-14T23:59:59.000Z

393

Proceedings of the 8 International Symposium on Heat Transfer  

E-Print Network [OSTI]

, contributions from radiation can be determined via solution of the Equation of Radiative Transfer (ERT equation can lead to significant error, due to the short time-duration of the transport processes, Beijing, China ISHT8-07-05 MODELING OF ULTRAFAST LASER TRANSPORT AND APPLICATIONS Zhixiong Guo Rutgers

Guo, Zhixiong "James"

394

Proceedings of the 15th International Heat Transfer Conference, IHTC-15 August 10-15, 2014, Kyoto, Japan  

E-Print Network [OSTI]

pressure drop and reduced heat transfer to the reaction zone. KEY WORDS: Solar energy, Carbon emission combustion as the process heat for calcination. Shimizu et al. performed a thermodynamic analysis on a pairProceedings of the 15th International Heat Transfer Conference, IHTC-15 August 10-15, 2014, Kyoto

395

Heat Transfer -1 You are given the following information for a fluid with thermal conductivity of k = 0.0284 W/m-K that  

E-Print Network [OSTI]

Heat Transfer - 1 You are given the following information for a fluid with thermal conductivity the flow is laminar near the wall. a) (30 points) Determine the corresponding heat transfer coefficient the heat transfer coefficient as a function of x. c) (25 points) Determine the average heat transfer

Virginia Tech

396

Enhancement of Pool Boiling Heat Transfer in Confined Space  

E-Print Network [OSTI]

on pool boiling. In the study, confinement was achieved by placing a flat plate over heated surface. The flat plate has a hole in the middle, and there is a gap between the flat plate and the heater. The diameters of hole are 2 mm, 3 mm, and 4 mm; the gap...

Hsu, Chia-Hsiang

2014-05-05T23:59:59.000Z

397

TRANSIENT HEAT TRANSFER ANALYSIS FOR SRS RADIOACTIVE TANK OPERATION  

SciTech Connect (OSTI)

The primary objective of the present work is to perform a heat balance study for type-I waste tank to assess the impact of using submersible mixer pumps during waste removal. The temperature results calculated by the model will be used to evaluate the temperatures of the slurry waste under various tank operating conditions. A parametric approach was taken to develop a transient model for the heat balance study for type-I waste tanks such as Tank 11, during waste removal by SMP. The tank domain used in the present model consists of two SMP?s for sludge mixing, one STP for the waste removal, cooling coil system with 36 coils, and purge gas system. The sludge waste contained in Tank 11 also has a decay heat load of about 43 W/m{sup 3} mainly due to the emission of radioactive gamma rays. All governing equations were established by an overall energy balance for the tank domain, and they were numerically solved. A transient heat balance model used single waste temperature model, which represents one temperature for the entire waste liquid domain contained in the tank at each transient time.

Lee, S.

2013-06-27T23:59:59.000Z

398

Experimental and numerical investigation of turbulent flow and heat (mass) transfer in a two-pass trapezoidal channel with turbulence promoters  

E-Print Network [OSTI]

attached on both the top and bottom walls in parallel sequence. A naphthalene sublimation technique was used, and the heat and mass transfer analogy was applied to convert the mass transfer coefficients to heat transfer coefficients. Numerical predictions...

Oh, Sung Hyuk

2009-05-15T23:59:59.000Z

399

Experimental investigations of uncovered-bundle heat transfer and two-phase mixture-level swell under high-pressure low heat-flux conditions. [PWR  

SciTech Connect (OSTI)

Results are reported from a series of uncovered-bundle heat transfer and mixture-level swell tests. Experimental testing was performed at Oak Ridge National Laboratory in the Thermal Hydraulic Test Facility (THTF). The THTF is an electrically heated bundle test loop configured to produce conditions similar to those in a small-break loss-of-coolant accident. The objective of heat transfer testing was to acquire heat transfer coefficients and fluid conditions in a partially uncovered bundle. Testing was performed in a quasi-steady-state mode with the heated core 30 to 40% uncovered. Linear heat rates varied from 0.32 to 2.22 kW/m.rod (0.1 to 0.68 kW/ft.rod). Under these conditions peak clad temperatures in excess of 1050 K (1430/sup 0/F) were observed, and total heat transfer coefficients ranged from 0.0045 to 0.037 W/cm/sup 2/.K (8 to 65 Btu/h.ft/sup 2/./sup 0/F). Spacer grids were observed to enhance heat transfer at, and downstream of, the grid. Radiation heat transfer was calculated to account for as much as 65% of total heat transfer in low-flow tests.

Anklam, T. M.; Miller, R. J.; White, M. D.

1982-03-01T23:59:59.000Z

400

Modeling studies of heat transfer and phase distribution in two-phase geothermal reservoirs  

SciTech Connect (OSTI)

Phase distribution as well as mass flow and heat transfer behavior in two-phase geothermal systems have been studied by numerical modeling. A two-dimensional porous-slab model was used with a non-uniform heat flux boundary conditions at the bottom. Steady-state solutions are obtained for the phase distribution and heat transfer behavior for cases with different mass of fluid (gas saturation) in place, permeabilities, and capillary pressures. The results obtained show very efficient heat transfer in the vapor-dominated zone due to the development of heat pipes and near-uniform saturations. The phase distribution below the vapor-dominated zone depends on permeability. For relatively high-permeability systems, single-phase liquid zones prevail, with convection providing the energy throughput. For lower permeability systems, a two-phase liquid-dominated zone develops, because single-phase liquid convection is not sufficient to dissipate heat released from the source. These results are consistent with observations from the field, where most high-temperature liquid-dominated two-phase systems have relatively low permeabilities e.g. Krafla, Iceland; Kenya; Baca, New Mexico. The numerical results obtained also show that for high heat flow a high-temperature single-phase vapor zone can develop below a typical (240 C) vapor-dominated zone, as has recently been found at the Geysers, California, and Larderello, Italy.

Lai, C.H.; Bodvarsson, G.S.; Truesdell, A.H. (Lawrence Berkeley Lab., CA (United States). Earth Sciences Div.)

1994-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

EXPERIMENTAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER OF IONIC LIQUID IN A RECTANGULAR ENCLOSURE HEATED FROM BELOW  

SciTech Connect (OSTI)

This paper presents an experimental study of natural convection heat transfer for an Ionic Liquid. The experiments were performed for 1-butyl-2, 3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, ([C{sub 4}mmim][NTf{sub 2}]) at a Raleigh number range of 1.26 x 10{sup 7} to 8.3 x 10{sup 7}. In addition to determining the convective heat transfer coefficients, this study also included experimental determination of thermophysical properties of [C{sub 4}mmim][NTf{sub 2}] such as, density, viscosity, heat capacity, and thermal conductivity. The results show that the density of [C{sub 4}mmim][NTf{sub 2}] varies from 1.437-1.396 g/cm{sup 3} within the temperature range of 10-50 C, the thermal conductivity varies from 0.105-0.116 W/m.K between a temperature of 10 to 60 C, the heat capacity varies from 1.015 J/g.K - 1.760 J/g.K within temperature range of 25-340 C and the viscosity varies from 18cp-243cp within temperature range 10-75 C. The results for density, thermal conductivity, heat capacity, and viscosity were in close agreement with the values in the literature. Measured dimensionless Nusselt number was observed to be higher for the ionic liquid than that of DI water. This is expected as Nusselt number is the ratio of heat transfer by convection to conduction and the ionic liquid has lower thermal conductivity (approximately 18%) than DI water.

Fox, E.; Visser, A.; Bridges, N.

2011-07-18T23:59:59.000Z

402

Heat transfer to a fluid flowing in an annulus  

E-Print Network [OSTI]

. ii I ~ DIMENSIONS AND SYMBOLS o ~ ~ ~ . ~ ~ ~ ~ I II e INTRODUCTION AND THEORY ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 3 IXI e APPARATUS AND PROCEDURES ~ ~ e ~ ~ ~ ~ ~ ~ ~ ~ 7 XV o RESULTS ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ e ~ ~ ~ ~ 17 V, DXSCUSSION OF RESULTS... of times 0 Prandtl nnnber~ e~& dimensionless initial temperature oi' surfaoe and fluids% D equivalent diameter& Di g~ L Q - volume flow rate~ L3/T V~ mass velooity, FT/L3 6 mass floe rate~ FT/L IMTRODUCTIOR AND THEORY This thesis comprises heat tz...

Logan, Earl

2012-06-07T23:59:59.000Z

403

Heat transfer and pollutant formation mechanisms in insulated combustion chambers  

SciTech Connect (OSTI)

The authors have studied the quenching situation as it can be found in constant volume combustion chambers for a methane flame over a range of wall temperatures between 300 K and 600 K using Direct Numerical Simulation. To do this, the authors solved the fully compressible, one-dimensional Navier-Stokes equations with detailed mechanisms for kinetics and diffusion. This approach allows to compare various reaction schemes, to identify the most important species and reaction paths, and to investigate the influence of different modeling assumptions. The computational results show that the dimensional wall heat flux increases with wall temperature over the whole range of wall temperatures studied; this agrees well with the most recent measurements in a strongly improved experimental setup. It is found that the wall can be modeled as chemically inert and thermal diffusion processes are negligible for low wall temperatures between 300 K and 400 K. However, at higher temperatures, due to a dramatically increasing radical concentration (H, Oh, OH) at the wall, both become increasingly important leading to large heat release rates directly at the metallic wall surface of the combustion chamber, and can thus not be neglected in the modeling of the quenching process. Furthermore, these high radical concentrations adjacent to the wall indicate that the uncertainties in wall heat flux measurements at high wall temperatures could be underestimated by the experimentalists. The UHC concentration at a wall temperature of 600 K is about 20 times smaller than for 300 K after quenching. 37 refs., 12 figs., 1 tab.

Popp, P.; Baum, M.

1995-12-31T23:59:59.000Z

404

Heat transfer including radiation and slag particles evolution in MHD channel-I  

SciTech Connect (OSTI)

Accurate estimates of convective and radiative heat transfer in the magnetohydrodynamic channel are provided. Calculations performed for a base load-size channel indicate that heat transfer by gas radiation almost equals that by convection for smooth walls, and amounts to 70% as much as the convective heat transfer for rough walls. Carbon dioxide, water vapor, and potassium atoms are the principal participating gases. The evolution of slag particles by homogeneous nucleation and condensation is also investigated. The particle-size spectrum so computed is later utilized to analyze the radiation enhancement by slag particles in the MHD diffuser. The impact of the slag particle spectrum on the selection of a workable and design of an efficient seed collection system is discussed.

Im, K.H.; Ahluwalia, R.K.

1980-01-01T23:59:59.000Z

405

Near-Field Radiative Heat Transfer between Metamaterials coated with Silicon Carbide Film  

E-Print Network [OSTI]

In this letter, we study the near-field radiative heat transfer between two metamaterial substrates coated with silicon carbide (SiC) thin films. It is known that metamaterials can enhance the near-field heat transfer over ordinary materials due to excitation of magnetic plasmons associated with s polarization, while strong surface phonon polariton exists for SiC.By careful tuning of the optical properties of metamaterial it is possible to excite electrical and magnetic resonance for the metamaterial and surface phonon polaritons for SiC at different spectral regions, resulting in the enhanced heat transfer. The effect of the SiC film thickness at different vacuum gaps is investigated. Results obtained from this study will be beneficial for application of thin film coatings for energy harvesting.

Basu, Soumyadipta; Wang, Liping

2014-01-01T23:59:59.000Z

406

Spray evaporation heat transfer performance in R-123 in tube bundles  

SciTech Connect (OSTI)

This study focuses on evaluating the heat transfer performance of refrigerant R-123 in the spray evaporation environment for pure refrigerant and for the case of lubricant addition. Tests were conducted with triangular-pitch tube bundles made from enhanced boiling tubes, enhanced condensation tubes, and plain-surface tubes. A second enhanced boiling surface tube bundle, made with a square-pitch tube alignment, was also tested so a comparison could be made between the square- and triangular-pitch geometries. In addition to pure refrigerant work, experiments were performed with small concentrations of a 305 SUS naphthenic mineral oil to evaluate its effect on falling-film heat transfer performance. Two different refrigerant supply rates were used in this work so the effects of film-feed supply rate could be interpreted from the data. Refrigerant was introduced to the test section via low-pressure-drop, wide-angle nozzles located directly over the tube bundle. Data were taken over a heat flux range of 40 kW/m{sup 2} (12,688 Btu/[h{center_dot}ft{sup 2}]) to 19 kW/m{sup 2} (6,027 Btu/[h{center_dot}ft{sup 2}]), while the refrigerant supply rate remained fixed. Collector tests were performed in parallel with the heat transfer experiments so the amount of refrigerant bypassing the tube bundle could be determined. It was found that the heat transfer coefficients were dependent upon film-feed supply rate, oil concentration, and heat flux. The enhanced boiling surface yielded higher heat transfer coefficients than either the enhanced condensation surface or the plain surface.

Moeykens, S. [Trane Co., LaCrosse, WI (United States); Kelly, J.E. [Kansas State Univ., Manhattan, KS (United States). Dept. of Mechanical Engineering; Pate, M.B. [Iowa State Univ., Ames, IA (United States). Mechanical Engineering Dept.

1996-12-31T23:59:59.000Z

407

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2  

SciTech Connect (OSTI)

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

Not Available

1992-06-01T23:59:59.000Z

408

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 1  

SciTech Connect (OSTI)

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

Not Available

1992-06-01T23:59:59.000Z

409

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 3  

SciTech Connect (OSTI)

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

Not Available

1992-06-01T23:59:59.000Z

410

Ultrasonic effect on the bubble nucleation and heat transfer of oscillating nanofluid  

SciTech Connect (OSTI)

Ultrasonic sound effect on bubble nucleation, oscillating motion activated by bubble formation, and its heat transfer enhancement of nanofluid was experimentally investigated. Nanofluid consists of distilled water and dysprosium (III) oxide (Dy{sub 2}O{sub 3}) nanoparticles with an average size of 98?nm and a mass ratio of 0.5%. Visualization results demonstrate that when the nanoparticles are added in the fluid influenced by the ultrasonic sound, bubble nucleation can be significantly enhanced. The oscillating motion initiated by the bubble formation of nanofluid under the influence of ultrasonic sound can significantly enhance heat transfer of nanofluid in an interconnected capillary loop.

Zhao, Nannan; Fu, Benwei [Institute of Marine Engineering and Thermal Science, College of Marine Engineering, Dalian Maritime University, Dalian 116026 (China); Key Laboratory of Marine, Mechanical and Manufacturing Engineering of the Ministry of Transport, Dalian 116026 (China); Ma, H. B., E-mail: mah@missouri.edu [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, Missouri 65211 (United States)

2014-06-30T23:59:59.000Z

411

Heat transfer through a thin film on a horizontal plate at high vacuum  

E-Print Network [OSTI]

on the theory for the operation of this type of fractionator, but no heat transfer data can be found for engineering design purposes. The data that are available were taken at pressures many times greater than the 1 mm. of mercury operating pressure now... being used. It is hoped that this study of heat transfer coefficients for boiling liquids below 5 mm. of mercury will furnish in? formation of value in this field of high vacuum. The effect of film thickness and types of boilin that were encountered...

Moore, Calvin Edward

1959-01-01T23:59:59.000Z

412

Massively-Parallel Direct Numerical Simulation of Gas Turbine Endwall Film-Cooling Conjugate Heat Transfer  

E-Print Network [OSTI]

MASSIVELY-PARALLEL DIRECT NUMERICAL SIMULATION OF GAS TURBINE ENDWALL FILM-COOLING CONJUGATE HEAT TRANSFER A Thesis by CHARLES MICHAEL MEADOR Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements... for the degree of MASTER OF SCIENCE December 2010 Major Subject: Mechanical Engineering MASSIVELY-PARALLEL DIRECT NUMERICAL SIMULATION OF GAS TURBINE ENDWALL FILM-COOLING CONJUGATE HEAT TRANSFER A Thesis by CHARLES MICHAEL MEADOR Submitted to the O ce of Graduate...

Meador, Charles Michael

2011-02-22T23:59:59.000Z

413

THERMOPHYSICAL PROPERTIES OF NANOPARTICLE-ENHANCED IONIC LIQUIDS HEAT TRANSFER FLUIDS  

SciTech Connect (OSTI)

An experimental investigation was completed on nanoparticle enhanced ionic liquid heat transfer fluids as an alternative to conventional organic based heat transfer fluids (HTFs). These nanoparticle-based HTFs have the potential to deliver higher thermal conductivity than the base fluid without a significant increase in viscosity at elevated temperatures. The effect of nanoparticle morphology and chemistry on thermophysical properties was examined. Whisker shaped nanomaterials were found to have the largest thermal conductivity temperature dependence and were also less likely to agglomerate in the base fluid than spherical shaped nanomaterials.

Fox, E.

2013-04-15T23:59:59.000Z

414

Graphene-assisted near-field radiative heat transfer between corrugated polar materials  

SciTech Connect (OSTI)

Graphene has attracted great attention in nanoelectronics, optics, and energy harvesting. Here, the near-field radiative heat transfer between graphene-covered corrugated silica is investigated based on the exact scattering theory. It is found that graphene can improve the radiative heat flux between silica gratings by more than one order of magnitude and alleviate the performance sensitivity to lateral shift. The underlying mechanism is mainly attributed to the improved photon tunneling of modes away from phonon resonances. Besides, coating with graphene leads to nonlocal radiative transfer that breaks Derjaguin's proximity approximation and enables corrugated silica to outperform bulk silica in near-field radiation.

Liu, X. L.; Zhang, Z. M., E-mail: zhuomin.zhang@me.gatech.edu [G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2014-06-23T23:59:59.000Z

415

Heat Transfer Fluids Containing Nanoparticles | Argonne National Laboratory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Bigfront.jpgcommunity200cell 9HarveyWellnessFebruaryWaterPortalHeat

416

The transfer of heat and mass to a vertical plate under frosting conditions  

E-Print Network [OSTI]

THE TRAESFPIR OF HEAT . 'ND NASH 10 A VERTICAL PLATE UNDER FROSTING CONDITIONS A Thesis Louis Joseph Poth, Jr. Submitted to the Graduate School of the Agricultural and Nechanioal College of Texas in partial fulfili ment of the requirements... of the Husselt-Grashof correlation for heat transfer. coefficient of saturation temper ture and concen- tration gradient correlation, for small temper- ature difference. ooefficient of frost specific gravity-thermal oonductivity correlation. coefficient...

Poth, Louis Joseph

1960-01-01T23:59:59.000Z

417

Study of heat transfer in attics with a small scale simulator  

E-Print Network [OSTI]

flux through the floor of the attic was reduced by about 16 percent. Experimental results were compared to a model that model was a modification of a existing three-region approximate solution developed at Oak Ridge National Laboratories (ORNL...' ) [31]. G. HEAT TRANSFER MODELS FOIL FlBROUS INSULATION Radiation is the most, significant component of the total heat, trans- 13 kg lb fer in insulation having densities lower than 32 ? (2 ? ), Oak Ridge I' fts National Laboratory (ORNL) has...

Katipamula, Srinivas

1985-01-01T23:59:59.000Z

418

Review of current status of high flux heat transfer techniques. Volume I. Text + Appendix A  

SciTech Connect (OSTI)

The scope of this work comprised two tasks. The first was to review high heat flux technology with consideration given to heat transfer panel configuration, diagnostics techniques and coolant supply. The second task was to prepare a report describing the findings of the review, to recommend the technology offering the least uncertainty for scale-up for the MFTF-B requirement and to recommend any new or perceived requirements for R and D effort.

Bauer, W.H.; Gordon, H.S.; Lackner, H.; Mettling, J.R.; Miller, J.E.

1980-09-01T23:59:59.000Z

419

Thermoacoustic sensor for nuclear fuel temperaturemonitoring and heat transfer enhancement  

SciTech Connect (OSTI)

A new acoustical sensing system for the nuclear power industry has been developed at The Pennsylvania State University in collaboration with Idaho National Laboratories. This sensor uses the high temperatures of nuclear fuel to convert a nuclear fuel rod into a standing-wave thermoacoustic engine. When a standing wave is generated, the sound wave within the fuel rod will be propagated, by acoustic radiation, through the cooling fluid within the reactor or spent fuel pool and can be monitored a remote location external to the reactor. The frequency of the sound can be correlated to an effective temperature of either the fuel or the surrounding coolant. We will present results for a thermoacoustic resonator built into a Nitonic-60 (stainless steel) fuel rod that requires only one passive component and no heat exchangers.

James A. Smith; Dale K. Kotter; Randall A. Alli; Steven L. Garrett

2013-05-01T23:59:59.000Z

420

Models for Metal Hydride Particle Shape, Packing, and Heat Transfer  

E-Print Network [OSTI]

A multiphysics modeling approach for heat conduction in metal hydride powders is presented, including particle shape distribution, size distribution, granular packing structure, and effective thermal conductivity. A statistical geometric model is presented that replicates features of particle size and shape distributions observed experimentally that result from cyclic hydride decreptitation. The quasi-static dense packing of a sample set of these particles is simulated via energy-based structural optimization methods. These particles jam (i.e., solidify) at a density (solid volume fraction) of 0.665+/-0.015 - higher than prior experimental estimates. Effective thermal conductivity of the jammed system is simulated and found to follow the behavior predicted by granular effective medium theory. Finally, a theory is presented that links the properties of bi-porous cohesive powders to the present systems based on recent experimental observations of jammed packings of fine powder. This theory produces quantitative experimental agreement with metal hydride powders of various compositions.

Kyle C. Smith; Timothy S. Fisher

2012-05-04T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Airfoil Heat Transfer Characteristics in Syngas and Hydrogen Turbines  

SciTech Connect (OSTI)

Hydrogen or coal-derivative syngas turbines promise increased efficiency with exceptionally low NOx emissions compared to the natural gas based turbines. To reach this goal, turbine inlet temperature (TIT) will need to be elevated to a level exceeding 1700°C [1, 2]. The thermal load induced by such a temperature increase alone will lead to immense challenges in maintaining material integrity of turbine components. In addition, as working fluid in the gas path will primarily be steam, possibly mixed with carbon oxides, the aero-thermal characteristic in a hydrogen turbine is expected to be far different from that of air/nitrogen enriched gas stream in a gas turbine. For instance, steam has distinctly higher density and specific heat in comparison to a mixture of air and combustion gases as they are expanded in a conventional gas turbine. Even if the temperature limits remain about the same, the expansion in a hydrogen turbine will have to proceed with a greater enthalpy drop and therefore requires a larger number of stages. This also implies that the flow areas may need to be expanded and blade span to be enlarged. Meanwhile, a greater number of stages and hot surfaces need to be protected. This also suggests that current cooling technology available for modern day gas turbines has to be significantly improved. The ultimate goal of the present study is to systematically investigate critical issues concerning cooling technology as it is applicable to oxy-fuel and hydrogen turbine systems, and the main scope is to develop viable means to estimate the thermal load on the turbine “gas side”, that is eventually to be removed from the “coolant side”, and to comparatively quantify the implication of external heat load and potential thermal barrier coating (TBC) degradation on the component durability and lifing. The analysis is based on two well-tested commercial codes, FLUENT and ANSYS.

Mazzotta, D.W. (Univ. of Pittsburgh); Chyu, M.K. (Univ. of Pittsburgh); Alvin, M.A.

2007-05-01T23:59:59.000Z

422

TEMP: A finite line heat transfer code for geologic repositories for nuclear waste  

SciTech Connect (OSTI)

TEMP is a FORTRAN computer code for calculating temperatures in a geologic repository for nuclear waste. It will calculate the incremental temperature contributed by a single heat source, by an infinite array of heat sources, or by heat sources geometrically arranged in a finite array. In the finite array geometry, different types of heat sources can be placed in different regions at different times to more closely approximate the emplacement of waste in a repository. TEMP uses a semi-analytical technique for solving the equation for a heat producing finite length line source in an infinite and isotropic medium. Temperature contributions from individual heat sources are superimposed to determine the temperature at a specific location and time in a repository of multiple heat sources. Thermal conductivity of the geologic medium can be a function of temperature, and, when it is, an approximation is made for the temperature dependence of thermal diffusivity. This report derives the equations solved by TEMP and documents its accuracy by comparing its results to known analytical solutions and to the finite-difference and finite-element heat transfer codes HEATING5, HEATING6, THAC-SIP-3D, SPECTROM-41, and STEALTH-2D. The temperature results from TEMP are shown to be very accurate when compared to the analytical solutions and to the results from the finite-difference and finite-element codes. 8 refs., 97 figs., 39 tabs.

Wurm, K.J.; Bloom, S.G.; Atterbury, W.G.; Hetteberg, J.R.

1987-10-01T23:59:59.000Z

423

Intermediate Heat Transfer Loop Study for High Temperature Gas-Cooled Reactor  

SciTech Connect (OSTI)

A number of possible configurations for a system that transfers heat between the nuclear reactor and the hydrogen and/or electrical generation plants were identified. These configurations included both direct and indirect cycles for the production of electricity. Both helium and liquid salts were considered as the working fluid in the intermediate heat transport loop. Methods were developed to perform thermal-hydraulic and cycleefficiency evaluations of the different configurations and coolants. The thermal-hydraulic evaluations estimated the sizes of various components in the intermediate heat transport loop for the different configurations. This paper also includes a portion of stress analyses performed on pipe configurations.

C. H. Oh; C. Davis; S. Sherman

2008-08-01T23:59:59.000Z

424

Method of measuring heat influx of a cryogenic transfer system. [Patent application  

DOE Patents [OSTI]

A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.

Niemann, R.C.; Zelipsky, S.A.; Rezmer, R.R.; Smelser, P.

1980-10-29T23:59:59.000Z

425

Heat and Mass Transfer Modeling of Dry Gases in the Cathode of PEM Fuel Cells  

E-Print Network [OSTI]

Heat and Mass Transfer Modeling of Dry Gases in the Cathode of PEM Fuel Cells M.J. Kermani1 J and N2, through the cathode of a proton exchange membrane (PEM) fuel cell is studied numerically) an energy equation, written in a form that has enthalpy as the dependent variable. Keywords: PEM fuel cells

Stockie, John

426

Study of the Effects of Surface Morphology and Droplet Growth Dynamics on Condensation Heat Transfer  

E-Print Network [OSTI]

system 2 on Sample 3 (50??m micropillar spacing hybrid surface) ............................................................................................... 66 Figure 24. Environmental scanning electron microscopy (ESEM) time- sequence images... tension gradients to promote and induce a droplet removal mechanism. They concluded that their gradient surface exhibited a higher heat transfer coefficient than a hydrophobic silane based surface. More recently, environmental scanning electron...

Yao, Chun-Wei

2014-04-23T23:59:59.000Z

427

PARALLEL COMPUTATIONS OF RADIATIVE HEAT TRANSFER USING THE DISCRETE ORDINATES METHOD  

E-Print Network [OSTI]

the radiative transport equation on parallel computers. Mathematical libraries developed by third parties the discrete ordi- nates method. They observed that the global nature of radiative transport resultedPARALLEL COMPUTATIONS OF RADIATIVE HEAT TRANSFER USING THE DISCRETE ORDINATES METHOD Gautham

Utah, University of

428

A Study of Heat Transfer in a Composite Wall Collector System with Porous Absorber  

E-Print Network [OSTI]

In this paper, heat transfer and flow in a composite solar wall with porous absorber has been studied. The unsteady numerical simulation is employed to analyze the performance of the flow and temperature field in the composite solar wall. The excess...

Chen, W.

2006-01-01T23:59:59.000Z

429

On exact and perturbation solutions to nonlinear equations for heat transfer models  

E-Print Network [OSTI]

We analyze some exact and approximate solutions to nonlinear equations for heat transfer models. We prove that recent results derived from a method based on Lie algebras are either trivial or wrong. We test a simple analytical expression based on the hypervirial theorem and also discuss earlier perturbation results.

Francisco M. Fernández

2009-11-03T23:59:59.000Z

430

MEASUREMENT OF HEAT TRANSFER DURING DROP-WISE CONDENSATION OF WATER ON POLYETHYLENE  

E-Print Network [OSTI]

MEASUREMENT OF HEAT TRANSFER DURING DROP-WISE CONDENSATION OF WATER ON POLYETHYLENE Gagan Deep distribution of temperature during drop-wise condensation over a polyethylene substrate was measured using on the substrate was simultaneously visualized. Static contact angles of water on polyethylene are measured

Khandekar, Sameer

431

Flow and Heat-Transfer Apparatus, Instrumentation and Data Acquisition Method  

E-Print Network [OSTI]

friction and convective heat transfer characteristics of nanofluids. Instead of a usual closed-loop system where pumps and after-cooling units are required, the developed apparatus utilizes nitrogen pressure-driven flow to test a single batch of fluid. This reduces the complexity of the system while improving its

Kostic, Milivoje M.

432

January 25, 2008/ARR 1 Heat and Mass Transfer in Fusion Energy  

E-Print Network [OSTI]

January 25, 2008/ARR 1 Heat and Mass Transfer in Fusion Energy Applications: from the "Very Cold, CA January 25, 2008 #12;January 25, 2008/ARR 2 Unique Set of Conditions Associated with Fusion · Realization of fusion energy imposes considerable challenges in the areas of engineering, physics and material

Raffray, A. René

433

Heat Transfer Performance of a Dry and Wet / Dry Advanced Cooling Tower Condenser  

E-Print Network [OSTI]

phase change pilot plant (0.6 MWth) located at UCC/Linde. The first unit consisted of integral shaved-fin-extruded aluminum tubing designed for dry operation. Heat transfer and air-side pressure loss characteristics were measured under varying air face...

Fricke, H. D.; Webster, D. J.; McIlroy, K.; Bartz, J. A.

1981-01-01T23:59:59.000Z

434

ASME Journal of Heat Transfer Vol. 121(3), pp.646-652, 1999  

E-Print Network [OSTI]

1 ASME Journal of Heat Transfer Vol. 121(3), pp.646-652, 1999 Variations of Buoyancy-Induced Mass Assistant Professor, Assoc. Mem. ASME Q. Liao* Research Associate P. Cheng Professor, Fellow ASME Department-8647; Fax: (852) 2358-1543. * Permanent Address: Dept. of Thermal Power Engineering, Chongqing University

Zhao, Tianshou

435

Conjugate Heat Transfer with Large Eddy Simulation for Gas Turbine Components.  

E-Print Network [OSTI]

Conjugate Heat Transfer with Large Eddy Simulation for Gas Turbine Components. Florent Duchaine constraint for GT (gas turbines). Most existing CHT tools are developped for chained, steady phenomena. A film-cooled turbine vane is then studied. Thermal conduction in the blade implies lower wall

Nicoud, Franck

436

Heat transfer and film-cooling for the endwall of a first stage turbine vane  

E-Print Network [OSTI]

as the pressure side horseshoe vortex, develops as the flow is turned by the turbine vane or rotor bladeHeat transfer and film-cooling for the endwall of a first stage turbine vane Karen A. Thole of the airfoils. One means of preventing degradation in the turbine is to film-cool components whereby coolant

Thole, Karen A.

437

Elevated freestream turbulence effects on heat transfer for a gas turbine vane  

E-Print Network [OSTI]

turbine airfoil, particularly for the first stage nozzle guide vane. For this study, augmentations. To incorporate all of the variables affecting boundary layer development on gas turbine airfoils, studies needElevated freestream turbulence effects on heat transfer for a gas turbine vane K.A. Thole a,*, R

Thole, Karen A.

438

Shape-independent limits to near-field radiative heat transfer  

E-Print Network [OSTI]

We derive shape-independent limits to the spectral radiative heat-transfer rate between two closely spaced bodies, generalizing the concept of a black body to the case of near-field energy transfer. By conservation of energy, we show that each body of susceptibility $\\chi$ can emit and absorb radiation at enhanced rates bounded by $|\\chi|^2 / \\operatorname{Im} \\chi$, optimally mediated by near-field photon transfer proportional to $1/d^2$ across a separation distance $d$. Dipole--dipole and dipole--plate structures approach restricted versions of the limit, but common large-area structures do not exhibit the material enhancement factor and thus fall short of the general limit. By contrast, we find that particle arrays interacting in an idealized Born approximation exhibit both enhancement factors, suggesting the possibility of orders-of-magnitude improvement beyond previous designs and the potential for radiative heat transfer to be comparable to conductive heat transfer through air at room temperature, and s...

Miller, Owen D; Rodriguez, Alejandro W

2015-01-01T23:59:59.000Z

439

Heat transfer and pressure drop in an annular channel with downflow  

SciTech Connect (OSTI)

The onset of a flow instability (OFI) determines the minimum flow rate for cooling in the flow channels of a nuclear fuel assembly. A test facility was constructed with full-scale models (length and diameter) of annular flow channels incorporating many instruments to measure heat transfer and pressure drop with downflow in the annulus. Tests were performed both with and without axial centering ribs at prototypical values of pressure, flow rate and uniform wall heat flux. The axial ribs have the effect of subdividing the annulus into quadrants, so the problem becomes one of parallel channel flow, unlike previous experiments in tubes (upflow and downflow). Other tests were performed to determine the effects if any of asymmetric and non-uniform circumferential wall heating, operating pressure level and dissolved gas concentration. Data from the tests are compared with models for channel heat transfer and pressure drop profiles in several regimes of wall heating from single-phase forced convection through partially and fully developed nucleate boiling. Minimum stable flow rates were experimentally determined as a function of wall heat flux and heat distribution and compared with the model for the transition to fully developed boiling which is a key criterion in determining the OFI condition in the channel. The heat transfer results in the channel without ribs are in excellent agreement with predictions from a computer model of the flow in the annulus and with empirical correlations developed from similar tests. The test results with centering ribs show that geometrical variations between the channels can lead to differences in subchannel behavior which can make the effect of the ribs and the geometry an important factor when assessing the power level at which the fuel assembly (and the reactor) can be operated to prevent overheating in the event of a loss-of-coolant-accident (LOCA).

Dolan, F.X.; Crowley, C.J. [Creare, Inc., Hanover, NH (United States); Qureshi, Z.H. [Westinghouse Savannah River Co., Aiken, SC (United States)

1992-06-01T23:59:59.000Z

440

Heat transfer and pressure drop in an annular channel with downflow  

SciTech Connect (OSTI)

The onset of a flow instability (OFI) determines the minimum flow rate for cooling in the flow channels of a nuclear fuel assembly. A test facility was constructed with full-scale models (length and diameter) of annular flow channels incorporating many instruments to measure heat transfer and pressure drop with downflow in the annulus. Tests were performed both with and without axial centering ribs at prototypical values of pressure, flow rate and uniform wall heat flux. The axial ribs have the effect of subdividing the annulus into quadrants, so the problem becomes one of parallel channel flow, unlike previous experiments in tubes (upflow and downflow). Other tests were performed to determine the effects if any of asymmetric and non-uniform circumferential wall heating, operating pressure level and dissolved gas concentration. Data from the tests are compared with models for channel heat transfer and pressure drop profiles in several regimes of wall heating from single-phase forced convection through partially and fully developed nucleate boiling. Minimum stable flow rates were experimentally determined as a function of wall heat flux and heat distribution and compared with the model for the transition to fully developed boiling which is a key criterion in determining the OFI condition in the channel. The heat transfer results in the channel without ribs are in excellent agreement with predictions from a computer model of the flow in the annulus and with empirical correlations developed from similar tests. The test results with centering ribs show that geometrical variations between the channels can lead to differences in subchannel behavior which can make the effect of the ribs and the geometry an important factor when assessing the power level at which the fuel assembly (and the reactor) can be operated to prevent overheating in the event of a loss-of-coolant-accident (LOCA).

Dolan, F.X.; Crowley, C.J. (Creare, Inc., Hanover, NH (United States)); Qureshi, Z.H. (Westinghouse Savannah River Co., Aiken, SC (United States))

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Simultaneous heat and mass transfer in absorption of gases in laminar liquid films  

SciTech Connect (OSTI)

A theoretical analysis of the combined heat and mass transfer process taking place in the absorption of a gas or vapor into a laminar liquid film is described. This type of process, which occurs in many gas-liquid systems, often releases only a small amount of heat, making the process almost isothermal. In some cases, however, the heat of absorption is significant and temperature variations cannot be ignored. One example, from which the present study originated, is in absorption heat pumps where mass transfer is produced specifically to generate a temperature change. The model analyzed describes a liquid film that flows over an inclined plane and has its free surface in contact with stagnant vapor. The absorption process at the surface creates nonuniform temperature and concentration profiles in the film, which develop until equilibrium between the liquid and vapor is achieved. The energy and diffusion equations are solved simultaneously to give the temperature and concentration variations at the interface and the wall. Two cases of interest are considered: constant-temperature and adiabatic walls. The Nusselt and Sherwood numbers are expressed in terms of the operating parameters, from which heat and mass transfer coefficients can be determined. The Nusselt and Sherwood numbers are found to depend on the Peclet and Lewis numbers as well as on the equilibrium characteristics of the working materials.

Grossman, G

1982-09-01T23:59:59.000Z

442

Heat transfer performance of an external receiver pipe under unilateral concentrated solar radiation  

SciTech Connect (OSTI)

The heat transfer and absorption characteristics of an external receiver pipe under unilateral concentrated solar radiation are theoretically investigated. Since the heat loss ratio of the infrared radiation has maximum at moderate energy flux, the heat absorption efficiency will first increase and then decrease with the incident energy flux. The local absorption efficiency will increase with the flow velocity, while the wall temperature drops quickly. Because of the unilateral concentrated solar radiation and different incident angle, the heat transfer is uneven along the circumference. Near the perpendicularly incident region, the wall temperature and absorption efficiency slowly approaches to the maximum, while the absorption efficiency sharply drops near the parallelly incident region. The calculation results show that the heat transfer parameters calculated from the average incident energy flux have a good agreement with the average values of the circumference under different boundary conditions. For the whole pipe with coating of Pyromark, the absorption efficiency of the main region is above 85%, and only the absorption efficiency near the parallelly incident region is below 80%. In general, the absorption efficiency of the whole pipe increases with flow velocity rising and pipe length decreasing, and it approaches to the maximum at optimal concentrated solar flux. (author)

Jianfeng, Lu; Jing, Ding [School of Engineering, Sun Yat-Sen University, Guangzhou 510006 (China); Jianping, Yang [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education, South China University of Technology, Guangzhou 510640 (China)

2010-11-15T23:59:59.000Z

443

Near-field heat transfer between a nanoparticle and a rough surface  

E-Print Network [OSTI]

In this work we focus on the surface roughness correction to the near-field radiative heat transfer between a nanoparticle and a material with a rough surface utilizing a direct perturbation theory up to second order in the surface profile. We discuss the different distance regimes for the local density of states above the rough material and the heat flux analytically and numerically. We show that the heat transfer rate is larger than that corresponding to a flat surface at short distances. At larger distances it can become smaller due to surface polariton scattering by the rough surface. For distances much smaller than the correlation length of the surface profile, we show that the results converge to a proximity approximation, whereas in the opposite limit the rough surface can be replaced by an equivalent surface layer.

Svend-Age Biehs; Jean-Jacques Greffet

2011-03-11T23:59:59.000Z

444

Conjugate heat transfer and particle transport in outside vapor deposition process  

SciTech Connect (OSTI)

A numerical study of conjugate heat transfer and particle transport has been carried out for the outside vapor deposition process. A buoyant jet flow impinging on a two-layered cylinder has been analyzed including heat conduction occurring through the two-layered cylinder, which consists of the original target rod and the deposited porous layers. Temperature and flow fields have been obtained by an iterative method, and thermophoretic particle deposition has been studied. Of particular interest are the effects of the thickness of deposited layers, the torch speed, the rotation speed of the cylinder, and the distance between the torch and the cylinder on the heat transfer and particle deposition. Effects of variable properties and tube rotation are also included.

Choi, M.; Song, Y.; Kang, S.H. [Seoul National Univ., Seoul (Korea, Republic of). Dept. of Mechanical Engineering

1995-07-01T23:59:59.000Z

445

Heat transfer measurements in a two-pass square duct via a transient liquid crystal image method  

E-Print Network [OSTI]

to obtain heat transfer coefficients. Heat transfer measurement distributions at 3 Reynolds numbers (10,000, 25,000, and 50,000) were studied. There were two geometric surface rib patterns attached to the channel. First was a 90° continuous rib...

Luna, Jesus Arturo

2000-01-01T23:59:59.000Z

446

A phase-field method for 3D simulation of two-phase heat transfer , H. Babaee a  

E-Print Network [OSTI]

the efficiency of the new method in simulating 3D multi-phase convective heat transfer on stationary gridsA phase-field method for 3D simulation of two-phase heat transfer X. Zheng a , H. Babaee a , S Keywords: Spectral element Non-moving grid Cahn­Hilliard equation Large thermal conductivity ratio a b

Dong, Suchuan "Steven"

447

Some investigations on the enhancement of boiling heat transfer from planer surface embedded with continuous open tunnels  

SciTech Connect (OSTI)

Boiling heat transfer from a flat surface can be enhanced if continuous open tunnel type structures are embedded in it. Further, improvement of boiling heat transfer from such surfaces has been tried by two separate avenues. At first, inclined tunnels are embedded over the solid surface and an effort is made to optimize the tunnel inclination for boiling heat transfer. Surfaces are manufactured in house with four different inclinations of the tunnels with or without a reentrant circular pocket at the end of the tunnel. Experiments conducted in the nucleate boiling regime showed that 45 deg inclination of the tunnels for both with and without base geometry provides the highest heat transfer coefficient. Next, active fluid rotation was imposed to enhance the heat transfer from tunnel type surfaces with and without the base geometry. Rotational speed imparted by mechanical stirrer was varied over a wide range. It was observed that fluid rotation enhances the heat transfer coefficient only up to a certain value of stirrer speed. Rotational speed values, beyond this limit, reduce the boiling heat transfer severely. A comparison shows that embedding continuous tunnel turns out to be a better option for the increase of heat transfer coefficient compared to the imposition of fluid rotation. But the behavior of inclined tunnels under the action of fluid rotation is yet to be established and can be treated as a future scope of the work. (author)

Das, A.K.; Das, P.K.; Saha, P. [Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721 302 (India)

2010-11-15T23:59:59.000Z

448

Proceedings of the 29th National Heat Transfer Conference of Italy, Politecnico di Torino, Torino, Italy, June 2022, 2011 INTRODUCTION  

E-Print Network [OSTI]

trends are known, no information about the local heat transfer coefficient in the evaporator U.D.) has been brazed on the main tube of the condenser section in order to connect the vacuum/filling valve transducer 20 Copper fitting FLOW PATTERNS AND CORRESPONDING LOCAL HEAT TRANSFER COEFFICIENTS IN A PULSATING

Khandekar, Sameer

449

Convective Heat Transfer and Reference Free-stream Temperature Determination near the Casing of an Axial Flow  

E-Print Network [OSTI]

of an Axial Flow Turbine B. Gumusel 2 and C. Camci 1 Turbomachinery Aero-Heat Transfer Laboratory Department on the casing of an axial flow turbine. The goal is to develop an accurate steady-state heat transfer method for the comparison of various casing surface and tip designs used for turbine performance improvements. The free

Camci, Cengiz

450

Experimental Analysis of the Single-Phase Heat Transfer and Friction Factor inside the Horizontal Internally Micro-Fin Tube  

E-Print Network [OSTI]

and shell-side condensers to increase heat transfer. This enables water chillers to reach high efficiency, it was observed that the buoyancy effect is present in the laminar region. The efficiency index (the ratio of tube is widely used in high flow rate applications because the heat transfer enhancement in high flow

Ghajar, Afshin J.

451

Structural, dynamic, and vibrational properties during heat transfer in Si/Ge superlattices: A Car-Parrinello molecular dynamics study  

SciTech Connect (OSTI)

The structural, dynamic, and vibrational properties during heat transfer process in Si/Ge superlattices are studied by analyzing the trajectories generated by the ab initio Car-Parrinello molecular dynamics simulation. The radial distribution functions and mean square displacements are calculated and further discussions are made to explain and probe the structural changes relating to the heat transfer phenomenon. Furthermore, the vibrational density of states of the two layers (Si/Ge) are computed and plotted to analyze the contributions of phonons with different frequencies to the heat conduction. Coherent heat conduction of the low frequency phonons is found and their contributions to facilitate heat transfer are confirmed. The Car-Parrinello molecular dynamics simulation outputs in the work show reasonable thermophysical results of the thermal energy transport process and shed light on the potential applications of treating the heat transfer in the superlattices of semiconductor materials from a quantum mechanical molecular dynamics simulation perspective.

Ji, Pengfei; Zhang, Yuwen, E-mail: zhangyu@missouri.edu [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, Missouri 65211 (United States); Yang, Mo [College of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China)

2013-12-21T23:59:59.000Z

452

7-106 A reversible heat pump is considered. The temperature of the source and the rate of heat transfer to the sink are to be determined.  

E-Print Network [OSTI]

7-39 7-106 A reversible heat pump is considered. The temperature of the source and the rate of heat transfer to the sink are to be determined. Assumptions The heat pump operates steadily. Analysis Combining.5¸ ¹ · ¨ © § ¸ ¸ ¹ · ¨ ¨ © § 1.6 1 1)K300( COP 1 1 maxHP, HL TT Based upon the definition of the heat pump coefficient

Bahrami, Majid

453

M. Bahrami ENSC 388 (F09) Steady Conduction Heat Transfer 1 Steady Heat Conduction  

E-Print Network [OSTI]

of the material. In the limiting case where x0, the equation above reduces to the differential form: W dx dT k is the only energy interaction; the energy balance for the wall can be expressed: dt dE QQ wall outin). Thermal Conductivity Thermal conductivity k [W/mK] is a measure of a material's ability to conduct heat

Bahrami, Majid

454

Effect of translucence of engineering ceramics on heat transfer in diesel engines  

SciTech Connect (OSTI)

This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition. Thus, to insure the optimum thermal barrier operation for either clean or heavily sooted surfaces, a ceramic material with high scattering coefficient provides the best choice.

Wahiduzzaman, S.; Morel, T. (Integral Technologies, Inc., Westmont, IL (United States))

1992-04-01T23:59:59.000Z

455

Effect of translucence of engineering ceramics on heat transfer in diesel engines. Final report  

SciTech Connect (OSTI)

This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition. Thus, to insure the optimum thermal barrier operation for either clean or heavily sooted surfaces, a ceramic material with high scattering coefficient provides the best choice.

Wahiduzzaman, S.; Morel, T. [Integral Technologies, Inc., Westmont, IL (United States)

1992-04-01T23:59:59.000Z

456

Polymer electrolyte membranes from fluorinated polyisoprene-block-sulfonated polystyrene: Structural evolution with hydration and heating  

SciTech Connect (OSTI)

Small-angle neutron scattering (SANS) and ultra-small-angle X-ray scattering (USAXS) have been used to study the structural changes in fluorinated polyisoprene/sulfonated polystyrene (FISS) diblock copolymers as they evolved from the dry state to the water swollen state. A dilation of the nanometer-scale hydrophilic domains has been observed as hydration increased, with greater dilation occurring in the more highly sulfonated samples or upon hydration at higher temperatures. Furthermore, a decrease in the order in these phase separated structures is observed upon swelling. The glass transition temperatures of the fluorinated blocks have been observed to decrease upon hydration of these materials, and at the highest hydration levels, differential scanning calorimetry (DSC) has shown the presence of tightly bound water. A precipitous drop in the mechanical integrity of the 50% sulfonated materials is also observed upon exceeding the glass transition temperature (Tg), as measured by dynamic mechanical analysis (DMA).

Sodeye, Akinbode [Department of Polymer Science and Engineering, University of Massachusetts; Huang, Tianzi [University of Tennessee, Knoxville (UTK); Gido, Samuel [University of Massachusetts, Amherst; Mays, Jimmy [ORNL

2011-01-01T23:59:59.000Z

457

Transient PVT measurements and model predictions for vessel heat transfer. Part II.  

SciTech Connect (OSTI)

Part I of this report focused on the acquisition and presentation of transient PVT data sets that can be used to validate gas transfer models. Here in Part II we focus primarily on describing models and validating these models using the data sets. Our models are intended to describe the high speed transport of compressible gases in arbitrary arrangements of vessels, tubing, valving and flow branches. Our models fall into three categories: (1) network flow models in which flow paths are modeled as one-dimensional flow and vessels are modeled as single control volumes, (2) CFD (Computational Fluid Dynamics) models in which flow in and between vessels is modeled in three dimensions and (3) coupled network/CFD models in which vessels are modeled using CFD and flows between vessels are modeled using a network flow code. In our work we utilized NETFLOW as our network flow code and FUEGO for our CFD code. Since network flow models lack three-dimensional resolution, correlations for heat transfer and tube frictional pressure drop are required to resolve important physics not being captured by the model. Here we describe how vessel heat transfer correlations were improved using the data and present direct model-data comparisons for all tests documented in Part I. Our results show that our network flow models have been substantially improved. The CFD modeling presented here describes the complex nature of vessel heat transfer and for the first time demonstrates that flow and heat transfer in vessels can be modeled directly without the need for correlations.

Felver, Todd G.; Paradiso, Nicholas Joseph; Winters, William S., Jr.; Evans, Gregory Herbert; Rice, Steven F.

2010-07-01T23:59:59.000Z

458

Gas Turbine/Solar Parabolic Trough Hybrid Design Using Molten Salt Heat Transfer Fluid: Preprint  

SciTech Connect (OSTI)

Parabolic trough power plants can provide reliable power by incorporating either thermal energy storage (TES) or backup heat from fossil fuels. This paper describes a gas turbine / parabolic trough hybrid design that combines a solar contribution greater than 50% with gas heat rates that rival those of natural gas combined-cycle plants. Previous work illustrated benefits of integrating gas turbines with conventional oil heat-transfer-fluid (HTF) troughs running at 390?C. This work extends that analysis to examine the integration of gas turbines with salt-HTF troughs running at 450 degrees C and including TES. Using gas turbine waste heat to supplement the TES system provides greater operating flexibility while enhancing the efficiency of gas utilization. The analysis indicates that the hybrid plant design produces solar-derived electricity and gas-derived electricity at lower cost than either system operating alone.

Turchi, C. S.; Ma, Z.

2011-08-01T23:59:59.000Z

459

Modeling Granular Materials as Compressible Non-Linear Fluids: Heat Transfer Boundary Value Problems  

SciTech Connect (OSTI)

We discuss three boundary value problems in the flow and heat transfer analysis in flowing granular materials: (i) the flow down an inclined plane with radiation effects at the free surface; (ii) the natural convection flow between two heated vertical walls; (iii) the shearing motion between two horizontal flat plates with heat conduction. It is assumed that the material behaves like a continuum, similar to a compressible nonlinear fluid where the effects of density gradients are incorporated in the stress tensor. For a fully developed flow the equations are simplified to a system of three nonlinear ordinary differential equations. The equations are made dimensionless and a parametric study is performed where the effects of various dimensionless numbers representing the effects of heat conduction, viscous dissipation, radiation, and so forth are presented.

Massoudi, M.C.; Tran, P.X.

2006-01-01T23:59:59.000Z

460

Heat Transfer -1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with  

E-Print Network [OSTI]

Heat Transfer - 1 A satellite in space orbits the sun. The satellite can be approximated as a flat plate with dimensions and properties given below. (a) Calculate the solar heat flux (W/m2 is at a distance where the solar heat flux (as defined above) is 500 W/m2 , and the flat plate is oriented

Virginia Tech

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

NUMERICAL DETERMINATION AND TREATMENT OF CONVECTIVE HEAT TRANSFER COEFFICIENT IN THE COUPLED BUILDING ENERGY AND CFD SIMULATION  

E-Print Network [OSTI]

for the correct prediction of the convective heat. A finer grid resolution in CFD does not always lead to a more conservation equations of flow on these grid cells. As shown in Figure 1(a), CFD calculates convective heat1 NUMERICAL DETERMINATION AND TREATMENT OF CONVECTIVE HEAT TRANSFER COEFFICIENT IN THE COUPLED

Chen, Qingyan "Yan"

462

Heat transfer and combustion characteristics of a burner with a rotary regenerative heat exchanger  

SciTech Connect (OSTI)

The authors have developed a Rotary Regenerative Combustion (RRX) System, which is coupled with a compact high efficiency regenerative air heat exchanger and a combustion burner. This system contributes to saving energy of fuel firing industrial furnaces and decreases NO{sub x} emission. This technology can be considered as a solution of greenhouse problem. This paper, discusses a compact high efficiency regenerative air heat exchanger in comparison with the existing types of regenerative burners and reverse firing with high momentum fuel jet (with motive fluid) in the furnace. This burner is compact in size, with high fuel efficiency, low NOx emission, easy to operate, and reliable, based on the results of field tests and commercial operations. The authors can say that the RRX system is a regenerative burner of the second generation.

Hirose, Yasuo; Kaji, Hitoshi; Arai, Norio

1998-07-01T23:59:59.000Z

463

Fundamental heat transfer processes related to phase change thermal storage media  

SciTech Connect (OSTI)

Research on fundamental heat transfer processes which occur in phase-change thermal storage systems is described. The research encompasses both melting and freezing, and includes both experiment and analysis. The status of four research problems is discussed. One of the freezing problems was focused on investigating, via experiment, the extent to which freezing can be enhanced by the attachment of fins to the external surface of a cooled vertical tube situated in a liquid phase-change medium. Very substantial enhancements were encountered which neutralize the degradation of freezing due to the thermal resistance of the frozen layer and to natural convection in the liquid phase. The second of the freezing problems was analytical in nature and sought to obtain solutions involving both the phase-change medium and the heat transfer fluid used either to add heat to or extract heat from the medium. For freezing on a plane wall, it was possible to obtain a closed-form analytical solution, while for freezing about a coolant-carrying circular tube, a new numerical methodology was devised to obtain finite-difference solutions. For melting, quantitative design-quality heat transfer coefficients were determined experimentally for melting adjacent to a heated vertical tube. These experiments explored the effects of solid-phase subcooling and of open versus closed top containment on the coefficients. A dimensionless correlation enables these results to be used for a wide range of phase-change media. Studies on melting of a phase-change material situated within a circular tube are in progress.

Sparrow, E. M.; Ramsey, J. W.

1981-01-01T23:59:59.000Z

464

Liquid Metal Bond for Improved Heat Transfer in LWR Fuel Rods  

SciTech Connect (OSTI)

A liquid metal (LM) consisting of 1/3 weight fraction each of Pb, Sn, and Bi has been proposed as the bonding substance in the pellet-cladding gap in place of He. The LM bond eliminates the large AT over the pre-closure gap which is characteristic of helium-bonded fuel elements. Because the LM does not wet either UO2 or Zircaloy, simply loading fuel pellets into a cladding tube containing LM at atmospheric pressure leaves unfilled regions (voids) in the bond. The HEATING 7.3 heat transfer code indicates that these void spaces lead to local fuel hot spots.

Donald Olander

2005-08-24T23:59:59.000Z

465

Effect of Mixed Working Fluid Composition on Binary Cycle Condenser Heat Transfer Coefficients  

SciTech Connect (OSTI)

Effect of Mixed Working Fluid Composition on Binary Cycle Condenser Heat Transfer Coefficients Dan Wendt, Greg Mines Idaho National Laboratory The use of mixed working fluids in binary power plants can provide significant increases in plant performance, provided the heat exchangers are designed to take advantage of these fluids non-isothermal phase changes. In the 1980's testing was conducted at DOE's Heat Cycle Research Facility (HCRF) where mixtures of different compositions were vaporized at supercritical pressures and then condensed. This testing had focused on using the data collected to verify that Heat Transfer Research Incorporated (HTRI) codes were suitable for the design of heat exchangers that could be used with mixtures. The HCRF data includes mixture compositions varying from 0% to 40% isopentane and condenser tube orientations of 15{sup o}, 60{sup o}, and 90{sup o} from horizontal. Testing was performed over a range of working fluid and cooling fluid conditions. Though the condenser used in this testing was water cooled, the working fluid condensation occurred on the tube-side of the heat exchanger. This tube-side condensation is analogous to that in an air-cooled condenser. Tube-side condensing heat transfer coefficient information gleaned from the HCRF testing is used in this study to assess the suitability of air-cooled condenser designs for use with mixtures. Results of an air-cooled binary plant process model performed with Aspen Plus indicate that that the optimal mixture composition (producing the maximum net power for the scenario considered) is within the range of compositions for which data exist. The HCRF data is used to assess the impact of composition, tube orientation, and process parameters on the condensing heat transfer coefficients. The sensitivity of the condensing coefficients to these factors is evaluated and the suitability of air-cooled condenser designs with mixtures is assessed. This paper summarizes the evaluation of the HCRF data and discusses the next steps in the project evaluation of air-cooled condenser designs that can take advantage of the performance gains possible with these fluids.

Dan Wendt; Greg Mines

2011-10-01T23:59:59.000Z

466

Molten Glass for Thermal Storage: Advanced Molten Glass for Heat Transfer and Thermal Energy Storage  

SciTech Connect (OSTI)

HEATS Project: Halotechnics is developing a high-temperature thermal energy storage system using a new thermal-storage and heat-transfer material: earth-abundant and low-melting-point molten glass. Heat storage materials are critical to the energy storage process. In solar thermal storage systems, heat can be stored in these materials during the day and released at night—when the sun is not out—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in these materials at night and released to produce electricity during daytime peak-demand hours. Halotechnics new thermal storage material targets a price that is potentially cheaper than the molten salt used in most commercial solar thermal storage systems today. It is also extremely stable at temperatures up to 1200°C—hundreds of degrees hotter than the highest temperature molten salt can handle. Being able to function at high temperatures will significantly increase the efficiency of turning heat into electricity. Halotechnics is developing a scalable system to pump, heat, store, and discharge the molten glass. The company is leveraging technology used in the modern glass industry, which has decades of experience handling molten glass.

None

2012-01-01T23:59:59.000Z

467

Local heat transfer distribution in a two-pass trapezoidal channel with a 180 [degree] turn via transient liquid crystal technique  

E-Print Network [OSTI]

cross section. Attention is focused on the effect of the 180' turn on the local heat transfer distributions on the interior surfaces of the various walls at the turn, under turbulent flow conditions. Transient heat transfer experiments, using...

Endley, Saurabh

1996-01-01T23:59:59.000Z

468

Film cooling and heat transfer of steam through an inclined injection hole  

E-Print Network [OSTI]

transfer coefficient at blowing rate M 0. 5 . . . . . . . . . . . . . . . . 37 NOMENCLATURE Symbol Description area circumference of the cross sectional area Cp D E, , Es, Es drag coefficient specific heat diameter of the injection hole minor... the experimental data at low blowing rates; however, the extension to higher injection rates is not correct, and an injected fluid other than air is not discussed. Goldstein [2] reviewed a number of semi- empirical correlations and predictions for two...

Chen, Hun Way

1983-01-01T23:59:59.000Z

469

A numerical model of convective heat transfer in a three dimensional channel with baffles  

E-Print Network [OSTI]

to minimize the effects of the temperature. Chandrupatla and Sastri (1977) used a finite difference method to study laminar heat transfer and fluid flow for Non-Newtonian fluids. In the limiting case of Newtonian fluids their results showed good agreement... and Sastri (1977) for developing laminar flow in a rectangular smooth channel. Figure 4. 1 shows the numerically predicted centerline axial velocity compared with the experimental data of Goldstein and Kreid (1967). The agreement between the numerical...

Lopez Buso, Jorge Ricardo

2012-06-07T23:59:59.000Z

470

Heat transfer issues in high-heat-load synchrotron x-ray beams  

SciTech Connect (OSTI)

In this paper, a short description of the synchrotron radiation x-ray sources and the associated power loads is given, followed by a brief description of typical synchrotron components and their heat load. It is emphasized that the design goals for most of these components is to limit (a) temperature, (b) stresses, or (c) strains in the system. Each design calls for a different geometry, material selection, and cooling scheme. Cooling schemes that have been utilized so far are primarily single phase and include simple macrochannel cooling, microchannel cooling, contact cooling, pin-post cooling, porous-flow cooling, jet cooling, etc. Water, liquid metals, and various cryogenic coolants have been used. Because the trend in x-ray beam development is towards brighter (i.e., more powerful) beams and assuming that no radical changes in the design of x-ray generating machines occurs in the next few years, it is fair to state that the utilization of various effective cooling schemes and, in particular, two-phase flow (e.g., subcooled boiling) warrants further investigation. This, however, requires a thorough examination of stability and reliability of two-phase flows for high-heat-flux components operating in ultrahigh vacuum with stringent reliability requirements.

Khounsary, A.M.; Mills, D.M.

1994-09-01T23:59:59.000Z

471

Heat Transfer from Condensate Droplets Falling through an Immiscible Layer of Tributyl Phosphate  

SciTech Connect (OSTI)

As part of a safety analysis of reactions in two-layer mixtures of nitric acid and tributyl phosphate (TBP), an experiment was conducted to study how steam condensate mixes with the TBP layer when steam passes over a TBP-nitric acid mixture. The experiments showed that the condensate does not form a separate layer on top of the TBP but instead percolates as droplets through the TBP layer. The temperature at the top surface of the TBP layer undergoes a step change increase when the initial condensate droplets reach the surface. Temperatures at the surface and within the TBP and aqueous layers subsequently approach a steady state distribution governed by laminar convection and radiation heat transfer from the vapor space above the two-layer mixture. The rate of temperature increase and the steady state temperature gradient are determined by a characteristic propagation velocity and a streamwise dispersion coefficient for heat transfer. The propagation velocity is the geometric mean of the thermal convection velocities for the organic and aqueous phases, and the dispersion coefficient equals 0.494 times the product of the superficial condensate droplet velocity and the diameter of the test vessel. The value of the dispersion coefficient agrees with the Joshi (1980) correlation for liquid phase backmixing in bubble columns. Transient perturbations occur in the TBP layer temperatures. A Fourier analysis shows that the dominant frequency of these perturbations equals the natural frequency given by the transient heat transfer solution.

Laurinat, James E.

2005-08-22T23:59:59.000Z

472

Pulse*Star Inertial Confinement Fusion Reactor: heat transfer loop and balance of plant considerations  

SciTech Connect (OSTI)

A conceptual heat transfer loop and balance of plant design for the Pulse*Star Inertial Confinement Fusion Reactor has been investigated and results are presented. The Pulse*Star reaction vessel, a perforated steel bell jar approximately 11 m in diameter, is immersed in Li/sub 17/Pb/sub 83/ coolant which flows through the perforations and forms a 1.5 m thick plenum of droplets around an 8 m diameter inner chamber. The reactor and associated pumps, piping, and steam generators are contained within a 17 m diameter pool of Li/sub 17/Pb/sub 83/ coolant to minimize structural requirements and occupied space, resulting in reduced cost. Four parallel heat transfer loops with flow rates of 5.5 m/sup 3//s each are necessary to transfer 3300 MWt of power. The steam generator design was optimized by finding the most cost-effective combination of heat exchanger area and pumping power. Power balance calculations based on an improved electrical conversion efficiency revealed a net electrical output of 1260 MWe to the bus bar and a resulting net efficiency of 39%. Suggested balance-of-plant layouts are also presented.

McDowell, M.W.; Murray, K.A.

1984-05-09T23:59:59.000Z

473

Method and system for simulating heat and mass transfer in cooling towers  

DOE Patents [OSTI]

The present invention is a system and method for simulating the performance of a cooling tower. More precisely, the simulator of the present invention predicts values related to the heat and mass transfer from a liquid (e.g., water) to a gas (e.g., air) when provided with input data related to a cooling tower design. In particular, the simulator accepts input data regarding: (a) cooling tower site environmental characteristics; (b) cooling tower operational characteristics; and (c) geometric characteristics of the packing used to increase the surface area within the cooling tower upon which the heat and mass transfer interactions occur. In providing such performance predictions, the simulator performs computations related to the physics of heat and mass transfer within the packing. Thus, instead of relying solely on trial and error wherein various packing geometries are tested during construction of the cooling tower, the packing geometries for a proposed cooling tower can be simulated for use in selecting a desired packing geometry for the cooling tower.

Bharathan, Desikan (Lakewood, CO); Hassani, A. Vahab (Golden, CO)

1997-01-01T23:59:59.000Z

474

Prediction of heat transfer for a supercritical water test with a four pin fuel bundle  

SciTech Connect (OSTI)

As a next step to validate prediction methods for core design of a Supercritical Water Cooled Reactor, a small, electrically heated fuel bundle with 4 pins is planned to be tested. This paper summarizes first heat transfer predictions for such a test, which were performed based on supercritical and subcritical sub-channel analyses. For heat transfer under supercritical pressure conditions, the sub-channel code STAFAS has been applied, which had been tested successfully already for a supercritical water reactor design. Design studies with different assembly box sizes at a given pin diameter and pitch have been performed to optimize the coolant temperature distribution. With a fuel pin outer diameter of 10 mm and a pitch to diameter ratio of 1.15, an optimum inner width of the assembly box was determined to be 24 mm. Coolant and cladding surface temperatures to be expected at subcritical pressure conditions have been predicted with the sub-channel code MATRA. As, different from typical PWR or BWR conditions, a dryout has been foreseen for the tests, this code had to be extended to include suitable dryout criteria as well as post dryout heat transfer correlations at higher enthalpies and pressures. Different from PWR or BWR design, the cladding surface temperature of fuel pins in supercritical water reactors can vary significantly around the circumference of each pin, causing bending towards its hotter side which, in turn, can cause additional sub-channel heat-up and thus additional thermal bending of the pin. To avoid a thermal instability by this effect, a sensitivity study with respect to thermal bending of fuel pins has been performed, which determines the minimum number of grid spacers needed for this test. (authors)

Behnke, L. [RWE Power AG, Essen (Germany); Himmel, S.; Waata, C.; Schulenberg, T. [Forschungszentrum Karlsruhe GmbH, Institute for Nuclear and Energy Technologies, PO Box 3640, D-76021 Karlsruhe (Germany); Laurien, E. [University of Stuttgart (Germany)

2006-07-01T23:59:59.000Z

475

Comparison of binary mixture heat and mass transfer analysis with single-component heat and mass transfer analysis in the design of GAX absorber/desorber[Generator-Absorber heat eXchange  

SciTech Connect (OSTI)

The GAX cycle is an elegant way of achieving higher effect performance with single-stage configuration. One of the key components of the GAX cycle is the absorber/desorber heat exchanger, which carries out internal heat recovery. This paper investigated two different models for the design of an absorber/desorber in the GAX system. In model A, single-component forced convective boiling with the physical properties of the mixture was assumed for the cocurrent desorption process, which is basically an approximation technique adopted widely so far. In model B, the multi-component effect of the binary mixture on the forced convective boiling transfer was considered. Significant degradation of heat and mass transfer was observed under binary mixture boiling condition as opposed to the single-component boiling. The results show that about 57% of extra heat transfer area would be needed under the case being investigated if the fluid is considered as a binary mixture rather than a single-component fluid. This paper provides a basic guideline for designing a properly sized GAX absorber-desorber.

Cao, J.; Christensen, R.N.

2000-07-01T23:59:59.000Z

476

Approved Module Information for ME3013, 2014/5 Module Title/Name: Heat Transfer and Turbomachinery Module Code: ME3013  

E-Print Network [OSTI]

Approved Module Information for ME3013, 2014/5 Module Title/Name: Heat Transfer and Turbomachinery Outcomes: The students will have developed an understanding of a range of advanced heat transfer and turbo-machinery. * Unsteady heat transfer Turbomachinery: * Momentum and energy equations for turbo-machines * Radial, axial

Neirotti, Juan Pablo

477

Heat Transfer -2 A pure platinum wire with diameter D = 3 mm and length L = 20 mm is placed outside on a day when air temperature  

E-Print Network [OSTI]

Heat Transfer - 2 A pure platinum wire with diameter D = 3 mm and length L = 20 mm is placed outside on a day when air temperature T = 10o C. The heat transfer coefficient at the wire's surface h equation that includes all heat transfer mechanisms involved in this problem. Write this energy balance

Virginia Tech

478

The 1st International Symposium on Micro & Nano Technology, 14-17 March, 2004, Honolulu, Hawaii, USA MOLECULAR DYNAMICS SIMULATIONS OF HEAT TRANSFER ISSUES  

E-Print Network [OSTI]

, USA MOLECULAR DYNAMICS SIMULATIONS OF HEAT TRANSFER ISSUES IN CARBON NANOTUBES S. Maruyama, Y-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, JAPAN ABSTRACT Several heat transfer problems related to single, and thermal boundary resistance in a junction of nanotubes are reviewed. Then, the heat transfer from an SWNT

Maruyama, Shigeo

479

Heat transfer between parallel plates: An approach based on the linearized Boltzmann equation for a binary mixture of rigid-sphere gases  

E-Print Network [OSTI]

Heat transfer between parallel plates: An approach based on the linearized Boltzmann equation a concise and particularly accurate solution of the heat-transfer problem for a binary gas mixture confined.1063/1.2511039 I. INTRODUCTION The heat-transfer problem within the context of rarefied gas dynamics has been

Siewert, Charles E.

480

RELAP5-3D Modeling of Heat Transfer Components (Intermediate Heat Exchanger and Helical-Coil Steam Generator) for NGNP Application  

SciTech Connect (OSTI)

The Next Generation Nuclear Plant project is aimed at the research and development of a helium-cooled high-temperature gas reactor that could generate both electricity and process heat for the production of hydrogen. The heat from the high-temperature primary loop must be transferred via an intermediate heat exchanger to a secondary loop. Using RELAP5-3D, a model was developed for two of the heat exchanger options a printed-circuit heat exchanger and a helical-coil steam generator. The RELAP5-3D models were used to simulate an exponential decrease in pressure over a 20 second period. The results of this loss of coolant analysis indicate that heat is initially transferred from the primary loop to the secondary loop, but after the decrease in pressure in the primary loop the heat is transferred from the secondary loop to the primary loop. A high-temperature gas reactor model should be developed and connected to the heat transfer component to simulate other transients.

N. A. Anderson; P. Sabharwall

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "block heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Ballistic vs. diffusive heat transfer across nanoscopic films of layered crystals  

SciTech Connect (OSTI)

We use non-equilibrium molecular dynamics to study the heat transfer mechanism across sandwich interfacial structures of Si/n-atomic-layers/Si, with 1???n???20 and atomic layers composed of WSe{sub 2} and/or graphene. In the case of WSe{sub 2} sheets, we observe that the thermal resistance of the sandwich structure is increasing almost linearly with the number of WSe{sub 2} sheets, n, indicating a diffusive phonon transport mechanism. By contrast in the case of n graphene layers, the interfacial thermal resistance is more or less independent on the number of layers for 1???n???10, and is associated with ballistic phonon transport mechanism. We attribute the diffusive heat transfer mechanism across WSe{sub 2} sheets to abundant low frequency and low group velocity optical modes that carry most of the heat across the interface. By contrast, in graphene, acoustic modes dominate the thermal transport across the interface and render a ballistic heat flow mechanism.

Shen, Meng; Keblinski, Pawel, E-mail: keblip@rpi.edu [Department of Materials Science and Engineering, and Rensselaer Nanotechnology Center, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2014-04-14T23:59:59.000Z

482

Lattice Boltzmann modeling of boiling heat transfer: The boiling curve and the effects of wettability  

E-Print Network [OSTI]

A hybrid thermal lattice Boltzmann (LB) model is presented to simulate thermal multiphase flows with phase change based on an improved pseudopotential LB approach [Q. Li, K. H. Luo, and X. J. Li, Phys. Rev. E 87, 053301 (2013)]. The present model does not suffer from the spurious term caused by the forcing-term effect, which was encountered in some previous thermal LB models for liquid-vapor phase change. Using the model, the liquid-vapor boiling process is simulated. The boiling curve together with the three boiling stages (nucleate boiling, transition boiling, and film boiling) is numerically reproduced in the LB community for the first time. The numerical results show that the basic features and the fundamental characteristics of boiling heat transfer are well captured, such as the severe fluctuation of transient heat flux in the transition boiling and the feature that the maximum heat transfer coefficient lies at a lower wall superheat than that of the maximum heat flux. Furthermore, the effects of the he...

Li, Q; Francois, M M; He, Y L; Luo, K H

2015-01-01T23:59:59.000Z

483

Experimental investigation of piston heat transfer under conventional diesel and reactivity-controlled compression ignition combustion regimes  

SciTech Connect (OSTI)

The piston of a heavy-duty single-cylinder research engine was instrumented with 11 fast-response surface thermocouples, and a commercial wireless telemetry system was used to transmit the signals from the moving piston. The raw thermocouple data were processed using an inverse heat conduction method that included Tikhonov regularization to recover transient heat flux. By applying symmetry, the data were compiled to provide time-resolved spatial maps of the piston heat flux and surface temperature. A detailed comparison was made between conventional diesel combustion and reactivity-controlled compression ignition combustion operations at matched conditions of load, speed, boost pressure, and combustion phasing. The integrated piston heat transfer was found to be 24% lower, and the mean surface temperature was 25 C lower for reactivity-controlled compression ignition operation as compared to conventional diesel combustion, in spite of the higher peak heat release rate. Lower integrated piston heat transfer for reactivity-controlled compression ignition was found over all the operating conditions tested. The results showed that increasing speed decreased the integrated heat transfer for conventional diesel combustion and reactivity-controlled compression ignition. The effect of the start of injection timing was found to strongly influence conventional diesel combustion heat flux, but had a negligible effect on reactivity-controlled compression ignition heat flux, even in the limit of near top dead center high-reactivity fuel injection timings. These results suggest that the role of the high-reactivity fuel injection does not significantly affect the thermal environment even though it is important for controlling the ignition timing and heat release rate shape. The integrated heat transfer and the dynamic surface heat flux were found to be insensitive to changes in boost pressure for both conventional diesel combustion and reactivity-controlled compression ignition. However, for reactivity-controlled compression ignition, the mean surface temperature increased with changes in boost suggesting that equivalence ratio affects steady-state heat transfer.

Splitter, Derek A [ORNL; Hendricks, Terry Lee [Sandia National Laboratories (SNL); Ghandhi, Jaal B [University of Wisconsin

2014-01-01T23:59:59.000Z

484

Determination of the controlling process in coupled heat and mass transfer  

SciTech Connect (OSTI)

The influence of non-condensable gases on condensation is well known going back to Nusselt. The non-condensables tend to form a blanket around the cooled surface which can significantly slow condensation rates by introducing a controlling mass transfer resistance. The coupled heat and mass transfer process that results has a significant impact on the optimum design of compact condenser bundles. One of the questions that arises in analyzing such a coupled process is which of the two processes is controlling the overall transfer process? One way to quantify a solution to this problem is to take a thermodynamic perspective and to compute the entropy generation associated with each of the individual processes. Then, the process that contributes the largest entropy generation is viewed as the controlling process. The result of such a determination provides insight as to how to augment the overall transfer process. The approach taken in this study is to use available CFD (computational fluid dynamics) codes to formulate and solve the condenser problem to gain insight into the coupled process. The resulting temperature, velocity and concentration data can then be analyzed to determine the entropy generation associated with each of the processes. Results are presented for a series of simplified geometries that define the magnitude of the effects contributed by each of the transfer processes.

Bell, B.; Kakavas, T.; Herold, K.E. [Univ. of Maryland, College Park, MD (United States). Center for Environmental Energy Engineering

1996-12-31T23:59:59.000Z

485

Thermal Performance of a Novel Heat Transfer Fluid Containing Multiwalled Carbon Nanotubes and Microencapsulated Phase Change Materials  

E-Print Network [OSTI]

The present research work aims to develop a new heat transfer fluid by combining multiwalled carbon nanotubes (MWCNT) and microencapsulated phase change materials (MPCMs). Stable nanofluids have been prepared using different sizes of multiwalled...

Tumuluri, Kalpana

2011-08-08T23:59:59.000Z

486

EIS-0302: Transfer of the Heat Source/Radioisotope Thermoelectric Generator Assembly and Test Operations From the Mound Site  

Broader source: Energy.gov [DOE]

This EIS analyzes DOE's proposed transfer of the Heat Source/Radioisotope Thermoelectric Generator (HS/RTG) operations at the Mound Site near Miamisburg, Ohio, to an alternative DOE site.

487

Turbulent heat transfer in a trapezoidal channel with transverse and v-shaped ribs on two opposite walls  

E-Print Network [OSTI]

This study investigates the turbulent heat transfer and friction in a trapezoidal channel with opposite walls roughened with transverse and v-shaped ribs. The roughened channel depicts the internal cooling passage of an aerofoil near the trailing...

Subramanian, Karthik

2006-04-12T23:59:59.000Z

488

IEA BESTEST In-Depth Diagnostic Cases for Ground Coupled Heat Transfer Related to Slab-on-Grade Construction: Preprint  

SciTech Connect (OSTI)

A set of validation test cases is presented to compare the results of midlevel detailed ground-coupled heat transfer models typically used with whole-building energy simulation software.

Neymark, J.; Judkoff, R.; Beausoleil-Morrison, I.; Ben-Nakhi, A.; Crowley, M.; Deru, M.; Henninger, R.; Ribberink, H.; Thornton, J.; Wijsman, A.; Witte, M.

2009-06-01T23:59:59.000Z

489

Design of an experimental loop for post-LOCA heat transfer regimes in a Gas-cooled Fast Reactor  

E-Print Network [OSTI]

The goal of this thesis is to design an experimental thermal-hydraulic loop capable of generating accurate, reliable data in various convection heat transfer regimes for use in the formulation of a comprehensive convection ...

Cochran, Peter A. (Peter Andrew)

2005-01-01T23:59:59.000Z

490

Thermal heat radiation, near-field energy density and near-field radiative heat transfer of coated materials  

E-Print Network [OSTI]

We investigate the thermal radiation and thermal near-field energy density of a metal-coated semi-infinite body for different substrates. We show that the surface polariton coupling within the metal coating leads to an enhancement of the TM-mode part of the thermal near-field energy density when a polar substrate is used. In this case the result obtained for a free standing metal film is retrieved. In contrast, in the case of a metal substrate there is no enhancement in the TM-mode part, as can also be explained within the framework of surface plasmon coupling within the coating. Finally, we discuss the influence of the enhanced thermal energy density on the near-field radiative heat transfer between a simple semi-infinite and a coated semi-infinite body for different material combinations.

Svend-Age Biehs

2011-03-15T23:59:59.000Z

491

BWR spent fuel storage cask performance test. Volume 1. Cask handling experience and decay heat, heat transfer, and shielding data  

SciTech Connect (OSTI)

This report documents a heat transfer and shielding performance test conducted on a Ridihalgh, Eggers and Associates REA 2023 boiling water reactor (BWR) spent fuel storage cask. The testing effort consisted of three parts: pretest preparations, performance testing, and post-test activities. Pretest preparations included conducting cask handling dry runs and characterizing BWR spent fuel assemblies from Nebraska Public Power District's Cooper Nuclear Station. The performance test matrix included 14 runs consisting of two loadings, two cask orientations, and three backfill environments. Post-test activities included calorimetry and axial radiation scans of selected fuel assemblies, in-basin sipping of each assembly, crud collection, video and photographic scans, and decontamination of the cask interior and exterior.

McKinnon, M.A.; Doman, J.W.; Tanner, J.E.; Guenther, R.J.; Creer, J.M.; King, C.E.

1986-02-01T23:59:59.000Z

492

Heat transfer and friction in a square channel with one-wall or two-wall rib turbulators  

E-Print Network [OSTI]

walls 83 66 Ribbed side Nusselt number ratio versus friction factor ratio for broken ribs on one wall 84 67 Smooth side Nusselt number ratio versus friction factor ratio for broken ribs on one wall . , 68 Ribbed side Nusselt number ratio versus... on one wall . 95 96 97 INTRODUCTION Early heat transfer study shows that roughening the surface is an effective way to enhance the heat transfer from a surface. Modern turbine design applies turbulence promoters/ribs inside cooling passages...

Huang, Jie Joy

1991-01-01T23:59:59.000Z

493

Aspect ratio effect on heat transfer in rotating two-pass rectangular channels with smooth walls and ribbed walls  

E-Print Network [OSTI]

buoyancy parameter, (?? /? )xRo2(Rx/Dh) Dh hydraulic diameter de diameter of coolant exit hole e rib height f friction factor fo fully developed friction factor in non-rotating smooth tube h heat transfer coefficient H channel height k...) . N. K. Anand (Member) . D. L. O?Neal (Head of Department) May 2005 Major Subject: Mechanical Engineering iii ABSTRACT Aspect Ratio Effect on Heat Transfer in Rotating Two...

Fu, Wen-Lung

2005-08-29T23:59:59.000Z

494

A parametric study of shock jump chemistry, electron temperature, and radiative heat transfer models in hypersonic flows  

E-Print Network [OSTI]

A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN GREENDYKE Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1988 Major Subject: Aerospace Engineering A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN...

Greendyke, Robert Brian

2012-06-07T23:59:59.000Z

495

Conceptual Design of Forced Convection Molten Salt Heat Transfer Testing Loop  

SciTech Connect (OSTI)

This report develops a proposal to design and construct a forced convection test loop. A detailed test plan will then be conducted to obtain data on heat transfer, thermodynamic, and corrosion characteristics of the molten salts and fluid-solid interaction. In particular, this report outlines an experimental research and development test plan. The most important initial requirement for heat transfer test of molten salt systems is the establishment of reference coolant materials to use in the experiments. An earlier report produced within the same project highlighted how thermophysical properties of the materials that directly impact the heat transfer behavior are strongly correlated to the composition and impurities concentration of the melt. It is therefore essential to establish laboratory techniques that can measure the melt composition, and to develop purification methods that would allow the production of large quantities of coolant with the desired purity. A companion report describes the options available to reach such objectives. In particular, that report outlines an experimental research and development test plan that would include following steps: •Molten Salts: The candidate molten salts for investigation will be selected. •Materials of Construction: Materials of construction for the test loop, heat exchangers, and fluid-solid corrosion tests in the test loop will also be selected. •Scaling Analysis: Scaling analysis to design the test loop will be performed. •Test Plan: A comprehensive test plan to include all the tests that are being planned in the short and long term time frame will be developed. •Design the Test Loop: The forced convection test loop will be designed including extensive mechanical design, instrument selection, data acquisition system, safety requirements, and related precautionary measures. •Fabricate the Test Loop. •Perform the Tests. •Uncertainty Analysis: As a part of the data collection, uncertainty analysis will be performed to develop probability of confidence in what is measured in the test loop. Overall, the testing loop will allow development of needed heat transfer related thermophysical parameters for all the salts, validate existing correlations, validate measuring instruments under harsh environment, and have extensive corrosion testing of materials of construction.

Manohar S. Sohal; Piyush Sabharwall; Pattrick Calderoni; Alan K. Wertsching; S. Brandon Grover

2010-09-01T23:59:59.000Z

496

Intraparticle heat and mass transfer characteristics of silica-gel/water vapor adsorption  

SciTech Connect (OSTI)

Recently, highly efficient energy utilization systems which extensively employ adsorption phenomena such as pressure swing adsorption, heat storage, adsorption heat pump, etc. are being regarded as one of the countermeasures for environmental issues such as green house effect and ozone layer destruction. An Adsorption Heat Pump (AHP) has been investigated as one of the important techniques via which cold heat energy is obtained from waste thermal energy below 373K without using electricity and CFCs. An AHP normally consists of an adsorber and an evaporator/condenser and cold heat energy is generated by latent heat of evaporation during adsorption process. For realizing the AHP technology, it has been pointed out that the development of an adsorber with optimum heat and mass transfer characteristics is essentially important. In this study, experimental studies were carried out which was based on the data of temperature inside the adsorbent particle and adsorptivity profiles at the adsorption/desorption process by volumetric method. To clarify adsorption mechanism relatively large silica-gel particle (7 mm f) was used. Temperature distribution in the particle is determined at the center, at one half radius in the radial direction and at the surface by using very thin (30 mm f) thermocouples. The temperatures at these points simultaneously increase/decrease as soon as the adsorption/desorption started, reached their respective maximum/minimum values and then return to initial temperature. The temperature profiles for the adsorption process show that the temperature at the surface is initially slightly higher than the other two points. All three points reached their respective maximum temperature at the same time with the temperature at the center point the highest and at the surface the lowest. The temperature profiles during the desorptive process are almost exactly the opposite to that of the adsorption process. This shows that the adsorption phenomena can take place not only at the surface but inside the adsorbent particle, implying that intraparticle vapor diffusion has a great influence on adsorptivity.

Yamamoto, Eri; Watanabe, Fujio; Hasatani, Masanobu

1999-07-01T23:59:59.000Z

497

Transient heat transfer in helium II due to a sudden vacuum break  

SciTech Connect (OSTI)

To ensure future cryogenic devices meet safety and operational specifications, significant value is gained from a developed understanding of the transient heat fluxes that result from failure of an insulating vacuum jacket around a helium II (He II)-cooled device. A novel, one-dimensional experiment is successfully performed examining the phenomena immediately following a vacuum rupture onto a cryosurface. In the experiment, a fast-opening (?10 ms) valve isolates a rigid container of ultra high purity nitrogen (N{sub 2}) gas kept at room temperature and adjustable pressure from a vertically oriented, highly evacuated (?10{sup ?3} Pa) tube roughly 1 m in length. The bottom of the evacuated tube is sealed via a 2.54 mm thick copper disk, whose bottom surface is in intimate contact with an open column of He II (?1.8 K). The evacuated tube, disk, and He II column share a diameter of 24 mm. Opening the valve results in a vacuum rupture. N{sub 2} gas is immediately drawn into the evacuated space and cryopumped onto the disk as a growing layer of solid cryodeposit. Various coupled transient heat transfer processes proceed as the internal energy of the warm gas is transferred through the growing layer of solid N{sub 2}, through the copper disk, and into the He II column. This work examines the qualitative nature of these transient phenomena and the magnitude of the heat fluxes present through each of the series of thermal resistances.

Bosque, Ernesto S.; Dhuley, Ram C.; Van Sciver, Steven W. [National High Magnetic Field Laboratory, Tallahassee, FL 32310, USA and FAMU-FSU College of Engineering, Tallahassee, FL 32310 (United States)

2014-01-29T23:59:59.000Z

498

Turbulent heat transfer in parallel flow boundary layers with streamwise step changes in surface conditions  

SciTech Connect (OSTI)

This paper examines the convective heat/mass transfer behavior of a turbulent boundary layer with parallel streamlines. The most notable example of such flow is an atmospheric boundary layer with a steady mean wind in the absence of topography. The classic, two-dimensional problem involves the surface boundary condition of a finite-length step change in temperature/concentration in the streamwise direction of an atmospheric flow. In the literature on geophysical evapotranspiration, this problem is known as Sutton's problem (cf. Sutton, 1934, and Brutsaert, 1984). This flow situation is equally applicable to heat/mass transfer in solar ponds, ground solar collectors, and heated roadways, as examples. The present note revisits the Sutton problem, with the can Driest eddy diffusivity model, and expands the types of boundary conditions that are examined to include surface changes in temperature/concentration and fluxes. The parallel streamline condition allows for Graetz-type solutions, with boundary conditions at the surface and in the far flow field. The predicted results are presented as a series of power law correlations of the relevant nondimensional parameters.

Lindberg, W.R.; Lee, R.C.; Smathers, L.B. (Univ. of Wyoming, Laramie (United States))

1989-11-01T23:59:59.000Z

499

Natural convection heat transfer from a plate in a semicircular enclosure  

SciTech Connect (OSTI)

The present paper is about characterizing the two-dimensional convective transfer across the air-filled region between a flat plate and a semicircular cylindrical enclosure. In the subject geometry, a long thin plate at uniform temperature is contained coaxially and symmetrically in a long semicircular trough closed at the top and having a uniform but different temperature. Heat flows across the air-filled region between the two by both natural convection and gaseous conduction. The problem of characterizing the free convective component of this heat transfer - that is, the component caused by bulk fluid motion - is treated experimentally by using a heat balance technique, with the measurements being repeated at different pressures, in order to cover a wide Rayleigh number range, from Ra {approximately} 10 to Ra {approximately} 10{sup 8}. Nusselt number versus Rayleigh number plots are presented for each of several combinations of plate-to-trough spacing and tilt angle, and the plots are correlated by equations. The problem of characterizing the conductive component is treated by numerically solving the steady diffusion equation in the air-filled region, and the results are correlated as a function of the spacing and the plate thickness.

Moore, G.A.; Hollands, K.G.T. (Univ. of Waterloo, Ontario (Canada))

1992-02-01T23:59:59.000Z

500

Experimental investigation on heat transfer and frictional characteristics of vertical upward rifled tube in supercritical CFB boiler  

SciTech Connect (OSTI)

Water wall design is a key issue for supercritical Circulating Fluidized Bed (CFB) boiler. On account of the good heat transfer performance, rifled tube is applied in the water wall design of a 600 MW supercritical CFB boiler in China. In order to investigate the heat transfer and frictional characteristics of the rifled tube with vertical upward flow, an in-depth experiment was conducted in the range of pressure from 12 to 30 MPa, mass flux from 230 to 1200 kg/(m{sup 2} s), and inner wall heat flux from 130 to 720 kW/m{sup 2}. The wall temperature distribution and pressure drop in the rifled tube were obtained in the experiment. The normal, enhanced and deteriorated heat transfer characteristics were also captured. In this paper, the effects of pressure, inner wall heat flux and mass flux on heat transfer characteristics are analyzed, the heat transfer mechanism and the frictional resistance performance are discussed, and the corresponding empirical correlations are presented. The experimental results show that the rifled tube can effectively prevent the occurrence of departure from nucleate boiling (DNB) and keep the tube wall temperature in a permissible range under the operating condition of supercritical CFB boiler. (author)

Yang, Dong; Pan, Jie; Zhu, Xiaojing; Bi, Qincheng; Chen, Tingkuan [State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049 (China); Zhou, Chenn Q. [Department of Mechanical Engineering, Purdue University Calumet, Hammond, IN 46323 (United States)

2011-02-15T23:59:59.000Z