Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
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. ,
Radiative heat transfer in porous uranium dioxide
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
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.
Radiative heat transfer between dielectric bodies
Svend-Age Biehs
2011-03-16T23:59:59.000Z
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.
Radiative Heat Transfer between Neighboring Particles
Alejandro Manjavacas; F. Javier Garcia de Abajo
2012-01-26T23:59:59.000Z
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.
RADIATIVE HEAT TRANSFER WITH QUASI-MONTE CARLO METHODS
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
RADIATIVE HEAT TRANSFER WITH QUASIMONTE CARLO METHODS \\Lambda
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
Enhanced radiative heat transfer between nanostructured gold plates
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
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.
Small distance expansion for radiative heat transfer between curved objects
Golyk, Vladyslav A.
We develop a small distance expansion for the radiative heat transfer between gently curved objects, in terms of the ratio of distance to radius of curvature. A gradient expansion allows us to go beyond the lowest-order ...
Giant radiation heat transfer through the micron gaps
Nefedov, Igor
2011-01-01T23:59:59.000Z
Near-field heat transfer between two closely spaced radiating media can exceed in orders radiation through the interface of a single black body. This effect is caused by exponentially decaying (evanescent) waves which form the photon tunnel between two transparent boundaries. However, in the mid-infrared range it holds when the gap between two media is as small as few tens of nanometers. We propose a new paradigm of the radiation heat transfer which makes possible the strong photon tunneling for micron thick gaps. For it the air gap between two media should be modified, so that evanescent waves are transformed inside it into propagating ones. This modification is achievable using a metamaterial so that the direct thermal conductance through the metamaterial is practically absent and the photovoltaic conversion of the transferred heat is not altered by the metamaterial.
Radiative heat transfer in a hydrous mantle transition zone Sylvia-Monique Thomas a,n
Jacobsen, Steven D.
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
Radiative heat transfer in 2D Dirac materials
Pablo Rodriguez-Lopez; Wang-Kong Tse; Diego A. R. Dalvit
2015-02-02T23:59:59.000Z
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.
Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application
New York at Stoney Brook, State University of
the parallelization of the radiative heat transfer model introduced by Naraghi and Nunes of Manhattan College [8
Radiative heat transfer at nanoscale mediated by surface plasmons for highly doped Emmanuel Rousseau
Paris-Sud XI, Université de
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
Heat transfer through a water spray curtain under the effect of a strong radiative source
Paris-Sud XI, Université de
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
Near field radiative heat transfer between two nonlocal dielectrics
Singer, F; Joulain, Karl
2015-01-01T23:59:59.000Z
We explore in the present work the near-field radiative heat transfer between two semi-infinite parallel nonlocal dielectric planes by means of fluctuational electrodynamics. We use atheory for the nonlocal dielectric permittivityfunction proposed byHalevi and Fuchs. This theory has the advantage to includedifferent models performed in the literature. According to this theory, the nonlocal dielectric function is described by a Lorenz-Drude like single oscillator model, in which the spatial dispersion effects are represented by an additional term depending on the square of the total wavevector k. The theory takes into account the scattering of the electromagneticexcitation at the surface of the dielectric material, which leads to the need of additional boundary conditions in order to solve Maxwell's equations and treat the electromagnetic transmission problem. The additional boundary conditions appear as additional surface scattering parameters in the expressions of the surface impedances. It is shown that the...
Radiative heat transfer in anisotropic many-body systems: Tuning and enhancement
Nikbakht, Moladad, E-mail: mnik@znu.ac.ir [Department of Physics, Faculty of Sciences, University of Zanjan, Zanjan 45371-38791 (Iran, Islamic Republic of)
2014-09-07T23:59:59.000Z
A general formalism for calculating the radiative heat transfer in many body systems with anisotropic component is presented. Our scheme extends the theory of radiative heat transfer in isotropic many body systems to anisotropic cases. In addition, the radiative heating of the particles by the thermal bath is taken into account in our formula. It is shown that the radiative heat exchange (HE) between anisotropic particles and their radiative cooling/heating (RCH) could be enhanced several order of magnitude than that of isotropic particles. Furthermore, we demonstrate that both the HE and RCH can be tuned dramatically by particles relative orientation in many body systems.
Radiative Heat Transfer Analysis of Fibrous Insulation Materials Using the ZonalGEF Method
Yuen, Walter W.
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
RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS
Guo, Zhixiong "James"
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
Glass foams: formation, transport properties, and heat, mass, and radiation transfer
Pilon, Laurent
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
Influence of Infrared Radiation on Attic Heat Transfer
Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.
1985-01-01T23:59:59.000Z
An experimental study concerned with different modes of heal transfer in fibrous and cellulose insulating material is presented. A series of experiments were conducted using an attic simulator to determine the effects of ventilation on attic heat...
HEAT AND MOISTURE TRANSFER THROUGH CLOTHING
Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie
2009-01-01T23:59:59.000Z
R. C. Eberhart (ed), Heat transfer in medicine and biology.between convective heat transfer and mass transferConvective and radiative heat transfer coefficients for
Heat and moisture transfer through clothing
Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie
2009-01-01T23:59:59.000Z
R. C. Eberhart (ed), Heat transfer in medicine and biology.Convective and radiative heat transfer coefficients forbetween convective heat transfer and mass transfer
Radiative component and combined heat transfer in the thermal calculation of finned tube banks
Stehlik, P. [Technical Univ. of Brno (Czech Republic). Dept. of Process Engineering] [Technical Univ. of Brno (Czech Republic). Dept. of Process Engineering
1999-01-01T23:59:59.000Z
For more exact calculation of combined heat transfer in the case of finned tube banks (e.g., in the convective section of a furnace), the radiative heat transfer cannot be neglected. A new method for relatively simple calculation of total heat flux (convection + radiation + conduction in fins) is fully compatible with that for bare tube banks/bundles developed earlier. It is based on the method of radiative coefficients. However, the resulting value of heat flux must be corrected due to fin thickness and especially due to the fin radiative influence. For this purpose the so-called multiplicator of heat flux was introduced. The applicability of this methods has been demonstrated on a tubular fired heater convective section. A developed computer program based on the method has also been used for an analysis of the influence of selected parameters to show the share of radiation on the total heat flux.
Investigation of spectral radiation heat transfer and NO{sub x} emission in a glass furnace
Golchert, B.; Zhou, C. Q.; Chang, S. L.; Petrick, M.
2000-08-02T23:59:59.000Z
A comprehensive radiation heat transfer model and a reduced NOx kinetics model were coupled with a computational fluid dynamics (CFD) code and then used to investigate the radiation heat transfer, pollutant formation and flow characteristics in a glass furnace. The radiation model solves the spectral radiative transport equation in the combustion space of emitting and absorbing media, i.e., CO{sub 2}, H{sub 2}O, and soot and emission/reflection from the furnace crown. The advanced numerical scheme for calculating the radiation heat transfer is extremely effective in conserving energy between radiation emission and absorption. A parametric study was conducted to investigate the impact of operating conditions on the furnace performance with emphasis on the investigation into the formation of NOx.
Graphene-assisted near-field radiative heat transfer between corrugated polar materials
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
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.
Effective-medium model of wire metamaterials in the problems of radiative heat transfer
Mirmoosa, M. S., E-mail: mohammad.mirmoosa@aalto.fi; Nefedov, I. S., E-mail: igor.nefedov@aalto.fi; Simovski, C. R., E-mail: konstantin.simovski@aalto.fi [Department of Radio Science and Engineering, School of Electrical Engineering, Aalto University, P. O. Box 13000, 00076 Aalto (Finland); Rüting, F., E-mail: felix.ruting@uam.es [Departamento de Física Teorica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autonoma de Madrid, E-28049 (Spain)
2014-06-21T23:59:59.000Z
In the present work, we check the applicability of the effective medium model (EMM) to the problems of radiative heat transfer (RHT) through so-called wire metamaterials (WMMs)—composites comprising parallel arrays of metal nanowires. It is explained why this problem is so important for the development of prospective thermophotovoltaic (TPV) systems. Previous studies of the applicability of EMM for WMMs were targeted by the imaging applications of WMMs. The analogous study referring to the transfer of radiative heat is a separate problem that deserves extended investigations. We show that WMMs with practically realizable design parameters transmit the radiative heat as effectively homogeneous media. Existing EMM is an adequate tool for qualitative prediction of the magnitude of transferred radiative heat and of its effective frequency band.
Paris-Sud XI, Université de
-cooled reactor. It is typically made of many prismatic blocks of graphite in which are inserted the nuclear fuel in the homogenization of heat transfer in periodic porous media where the fluid part is made of long thin parallel in the solid part of the domain and by conduction, convection and radiative transfer in the fluid part (the
The effect of the number of wavebands used in spectral radiation heat transfer calculations
Chang, S. L.; Golchert, B.; Petrick, M.
2000-05-09T23:59:59.000Z
A spectral radiation heat transfer model that conserves emitted and absorbed energy has been developed and used to model the combustion space of an industrial glass furnace. This comprehensive radiation heat transfer model coupled with a computational fluid dynamics (CFD) code was used to investigate the effect of spectral dependencies on the computed results. The results of this work clearly indicate the need for a spectral approach as opposed to a gray body approach since the gray body approach (one waveband) severely underestimates the energy emitted via radiation.
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
slabs. Moreover, the total heat input during furnace heatingperformed for the same heat input. The optical propertiesheating for the same total heat input. Similarly, Figure 7
A convective-radiative heat transfer model for gas core reactors
Chen, G.; Anghaie, S. [Univ. of Florida, Gainesville, FL (United States)
1995-12-31T23:59:59.000Z
A convective-radiative heat transfer model is developed and used to predict the temperature distribution in gaseous fuel nuclear reactor cores. The axisymmetric, thin layer Navier-Stokes equations with diffusive radiation source term are the basis for this modeling approach. An algebraic turbulence model is used to calculate the eddy viscosity. The Rosseland diffusion approximation is used to model the radiative heat transfer. A hybrid implicit-explicit numerical scheme with Gauss-Seidel iterative process and a highly stretched grid system near wall is employed to solve the governing equations. Several cases with different internal heat generation rates are modeled and analyzed. Results of the temperature distribution, wall heat flux and the associated Nusselt number are presented. The influence of the internal heat generation rate and the wall temperature on the radiative and convective wall heat fluxes are discussed. At gas and wall temperatures close to 3,500 K and 1,600 K, respectively, the radiative and convective heat transfer rates have similar values.
Heat transfer including radiation and slag particles evolution in MHD channel-I
Im, K.H.; Ahluwalia, R.K.
1980-01-01T23:59:59.000Z
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.
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
by a heating lamp emitting in the visible and near infraredwith heating in a furnace at 400 o C. The infrared lamp was
Svend-Age Biehs
2011-03-15T23:59:59.000Z
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.
Nonlocal study of the near field radiative heat transfer between two n-doped semiconductors
Singer, F; Joulain, Karl
2015-01-01T23:59:59.000Z
We study in this work the near-field radiative heat transfer between two semi-infinite parallel planes of highly n-doped semiconductors. Using a nonlocal model of the dielectric permittivity, usually used for the case of metallic planes, we show that the radiative heat transfer coefficientsaturates as the separation distance is reduced for high doping concentration. These results replace the 1/d${}^2$ infinite divergence obtained in the local model case. Different features of the obtained results are shown to relate physically to the parameters of the materials, mainly the doping concentration and the plasmon frequency.
Radiative heat transfer in a parallelogram shaped cavity
Dez, V Le
2015-01-01T23:59:59.000Z
An exact analytical description of the internal radiative field inside an emitting-absorbing gray semi-transparent medium enclosed in a two-dimensional parallelogram cavity is proposed. The expressions of the incident radiation and the radiative flux field are angularly and spatially discretized with a double Gauss quadrature, and the temperature field is obtained by using an iterative process. Some numerical solutions are tabulated and graphically presented as the benchmark solutions. Temperature and two components of the radiative flux are finally sketched on the whole domain. It is shown that the proposed method gives perfectly smooth results.
Liberman, M A; Kiverin, A D
2015-01-01T23:59:59.000Z
In this study we examine influence of the radiation heat transfer on the combustion regimes in the mixture, formed by suspension of fine inert particles in hydrogen gas. The gaseous phase is assumed to be transparent for the thermal radiation, while the radiant heat absorbed by the particles is then lost by conduction to the surrounding gas. The particles and gas ahead of the flame is assumed to be heated by radiation from the original flame. It is shown that the maximum temperature increase due to the radiation preheating becomes larger for a flame with lower velocity. For a flame with small enough velocity temperature of the radiation preheating may exceed the crossover temperature, so that the radiation heat transfer may become a dominant mechanism of the flame propagation. In the case of non-uniform distribution of particles, the temperature gradient formed due to the radiation preheating can initiate either deflagration or detonation ahead of the original flame via the Zel'dovich's gradient mechanism. Th...
Author's personal copy Radiative heat transfer in enhanced hydrogen
Pilon, Laurent
the physical mechanisms responsible for experimental observations that led to the definition of ``photo 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
Influence of Infrared Radiation on Attic Heat Transfer
Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.
1985-01-01T23:59:59.000Z
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...
Boyer, Edmond
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
Shape-independent limits to near-field radiative heat transfer
Miller, Owen D; Rodriguez, Alejandro W
2015-01-01T23:59:59.000Z
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...
Effect of radiative heat transfer on the coagulation dynamics of combustion-generated particles
Mackowski, D.W. (Auburn Univ., AL (United States)); Tassopoulos, M.; Rosner, D.E. (Yale Univ., New Haven, CT (United States))
1994-01-01T23:59:59.000Z
We examine the influences of radiation heat transfer on the size and number density evolution of small coagulating particles. On a microscopic level, radiative emission and/or absorption by the particle will perturb the gas temperature field adjacent to each particle. As a result of thermophoretic particle transport, the nonequilibrium condition can alter the collision rates with neighboring particles. A simplified analysis of the thermophoretic coagulation mechanism suggests that net radiative cooling of the particles can lead to an accelerated growth of [mu]m-sized particles, whereas net radiative heating can act to essentially freeze coagulation rates. On the macroscopic level, the addition or removal of heat in the gas through radiative absorption emission by the particle cloud can also significantly alter, through thermophoretic transport, the local particle number density. Under certain cases these effects can augment the accelerated coagulation rates that occur under radiative cooling conditions. We also examine the particular situation of equilibrium between particle cloud radiative absorption and emission - which results in no net macroscopic effect on the gas. 30 refs., 9 figs.
Greendyke, Robert Brian
1988-01-01T23:59:59.000Z
will examine the radiance model and various step models in order to determine their appropriateness to the flight regime of the AOTV. The final area to be investigated will be the effect of nonequilibrium corrections on the radiative heat transfer models... of T and e T will be valid as long as there is a reasonable amount vNs of nitrogen molecules in the flow. Radiative Heat Transfer Models For this study, four radiative heat transfer models were examined. One of these models is an optically thin radiance...
Greendyke, Robert Brian
1988-01-01T23:59:59.000Z
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...
Radiative heat transfer between two dielectric nanogratings in the scattering approach
J. Lussange; R. Guérout; F. S. S. Rosa; J. -J. Greffet; A. Lambrecht; S. Reynaud
2012-06-01T23:59:59.000Z
We present a theoretical study of radiative heat transfer between dielectric nanogratings in the scattering approach. As a comparision with these exact results, we also evaluate the domain of validity of Derjaguin's Proximity Approximation (PA). We consider a system of two corrugated silica plates with various grating geometries, separation distances, and lateral displacement of the plates with respect to one another. Numerical computations show that while the PA is a good approximation for aligned gratings, it cannot be used when the gratings are laterally displaced. We illustrate this by a thermal modulator device for nanosystems based on such a displacement.
RADIATION HEAT TRANSFER ENVIRONMENT IN FIRE AND FURNACE TESTS OF RADIOACTIVE MATERIALS PAKCAGES
Smith, A
2008-12-31T23:59:59.000Z
The Hypothetical Accident Conditions (HAC) sequential test of radioactive materials packages includes a thermal test to confirm the ability of the package to withstand a transportation fire event. The test specified by the regulations (10 CFR 71) consists of a 30 minute, all engulfing, hydrocarbon fuel fire, with an average flame temperature of at least 800 C. The requirements specify an average emissivity for the fire of at least 0.9, which implies an essentially black radiation environment. Alternate test which provide equivalent total heat input at the 800 C time averaged environmental temperature may also be employed. When alternate tests methods are employed, such as furnace or gaseous fuel fires, the equivalence of the radiation environment may require justification. The effects of furnace and open confinement fire environments are compared with the regulatory fire environment, including the effects of gases resulting from decomposition of package overpack materials. The results indicate that furnace tests can produce the required radiation heat transfer environment, i.e., equivalent to the postulated pool fire. An open enclosure, with transparent (low emissivity) fire does not produce an equivalent radiation environment.
Joulain, Karl; Drevillon, Jeremie; Ben-Abdallah, Philippe
2015-01-01T23:59:59.000Z
We show in this article that phase change materials (PCM) exhibiting a phase transition between a dielectric state and a metallic state are good candidates to perform modulation as well as amplification of radiative thermal flux. We propose a simple situation in plane parallel geometry where a so-called radiative thermal transistor could be achieved. In this configuration, we put a PCM between two blackbodies at different temperatures. We show that the transistor effect can be achieved easily when this material has its critical temperature between the two blackbody temperatures. We also see, that the more the material is reflective in the metallic state, the more switching effect is realized whereas the more PCM transition is stiff in temperature, the more thermal amplification is high. We finally take the example of VO2 that exhibits an insulator-metallic transition at 68{\\textdegree}C. We show that a demonstrator of a radiative transistor could easily be achieved in view of the heat flux levels predicted. F...
Radiation heat transfer in multitube, alkaline-metal thermal-to-electric converter
Tournier, J.M.P.; El-Genk, M.S. [Univ. of New Mexico, Albuquerque, NM (United States)
1999-02-01T23:59:59.000Z
Vapor anode, multitube Alkali-Metal Thermal-to-Electric Converters (AMTECs) are being considered for a number of space missions, such as the NASA Pluto/Express (PX) and Europa missions, scheduled for the years 2004 and 2005, respectively. These static converters can achieve a high fraction of Carnot efficiency at relatively low operating temperatures. An optimized cell can potentially provide a conversion efficiency between 20 and 30 percent, when operated at a hot-side temperature of 1000--1200 K and a cold-side temperature of 550--650 K. A comprehensive modeling and testing program of vapor anode, multitube AMTEC cells has been underway for more than three years at the Air Force Research Laboratory`s Power and Thermal Group (AFRL/VSDVP), jointly with the University of New Mexico`s Institute for Space and Nuclear Power Studies. The objective of this program is to demonstrate the readiness of AMTECs for flight on future US Air Force space missions. A fast, integrated AMTEC Performance and Evaluation Analysis Model (APEAM) has been developed to support ongoing vacuum tests at AFRL and perform analyses and investigate potential design changes to improve the PX-cell performance. This model consists of three major components (Tournier and El-Genk 1998a, b): (a) a sodium vapor pressure loss model, which describes continuum, transition and free-molecule flow regimes in the low-pressure cavity of the cell; (b) an electrochemical and electrical circuit model; and (c) a radiation/conduction heat transfer model, for calculating parasitic heat losses. This Technical Note describes the methodology used to calculate the radiation view factors within the enclosure of the PX-cells, and the numerical procedure developed in this work to determine the radiation heat transport and temperatures within the cell cavity.
Lee, K.H.; Lee, J.S.; Choi, M. [Seoul National Univ. (Korea, Republic of). Dept. of Mechanical Engineering
1996-02-09T23:59:59.000Z
In the outside vapor deposition (OVD) process, silica particles are deposited by thermophoretic force on the surface of a cylinder. This process is associated with complex physical phenomena such as heat transfer between a torch and a cylinder, chemical reaction for silica particle formation, and particle deposition. Since the OVD process is carried out in a very high temperature environment, radiative heat transfer should be taken into consideration. Here, the radiative-convective heat transfer around a circular cylinder in a cross flow of a radiating gas has been numerically analyzed using the finite volume radiation solution method in a nonorthogonal coordinate system. The cross-flow Reynolds number based on the cylinder diameter is 40, and the fluid Prandtl number is assumed to be 0.7. The radiative heat transfer coupled with convection is reasonably predicted by the finite volume radiation solution method. Distributions of the local Nusselt number are investigated according to the variation of radiation parameters such as conduction-to-radiation parameter, optical thickness, scattering albedo, and cylinder wall emissivity.
Development of a Heat Transfer Model for the Integrated Facade Heating
Gong, X.; Archer, D. H.; Claridge, D. E.
2007-01-01T23:59:59.000Z
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...
Development of a Heat Transfer Model for the Integrated Facade Heating
Gong, X.; Archer, D. H.; Claridge, D. E.
2007-01-01T23:59:59.000Z
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...
McCauley, Alexander P; Krüger, Matthias; Johnson, Steven G
2011-01-01T23:59:59.000Z
We examine the non-equilibrium radiative heat transfer between a plate and finite cylinders and cones, making the first accurate theoretical predictions for the total heat transfer and the spatial heat flux profile for three-dimensional compact objects including corners or tips. We find qualitatively different scaling laws for conical shapes at small separations, and in contrast to a flat/slightly-curved object, a sharp cone exhibits a local \\emph{minimum} in the spatially resolved heat flux directly below the tip. The method we develop, in which a scattering-theory formulation of thermal transfer is combined with a boundary-element method for computing scattering matrices, can be applied to three-dimensional objects of arbitrary shape.
Lenert, Andrej
2012-01-01T23:59:59.000Z
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 ...
Kandlikar, Satish
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
Multigroup half space moment approximations to the radiative heat transfer equations q
Coudičre, Yves
cooling) over astrophysics to combustion (e.g., in gas turbine combustion chambers). Since radiative heat into direction l 2 ˝Ŕ1; 1. Furthermore, T đx; tŢ is the material temperature. The heat conductivity is denoted with the following boundary conditions. For the material temper
Heat transfer pathways in underfloor air distribution (UFAD) systems
Bauman, F.; Jin, H.; Webster, T.
2006-01-01T23:59:59.000Z
is little radiative heat transfer and little impact on thereturn air extrac- tion and heat transfer to the plenum. ItUFAD is often used and heat transfer out of the room through
Gustavsen, Arild
2009-01-01T23:59:59.000Z
free convection. In: Heat Transfer and Turbulent Buoyantof convection heat transfer and develop correlations.and radiation heat transfer and develop correlations for
Moncada-Villa, Edwin; Garcia-Vidal, Francisco J; Garcia-Martin, Antonio; Cuevas, Juan Carlos
2015-01-01T23:59:59.000Z
We present a comprehensive theoretical study of the magnetic field dependence of the near-field radiative heat transfer (NFRHT) between two parallel plates. We show that when the plates are made of doped semiconductors, the near-field thermal radiation can be severely affected by the application of a static magnetic field. We find that irrespective of its direction, the presence of a magnetic field reduces the radiative heat conductance, and dramatic reductions up to 700% can be found with fields of about 6 T at room temperature. We show that this striking behavior is due to the fact that the magnetic field radically changes the nature of the NFRHT. The field not only affects the electromagnetic surface waves (both plasmons and phonon polaritons) that normally dominate the near-field radiation in doped semiconductors, but it also induces hyperbolic modes that progressively dominate the heat transfer as the field increases. In particular, we show that when the field is perpendicular to the plates, the semicond...
PARALLEL COMPUTATIONS OF RADIATIVE HEAT TRANSFER USING THE DISCRETE ORDINATES METHOD
Utah, University of
of the important radiatively active species (CO2, H2O, soot) and temperature, which are calculated on the spatially increasingly tractable. Issues relating to the use of high-performance computing in participating media heat properties. First we summarize previous applications of spatial decomposition strategies to finite
Enhanced heat transfer for thermionic power modules
Johnson, D.C.
1981-07-01T23:59:59.000Z
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.
Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference
Guo, Zhixiong "James"
-dependent radiation and conduction bio-heat transfer model. Ultrashort pulsed radiation transport in the cylindrical a combined transient heat transfer and Pennes bio-heat transfer model is developed to simulate the heat transfer models; and concluded that the Pennes model is still the most practical for fast prediction
Smart, John P.; Patel, Rajeshriben; Riley, Gerry S. [RWEnpower, Windmill Hill Business Park, Whitehill Way, Swindon, Wiltshire SN5 6PB, England (United Kingdom)
2010-12-15T23:59:59.000Z
This paper focuses on results of co-firing coal and biomass under oxy-fuel combustion conditions on the RWEn 0.5 MWt Combustion Test Facility (CTF). Results are presented of radiative and convective heat transfer and burnout measurements. Two coals were fired: a South African coal and a Russian Coal under air and oxy-fuel firing conditions. The two coals were also co-fired with Shea Meal at a co-firing mass fraction of 20%. Shea Meal was also co-fired at a mass fraction of 40% and sawdust at 20% with the Russian Coal. An IFRF Aerodynamically Air Staged Burner (AASB) was used. The thermal input was maintained at 0.5 MWt for all conditions studied. The test matrix comprised of varying the Recycle Ratio (RR) between 65% and 75% and furnace exit O{sub 2} was maintained at 3%. Carbon-in-ash samples for burnout determination were also taken. Results show that the highest peak radiative heat flux and highest flame luminosity corresponded to the lowest recycle ratio. The effect of co-firing of biomass resulted in lower radiative heat fluxes for corresponding recycle ratios. Furthermore, the highest levels of radiative heat flux corresponded to the lowest convective heat flux. Results are compared to air firing and the air equivalent radiative and convective heat fluxes are fuel type dependent. Reasons for these differences are discussed in the main text. Burnout improves with biomass co-firing under both air and oxy-fuel firing conditions and burnout is also seen to improve under oxy-fuel firing conditions compared to air. (author)
Ganapathy, V.
1982-01-01T23:59:59.000Z
Heat transfer principles are discussed with emphasis on the practical aspects of the problems. Correlations for heat transfer and pressure drop from several worldwide sources for flow inside and outside of tubes, including finned tubes are presented, along with design and performance calculations of heat exchangers economizers, air heaters, condensers, waste-heat boilers, fired heaters, superheaters, and boiler furnaces. Vibration analysis for tube bundles and heat exchangers are also discussed, as are estimating gas-mixture properties at atmospheric and elevated pressures and life-cycle costing techniques. (JMT)
The radiative heat transfer between a rotating nanoparticle and a plane surface
Vahid Ameri; Mehdi Shafei Aporvari; Fardin Kheirandish
2015-06-03T23:59:59.000Z
Based on a microscopic approach, we propose a Lagrangian for the combined system of a rotating dielectric nanoparticle above a plane surface in the presence of electromagnetic vacuum fluctuations. In the framework of canonical quantization, the electromagnetic vacuum field is quantized in the presence of dielectric fields describing the nanoparticle and a semi-infinite dielectric with planar interface. The radiative heat power absorbed by the rotating nanoparticle is obtained and the result is in agreement with previous results when the the rotational frequency of the nanoparticle is zero or much smaller than the relaxation frequency of the dielectrics. The well known near field effect is reexamined and discussed in terms of the rotational frequency. The radiative heat power absorbed by the nanoparticle for well-known peak frequencies, is plotted in terms of the rotational frequency showing an interesting effect resembling a phase transition around a critical frequency, determined by the relaxation frequency of the dielectrics.
ME 339 Heat Transfer ABET EC2000 syllabus
Ben-Yakar, Adela
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
Gritzo, L.A.; Skocypec, R.D. [Sandia National Labs., Albuquerque, NM (United States); Tong, T.W. [Arizona State Univ., Tempe, AZ (United States). Dept. of Mechanical and Aerospace Engineering
1995-01-11T23:59:59.000Z
Radiation in participating media is an important transport mechanism in many physical systems. The simulation of complex radiative transfer has not effectively exploited high-performance computing capabilities. In response to this need, a workshop attended by members active in the high-performance computing community, members active in the radiative transfer community, and members from closely related fields was held to identify how high-performance computing can be used effectively to solve the transport equation and advance the state-of-the-art in simulating radiative heat transfer. This workshop was held on March 29-30, 1994 in Albuquerque, New Mexico and was conducted by Sandia National Laboratories. The objectives of this workshop were to provide a vehicle to stimulate interest and new research directions within the two communities to exploit the advantages of high-performance computing for solving complex radiative heat transfer problems that are otherwise intractable.
Faculty Positions Heat Transfer and
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
Cooperative heat transfer and ground coupled storage system
Metz, Philip D. (Rocky Point, NY)
1982-01-01T23:59:59.000Z
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.
Eryou, N. Dennis
1969-01-01T23:59:59.000Z
One dimensional temperature profiles and heat fluxes within a slab of molten glass were measured experimentally. The glass slab was contained in a platinum foil lined ceramic tray inside a high temperature furnace. An ...
Urban Sewage Delivery Heat Transfer System (2): Heat Transfer
Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.
2006-01-01T23:59:59.000Z
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...
Urban Sewage Delivery Heat Transfer System (2): Heat Transfer
Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.
2006-01-01T23:59:59.000Z
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...
Order Reduction of the Radiative Heat Transfer Model for the Simulation of Plasma Arcs
Fagiano, Lorenzo
2015-01-01T23:59:59.000Z
An approach to derive low-complexity models describing thermal radiation for the sake of simulating the behavior of electric arcs in switchgear systems is presented. The idea is to approximate the (high dimensional) full-order equations, modeling the propagation of the radiated intensity in space, with a model of much lower dimension, whose parameters are identified by means of nonlinear system identification techniques. The low-order model preserves the main structural aspects of the full-order one, and its parameters can be straightforwardly used in arc simulation tools based on computational fluid dynamics. In particular, the model parameters can be used together with the common approaches to resolve radiation in magnetohydrodynamic simulations, including the discrete-ordinate method, the P-N methods and photohydrodynamics. The proposed order reduction approach is able to systematically compute the partitioning of the electromagnetic spectrum in frequency bands, and the related absorption coefficients, tha...
Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff
2006-10-10T23:59:59.000Z
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.
Ko, Min Seok
2009-05-15T23:59:59.000Z
? =0.1, 0.2, and 0.4) and scattering albedo ( ?=0, 0.25, 0.5, 0.75 and 1). Variation of thermophysical properties with temperature was considered in this study. In this work consideration was given only to cooling. Effects of those radiative...
asme heat transfer: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
fundamental laws of heat transfer (conduction, convection and radiation) and give useful data specific to cryogenic conditions (thermal contact resistance, total emissivity of...
Heat Transfer between Graphene and Amorphous SiO2
B. N. J. Persson; H. Ueba
2010-07-22T23:59:59.000Z
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.
Three Dimensional Radiative Transfer
Tom Abel
2000-05-09T23:59:59.000Z
Radiative Transfer (RT) effects play a crucial role in the thermal history of the intergalactic medium. Here I discuss recent advances in the development of numerical methods that introduce RT to cosmological hydrodynamics. These methods can also readily be applied to time dependent problems on interstellar and galactic scales.
Virginia Tech
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
Siewert, Charles E.
-grey heat transfer model is that of SIMMONS and FERZIGER(~)who used the normal modes(4) of the equation
Radiation detector system having heat pipe based cooling
Iwanczyk, Jan S.; Saveliev, Valeri D.; Barkan, Shaul
2006-10-31T23:59:59.000Z
A radiation detector system having a heat pipe based cooling. The radiation detector system includes a radiation detector thermally coupled to a thermo electric cooler (TEC). The TEC cools down the radiation detector, whereby heat is generated by the TEC. A heat removal device dissipates the heat generated by the TEC to surrounding environment. A heat pipe has a first end thermally coupled to the TEC to receive the heat generated by the TEC, and a second end thermally coupled to the heat removal device. The heat pipe transfers the heat generated by the TEC from the first end to the second end to be removed by the heat removal device.
General Relativistic Radiative Transfer
S. Knop; P. H. Hauschildt; E. Baron
2006-11-30T23:59:59.000Z
We present a general method to calculate radiative transfer including scattering in the continuum as well as in lines in spherically symmetric systems that are influenced by the effects of general relativity (GR). We utilize a comoving wavelength ansatz that allows to resolve spectral lines throughout the atmosphere. The used numerical solution is an operator splitting (OS) technique that uses a characteristic formal solution. The bending of photon paths and the wavelength shifts due to the effects of GR are fully taken into account, as is the treatment of image generation in a curved spacetime. We describe the algorithm we use and demonstrate the effects of GR on the radiative transport of a two level atom line in a neutron star like atmosphere for various combinations of continuous and line scattering coefficients. In addition, we present grey continuum models and discuss the effects of different scattering albedos on the emergent spectra and the determination of effective temperatures and radii of neutron star atmospheres.
Âdifferential equations that model steadyÂstate combined conductiveÂradiative heat transfer. This system of equationsÂBrakhage algorithm. Key words. conductiveÂradiative heat transfer, multilevel algorithm, compact fixed point problems integroÂdifferential equations that model steadyÂstate combined conductiveÂradiative heat transfer
Enhanced heat transfer using nanofluids
Choi, Stephen U. S. (Lisle, IL); Eastman, Jeffrey A. (Naperville, IL)
2001-01-01T23:59:59.000Z
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.
Nanoscale heat transfer - from computation to experiment
Luo, Tengfei
2013-04-09T23:59:59.000Z
Heat transfer can differ distinctly at the nanoscale from that at the macroscale. Recent advancement in
HEAT TRANSFER IN UNDERGROUND HEATING EXPERIMENTS IN GRANITE, STRIPA, SWEDEN
Chan, T.
2010-01-01T23:59:59.000Z
Session on Heat Transfer in Nuclear Waste Disposal, C'.heat transfer processes associated with underground nuclear wasteheat transfer and related processes in an un derground environment similar to that expected in a mined nuclear waste
Heat Transfer in Complex Fluids
Mehrdad Massoudi
2012-01-01T23:59:59.000Z
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
He, Xing; Lee, Euntaek; Wilcox, Lucas; Munipalli, Ramakanth; Pilon, Laurent
2013-01-01T23:59:59.000Z
of radiative transfer in combustion systems”, Int. J. Numer.c, “Radiation heat transfer in combustion systems”, Progressin Energy and Combustion Science, vol. 13, no. 2, pp. 97–
Lefevre, M. R.
1984-01-01T23:59:59.000Z
crossflow and counterflow plume. 3) COMBINATION OF HET AND DRY TOWERS When there is not enough water available to provide the makeup for a conventional wet cooling tower, the only solution is to use "DRY" cooling to dissipate part of the heat load. a... 11. The water is cooled first in the DRY section because DRY cooling is much more expensive than WET cooling and this arrangement leads to the smallest DRY tower. It must also be kept in mind that the DRY tower has a physical cooling limit equal...
Virginia Tech
Spring 2014 1 Heat Transfer - 1 Consider a cylindrical nuclear fuel rod of length L and diameter df the fuel rod, and the volumetric generation rate is known to vary sinusoidally with distance along the rod to exist between the surface of the rod and the water. Axial conduction can be neglected in rod and fluid
Kihm, IconKenneth David
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
AN EXPERIMENTAL INVESTIGATION OF THE HEAT TRANSFER FROM A BUOYANT GAS PLUME TO A
Winfree, Erik
Temperature E. Heat Transfer Model 1. Determining the Ceiling Heat Transfer 2. Ceiling Heat Transfer
Heat transfer via dropwise condensation on hydrophobic microstructured surfaces
Ruleman, Karlen E. (Karlen Elizabeth)
2009-01-01T23:59:59.000Z
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 ...
Heat Transfer Research, 2010, Vol. 41, No. 6 Turbine Aero-Heat Transfer Studies
Camci, Cengiz
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
Acoustically Enhanced Boiling Heat Transfer
Z. W. Douglas; M. K. Smith; A. Glezer
2008-01-07T23:59:59.000Z
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.
Heat exchanger device and method for heat removal or transfer
Koplow, Jeffrey P
2013-12-10T23:59:59.000Z
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.
Heat exchanger device and method for heat removal or transfer
Koplow, Jeffrey P. (San Ramon, CA)
2012-07-24T23:59:59.000Z
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.
Heat-Traced Fluid Transfer Lines
Schilling, R. E.
1984-01-01T23:59:59.000Z
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...
Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal...
heat flow values as high as several watts per meter squared can be found. Systematic interpretation of heat flow patterns sheds light on heat transfer mechanisms at depth on...
Heat transfer between elastic solids with randomly rough surfaces
B. N. J. Persson; B. Lorenz; A. I. Volokitin
2009-08-27T23:59:59.000Z
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.
JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 14, No. 4, OctoberDecember 2000
Guo, Zhixiong "James"
JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 14, No. 4, OctoberÂDecember 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
Heat Transfer and Cooling Techniques at Low Temperature
Baudouy, B
2014-01-01T23:59:59.000Z
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.
Nuclear reactor safety heat transfer
Jones, O.C.
1982-07-01T23:59:59.000Z
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.
"Developing novel heat transfer diagnostics for nanosystems."
Acton, Scott
become an increasingly popular technology for waste heat recovery in the last few years. The efficiency"Developing novel heat transfer diagnostics for nanosystems." Patrick Hopkins Assistant Professor Young Investigator Award for heat transfer across solid/fluid interfaces · 2013 AFOSR Young Investigator
Heat-transfer coefficients in agitated vessels. Latent heat models
Kumpinsky, E. [Ashland Chemical Co., Columbus, OH (United States)] [Ashland Chemical Co., Columbus, OH (United States)
1996-03-01T23:59:59.000Z
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.
Analysis of heat transfer in unlooped and looped pulsating
Zhang, Yuwen
, Tubing Abstract An advanced heat transfer model for both unlooped and looped Pulsating Heat Pipes (PHPs
Heat Transfer Fluids Containing Nanoparticles | Argonne National...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Containing Nanoparticles Technology available for licensing: A stable, nonreactive nanofluid that exhibits enhanced heat transfer properties with only a minimal increase in...
Patel, Bhagubhai Desaibhai
1966-01-01T23:59:59.000Z
? FOR RADIATION NUMBER N + o 5 o MODULUS M = 4? USUAL PROCEDURE ~ S I NK' NTHI TA NODE I NO DE 2 NODE3 NODE4 NODE5 NODE6 0 ' oo0o n, 0100 0 ' 0200 n ~ c'300 0 ' 0400 0 ~ 0500 O, oeoo 0 ' 0700 Oe0800 0 ' 0900 Oe1000 n ~ 1100 Oe1200 Oo1300 0... of this method can be I'ound in the graphical method commonly known as the Schmidt method, but, Binder first developed it independently. During the peri, od in which these meth+de were developed the temperatures normally worked with were 'relatively lower...
Radiative transfer in molecular lines
A. Asensio Ramos; J. Trujillo Bueno; J. Cernicharo
2001-02-15T23:59:59.000Z
The highly convergent iterative methods developed by Trujillo Bueno and Fabiani Bendicho (1995) for radiative transfer (RT) applications are generalized to spherical symmetry with velocity fields. These RT methods are based on Jacobi, Gauss-Seidel (GS), and SOR iteration and they form the basis of a new NLTE multilevel transfer code for atomic and molecular lines. The benchmark tests carried out so far are presented and discussed. The main aim is to develop a number of powerful RT tools for the theoretical interpretation of molecular spectra.
Tropical Cloud Properties and Radiative Heating Profiles
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Mather, James
We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.
MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER
Lahey, Richard T.
MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL AND CHAOS THEORY" RICHARD T. LAHEY, JR. Center for Multiphase Research Rensselaer Polytechnic Institute Troy and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts
Fourier analysis of conductive heat transfer for glazed roofing materials
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
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.
"Nanotechnology Enabled Advanced Industrial Heat Transfer Fluids"
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
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
Heat and mass transfer considerations in advanced heat pump systems
Panchal, C.B.; Bell, K.J.
1992-08-01T23:59:59.000Z
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.
Heat and mass transfer considerations in advanced heat pump systems
Panchal, C.B.; Bell, K.J.
1992-01-01T23:59:59.000Z
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.
Heat-transfer coefficients in agitated vessels. Sensible heat models
Kumpinsky, E. [Ashland Chemical Co., Columbus, OH (United States). Research and Development Dept.
1995-12-01T23:59:59.000Z
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.
Heat Transfer Derivation of differential equations for heat transfer conduction
Veress, Alexander
) 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
HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME
Boyer, Edmond
1 HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME P. H and the sheet metal: This is ventilation by natural convection. The remaining conductive heat from the sheet or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers
Dynamics of heat transfer between nano systems
Svend-Age Biehs; Girish S. Agarwal
2012-10-18T23:59:59.000Z
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.
Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger
Im, Kwan H. (Naperville, IL); Ahluwalia, Rajesh K. (Burr Ridge, IL)
1994-01-01T23:59:59.000Z
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.
Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger
Im, K.H.; Ahluwalia, R.K.
1994-10-18T23:59:59.000Z
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.
HEAT TRANSFER DURING THE SHOCK-INDUCED IGNITION OF AN EXPOLSIVE GAS
Heperkan, H.
2013-01-01T23:59:59.000Z
Proceedings of the 1963 Heat Transfer and Fluid Mechanicsto the Journal of Heat Transfer HEAT TRANSFER DURING THETechniques for Heat Transfer and Force Measurements in a
About convective heat transfer in geothermal systems
Pashkevich, R.I. [Kamchatsky Complex Department of NIPIgeotherm Institute, Petropavlovsk-Kamchatsky (Russian Federation)
1996-12-31T23:59:59.000Z
The interphase fluid-rock heat exchange in convective beat transfer in geothermal systems is investigated Nonlinear model of interphase heat exchange is suggested. Calculation for one dimension case and comparison with known Anzelius-Schumann solution is presented Generalized type block heat transfer model is formulated. The model is adequate for case of geothermal systems and reservoir when a rock block size is comparable with filtration path length. Criterion equations for nonstationary coefficients of interphase heat exchange we presented these equations were obtained in laboratory experiments with diorites.
Modelling Heat Transfer of Carbon Nanotubes
Yang, Xin-She
2010-01-01T23:59:59.000Z
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.
Analysis of Heat Transfer in Metal Hydride Based Hydrogen Separation
Fleming, W.H. Jr.
1999-10-20T23:59:59.000Z
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.
Clean Boiler Waterside Heat Transfer Surfaces
Not Available
2006-01-01T23:59:59.000Z
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.
Ivanov, Michael A Liberman M F
2015-01-01T23:59:59.000Z
We examines regimes of the hydrogen flames propagation and ignition of mixtures heated by the radiation emitted from the flame. The gaseous phase is assumed to be transparent for radiation, while the suspended particles of the dust cloud ahead of the flame absorb and reemit the radiation. The radiant heat absorbed by the particles is then lost by conduction to the surrounding unreacted gaseous phase so that the gas phase temperature lags that of the particles. The direct numerical simulations solve the full system of two phase gas dynamic time-dependent equations with a detailed chemical kinetics for a plane flames propagating through a dust cloud. Depending on the spatial distribution of the dispersed particles and on the value of radiation absorption length the consequence of the radiative preheating of the unreacted mixture can be either the increase of the flame velocity for uniformly dispersed particles or ignition deflagration or detonation ahead of the flame via the Zel'dovich gradient mechanism in the...
None
2011-12-05T23:59:59.000Z
HEATS Project: USF is developing low-cost, high-temperature phase-change materials (PCMs) for use in thermal energy storage systems. 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. Most PCMs do not conduct heat very well. Using an innovative, electroless encapsulation technique, USF is enhancing the heat transfer capability of its PCMs. The inner walls of the capsules will be lined with a corrosion-resistant, high-infrared emissivity coating, and the absorptivity of the PCM will be controlled with the addition of nano-sized particles. USF’s PCMs remain stable at temperatures from 600 to 1,000°C and can be used for solar thermal power storage, nuclear thermal power storage, and other applications.
Nanoparticle enhanced ionic liquid heat transfer fluids
Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.; Gray, Joshua R.; Garcia-Diaz, Brenda L.
2014-08-12T23:59:59.000Z
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.
Near-field heat transfer between gold nanoparticle arrays
Phan, Anh D., E-mail: anhphan@mail.usf.edu [Department of Physics, University of South Florida, Tampa, Florida 33620 (United States); Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Ba Dinh, Hanoi 10000 (Viet Nam); Phan, The-Long, E-mail: ptlong2512@yahoo.com [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Woods, Lilia M. [Department of Physics, University of South Florida, Tampa, Florida 33620 (United States)
2013-12-07T23:59:59.000Z
The radiative heat transfer between gold nanoparticle layers is presented using the coupled dipole method. Gold nanoparticles are modelled as effective electric and magnetic dipoles interacting via electromagnetic fluctuations. The effect of higher-order multipoles is implemented in the expression of electric polarizability to calculate the interactions at short distances. Our findings show that the near-field radiation reduces as the radius of the nanoparticles is increased. Also, the magnetic dipole contribution to the heat exchange becomes more important for larger particles. When one layer is displayed in parallel with respect to the other layer, the near-field heat transfer exhibits oscillatory-like features due to the influence of the individual nanostructures. Further details about the effect of the nanoparticles size are also discussed.
Examination of Liquid Fluoride Salt Heat Transfer
Yoder Jr, Graydon L [ORNL] [ORNL
2014-01-01T23:59:59.000Z
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.
Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger
Singh, K. P.
1979-01-01T23:59:59.000Z
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...
Heat transfer in gas tungsten arc welding
Smartt, H.B.; Stewart, J.A.; Einerson, C.J.
1986-05-01T23:59:59.000Z
The heat transferred from an electrode negative, argon gas tungsten arc to an anode has been measured for a wide range of conditions suitable for mechanized welding applications. The results are given as (1) the arc efficiency; and (2) the anode heat and current input distribution functional shapes and radii for various anode materials and groove shapes over a wide range of current and voltage, using different electrode geometries, as well as both He and Ar-He shielding gases. The nominal arc is Gaussian with a diameter of about 4 mm and a heat transfer efficiency to the anode of about 75%. Variations from these values are discussed in terms of current knowledge of the electrical and thermal energy transport mechanisms. A new method of measuring the heat transferred from the arc to the anode, using a boiling liquid nitrogen calorimeter, has been developed which gives rapid, accurate values.
Study of heat transfer in attics with a small scale simulator
Katipamula, Srinivas
1985-01-01T23:59:59.000Z
University Chairman of Advisory Committee: W. D. Turner An experimental study concerned with different modes of heat. transfer in fibrous and cellulose insulating material is presented. A series of experiments was conducted using an attic simulator... to deter- mine the effects of ventilation on attic heat transfer. and the effect of infrared radiation on the thcrn&al conductivity of th& insulation sys- tem and on attic heat transfer. All the tests were perl'ormed at, steady state conditions...
Computation of radiative heat transport across a nanoscale vacuum gap
Budaev, Bair V., E-mail: bair@berkeley.edu; Bogy, David B., E-mail: dbogy@berkeley.edu [University of California, Etcheverry Hall, MC 1740, Berkeley, California 94720-1740 (United States)
2014-02-10T23:59:59.000Z
Radiation heat transport across a vacuum gap between two half-spaces is studied. By consistently applying only the fundamental laws of physics, we obtain an algebraic equation that connects the temperatures of the half-spaces and the heat flux between them. The heat transport coefficient generated by this equation for such structures matches available experimental data for nanoscale and larger gaps without appealing to any additional specific mechanisms of energy transfer.
Impact of surface inhomogeneity on solar radiative transfer under overcast conditions
Li, Zhanqing
Impact of surface inhomogeneity on solar radiative transfer under overcast conditions Zhanqing Li1. Introduction [2] Solar radiative heating is the primary driving force of atmospheric and oceanic movements underlines the impact of surface inhomogeneity on the closure of SW radiative transfer. It also leads
Indirect Heat Transfer Technology For Waste Heat Recovery Can Save You Money
Beyrau, J. A.; Bogel, N. G.; Seifert, W. F.; Wuelpern, L. E.
1984-01-01T23:59:59.000Z
constraints of an existing installation makes the conventional flue gas to air energy recovery technology impractical to employ. A successful alternative is the transfer of waste heat to an intermediate heat transfer fluid (i.e., DOWTHERM Heat Transfer Fluid...
Heat transfer 1990. Proceedings of the ninth international heat transfer conference
Hetsroni, G.
1990-01-01T23:59:59.000Z
This book contains the proceedings of the Ninth International Heat Transfer Conference. Included in Volume 6 are the following chapters: Local void fraction measurements in finned tube bundles, Unsteady heat and mass transfer in low two-phase flows and The effect of physical properties on drop size in annular flow.
Numerical methods in heat transfer
Emery, A.F.; Douglass, R.W.
1988-01-01T23:59:59.000Z
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.
5. Heat transfer Ron Zevenhoven
Zevenhoven, Ron
) Heat conductance as Gheat =1/Rheat = Q/T (unit: W/K or W/°C) For a plane material with thickness L (m) and conductivity (W/mK): Gheat = ·A/L Rheat = L/(·A) . . . Ĺbo Akademi University | Thermal and Flow Engineering rate Q through a cross-sectional area A (m2). If is a constant: with thermal conductivity , unit: W
Solid state radiative heat pump
Berdahl, P.H.
1984-09-28T23:59:59.000Z
A solid state radiative heat pump operable at room temperature (300 K) utilizes a semiconductor having a gap energy in the range of 0.03-0.25 eV and operated reversibly to produce an excess or deficit of change carriers as compared equilibrium. In one form of the invention an infrared semiconductor photodiode is used, with forward or reverse bias, to emit an excess or deficit of infrared radiation. In another form of the invention, a homogenous semiconductor is subjected to orthogonal magnetic and electric fields to emit an excess or deficit of infrared radiation. Three methods of enhancing transmission of radiation the active surface of the semiconductor are disclosed. In one method, an anti-refection layer is coated into the active surface of the semiconductor, the anti-reflection layer having an index of refraction equal to the square root of that of the semiconductor. In the second method, a passive layer is speaced trom the active surface of the semiconductor by a submicron vacuum gap, the passive layer having an index of refractive equal to that of the semiconductor. In the third method, a coupler with a paraboloid reflecting surface surface is in contact with the active surface of the semiconductor, the coupler having an index of refraction about the same as that of the semiconductor.
Solid state radiative heat pump
Berdahl, Paul H. (Oakland, CA)
1986-01-01T23:59:59.000Z
A solid state radiative heat pump (10, 50, 70) operable at room temperature (300.degree. K.) utilizes a semiconductor having a gap energy in the range of 0.03-0.25 eV and operated reversibly to produce an excess or deficit of charge carriers as compared to thermal equilibrium. In one form of the invention (10, 70) an infrared semiconductor photodiode (21, 71) is used, with forward or reverse bias, to emit an excess or deficit of infrared radiation. In another form of the invention (50), a homogeneous semiconductor (51) is subjected to orthogonal magnetic and electric fields to emit an excess or deficit of infrared radiation. Three methods of enhancing transmission of radiation through the active surface of the semiconductor are disclosed. In one method, an anti-reflection layer (19) is coated into the active surface (13) of the semiconductor (11), the anti-reflection layer (19) having an index of refraction equal to the square root of that of the semiconductor (11). In the second method, a passive layer (75) is spaced from the active surface (73) of the semiconductor (71) by a submicron vacuum gap, the passive layer having an index of refractive equal to that of the semiconductor. In the third method, a coupler (91) with a paraboloid reflecting surface (92) is in contact with the active surface (13, 53) of the semiconductor (11, 51), the coupler having an index of refraction about the same as that of the semiconductor.
Selective radiative heating of nanostructures using hyperbolic metamaterials
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ding, Ding; Minnich, Austin J
2015-01-01T23:59:59.000Z
Hyperbolic metamaterials (HMM) are of great interest due to their ability to break the diffraction limit for imaging and enhance near-field radiative heat transfer. Here we demonstrate that an annular, transparent HMM enables selective heating of a sub-wavelength plasmonic nanowire by controlling the angular mode number of a plasmonic resonance. A nanowire emitter, surrounded by an HMM, appears dark to incoming radiation from an adjacent nanowire emitter unless the second emitter is surrounded by an identical lens such that the wavelength and angular mode of the plasmonic resonance match. Our result can find applications in radiative thermal management.
Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids
Raade, Justin; Roark, Thomas; Vaughn, John; Bradshaw, Robert
2013-07-22T23:59:59.000Z
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.
Self supporting heat transfer element
Story, Grosvenor Cook (Livermore, CA); Baldonado, Ray Orico (Livermore, CA)
2002-01-01T23:59:59.000Z
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.
Convective heat transfer in rotating, circular channels
Hogan, Brenna Elizabeth
2012-01-01T23:59:59.000Z
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 ...
Enhanced convective and film boiling heat transfer by surface gas injection
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
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.
Enhanced convective and film boiling heat transfer by surface gas injection
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
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.
Radiative transfer for the FIRST era
J. Trujillo Bueno
2001-02-15T23:59:59.000Z
This paper presents a brief overview of some recent advances in numerical radiative transfer, which may help the molecular astrophysics community to achieve new breakthroughs in the interpretation of spectro-(polarimetric) observations.
Boiling heat transfer in a hydrofoil-based micro pin fin heat sink
Peles, Yoav
transfer in a horizontal tube bundle and reported an increase in local heat transfer coefficient boiling heat transfer of water in small horizontal tube bundles at low velocities. How- ever, the dataBoiling heat transfer in a hydrofoil-based micro pin fin heat sink Ali Kosßar, Yoav Peles
Coupled Reactor Kinetics and Heat Transfer Model for Heat Pipe Cooled Reactors
WRIGHT,STEVEN A.; HOUTS,MICHAEL
2000-11-22T23:59:59.000Z
Heat pipes are often proposed as cooling system components for small fission reactors. SAFE-300 and STAR-C are two reactor concepts that use heat pipes as an integral part of the cooling system. Heat pipes have been used in reactors to cool components within radiation tests (Deverall, 1973); however, no reactor has been built or tested that uses heat pipes solely as the primary cooling system. Heat pipe cooled reactors will likely require the development of a test reactor to determine the main differences in operational behavior from forced cooled reactors. The purpose of this paper is to describe the results of a systems code capable of modeling the coupling between the reactor kinetics and heat pipe controlled heat transport. Heat transport in heat pipe reactors is complex and highly system dependent. Nevertheless, in general terms it relies on heat flowing from the fuel pins through the heat pipe, to the heat exchanger, and then ultimately into the power conversion system and heat sink. A system model is described that is capable of modeling coupled reactor kinetics phenomena, heat transfer dynamics within the fuel pins, and the transient behavior of heat pipes (including the melting of the working fluid). The paper focuses primarily on the coupling effects caused by reactor feedback and compares the observations with forced cooled reactors. A number of reactor startup transients have been modeled, and issues such as power peaking, and power-to-flow mismatches, and loading transients were examined, including the possibility of heat flow from the heat exchanger back into the reactor. This system model is envisioned as a tool to be used for screening various heat pipe cooled reactor concepts, for designing and developing test facility requirements, for use in safety evaluations, and for developing test criteria for in-pile and out-of-pile test facilities.
CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER
Kandlikar, Satish
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
Direct numerical simulation of turbulent heat transfer in annuli: effect of heat flux ratio.
Paris-Sud XI, Université de
Direct numerical simulation of turbulent heat transfer in annuli: effect of heat flux ratio. M-la-Vall´ee cedex 2, France (Dated: October 23, 2008) Abstract Fully developed turbulent flow and heat transfer square (rms) of temperature fluctuations, turbulent heat fluxes, heat transfer, ...). To validate
Fort, James A.; Cuta, Judith M.; Bajwa, C.; Baglietto, E.
2010-07-18T23:59:59.000Z
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.
A FAST FORWARD SOLVER OF RADIATIVE TRANSFER HAO GAO AND HONGKAI ZHAO
Soatto, Stefano
finite difference schemes (FD), the finite element method (FEM) [17, 20], the finite volume method (FVM transport equation [4, 13] in the field of neutron transport [4], atmospheric radiative transfer [1], heat. Key words and phrases. radiative transfer equation (RTE), optical imaging, discrete ordinate method
A CONVECTIVE HEAT TRANSFER MODEL FOR SIMULATION OF ROOMS WITH
A CONVECTIVE HEAT TRANSFER MODEL FOR SIMULATION OF ROOMS WITH ATTACHED WALL JETS By WEIXIU KONGQuest Information and Learning Company. #12;II A CONVECTIVE HEAT TRANSFER MODEL FOR SIMULATION OF ROOMS
July 2008 Mold heat transfer in continuous casting
Thomas, Brian G.
with the 1-D heat transfer model, CON1D. To account for the multi- dimensional thermal behavior around speeds and new mold designs. COND Model Description The heat transfer model CON1D1 models sev- eral
Hydrodynamics, heat transfer and flow boiling instabilities in microchannels
Barber, Jacqueline Claire
2010-01-01T23:59:59.000Z
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 ...
Nanofluid heat transfer enhancement for nuclear reactor applications
Buongiorno, Jacopo
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, ...
Experimental evaluation of heat transfer characteristics of silica nanofluid
Zhang, Zihao, S.B. Massachusetts Institute of Technology
2010-01-01T23:59:59.000Z
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 ...
Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet)
Not Available
2010-08-01T23:59:59.000Z
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.
DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION
Yee, G.
2010-01-01T23:59:59.000Z
DEVELOpiNG FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS9092 Developing Flow and Heat Transfer in Strongly CurvedForced Convection Heat Transfer in Curved Rectangular
TOPAZ3D. 3-D Finite Element Heat Transfer
Shapiro, A.B. [Lawrence Livermore National Lab., CA (United States)
1992-02-24T23:59:59.000Z
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.
Heat transfer of finned tube bundles in crossflow
Stasiulevicius, J.; Skrinska, A.; Zukauskas, A.
1988-01-01T23:59:59.000Z
This volume correlates findings on heat transfer and hydraulic drag of bundles of finned tubes in crossflow at Reynolds numbers from 10/sup 4/ to 10/sup 6/. These studies illustrate fin, local, and mean heat transfer coefficients; effects of geometric parameters of the fins; effect of tube location within the bundle on heat transfer and hydraulic drag; and resistance of finned tube bundles.
Dt2boool2> Nora Heat Transfer Correlations
Dt2boool2> Nora Heat Transfer Correlations in Nuclear Reactor Safety Calculations VW ÉAiiattÉaii #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
Proceeding of the 1st International Forum on Heat Transfer
Maruyama, Shigeo
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
Proceedings of NHTC'00: 34 th National Heat Transfer Conference
Kandlikar, Satish
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
High flux heat transfer in a target environment
McDonald, Kirk
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
Low-melting point heat transfer fluid
Cordaro, Joseph Gabriel (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)
2010-11-09T23:59:59.000Z
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.
Near-field thermal radiation transfer controlled by plasmons in graphene
Ilic, Ognjen
It is shown that thermally excited plasmon-polariton modes can strongly mediate, enhance, and tune the near-field radiation transfer between two closely separated graphene sheets. The dependence of near-field heat exchange ...
Heat Transfer Operators Associated with Quantum Operations
Ç. Aksak; S. Turgut
2011-04-14T23:59:59.000Z
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.
Paris-Sud XI, Université de
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
Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers
Thole, Karen A.
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
Journal of Enhanced Heat Transfer, 19 (5): 457476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT
Ghajar, Afshin J.
2012-01-01T23:59:59.000Z
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
Numerical study of high heat ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b
Maruyama, Shigeo
Numerical study of high heat Żux 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
Radiative Transfer Models for Gamma-Ray Bursts
Vurm, Indrek
2015-01-01T23:59:59.000Z
We present global radiative transfer models for heated relativistic jets. The simulations include all relevant radiative processes, starting deep in the opaque zone and following the evolution of radiation to and beyond the photosphere of the jet. The transfer models are compared with three gamma-ray bursts GRB 990123, GRB 090902B, and GRB 130427A, which have well-measured and different spectra. The models provide good fits to the observed spectra in all three cases. The fits give estimates for the jet magnetization parameter $\\varepsilon_{\\rm B}$ and the Lorentz factor $\\Gamma$. In the small sample of three bursts, $\\varepsilon_{\\rm B}$ varies between 0.01 and 0.1, and $\\Gamma$ varies between 340 and 1200.
RADIATIVE HEATING OF THE SOLAR CORONA
Moran, Thomas G., E-mail: moran@grace.nascom.nasa.gov [Physics Department, Catholic University of America, 200 Hannan Hall, Washington, DC 20064 (United States) and NASA/GSFC, Code 671, Greenbelt, MD 20771 (United States)
2011-10-20T23:59:59.000Z
We investigate the effect of solar visible and infrared radiation on electrons in the Sun's atmosphere using a Monte Carlo simulation of the wave-particle interaction and conclude that sunlight provides at least 40% and possibly all of the power required to heat the corona, with the exception of dense magnetic flux loops. The simulation uses a radiation waveform comprising 100 frequency components spanning the solar blackbody spectrum. Coronal electrons are heated in a stochastic manner by low coherence solar electromagnetic radiation. The wave 'coherence time' and 'coherence volume' for each component is determined from optical theory. The low coherence of solar radiation allows moving electrons to gain energy from the chaotic wave field which imparts multiple random velocity 'kicks' to these particles causing their velocity distribution to broaden or heat. Monte Carlo simulations of broadband solar radiative heating on ensembles of 1000 electrons show heating at per particle levels of 4.0 x 10{sup -21} to 4.0 x 10{sup -20} W, as compared with non-loop radiative loss rates of {approx}1 x 10{sup -20} W per electron. Since radiative losses comprise nearly all of the power losses in the corona, sunlight alone can explain the elevated temperatures in this region. The volume electron heating rate is proportional to density, and protons are assumed to be heated either by plasma waves or through collisions with electrons.
Triplett, C.E.
1996-12-01T23:59:59.000Z
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.
Impact of subgrid-scale radiative heating variability on the...
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subgrid-scale radiative heating variability on the stratocumulus-to-trade cumulus transition in climate models. Impact of subgrid-scale radiative heating variability on the...
Analysis of tropical radiative heating profiles: A comparison...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
diurnal variability in the radiative heating profiles; and a significantly lower level of zero net radiative heating. Citation: McFarlane SA, JH Mather, and TP...
Analysis of radial fin assembly heat transfer with dehumidification
Rosario, L.; Rahman, M.M. [Univ. of South Florida, Tampa, FL (United States). Dept. of Mechanical Engineering
1996-12-31T23:59:59.000Z
The aim of this paper is the analysis of heat transfer in a radial fin assembly during the process of dehumidification. An individual finned tube geometry is a reasonable representation of heat exchangers used in air conditioning. The condensation process involves both heat and mass transfer and the cooling takes place by the removal of sensible as well as latent heat. The ratio of sensible to total heat is an important quantity that defines the heat transfer process during a dehumidifier operation. A one-dimensional model for heat transfer in the fin and the heat exchanger block is developed to study the effects of condensation on the fin surface. The combined heat and mass transfer process is modeled by incorporating the ratio of sensible to total heat in the formulation. The augmentation of heat transfer due to fin was established by comparing heat transfer rate with and without fins under the same operating conditions. Numerical calculations were carried out to study the effects of relative humidity and dry bulb temperature of the incoming air, and cold fluid temperature inside the coil on the performance of the heat exchanger. Results were compared to those published for rectangular fin under humid condition showed excellent agreement when the present model was used to compute that limiting condition. It was found that the heat transfer rate increased with increment in both dry bulb temperature and relative humidity of the air. The augmentation factor, however, decreased with increment in relative humidity and the dry bulb temperature.
Martin, Timothy
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
Thermal conductivity and heat transfer in superlattices
Chen, G.; Neagu, M.; Borca-Tasciuc, T.
1997-07-01T23:59:59.000Z
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.
Outside heat transfer coefficients for atmospheric coolers
George, David Mark
1950-01-01T23:59:59.000Z
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...
FLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS
Sen, Mihir
= 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 Â· Shallow water analogy Â· Vorticity dynamics Â· Linear stability analysis Â· Numerical simulations of heat
Heat transfer to impacting drops and post critical heat flux dispersed flow
Kendall, Gail E.
1978-01-01T23:59:59.000Z
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 ...
Heat transfer assembly for a fluorescent lamp and fixture
Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.
1992-12-29T23:59:59.000Z
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.
On the design of heat-transfer probes
Brich, M.A.; Ganzha, V.L.; Saxena, S.C. [Univ. of Illinois, Chicago, IL (United States)] [Univ. of Illinois, Chicago, IL (United States)
1997-03-01T23:59:59.000Z
Saxena and coworkers have reported heat-transfer coefficient values for magnetofluidized beds using electrically heated heat-transfer probes. Here, a two-dimensional heat-transfer model is employed to investigate the influence of significant design features on measured parameters. Numerical calculations reveal that the thermal conductivity of the probe material has an insignificant contribution but the material of end caps and relative sizes and locations of the probe and heater appreciably influence the heat-transfer rates through end-conduction.
Heat transfer assembly for a fluorescent lamp and fixture
Siminovitch, Michael J. (Richmond, CA); Rubenstein, Francis M. (Berkeley, CA); Whitman, Richard E. (Richmond, CA)
1992-01-01T23:59:59.000Z
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.
CORQUENCH: A model for gas sparging-enhanced, melt-water, film-boiling heat transfer
Farmer, M.T.; Sienicki, J.J.; Spencer, B.W.
1990-01-01T23:59:59.000Z
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.
CONDUCTION HEAT TRANSFER Dr. Ruhul Amin Fall 2011
Dyer, Bill
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
Photon Radiation in a Heat Bath
P V Landshoff; J C Taylor
1994-04-26T23:59:59.000Z
We discuss the bremsstrahlung of photons into a heat bath, and calculate from first principles the energy radiated. Even to lowest order the spectrum of the radiation at low frequency is no more singular than at zero temperature. In addition to the obvious contributions, this spectrum includes terms associated with fluctuations. [Revised version has additional explanations
Heat Transfer Boundary Conditions in the RELAP5-3D Code
Richard A. Riemke; Cliff B. Davis; Richard R. Schultz
2008-05-01T23:59:59.000Z
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.
accelerated radiative transfer: Topics by E-print Network
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influence of particle shape on the radiative forcing caused by a cloud composed of small ice 123 Journal of Quantitative Spectroscopy & Radiative Transfer 101 (2006) 556...
art heat transfer: Topics by E-print Network
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Transfer Texas A&M University - TxSpace Summary: ICEBO2006, Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-8-5 Urban Sewage Delivery Heat Transfer System...
accident heat transfer: Topics by E-print Network
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Transfer Texas A&M University - TxSpace Summary: ICEBO2006, Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-8-5 Urban Sewage Delivery Heat Transfer System...
accurate heat transfer: Topics by E-print Network
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Transfer Texas A&M University - TxSpace Summary: ICEBO2006, Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-8-5 Urban Sewage Delivery Heat Transfer System...
Heat transfer enhancement resulting from induction electrohydrodynamic pumping
Margo, Bryan David
1992-01-01T23:59:59.000Z
pump operated at various tilt angles with two working fluids. The main difference between this study and other work in EHD heat transfer enhancement is that the induction EHD pump is the only source of pumping as well as the basis for heat transfer... 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...
Sensitivity Analysis of the Gap Heat Transfer Model in BISON.
Swiler, Laura Painton; Schmidt, Rodney C.; Williamson, Richard (INL); Perez, Danielle (INL)
2014-10-01T23:59:59.000Z
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.
Heat transfer in bundles of finned tubes in crossflow
Stasiulevicius, J.; Skrinska, A.; Zukauskas, A.; Hewitt, G.F.
1986-01-01T23:59:59.000Z
This book provides correlations of heat transfer and hydraulic data for bundles of finned tubes in crossflow at high Reynolds numbers. Results of studies of the effectiveness of the fin, local, and mean heat transfer coefficients are presented. The effect of geometric parameters of the fins and of the location of tubes in the bundle on heat transfer and hydraulic drag are described. The resistance of the finned tube bundles under study and other factors are examined.
Heat transfer analysis capabilities of the scale computational system
Parks, C.V.; Giles, G.E.; Childs, K.W.; Bryan, C.B.
1986-01-01T23:59:59.000Z
The heat transfer capabilities within the modular SCALE computational system are centered about the HEATING6 functional module. This paper reviews the features and modeling capabilities of HEATING6, discusses the supportive plotting capabilities of REGPLOT6 and HEATPLOT-S, and finally provides a general description of the Heat Transfer Analysis Sequence No.1 (HTASI) available in SCALE for performing thermal analyses of transport casks via HEATING6. The HTASI control module is an easy-to-use tool that allows an inexperienced HEATING6 user to obtain reliable thermal analysis results. A summary of the recent verification efforts undertaken for HEATING6 is also provided. 16 refs., 14 figs.
Heat Transfer Study of Polymer Solutions with Different Rigidities
Huang, Yao
2014-05-08T23:59:59.000Z
The heat transfer behaviors of non-Newtonian fluids under laminar flow conditions in circular tubes are presented in this study. The constant wall heat flux is considered as a boundary condition for dilute polymer solutions with different polymer...
2.51 Intermediate Heat and Mass Transfer, Fall 2001
Lienhard, John H., 1961-
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 ...
Heat transfer and pressure drop in tape generated swirl flow
Lopina, Robert F.
1967-01-01T23:59:59.000Z
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 ...
Heat Transfer Interface for Thermo-Solar Energy - Energy Innovation...
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Thermal Solar Thermal Building Energy Efficiency Building Energy Efficiency Find More Like This Return to Search Heat Transfer Interface for Thermo-Solar Energy Lawrence Berkeley...
Characterization and Development of Advanced Heat Transfer Technologie...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
May 18-22, 2009 -- Washington D.C. ape11kelly.pdf More Documents & Publications Characterization and Development of Advanced Heat Transfer Technologies Advanced Power Electronics...
Tracer Testing for Estimating Heat Transfer Area in Fractured Reservoirs
Pruess, Karsten; van Heel, Ton; Shan, Chao
2004-01-01T23:59:59.000Z
Heat Flow in Fractured Reservoirs, SPE Advanced TechnologyTransfer Area in Fractured Reservoirs Karsten Pruess 1 , Tonbehavior arises in fractured reservoirs. As cold injected
Effects of solar photovoltaic panels on roof heat transfer
Dominguez, Anthony; Kleissl, Jan; Luvall, Jeffrey C
2011-01-01T23:59:59.000Z
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
advanced heat transfer: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
to save energy in industrial processes. The approach has emphasized developing better heat pump technology and transferring that technology to the private sector. DOE requires...
Proceedings of HT'03 2003 Summer Heat Transfer Conference
Walker, D. Greg
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
Nanofluids for heat transfer : an engineering approach.
Timofeeva, E. V.; Yu, W.; France, D. M.; Singh, D.; Routbort, J. L. (Energy Systems); ( NE); (Univ. of Illinois at Chicago)
2011-02-28T23:59:59.000Z
An overview of systematic studies that address the complexity of nanofluid systems and advance the understanding of nanoscale contributions to viscosity, thermal conductivity, and cooling efficiency of nanofluids is presented. A nanoparticle suspension is considered as a three-phase system including the solid phase (nanoparticles), the liquid phase (fluid media), and the interfacial phase, which contributes significantly to the system properties because of its extremely high surface-to-volume ratio in nanofluids. The systems engineering approach was applied to nanofluid design resulting in a detailed assessment of various parameters in the multivariable nanofluid systems. The relative importance of nanofluid parameters for heat transfer evaluated in this article allows engineering nanofluids with desired set of properties.
Low-melting point heat transfer fluid
Cordaro, Joseph G. (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)
2011-04-12T23:59:59.000Z
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.
Submersible pumping system with heat transfer mechanism
Hunt, Daniel Francis Alan; Prenger, F. Coyne; Hill, Dallas D; Jankowski, Todd Andrew
2014-04-15T23:59:59.000Z
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.
Neutron behavior, reactor control, and reactor heat transfer. Volume four
Not Available
1986-01-01T23:59:59.000Z
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).
Geb, David; Zhou, Feng; Catton, Ivan
2012-01-01T23:59:59.000Z
the Hydraulic Drag and Heat Transfer Coefficients in Porous5] Locke, G. L. , 1950, “Heat Transfer and Flow FrictionA. P. , 1993, “Heat Transfer and Hydraulic Resistance in
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)
1996-12-03T23:59:59.000Z
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.
Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel
Aussillous, Pascale
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
Radiative transfer with scattering from closely-spaced spheres
Drolen, B.L.
1986-01-01T23:59:59.000Z
Many heat-transfer applications including fluidized and packed beds, microsphere insulations, and reactor fuel pellets require the analysis of radiative transfer in packed-sphere systems. The radiative properties of surface deposits such as paint and soot layers, and of aerosols such as soot, may be determined by treating them as a collection of spheres. These properties are important for predicting heat transfer in furnaces and flames and for assessing atmospheric attenuation in nuclear-winter scenarios. For many applications when the particle size is larger than the wavelength, or when the volume fraction is small, scattering from individual spheres in the medium is independent of the influence of neighboring particles. Therefore the extinction characteristics of these systems are based on the properties of the discrete particles. This approach is shown to be in good agreement with published experimental data for a packed bed of spheres. When dependent scattering is important, effects caused by the proximity of the neighboring particles must be included. This model examines interference between the scattered waves from each of the particles in the medium. The particle centers correlate via a distribution function which represents the distribution of neighboring particles about a central particle.
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI); Marsala, Joseph (Glen Ellyn, IL)
1994-11-29T23:59:59.000Z
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 Coupled AtmosphereOcean Radiative Transfer System Using the Analytic Four-Stream Approximation
Liou, K. N.
of the ocean. Shortwave radiation from the sun contributes most of the heat fluxes that penetrate the airA Coupled AtmosphereOcean Radiative Transfer System Using the Analytic Four-Stream Approximation WEI-LIANG LEE AND K. N. LIOU Department of Atmospheric and Oceanic Sciences, University of California
Mechanical Engineering Laboratory of Heat and Mass Transfer
Diggavi, Suhas
the prediction methods. The local condensation heat transfer behavior of two new refrigerants(R236fa and R1234ze refrigerants. Effect of different parameters was investigated for present database. Koyama method was modified. Jung E. Park Comparing refrigerant performance, the higher heat transfer coefficients (about 15
Measurement and analysis of gas turbine blade endwall heat transfer
Lee, Joon Ho
2001-01-01T23:59:59.000Z
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...
Heat transfer in proteinwater interfaces Anders Lervik,ab
Kjelstrup, Signe
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
An upgraded heat transfer fluid eliminates odors and leaks
NONE
1995-10-01T23:59:59.000Z
At Morton, persistent leakage of an aromatics-based heat transfer fluid left its mark--a black, oxidized residue at flange and valve locations. By switching to a high-purity fluid from a paraffinic hydrocarbon base stock, the firm eliminated odors and sticky residue, and improved heat transfer. After four years of operation with the paraffinic heat transfer fluid, Morton continues to have no odor problems and virtually no flange or packing leakage. As an added bonus, the heat transfer coefficient of the new fluid allows Morton to operate the systems 10--15 F cooler than when the company used the traditional, aromatic fluid. This has cut fuel use and reduced the potential for thermal damage to the heat transfer fluid, process fluid and process equipment.
Gas heat transfer in a heated vertical channel under deteriorated turbulent heat transfer regime
Lee, Jeongik
2007-01-01T23:59:59.000Z
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 ...
Gas Heat Transfer in a Heated Vertical Channel under Deteriorated Turbulent Heat Transfer Regime
Lee, Jeongik
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 ...
Research on Convective Heat Transfer and Mass Transfer of the Evaporator in Micro/Mini-Channel
Su, J.; Li, J.
2006-01-01T23:59:59.000Z
With the development of science and technology, various heating and cooling equipment have a development trend of micromation. Micro-fabrication processes make it possible to conduct research on condensation heat transfer ...
Heat transfer and film cooling with steam injection
Conklin, Gary Eugene
1982-01-01T23:59:59.000Z
HEAT TRANSFER AND FILM COOLING WITH STEAM INJECTION A Thesis by GARY EUGENE CONKLIN Submitted to the Graduate College of Texas AIM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1982 Major... Subject: Mechanical Engineering HEAT TRANSFER AND FILM COOLING WITH STEAM INJECTION A Thesis by GARY EUGENE CONKLIN Approved as to style and content by: (Chairm of Committee) (Member) (Memb e r) (Me r (Head Departme ) May 1982 ABSTRACT Heat...
Enhanced two phase flow in heat transfer systems
Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D
2013-12-03T23:59:59.000Z
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.
Natural convection heat transfer from two horizontal cylinders
Reymond, Olivier; Murray, Darina B. [Department of Mechanical and Manufacturing Engineering, Trinity College Dublin (Ireland); O'Donovan, Tadhg S. [School of Engineering and Physical Sciences, Heriot-Watt University, Nasmyth Building, Edinburgh EH14 4AS (United Kingdom)
2008-09-15T23:59:59.000Z
Natural convection heat transfer from a single horizontal cylinder and a pair of vertically aligned horizontal cylinders is investigated. Surface heat transfer distributions around the circumference of the cylinders are presented for Rayleigh numbers of 2 x 10{sup 6}, 4 x 10{sup 6} and 6 x 10{sup 6} and a range of cylinder spacings of 1.5, 2 and 3 diameters. With a cylinder pairing the lower cylinder is unaffected by the presence of the second cylinder; the same is true of the upper cylinder if the lower one is not heated. However, when both cylinders are heated it has been found that a plume rising from the heated lower cylinder interacts with the upper cylinder and significantly affects the surface heat transfer distribution. Spectral analysis of surface heat transfer signals has established the influence of the plume oscillations on the heat transfer. Thus, when the plume from the lower cylinder oscillates out of phase with the flow around the upper cylinder it increases the mixing and results in enhanced heat transfer. (author)
Dual circuit embossed sheet heat transfer panel
Morgan, G.D.
1984-02-21T23:59:59.000Z
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.
Study on the heat transfer of heat exchangers for the Stirling Engine
Kanzaka, M. (Nagasaki Research and Development Center (JP)); Iwabuchi, M. (Advanced Technology Research Center, Mitsubishi Heavy Industries, Ltd. (JP))
1991-01-01T23:59:59.000Z
This paper reports that heat-transfer characteristics in heated tubes under periodically reversing flow conditions have been investigated experimentally using a test apparatus that simulates the heat exchangers for the actual Sterling engine. It was shown that the heat-transfer characteristics under these conditions were greatly affected by the piston phase-angle difference that generates the reversing flow of the working gas, and this phenomenon was proper to the heat transfer under the periodically reversing flow and was different from conventional heat transfer in steady flow. The experimental correlation considering the influence of the piston phase-angle difference for the heat-transfer coefficient has been induced by the use of the working gas velocity evaluated from the Schmidt cycle model which is one of the ideal Sterling cycles.
ME 544 Advanced Heat Transfer Spring 2013 Time: 2pm-3pm MWF
are demonstrated for a variety of engineering problems. Since most engineering devices have thermal energy and engineering applications of heat transfer including conduction, convection, and radiation. Course Learning Objectives: In this course, students will learn how to 1. Model engineering problems that have conduction
The deterioration in heat transfer to fluids at supercritical pressure and high heat fluxes
Shiralkar, B. S.
1968-01-01T23:59:59.000Z
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 ...
Gaskill, Travis
2012-02-14T23:59:59.000Z
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...
Tetreault-Friend, Melanie
2014-01-01T23:59:59.000Z
Predicting the conditions of critical heat flux (CHF) is of considerable importance for safety and economic reasons in heat transfer units, such as in nuclear power plants. It is greatly advantageous to increase this thermal ...
Nano-engineering the boiling surface for optimal heat transfer rate and critical heat flux
Phillips, Bren Andrew
2011-01-01T23:59:59.000Z
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 ...
Gaskill, Travis
2012-02-14T23:59:59.000Z
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...
Heat transfer near spacer grids in rod bundles
Yoder, G.L.
1985-01-01T23:59:59.000Z
Heat transfer data from several sources have been assembled which show the effect of spacer grids on local heat transfer within a rod bundle. Both single phase (air and steam) data and two phase (steam/water) data show heat transfer augmentation in the grid region. Heat transfer improvement immediately beyond the grid ranges from a few percent to over fifty percent in these experiments, depending on flow conditions. The data are examined using several nondimensional parameters which relate the above effects to known quantities. The relative effect of the grid on local heat transfer is altered by both the Reynolds number and blockage ratio. Twenty to thirty hydraulic diameters are required before the local effect of the grid dissipates. Locally, both the single phase and two phase data show the same trends. Comparison of the single and two phase data also shown some differences. Some film boiling data indicate that an altered heat transfer regime may exist near the grid. High rod heat transfer coefficients at the grid locations indicate either a rewet of the rods or at least a change from film boiling to transition boiling near the spacer. The comparison also indicates that the film boiling data is affected on a global as well as local basis. This is due to the effect of the grid on the liquid distribution.
Effect of translucence of engineering ceramics on heat transfer in diesel engines
Wahiduzzaman, S.; Morel, T. (Integral Technologies, Inc., Westmont, IL (United States))
1992-04-01T23:59:59.000Z
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.
Effect of translucence of engineering ceramics on heat transfer in diesel engines. Final report
Wahiduzzaman, S.; Morel, T. [Integral Technologies, Inc., Westmont, IL (United States)
1992-04-01T23:59:59.000Z
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.
Experimental and numerical study of laminar forced convection heat transfer for a dimpled heat sink
Park, Do Seo
2009-05-15T23:59:59.000Z
EXPERIMENTAL AND NUMERICAL STUDY OF LAMINAR FORCED CONVECTION HEAT TRANSFER FOR A DIMPLED HEAT SINK A Thesis by DO SEO PARK 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 August 2007 Major Subject: Mechanical Engineering EXPERIMENTAL AND NUMERICAL STUDY OF LAMINAR FORCED CONVECTION HEAT TRANSFER FOR A DIMPLED HEAT SINK A Thesis by DO SEO PARK...
A Small Artery Heat Transfer Model for Self-Heated Thermistor Measurements of Perfusion in the
A Small Artery Heat Transfer Model for Self-Heated Thermistor Measurements of Perfusion model (SAM) for self-heated thermistor measurements of perfusion in the canine kidney is developed based clinical method to quantify perfusion for a majority of applications. Self-heated thermistor techniques
Investigating Mould Heat Transfer in Thin Slab Casting with CON1D Begoa Santillana
Thomas, Brian G.
. Heat transfer in the thin slab casting mould is being investigated with the 1-D heat transfer model MODEL DESCRIPTION The heat transfer model, CON1D1 , models several aspects of the continuous casting
Grossmann, Ignacio E.
Heat transfer model of large shipping containers 1Chemical Engineering Department - Carnegie Mellon to the inside air 3. Heat transfer at the cargo on the pallets I. The heat transfer model Outline: II. Case
Impingement cooling and heat transfer measurement using transient liquid crystal technique
Huang, Yizhe
1996-01-01T23:59:59.000Z
is used in this study to obtain the detailed heat transfer coefficient. Results show that a higher Reynolds number increases heat transfer over the entire impingement target surface. The flow exit orientation with crossflow affects the heat transfer...
Heat transfer rates in fixed bed catalytic reactors
Levelton, Bruce Harding
1951-01-01T23:59:59.000Z
HEAT TRANSFER RATES IN FIXED BED CATALYTIC REACTORS H EATTRNSFSAIX DB DNCLR YFNOAXa rRJRuSIX nSeR 1951i HssNIJFu FT SI TSBuR FXO LIXSRXS NRLIeeRXOROt HEAT TRANSFER RATES IN FIXED BED CATALYTIC REACTORS H EATTRNSFSAIX BSar DNCLR YFNOAXa r...RJRuSIX June 1951 HEAT TRANSFER RATES IN FIXED BED CATALYTIC REACTORS A Dissertation Submitted to the Faculty of the Agricultural and Mechanical College of Texas in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Major...
Heat Transfer Calculations for a Fixed CST Bed Column
Lee, S.Y.
2001-03-28T23:59:59.000Z
In support of the crystalline silicotitanate (CST) ion exchange project of High-Level Waste (HLW) Process Engineering, a transient two-dimensional heat transfer model that includes the conduction process neglecting the convection cooling mechanism inside the CST column has been constructed and heat transfer calculations made for the present design configurations. For this situation, a no process flow condition through the column was assumed as one of the reference conditions for the simulation of a loss-of-flow accident. The modeling and calculations were performed using a computational heat transfer approach.
Heat transfer from nanoparticles: a corresponding state analysis
Paris-Sud XI, Université de
temperatures using laser heating of nanoparticles [8, 9, 10], even reaching the melting point of gold particles is relevant to experiments in which a fluid is locally heated using selective absorption of radiation by solid surfaces, lo- cal heating of fluids by selective absorption from nanoparti- cles, with possible biomedical
Modeling of Heat Transfer in Geothermal Heat Exchangers
Cui, P.; Man, Y.; Fang, Z.
2006-01-01T23:59:59.000Z
Ground-coupled heat pump (GCHP) systems have been gaining increasing popularity for space conditioning in residential and commercial buildings. The geothermal heat exchanger (GHE) is devised for extraction or injection of thermal energy from...
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...
Modeling of Heat Transfer in Rooms in the Modelica Buildings Library
Wetter, Michael
2013-01-01T23:59:59.000Z
of the room heat transfer model in the free open-sourcea layer-by-layer heat transfer model that computes infrared
Parameterization and Analysis of 3-D Solar Radiative Transfer in Clouds: Final Report
Jerry Y. Harrington
2012-09-21T23:59:59.000Z
This document reports on the research that we have done over the course of our two-year project. The report also covers the research done on this project during a 1 year no-cost extension of the grant. Our work has had two main, inter-related thrusts: The first thrust was to characterize the response of stratocumulus cloud structure and dynamics to systematic changes in cloud infrared radiative cooling and solar heating using one-dimensional radiative transfer models. The second was to couple a three-dimensional (3-D) solar radiative transfer model to the Large Eddy Simulation (LES) model that we use to simulate stratocumulus. The purpose of the studies with 3-D radiative transfer was to examine the possible influences of 3-D photon transport on the structure, evolution, and radiative properties of stratocumulus. While 3-D radiative transport has been examined in static cloud environments, few studies have attempted to examine whether the 3-D nature of radiative absorption and emission influence the structure and evolution of stratocumulus. We undertook this dual approach because only a small number of LES simulations with the 3-D radiative transfer model are possible due to the high computational costs. Consequently, LES simulations with a 1-D radiative transfer solver were used in order to examine the portions of stratocumulus parameter space that may be most sensitive to perturbations in the radiative fields. The goal was then to explore these sensitive regions with LES using full 3-D radiative transfer. Our overall goal was to discover whether 3-D radiative processes alter cloud structure and evolution, and whether this may have any indirect implications for cloud radiative properties. In addition, we collaborated with Dr. Tamas Varni, providing model output fields for his attempt at parameterizing 3-D radiative effects for cloud models.
Cloud Properties and Radiative Heating Rates for TWP
Comstock, Jennifer
2013-11-07T23:59:59.000Z
A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.
Cloud Properties and Radiative Heating Rates for TWP
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Comstock, Jennifer
A cloud properties and radiative heating rates dataset is presented where cloud properties retrieved using lidar and radar observations are input into a radiative transfer model to compute radiative fluxes and heating rates at three ARM sites located in the Tropical Western Pacific (TWP) region. The cloud properties retrieval is a conditional retrieval that applies various retrieval techniques depending on the available data, that is if lidar, radar or both instruments detect cloud. This Combined Remote Sensor Retrieval Algorithm (CombRet) produces vertical profiles of liquid or ice water content (LWC or IWC), droplet effective radius (re), ice crystal generalized effective size (Dge), cloud phase, and cloud boundaries. The algorithm was compared with 3 other independent algorithms to help estimate the uncertainty in the cloud properties, fluxes, and heating rates (Comstock et al. 2013). The dataset is provided at 2 min temporal and 90 m vertical resolution. The current dataset is applied to time periods when the MMCR (Millimeter Cloud Radar) version of the ARSCL (Active Remotely-Sensed Cloud Locations) Value Added Product (VAP) is available. The MERGESONDE VAP is utilized where temperature and humidity profiles are required. Future additions to this dataset will utilize the new KAZR instrument and its associated VAPs.
DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2
Not Available
1992-06-01T23:59:59.000Z
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.
DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 1
Not Available
1992-06-01T23:59:59.000Z
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.
DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 3
Not Available
1992-06-01T23:59:59.000Z
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.
Enhancement of Pool Boiling Heat Transfer in Confined Space
Hsu, Chia-Hsiang
2014-05-05T23:59:59.000Z
Pool boiling is an effective method used in many technical applications for a long time. Its highly efficient heat transfer performance results from not only the convection effect but also the phase change process in pool boiling. Pool boiling...
Numerical Study of Flow and Heat Transfer in Rotating Microchannels
Roy, Pratanu
2014-10-07T23:59:59.000Z
Investigation of fluid flow and heat transfer in rotating microchannels is important for centrifugal microfluidics, which has emerged as an advanced technique in biomedical applications and chemical separations. The centrifugal force...
16 Heat Transfer and Air Flow in a Domestic Refrigerator
Paris-Sud XI, Université de
445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR Génie Industriel...............................................447 16.2.1 Studies in Domestic Refrigerators...................................................................................... 451 16.3 Cold Production System in Domestic Refrigerators
Wellbore Heat Transfer Model for Wax Deposition in Permafrost Region
Cui, Xiaoting
2012-05-31T23:59:59.000Z
Producing waxy oil in arctic area may cause wax deposited on the well wall. Since wax deposition is strongly thermal related, accurate heat transfer model is necessary in predicting and preventing wax depostion. A mathematical model was derived...
Non-intrusive characterization of heat transfer fluid aerosol formation
Krishna, Kiran
2001-01-01T23:59:59.000Z
Heat transfer fluids are widely used in the chemical process industry and are available in a wide range of properties. These fluids are flammable above their flash points and can cause explosions. Though the possibility of aerosol explosions has...
Survey and evaluation of techniques to augment convective heat transfer
Bergles A. E.
1965-01-01T23:59:59.000Z
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 ...
Boiling heat transfer on superhydrophilic, superhydrophobic, and superbiphilic surfaces
Attinger, Daniel
Boiling heat transfer on superhydrophilic, superhydrophobic, and superbiphilic surfaces Amy Rachel in revised form 30 October 2012 Accepted 31 October 2012 Keywords: Superhydrophobic Superhydrophilic Biphilic- and nanofabrication, superhydrophilic and superhydrophobic surfaces have been developed. The statics and dynamics
Natural convection heat transfer within horizontal spent nuclear fuel assemblies
Canaan, R.E.
1995-12-01T23:59:59.000Z
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.
Morris, J. F.
1985-03-19T23:59:59.000Z
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.
Heat transfer and oil displacement models for tar sands reservoirs
Ward, C.E.; Ward, G.D.
1984-09-01T23:59:59.000Z
A convective heat transfer model and one dimensional displacement model applicable to tar sands and heavy oils for use with a microcomputer are presented. The convective heat transfer model describes the temperature profiles in a thermal operation. The displacement model offers insight into the effect of process variables on the steam/oil or air/oil ratio of thermal operations. A method is presented for predicting the fuel burn in a fireflood.
Enhanced heat transfer in partially-saturated hydrothermal systems
Bixler, N.E.; Carrigan, C.R.
1986-01-01T23:59:59.000Z
The role of capillarity is potentially important for determining heat transfer in hydrothermal regions. Capillarity allows mixing of phases in liquid/vapor systems and results in enhanced two-phase convection. Comparisons involving a numerical model with capillarity and analytical models without indicate that heat transfer can be enhanced by about an order of magnitude. Whether capillarity can be important for a particular hydrothermal region will depend on the nature of mineral precipitation as well as pore and fracture size distributions.
Mpemba effect, Newton cooling law and heat transfer equation
Vladan Pankovic; Darko V. Kapor
2012-12-11T23:59:59.000Z
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).
Heat transfer enhancement resulting from induction electrohydrodynamic pumping
Margo, Bryan David
1992-01-01T23:59:59.000Z
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...
Transient Heat Transfer in TCAP Coils
Steimke, J.L.
1999-03-09T23:59:59.000Z
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.
Literature survey of heat transfer enhancement techniques in refrigeration applications
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
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.
Heat transfers in a double-skin roof ventilated by natural convection in summer time
Biwole, Pascal; Pompeo, C
2013-01-01T23:59:59.000Z
The double-skin roofs investigated in this paper are formed by adding a metallic screen on an existing sheet metal roof. The system enhances passive cooling of dwellings and can help diminishing power costs for air conditioning in summer or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers are investigated. Depending on its surface properties, the screen reflects a large amount of oncoming solar radiation. Natural convection in the channel underneath drives off the residual heat. The bi-dimensional numerical simulation of the heat transfers through the double skin reveals the most important parameters for the system's efficiency. They are, by order of importance, the sheet metal surface emissivity, the screen internal and external surface emissivity, the insulation thickness and the inclination angle for a channel width over 6 cm. The influence of those parameters on Rayleigh and Nusselt numbers is also investigated. Temperature and air velocity profiles on seve...
Proceedings of HT2005 2005 ASME Summer Heat Transfer Conference
Aguilar, Guillermo
Proceedings of HT2005 2005 ASME Summer Heat Transfer Conference July 17-22, 2005, San Francisco absorption and increasing the thickness of the protected region. A 2D finite volume numerical code based interface location density (kg m-3 ) 1 Copyright © 2005 by ASME Proceedings of HT2005 2005 ASME Summer Heat
Heat transfer model of above and underground insulated piping systems
Kwon, K.C.
1998-07-01T23:59:59.000Z
A simplified heat transfer model of above and underground insulated piping systems was developed to perform iterative calculations for fluid temperatures along the entire pipe length. It is applicable to gas, liquid, fluid flow with no phase change. Spreadsheet computer programs of the model have been developed and used extensively to perform the above calculations for thermal resistance, heat loss and core fluid temperature.
Heat transfer in the plate heat exchanger of an ammonia-synthesis column
Obolentsev, Y.G.; Chus', M.S.; Norobchanskii, O.A.; Teplitshi, Y.S.; Tovazhnyanskii, L.L.
1983-01-01T23:59:59.000Z
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.
INVESTIGATING THE EFFECT OF HEATING METHOD ON POOL BOILING HEAT TRANSFER
Kandlikar, Satish
INVESTIGATING THE EFFECT OF HEATING METHOD ON POOL BOILING HEAT TRANSFER Satish G. Kandlikar Department Rochester Institute of Technology Rochester, NY, USA Phone: (716) 475-6728; Fax: (716) 475-7710 E-mail: SGKEME@RIT.EDU ABSTRACT Pool boiling experiments are generally conducted with electrically heated
Error Analysis of Heat Transfer for Finned-Tube Heat-Exchanger Text-Board
Chen, Y.; Zhang, J.
2006-01-01T23:59:59.000Z
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...
Gustavsen, Arild; Arasteh, Dariush; Jelle, Bjorn Petter; Curcija, Charlie; Kohler, Christian
2008-09-11T23:59:59.000Z
While window frames typically represent 20-30% of the overall window area, their impact on the total window heat transfer rates may be much larger. This effect is even greater in low-conductance (highly insulating) windows that incorporate very low-conductance glazing. Developing low-conductance window frames requires accurate simulation tools for product research and development. Based on a literature review and an evaluation of current methods of modeling heat transfer through window frames, we conclude that current procedures specified in ISO standards are not sufficiently adequate for accurately evaluating heat transfer through the low-conductance frames. We conclude that the near-term priorities for improving the modeling of heat transfer through low-conductance frames are: (1) Add 2D view-factor radiation to standard modeling and examine the current practice of averaging surface emissivity based on area weighting and the process of making an equivalent rectangular frame cavity. (2) Asses 3D radiation effects in frame cavities and develop recommendation for inclusion into the design fenestration tools. (3) Assess existing correlations for convection in vertical cavities using CFD. (4) Study 2D and 3D natural convection heat transfer in frame cavities for cavities that are proven to be deficient from item 3 above. Recommend improved correlations or full CFD modeling into ISO standards and design fenestration tools, if appropriate. (5) Study 3D hardware short-circuits and propose methods to ensure that these effects are incorporated into ratings. (6) Study the heat transfer effects of ventilated frame cavities and propose updated correlations.
Heat transfer to a silicon carbide/water nanofluid.
Yu, W.; France , D. M.; Smith, D. S.; Singh, D.; Timofeeva, E. V.; Routbort, J. L.; Univ. of Illinois at Chicago
2009-07-01T23:59:59.000Z
Heat transfer experiments were performed with a water-based nanofluid containing 170-nm silicon carbide particles at a 3.7% volume concentration and having potential commercial viability. Heat transfer coefficients for the nanofluid are presented for Reynolds numbers ranging from 3300 to 13,000 and are compared to the base fluid water on the bases of constant Reynolds number, constant velocity, and constant pumping power. Results were also compared to predictions from standard liquid correlations and a recently altered nanofluid correlation. The slip mechanisms of Brownian diffusion and thermophoresis postulated in the altered correlation were investigated in a series of heating and cooling experiments.
Thole, Karen A.
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
O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert
2002-08-01T23:59:59.000Z
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.
Modeling of Heat Transfer in Geothermal Heat Exchangers
Cui, P.; Man, Y.; Fang, Z.
2006-01-01T23:59:59.000Z
, 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...
Temperature and Heat Transfer Measurements Cengiz Camci
Camci, Cengiz
mainly because of thermal reasons. Satel- lite thermal management systems, hot sections of propulsion systems, combustors, aerodynamic heating of supersonic/ hypersonicvehiclesurfaces is not meaningful, since there are no agitated particles in empty space. A body in which "thermal agitation
Pool boiling heat transfer characteristics of nanofluids
Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology
2007-01-01T23:59:59.000Z
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 ...
Active heat transfer enhancement in integrated fan heat sinks
Staats, Wayne Lawrence
2012-01-01T23:59:59.000Z
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 ...
Modeling Granular Materials as Compressible Non-Linear Fluids: Heat Transfer Boundary Value Problems
Massoudi, M.C.; Tran, P.X.
2006-01-01T23:59:59.000Z
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.
Research on Convective Heat Transfer and Mass Transfer of the Evaporator in Micro/Mini-Channel
Su, J.; Li, J.
2006-01-01T23:59:59.000Z
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...
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)
1998-07-21T23:59:59.000Z
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.
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Phillips, B.A.; Zawacki, T.S.
1998-07-21T23:59:59.000Z
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.
ECI International Conference on Boiling Heat Transfer Florianpolis-SC-Brazil, 3-7 May 2009
Yanikoglu, Berrin
. Recently the study of heat transfer in micro pin fin heat sinks has been extended to flow boiling by Koar and Peles (2006c), who studied boiling heat transfer in a hydrofoil-based micro pin fin heat sinkECI International Conference on Boiling Heat Transfer Florianópolis-SC-Brazil, 3-7 May 2009
A 2-D Test Problem for CFD Modeling Heat Transfer in Spent Fuel Transfer Cask Neutron Shields
Zigh, Ghani; Solis, Jorge; Fort, James A.
2011-01-14T23:59:59.000Z
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
Forced convective heat transfer in channels with internal longitudinal fins
Ong, Liang Eng
1987-01-01T23:59:59.000Z
and f in surface temperatures (g ? $b), and the local surface heat flux (q"/Q"). The relative amounts of heat transfer from the exposed channel wall, the surface of the fin along the fin axis, and the fin tip are also calculated individually... heat flux on the tip of the fin. 18 4. RESULTS AND DISCUSSION The results of the computational investigation are presented in this section. They consist of the d istr ibut ions of the d imens ionless temperature (4w ? gb), and the heat flux (q"/Q...
Shape factors in conductive heat transfer
Faulkner, Richard Campbell
1954-01-01T23:59:59.000Z
flow bg gonduotion 'between flat parallel plates with insulated edges and a uniform oxoes-seotional area for heat flow. )see Pig. IX) Kx. steady state, -- 0 Shen ? X :, . x a eg Sub st ' tut ills boundary cordi'tionel el (0) e e@ to + ((t...
Heat transfer coefficients for atmospheric coolers
Robinson, Robert McCollum
1950-01-01T23:59:59.000Z
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 1 0 6 kppendixo ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 110 li Heating System. . ~ ~ ~ ~ ~ . ~ . ? ~ ~ ~ ~ Page ~ . ~ 25 2. Cooling System. . . . . . . ~ ~ ~ ~ ~ 28 3. Outside F11m Coeffioient versus... per Minute. . . . 95 6i Outside Film Coeffioient versus Tube Row Depth; Shell Side Rata, 21 Gallons per Minuteo ~ ~ ~ ~ ~ ~ o ~ e ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ I ~ ~ Ii ~ ~ o ~ ~ ~ ~ 96 VS Outside F1lm Coeffioient vers1s Tube Row Depth...
Preliminary Heat Transfer Studies for the Double Shell Tanks (DST) Transfer Piping
HECHT, S.L.
2000-02-15T23:59:59.000Z
Heat transfer studies were made to determine the thermal characteristics of double-shell tank transfer piping under both transient and steady-state conditions. A number of design and operation options were evaluated for this piping system which is in its early design phase.
A vectorized heat transfer model for solid reactor cores
Rider, W.J.; Cappiello, M.W.; Liles, D.R.
1990-01-01T23:59:59.000Z
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.
Nuclear reactor fuel element having improved heat transfer
Garnier, J.E.; Begej, S.; Williford, R.E.; Christensen, J.A.
1982-03-03T23:59:59.000Z
A nuclear reactor fuel element having improved heat transfer between fuel material and cladding is described. The element consists of an outer cladding tube divided into an upper fuel section containing a central core of fissionable or mixed fissionable and fertile fuel material, slightly smaller in diameter than the inner surface of the cladding tube and a small lower accumulator section, the cladding tube being which is filled with a low molecular weight gas to transfer heat from fuel material to cladding during irradiation. A plurality of essentially vertical grooves in the fuel section extend downward and communicate with the accumulator section. The radial depth of the grooves is sufficient to provide a thermal gradient between the hot fuel surface and the relatively cooler cladding surface to allow thermal segregation to take place between the low molecular weight heat transfer gas and high molecular weight fission product gases produced by the fuel material during irradiation.
Heat and mass transfer analysis of a desiccant dehumidifier matrix
Pesaran, A.A.
1986-07-01T23:59:59.000Z
This report documents the SERI Single-Blow Test Facility's design, fabrication, and testing for characterizing desiccant dehumidifiers for solar cooling applications. The first test article, a silica-gel parallel-plate dehumidifier with highly uniform passages, was designed and fabricated. Transient heat and mass transfer data and pressure drop data across the dehumidifier were obtained. Available heat and mass transfer models were extended to the parallel-place geometry, and the experimental data were compared with model predictions. Pressure drop measurements were also compared with model predictions of the fully developed laminar flow theory. The comparisons between the lumped-capacitance model and the experimental data were satisfactory. The pressure drop data compared satisfactorily with the theory (within 15%). A solid-side resistance model that is more detailed and does not assume symmetrical diffusion in particles was recommended for performance. This study has increased our understanding of the heat and mass transfer in silica gel parallel-plate dehumidifiers.
Modelling of heat transfer and crystallation kinetics in thermoplastic pultrusion
Carlsson, A.; Astroem, B.T. [Royal Institute of Technology, Stockholm (Sweden)
1996-12-31T23:59:59.000Z
While pultrusion with thermoset resins has been widely analyses, there is a scarcity of knowledge about pultrusion with thermoplastic resins. The objective of the present study is to develop a realistic heat transfer model for the entire thermoplastic pultrusion process, from room temperature prepreg, through preheater and dies, to room temperature composite. The aim is to determine dominating heat transfer mechanisms and to be able to predict residual stresses and crystallinity, which depend on the thermal history of the composite. A complete heat transfer model including crystallization kinetics is presented. Results show reasonably good agreement with experimental data and the model thus provides a tool for process simulations with a variety of processing parameters.
Soljačić, Marin
2012-01-01T23:59:59.000Z
in graphene Ognjen Ilic,1,* Marinko Jablan,2 John D. Joannopoulos,1 Ivan Celanovic,3 Hrvoje Buljan,2 and Marin-field radiation transfer between two closely separated graphene sheets. The dependence of near-field heat exchange interband or intraband processes. We predict maximum transfer at low doping and for plasmons in two graphene
Zhao, J.M., E-mail: jmzhao@hit.edu.cn [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, People's Republic of China (China); Tan, J.Y., E-mail: tanjy@hit.edu.cn [School of Auto Engineering, Harbin Institute of Technology at Weihai, 2 West Wenhua Road, Weihai 264209, People's Republic of China (China); Liu, L.H., E-mail: lhliu@hit.edu.cn [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001, People's Republic of China (China); School of Auto Engineering, Harbin Institute of Technology at Weihai, 2 West Wenhua Road, Weihai 264209, People's Republic of China (China)
2013-01-01T23:59:59.000Z
A new second order form of radiative transfer equation (named MSORTE) is proposed, which overcomes the singularity problem of a previously proposed second order radiative transfer equation [J.E. Morel, B.T. Adams, T. Noh, J.M. McGhee, T.M. Evans, T.J. Urbatsch, Spatial discretizations for self-adjoint forms of the radiative transfer equations, J. Comput. Phys. 214 (1) (2006) 12-40 (where it was termed SAAI), J.M. Zhao, L.H. Liu, Second order radiative transfer equation and its properties of numerical solution using finite element method, Numer. Heat Transfer B 51 (2007) 391-409] in dealing with inhomogeneous media where some locations have very small/zero extinction coefficient. The MSORTE contains a naturally introduced diffusion (or second order) term which provides better numerical property than the classic first order radiative transfer equation (RTE). The stability and convergence characteristics of the MSORTE discretized by central difference scheme is analyzed theoretically, and the better numerical stability of the second order form radiative transfer equations than the RTE when discretized by the central difference type method is proved. A collocation meshless method is developed based on the MSORTE to solve radiative transfer in inhomogeneous media. Several critical test cases are taken to verify the performance of the presented method. The collocation meshless method based on the MSORTE is demonstrated to be capable of stably and accurately solve radiative transfer in strongly inhomogeneous media, media with void region and even with discontinuous extinction coefficient.
Heat transfer education : Keeping it relevant and vibrant.
Khounsary, A. M.
1998-08-14T23:59:59.000Z
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.
Effect of turbulent heat transfer on continuous ingot solidification
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
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.
Enhanced boiling heat transfer in horizontal test bundles
Trewin, R.R.; Jensen, M.K.; Bergles, A.E.
1994-08-01T23:59:59.000Z
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.
Combined heat and mass transfer device for improving separation process
Tran, Thanh Nhon (Flossmoor, IL)
1999-01-01T23:59:59.000Z
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.
Combined heat and mass transfer device for improving separation process
Tran, T.N.
1999-08-24T23:59:59.000Z
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.
A simplistic model of cyclic heat transfer phenomena in closed spaces
Lee, K.
1983-08-01T23:59:59.000Z
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.
Convective heat transfer inside passive solar buildings
Jones, R.W.; Balcomb, J.D.; Yamaguchi, K.
1983-01-01T23:59:59.000Z
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.
Convective heat transfer inside passive solar buildings
Jones, R.W.; Balcomb, J.D.; Yamaguchi, K.
1983-11-01T23:59:59.000Z
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.
Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter
American Society for Testing and Materials. Philadelphia
2005-01-01T23:59:59.000Z
1.1 This test method covers the design and use of a thin metallic calorimeter for measuring heat transfer rate (also called heat flux). Thermocouples are attached to the unexposed surface of the calorimeter. A one-dimensional heat flow analysis is used for calculating the heat transfer rate from the temperature measurements. Applications include aerodynamic heating, laser and radiation power measurements, and fire safety testing. 1.2 Advantages 1.2.1 Simplicity of ConstructionThe calorimeter may be constructed from a number of materials. The size and shape can often be made to match the actual application. Thermocouples may be attached to the metal by spot, electron beam, or laser welding. 1.2.2 Heat transfer rate distributions may be obtained if metals with low thermal conductivity, such as some stainless steels, are used. 1.2.3 The calorimeters can be fabricated with smooth surfaces, without insulators or plugs and the attendant temperature discontinuities, to provide more realistic flow conditions for ...
Near-field heat transfer between a nanoparticle and a rough surface
Svend-Age Biehs; Jean-Jacques Greffet
2011-03-11T23:59:59.000Z
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.
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
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.
Three-dimensional Radiative Transfer with Multilevel Atoms
P. Fabiani Bendicho; J. Trujillo Bueno
2007-10-29T23:59:59.000Z
The efficient numerical solution of Non-LTE multilevel transfer problems requires the combination of highly convergent iterative schemes with fast and accurate formal solution methods of the radiative transfer (RT) equation. This contribution begins presenting a method for the formal solution of the RT equation in three-dimensional (3D) media with horizontal periodic boundary conditions. This formal solver is suitable for both, unpolarized and polarized 3D radiative transfer and it can be easily combined with the iterative schemes for solving non-LTE multilevel transfer problems that we have developed over the last few years. We demonstrate this by showing some schematic 3D multilevel calculations that illustrate the physical effects of horizontal radiative transfer. These Non-LTE calculations have been carried out with our code MUGA 3D, a 3D multilevel Non-LTE code based on the Gauss-Seidel iterative scheme that Trujillo Bueno and Fabiani Bendicho (1995) developed for RT applications.
Evaporation and Condensation Heat Transfer Performance of Flammable Refrigerants in a
Oak Ridge National Laboratory
Evaporation and Condensation Heat Transfer Performance of Flammable Refrigerants in a Brazed Plate and Condensation Heat Transfer Performance of Flammable Refrigerants in a Brazed Plate Heat Exchanger Sheila C ........................................................... 8 3. Average relative difference (%) in calculated heat transfer rates for refrigerants and HTF
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with
Paris-Sud XI, Université de
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
EFFECT OF REACTOR HEAT TRANSFER LIMITATIONS ON CO PREFERENTIAL OXIDATION
Besser, Ronald S.
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
Integration of Heat Transfer, Stress, and Particle Trajectory Simulation
Thuc Bui; Michael Read; Lawrence ives
2012-05-17T23:59:59.000Z
Calabazas Creek Research, Inc. developed and currently markets Beam Optics Analyzer (BOA) in the United States and abroad. BOA is a 3D, charged particle optics code that solves the electric and magnetic fields with and without the presence of particles. It includes automatic and adaptive meshing to resolve spatial scales ranging from a few millimeters to meters. It is fully integrated with CAD packages, such as SolidWorks, allowing seamless geometry updates. The code includes iterative procedures for optimization, including a fully functional, graphical user interface. Recently, time dependent, particle in cell capability was added, pushing particles synchronically under quasistatic electromagnetic fields to obtain particle bunching under RF conditions. A heat transfer solver was added during this Phase I program. Completed tasks include: (1) Added a 3D finite element heat transfer solver with adaptivity; (2) Determined the accuracy of the linear heat transfer field solver to provide the basis for development of higher order solvers in Phase II; (3) Provided more accurate and smoother power density fields; and (4) Defined the geometry using the same CAD model, while maintaining different meshes, and interfacing the power density field between the particle simulator and heat transfer solvers. These objectives were achieved using modern programming techniques and algorithms. All programming was in C++ and parallelization in OpenMP, utilizing state-of-the-art multi-core technology. Both x86 and x64 versions are supported. The GUI design and implementation used Microsoft Foundation Class.
RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1
Paris-Sud XI, UniversitĂ© de
509 RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1 C. JOHANNES Service de Recherches AppliquĂ©es, L'hĂ©lium hypercritique. Abstract. - Conditions of thermal exchange in helium 1 are reviewed. Pool boiling thermosi- phon are given. Use of hypercritical helium. REVUE DE PHYSIQUE APPLIQUĂ?E TOME 6, DĂ?CEMBRE 1971, PAGE Introduction
Heat transfer in inertial confinement fusion reactor systems
Hovingh, J.
1980-04-23T23:59:59.000Z
The short time and deposition distance for the energy from inertial fusion products results in local peak power densities on the order of 10/sup 18/ watts/m/sup 3/. This paper presents an overview of the various inertial fusion reactor designs which attempt to reduce these peak power intensities and describes the heat transfer considerations for each design.
FINITE ELEMENT METHOD IN FLUID MECHANICS & HEAT TRANSFER
Camci, Cengiz
completed this course should be able to perform quick analysis of small problems using the finite element of Fluid Mechanics and Heat Transfer An Introduction to Finite Element Analysis Using "Galerkin Weak of Euler's Equation in Finite Element Analysis Generalized Form of Euler's Equation in Three Dimensional
COMPARING THE EFFECT OF RADIATIVE TRANSFER SCHEMES ON CONVECTION SIMULATIONS
Tanner, Joel D.; Basu, Sarbani; Demarque, Pierre [Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)
2012-11-10T23:59:59.000Z
We examine the effect of different radiative transfer schemes on the properties of three-dimensional (3D) simulations of near-surface stellar convection in the superadiabatic layer, where energy transport transitions from fully convective to fully radiative. We employ two radiative transfer schemes that fundamentally differ in the way they cover the 3D domain. The first solver approximates domain coverage with moments, while the second solver samples the 3D domain with ray integrations. By comparing simulations that differ only in their respective radiative transfer methods, we are able to isolate the effect that radiative efficiency has on the structure of the superadiabatic layer. We find the simulations to be in good general agreement, but they show distinct differences in the thermal structure in the superadiabatic layer and atmosphere.
Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants
Mathur, Anoop [Terrafore Inc.] [Terrafore Inc.
2013-08-14T23:59:59.000Z
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.
MHD Effects on Heat Transfer in a Molten Salt Blanket
Smolentsev, Sergey; Miraghaie, Reza; Abdou, Mohamed [University of California (United States)
2005-04-15T23:59:59.000Z
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.
Mass and heat transfer model of Tubular Solar Still
Ahsan, Amimul [University Putra Malaysia, Dept. Civil Engineering, Faculty of Engineering, 43400 UPM Serdang, Selangor (Malaysia); Fukuhara, Teruyuki [University of Fukui, Graduate School of Engineering, 3-9-1 Bunkyo, Fukui 910-8507 (Japan)
2010-07-15T23:59:59.000Z
In this paper, a new mass and heat transfer model of a Tubular Solar Still (TSS) was proposed incorporating various mass and heat transfer coefficients taking account of the humid air properties inside the still. The heat balance of the humid air and the mass balance of the water vapor in the humid air were formulized for the first time. As a result, the proposed model enabled to calculate the diurnal variations of the temperature, water vapor density and relative humidity of the humid air, and to predict the hourly condensation flux besides the temperatures of the water, cover and trough, and the hourly evaporation flux. The validity of the proposed model was verified using the field experimental results carried out in Fukui, Japan and Muscat, Oman in 2008. The diurnal variations of the calculated temperatures and water vapor densities had a good agreement with the observed ones. Furthermore, the proposed model can predict the daily and hourly production flux precisely. (author)
Boiling Heat Transfer on Superhydrophilic, Superhydrophobic, and Superbiphilic Surfaces
Betz, Amy Rachel; Kim, Chang-Jin 'CJ'; Attinger, Daniel
2012-01-01T23:59:59.000Z
With recent advances in micro- and nanofabrication, superhydrophilic and superhydrophobic surfaces have been developed. The statics and dynamics of fluids on these surfaces have been well characterized. However, few investigations have been made into the potential of these surfaces to control and enhance other transport phenomena. In this article, we characterize pool boiling on surfaces with wettabilities varied from superhydrophobic to superhydrophilic, and provide nucleation measurements. The most interesting result of our measurements is that the largest heat transfer coefficients are reached not on surfaces with spatially uniform wettability, but on biphilic surfaces, which juxtapose hydrophilic and hydrophobic regions. We develop an analytical model that describes how biphilic surfaces effectively manage the vapor and liquid transport, delaying critical heat flux and maximizing the heat transfer coefficient. Finally, we manufacture and test the first superbiphilic surfaces (juxtaposing superhydrophobic ...
Zhang, Yuwen
transfer Non-equilibrium Dual-phase lag a b s t r a c t Based on a nonequilibrium heat transfer model
Modelling of Radiative Transfer in Light Sources
Eindhoven, Technische Universiteit
. . . . . . . . . . . . . . . 30 2.5.3 Temperature distribution . . . . . . . . . . . . . . . . . . . . . . . . . 32 2-X radiative transition that is responsible for the sulfur lamp's bright sun-like spectrum #12;Contents 1
Reduce Radiation Losses from Heating Equipment
Not Available
2006-01-01T23:59:59.000Z
This DOE Industrial Technologies Program tip sheet describes how to save energy and costs by reducing expensive heat losses from industrial heating equipment, such as furnaces.
Heat Transfer Analysis for a Fixed CST Column
Lee, S.Y.
2004-02-19T23:59:59.000Z
In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, a transient two-dimensional heat transfer model that includes the conduction process neglecting the convection cooling mechanism inside the crystalline silicotitanate (CST) column has been constructed and heat transfer calculations made for the present design configurations. For this situation, a no process flow condition through the column was assumed as one of the reference conditions for the simulation of a loss-of-flow accident. A series of the modeling calculations has been performed using a computational heat transfer approach. Results for the baseline model indicate that transit times to reach 130 degrees Celsius maximum temperature of the CST-salt solution column are about 96 hours when the 20-in CST column with 300 Ci/liter heat generation source and 25 degrees Celsius initial column temperature is cooled by natural convection of external air as a primary heat transfer mechanism. The modeling results for the 28-in column equipped with water jacket systems on the external wall surface of the column and water coolant pipe at the center of the CST column demonstrate that the column loaded with 300 Ci/liter heat source can be maintained non-boiling indefinitely. Sensitivity calculations for several alternate column sizes, heat loads of the packed column, engineered cooling systems, and various ambient conditions at the exterior wall of the column have been performed under the reference conditions of the CST-salt solution to assess the impact of those parameters on the peak temperatures of the packed column for a given transient time. The results indicate that a water-coolant pipe at the center of the CST column filled with salt solution is the most effective one among the potential design parameters related to the thermal energy dissipation of decay heat load. It is noted that the cooling mechanism at the wall boundary of the column has significant impact on maximum and wall temperatures of the column. In addition, the results computed by the present model were verified by the theoretical results. The analysis results will provide quantitative information associated with the process heat control and management of the CST base design. For example, transient responses of the CST system under a loss-of-flow accident condition will provide safety design information for an emergency cooling system of the column.
Adaptive Ray Tracing for Radiative Transfer around Point Sources
Tom Abel; Benjamin D. Wandelt
2001-11-01T23:59:59.000Z
We describe a novel adaptive ray tracing scheme to solve the equation of radiative transfer around point sources in hydrodynamical simulations. The angular resolution adapts to the local hydrodynamical resolution and hence is of use for adaptive meshes as well as adaptive smooth particle hydrodynamical simulations. Recursive creation of rays ensures ease of implementation. The multiple radial integrations needed to solve the time dependent radiative transfer are sped up significantly using a quad-tree once the rays are cast. Simplifications advantageous for methods with one radiation source are briefly discussed. The suggested method is easily generalized to speed up Monte Carlo radiative transfer techniques. In summary a nearly optimal use of long characteristics is presented and aspects of its implementation and comparison to other methods are given.
FLOW AND HEAT TRANSFER IN MICROFLUIDIC DEVICES WITH APPLICATION TO OPTOTHERMAL
Bahrami, Majid
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
Jet impingement heat transfer in two-pass rotating rectangular channels
Zhang, Yuming
1996-01-01T23:59:59.000Z
The combined effects of rotation and jet impingement on local heat transfer in a two-pass rotating rectangular channel is studied. The results of an experimental investigation on the surface heat transfer coefficients under a perforated plate...
Impingement cooling and heat transfer measurement using transient liquid crystal technique
Huang, Yizhe
1996-01-01T23:59:59.000Z
A heat transfer study on jet impingement cooling is presented. The study focuses on the effect of impingement jet flow rate, jet angle, and flow exit direction on various target surface heat transfer distributions. A two-channel test section...
A visualization comparison of convective flow boiling heat transfer augmentation devices
Lundy, Brian Franklin
1998-01-01T23:59:59.000Z
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...
Heat transfer during film condensation of potassium vapor on a horizontal plate
Meyrial, Paul M.
1968-01-01T23:59:59.000Z
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 ...
Remote administration and user experience evaluation of the iLab Heat Transfer Project site
Graham, Rodney K
2006-01-01T23:59:59.000Z
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 ...
Modeling of fuel-to-steel heat transfer in core disruptive accidents
Smith, Russell Charles
1980-01-01T23:59:59.000Z
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 ...
Measurements of Heat Transfer Coefficients to Cylinders in Shallow Bubble Columns
Tow, Emily W.
High heat transfer coefficients and large interfacial areas make bubble columns ideal for dehumidification. However, the effect of geometry on the heat transfer coefficients outside cooling coils in shallow bubble columns, ...
air-side heat transfer: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
space to satisfy the space cooling load (free cooling... Shami, U. F. 1996-01-01 12 HEAT TRANSFER ANALYSIS OF A PULSE DETONATION Engineering Websites Summary: HEAT TRANSFER...
Heat transfer rates for filmwise, dropwise, and superhydrophobic condensation on silicon substrates
Hery, Travis M
2011-01-01T23:59:59.000Z
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 ...
A Prototype Roof Deck Designed to Self-Regulate Deck Temperature and Reduce Heat Transfer
Miller, William A [ORNL] [ORNL
2011-01-01T23:59:59.000Z
A prototype roof and attic assembly exploits the use of radiation, convection and insulation controls to reduce its peak day heat transfer by almost 85 percent of the heat transfer crossing a conventional roof and attic assembly. The assembly exhibits attic air temperatures that do not exceed the maximum daily outdoor ambient temperature. The design includes a passive ventilation scheme that pulls air from the soffit and attic into an inclined air space above the roof deck. The design complies with fire protection codes because the air intake is internal and closed to the elements. Field data were benchmarked against an attic computer tool and simulations made for new and retrofit constructions in hot, moderate and cold climates to gauge the cost of energy savings and potential payback.
A Prototype Roof Deck Designed to Self-Regulate Deck Temperature and Reduce Heat Transfer
Miller, William A [ORNL] [ORNL
2011-01-01T23:59:59.000Z
A prototype roof and attic assembly exploits the use of radiation, convection and insulation controls to reduce the heat transfer penetrating its roof deck by almost 85% of the heat transfer crossing a conventional roof and attic assembly. The assembly exhibited attic air temperatures that did not exceed the peak day outdoor ambient temperature. The design includes a passive ventilation scheme that pulls air from the soffit and attic into an inclined air space above the deck. The design complies with fire protection codes because the air intake is internal and closed to the elements. Field data were benchmarked against an attic computer tool and simulations made for new and retrofit home constructions in hot, moderate and cold climates to access economics for the assembly.
Numerical methods for multidimensional radiative transfer
radiation plays a key role in various scientific applications, such as combustion physics, thermonuclear fusion and astrophysics. The equa- tion describing the transport of photons or neutrons through a medium
MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA "BUILDINGS" LIBRARY
describes the implementation of the room heat transfer model in the free open-source Modelica "Buildings
A Numerical Study of a 3D Bioheat Transfer Problem with Different Spatial Heating \\Lambda
Zhang, Jun
, and thermal parameter estimation. 1 #12; 2 Heat Transfer Model Figure 1 reflects a typical cancer hyperthermia
Optical Properties of Saharan Dust and Asian Dust: Application to Radiative Transfer Simulations
Fang, Guangyang
2012-07-16T23:59:59.000Z
properties for radiative transfer simulations. Using a Rapid Radiative Transfer Model (RRTM), the radiative forcing of mineral dust was computed at both the top of the atmosphere and the surface. By analyzing samples from various in-situ measurements, we...
Heat transfer modeling of dry spent nuclear fuel storage facilities
Lee, S.Y.
1999-07-01T23:59:59.000Z
The present work was undertaken to provide heat transfer model that accurately predicts the thermal performance of dry spent nuclear fuel storage facilities. One of the storage configurations being considered for DOE Aluminum-clad Spent Nuclear Fuel (Al-SNF), such as the Material and Testing Reactor (MTR) fuel, is in a dry storage facility. To support design studies of storage options a computational and experimental program has been conducted at the Savannah River Site (SRS). The main objective is to develop heat transfer models including natural convection effects internal to an interim dry storage canister and to geologic codisposal Waste Package (WP). Calculated temperatures will be used to demonstrate engineering viability of a dry storage option in enclosed interim storage and geologic repository WP and to assess the chemical and physical behaviors of the Al-SNF in the dry storage facilities. The current paper describes the modeling approaches and presents the computational results along with the experimental data.
Heat Transfer Modeling of Dry Spent Nuclear Fuel Storage Facilities
Lee, S.Y.
1999-01-13T23:59:59.000Z
The present work was undertaken to provide heat transfer model that accurately predicts the thermal performance of dry spent nuclear fuel storage facilities. One of the storage configurations being considered for DOE Aluminum-clad Spent Nuclear Fuel (Al-SNF), such as the Material and Testing Reactor (MTR) fuel, is in a dry storage facility. To support design studies of storage options a computational and experimental program has been conducted at the Savannah River Site (SRS). The main objective is to develop heat transfer models including natural convection effects internal to an interim dry storage canister and to geological codisposal Waste Package (WP). Calculated temperatures will be used to demonstrate engineering viability of a dry storage option in enclosed interim storage and geological repository WP and to assess the chemical and physical behaviors of the Al-SNF in the dry storage facilities. The current paper describes the modeling approaches and presents the computational results along with the experimental data.
Boyer, Edmond
Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated has been developed based on periodic excitation by Joule effect and infrared thermography measurement. It has been applied to measure heat transfer coefficients of water flowing in a round tube
Chen, Du; Bogy, David B.
2010-01-01T23:59:59.000Z
Bogy, D.B. : A heat transfer model for thermal ?uctuation inA phenomenological heat transfer model for the molecular gasA generalized heat transfer model for thin ?lm bearings at
Nottrott, A.; Onomura, S.; Inagaki, A.; Kanda, M.; Kleissl, J.
2011-01-01T23:59:59.000Z
Vortex structure and heat transfer in turbulent flow over asurface, Proc. 5 th Int. Heat Transfer Conf. 3 (1974) 129-a vertical plate, J. Heat Transfer 109(1) [13] K. Patel,
Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal Thermography
Ghajar, Afshin J.
62 TC02-007 Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal thermography (LCT) method was developed for surface temperature measurements on a horizontal 2000m macro-tube and 1000m micro-tube. In the single-phase heat transfer experiments, the fully-developed flow heat transfer
Heat Transfer Engineering, 29(9):793804, 2008 Copyright C Taylor and Francis Group, LLC
Ghajar, Afshin J.
for Laminar and Turbulent Flow Convection Heat Transfer in a Horizontal Tube Using Artificial Neural Network. INTRODUCTION Heat transfer inside horizontal tubes in the laminar, transi- tional, and turbulent flow regimes was used to develop empirical correlations for laminar and turbulent heat transfer in a horizontal tube
Int. Symp. on Heat Transfer in Gas Turbine Systems 9 14 August, 2009, Antalya, Turkey
Camci, Cengiz
for turbine aero heat transfer work performed under rotational conditions. A flow coefficient and a loading candidates to generate very realistic gas turbine heat transfer data, the initial investment made generate an accurately measurable amount of heat transfer from the gas side to turbine blades in a linear
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
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
HEAT TRANSFER ON A HYPERSONIC SPHERE WITH DIFFUSE RAREFIED-GAS INJECTION
Riabov, Vladimir V.
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
Heat Transfer Engineering, 28(6):525540, 2007 Copyright C Taylor and Francis Group, LLC
Ghajar, Afshin J.
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
FLIHY EXPERIMENTAL FACILITIES FOR STUDYING OPEN CHANNEL TURBULENT FLOWS AND HEAT TRANSFER
California at Los Angeles, University of
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
Heat Transfer Engineering, 27(5):2338, 2006 Copyright C Taylor and Francis Group, LLC
Ghajar, Afshin J.
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
Flow Boiling Heat Transfer Coefficient In Minichannels Correlation and Trends Satish G. Kandlikar
Kandlikar, Satish
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
Proceedings of HT2007 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference
Ghajar, Afshin J.
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
Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based
Le Roy, Robert J.
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
Scaling of Heat Transfer Coefficients Along Louvered Fins A. C. Lyman1
Thole, Karen A.
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
SINGLE-PHASE LIQUID HEAT TRANSFER IN PLAIN AND ENHANCED MICROCHANNELS Mark E. Steinke
Kandlikar, Satish
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
Assignment 6: Heat Transfer Page 1 of 8 600.112: Introduction to Programming
Fröhlich, Peter
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
Heat transfer in soft nanoscale interfaces: the influence of interface curvature
Kjelstrup, Signe
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
A Scaleless Snake: Tests of the Role of Reptilian Scales in Water Loss and Heat Transfer
Bennett, Albert F.
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
Convective heat transfer as a function of wavelength: Implications for the cooling of the Earth
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
Nanoscale Heat Transfer at Contact Between a Hot Tip and a Substrate Stphane Lefvre
Boyer, Edmond
Nanoscale Heat Transfer at Contact Between a Hot Tip and a Substrate Stéphane Lefčvre 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
FliHy experimental facilities for studying open channel turbulent flows and heat transfer
Abdou, Mohamed
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
Convective heat transfer characteristics of China RP-3 aviation kerosene at supercritical pressure
Guo, Zhixiong "James"
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
Heat Transfer on a Hypersonic Sphere with Gas Injection Vladimir V. Riabov
Riabov, Vladimir V.
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
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law
Boyer, Edmond
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
Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a,
Kandlikar, Satish
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
Nonaqueous purification of mixed nitrate heat transfer media
Fiorucci, Louis C. (Hamden, CT); Morgan, Michael J. (Guilford, CT)
1983-12-20T23:59:59.000Z
A nonaqueous, in-line method for removing carbonate and hydroxide contamination from a molten mixed sodium nitrate/potassium nitrate heat transfer salt. The method comprises dissolving a stoichiometric quantity of anhydrous Ca(NO.sub.3).sub.2 in the melt whereby an insoluble CaCO.sub.3 and Ca(OH).sub.2 precipitate is formed. The precipitate can be removed by settling, filtration or floatation techniques.
Heat transfer enhancement in a channel with porous baffles
Ko, Kang-Hoon
2005-02-17T23:59:59.000Z
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...
HEAT TRANSFER ANALYSIS FOR NUCLEAR WASTE SOLIDIFICATION CONTAINER
Lee, S.
2009-06-01T23:59:59.000Z
The Nuclear Nonproliferation Programs Design Authority is in the design stage of the Waste Solidification Building (WSB) for the treatment and solidification of the radioactive liquid waste streams generated by the Pit Disassembly and Conversion Facility (PDCF) and Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The waste streams will be mixed with a cementitious dry mix in a 55-gallon waste container. Savannah River National Laboratory (SRNL) has been performing the testing and evaluations to support technical decisions for the WSB. Engineering Modeling & Simulation Group was requested to evaluate the thermal performance of the 55-gallon drum containing hydration heat source associated with the current baseline cement waste form. A transient axi-symmetric heat transfer model for the drum partially filled with waste form cement has been developed and heat transfer calculations performed for the baseline design configurations. For this case, 65 percent of the drum volume was assumed to be filled with the waste form, which has transient hydration heat source, as one of the baseline conditions. A series of modeling calculations has been performed using a computational heat transfer approach. The baseline modeling results show that the time to reach the maximum temperature of the 65 percent filled drum is about 32 hours when a 43 C initial cement temperature is assumed to be cooled by natural convection with 27 C external air. In addition, the results computed by the present model were compared with analytical solutions. The modeling results will be benchmarked against the prototypic test results. The verified model will be used for the evaluation of the thermal performance for the WSB drum. Detailed results and the cases considered in the calculations will be discussed here.
Debris Disk Radiative Transfer Simulation Tool (DDS)
S. Wolf; L. A. Hillenbrand
2005-06-17T23:59:59.000Z
A WWW interface for the simulation of spectral energy distributions of optically thin dust configurations with an embedded radiative source is presented. The density distribution, radiative source, and dust parameters can be selected either from an internal database or defined by the user. This tool is optimized for studying circumstellar debris disks where large grains are expected to determine the far-infrared through millimeter dust reemission spectral energy distribution. The tool is available at http://aida28.mpia-hd.mpg.de/~swolf/dds
Modeling of Heat and Mass Transfer in Fusion Welding
Zhang, Wei [ORNL
2011-01-01T23:59:59.000Z
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.
Corrosive resistant heat exchanger
Richlen, Scott L. (Annandale, VA)
1989-01-01T23:59:59.000Z
A corrosive and errosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is conveyed through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium.
Molten salt as a heat transfer fluid for heating a subsurface formation
Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)
2010-11-16T23:59:59.000Z
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.
Edwards, Bronwyn K
2009-01-01T23:59:59.000Z
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 ...
Barr and Showman: Heat Transfer in Europa's Icy Shell 405 Heat Transfer in Europa's Icy Shell
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
Application of the TEMPEST computer code to canister-filling heat transfer problems
Farnsworth, R.K.; Faletti, D.W.; Budden, M.J.
1988-03-01T23:59:59.000Z
Pacific Northwest Laboratory (PNL) researchers used the TEMPEST computer code to simulate thermal cooldown behavior of nuclear waste glass after it was poured into steel canisters for long-term storage. The objective of this work was to determine the accuracy and applicability of the TEMPEST code when used to compute canister thermal histories. First, experimental data were obtained to provide the basis for comparing TEMPEST-generated predictions. Five canisters were instrumented with appropriately located radial and axial thermocouples. The canister were filled using the pilot-scale ceramic melter (PSCM) at PNL. Each canister was filled in either a continous or a batch filling mode. One of the canisters was also filled within a turntable simulant (a group of cylindrical shells with heat transfer resistances similar to those in an actual melter turntable). This was necessary to provide a basis for assessing the ability of the TEMPEST code to also model the transient cooling of canisters in a melter turntable. The continous-fill model, Version M, was found to predict temperatures with more accuracy. The turntable simulant experiment demonstrated that TEMPEST can adequately model the asymmetric temperature field caused by the turntable geometry. Further, TEMPEST can acceptably predict the canister cooling history within a turntable, despite code limitations in computing simultaneous radiation and convection heat transfer between shells, along with uncertainty in stainless-steel surface emissivities. Based on the successful performance of TEMPEST Version M, development was initiated to incorporate 1) full viscous glass convection, 2) a dynamically adaptive grid that automatically follows the glass/air interface throughout the transient, and 3) a full enclosure radiation model to allow radiation heat transfer to non-nearest neighbor cells. 5 refs., 47 figs., 17 tabs.
CORQUENCH: A model for gas sparging-enhanced melt-water, film boiling heat transfer
Farmer, M.T.; Sienicki, J.J.; Spencer, B.W.
1990-01-01T23:59:59.000Z
A phenomenological model (CORQUENCH) has been developed to describe the gas-sparging enhanced film boiling heat transfer between a molten pool of corium and an overlying water layer. The model accounts for thermal radiation across the vapor film, bulk liquid subcooling, interfacial area enhancement due to sparging gas, and melt entrainment into the overlying water layer. In this paper, the modeling approach is described, and a comparison with the lead-Freon 11 and lead-water film boiling experiment data of Greene is made. Predictions are then made for the case of film boiling over corium in the presence of sparging concrete decomposition gases. 15 refs., 3 figs.
Radiative Heating in Underexplored Bands Campaign (RHUBC)
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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection Radiation Protection Regulations: The FederalRadiative Effects of
Radiative Heating in Underexplored Bands Campaign (RHUBC)
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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection Radiation Protection Regulations: The FederalRadiative Effects of
Journal of Quantitative Spectroscopy & Radiative Transfer 104 (2007) 384399
Pilon, Laurent
thickness, the single scattering albedo of the materials, and the incident pulse width have been developed inversion schemes accounting for anisotropic scattering. r 2006 Elsevier Ltd. All rights reserved. Keywords is the so-called radiative transfer equation (RTE). It expresses an energy balance in a unit solid angle d
Couette flow regimes with heat transfer in rarefied gas
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
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.
Lopez, Jose M; Avila, Marc
2015-01-01T23:59:59.000Z
The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction, in which cases heat transfer occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. We obtain a simple linear criterion that determines whether the infinite-cylinder assumption can be employed. The curvature of the cylinders enters this linear relationship through the slope and additive constant. For a given length-to-gap aspect ratio there is a critical Rayleigh number beyond which the laminar flow in the finite system is convective and so the behaviour is entirely different from the periodic case. The criterion does not depend on the Pra...
Flexible profile approach to the conjugate heat transfer problem
M. -N. Sabry
2008-01-07T23:59:59.000Z
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.
Low-melting point inorganic nitrate salt heat transfer fluid
Bradshaw, Robert W. (Livermore, CA); Brosseau, Douglas A. (Albuquerque, NM)
2009-09-15T23:59:59.000Z
A low-melting point, heat transfer fluid made of a mixture of four inorganic nitrate salts: 9-18 wt % NaNO.sub.3, 40-52 wt % KNO.sub.3, 13-21 wt % LiNO.sub.3, and 20-27 wt % Ca(NO.sub.3).sub.2. These compositions can have liquidus temperatures less than 100 C; thermal stability limits greater than 500 C; and viscosity in the range of 5-6 cP at 300 C; and 2-3 cP at 400 C.
Grid-independent Issue in Numerical Heat Transfer
Yao Wei; Wang Jian; Liao Guangxuan
2006-09-26T23:59:59.000Z
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.
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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cn SunnybankD.jpgHanfordDepartment ofHeat Transfer in GE Jet Engines Click to
Veron, Dana E
2009-03-12T23:59:59.000Z
This project had two primary goals: 1) development of stochastic radiative transfer as a parameterization that could be employed in an AGCM environment, and 2) exploration of the stochastic approach as a means for representing shortwave radiative transfer through mixed-phase layer clouds. To achieve these goals, an analysis of the performance of the stochastic approach was performed, a simple stochastic cloud-radiation parameterization for an AGCM was developed and tested, a statistical description of Arctic mixed phase clouds was developed and the appropriateness of stochastic approach for representing radiative transfer through mixed-phase clouds was assessed. Significant progress has been made in all of these areas and is detailed below.
Dana E. Veron
2012-04-09T23:59:59.000Z
This project had two primary goals: (1) development of stochastic radiative transfer as a parameterization that could be employed in an AGCM environment, and (2) exploration of the stochastic approach as a means for representing shortwave radiative transfer through mixed-phase layer clouds. To achieve these goals, climatology of cloud properties was developed at the ARM CART sites, an analysis of the performance of the stochastic approach was performed, a simple stochastic cloud-radiation parameterization for an AGCM was developed and tested, a statistical description of Arctic mixed phase clouds was developed and the appropriateness of stochastic approach for representing radiative transfer through mixed-phase clouds was assessed. Significant progress has been made in all of these areas and is detailed in the final report.
Paris-Sud XI, Université de
transmitter radiates a strong beam of high- frequency (HF) waves modulated at ELF. This HF heating modulates-frequency (HF) radiation in the megahertz range [7]. This heating modulates the electron's temperature in the D
Kandlikar, Satish
. (2004) developed three- zone flow boiling heat transfer model to describe evaporation of elongated
2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 Molecular dynamics methods in
Maruyama, Shigeo
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
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S modeling of the turbulent flow in a rotor-stator cavity subjected to a superimposed throughflow with heat the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial
Accepted Manuscript A wall heat transfer correlation for the baffled-rotary kilns with secondary air
Boyer, Edmond
Accepted Manuscript A wall heat transfer correlation for the baffled-rotary kilns with secondary Date: 22 January 2014 Please cite this article as: L.G. Lauredan, H. Florian, D. Jean, A wall heat;1 A wall heat transfer correlation for the baffled- rotary kilns with secondary air flow and recycled
Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland
Graaf, Martin de
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
Fluid flow and heat transfer modeling for castings
Domanus, H.M.; Liu, Y.Y.; Sha, W.T.
1986-01-01T23:59:59.000Z
Casting is fundamental to manufacturing of many types of equipment and products. Although casting is a very old technology that has been in existence for hundreds of years, it remains a highly empirical technology, and production of new castings requires an expensive and time-consuming trial-and-error approach. In recent years, mathematical modeling of casting has received increasing attention; however, a majority of the modeling work has been in the area of heat transfer and solidification. Very little work has been done in modeling fluid flow of the liquid melt. This paper presents a model of fluid flow coupled with heat transfer of a liquid melt for casting processes. The model to be described in this paper is an extension of the COMMIX code and is capable of handling castings with any shape, size, and material. A feature of this model is the ability to track the liquid/gas interface and liquid/solid interface. The flow of liquid melt through the sprue and runners and into the mold cavity is calculated as well as three-dimensional temperature and velocity distributions of the liquid melt throughout the casting process. 14 refs., 13 figs.
McKinnon, M.A.; Doman, J.W.; Tanner, J.E.; Guenther, R.J.; Creer, J.M.; King, C.E.
1986-02-01T23:59:59.000Z
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.
Application of three-dimensional solar radiative transfer to mountains Y. Chen,1,2
Liou, K. N.
Application of three-dimensional solar radiative transfer to mountains Y. Chen,1,2 A. Hall,1 and K November 2006. [1] We developed a three-dimensional radiative transfer model simulating solar fluxes over (2006), Application of three-dimensional solar radiative transfer to mountains, J. Geophys. Res., 111, D
Kihm, IconKenneth David
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
Heat and Mass Transfer manuscript No. (will be inserted by the editor)
Paris-Sud XI, Université de
Heat and Mass Transfer manuscript No. (will be inserted by the editor) On the modeling of aiding to the onset of recirculation cells in the entry re- gion while the heat transfer is slightly increased under acceleration [m s-2 ] GrH Grashof number based on H, GrH = g0TH3 /2 0 h heat transfer coefficient [W m-2 K-1
TRANSIENT HEAT TRANSFER MODEL FOR SRS WASTE TANK OPERATIONS
Lee, S; Richard Dimenna, R
2007-03-27T23:59:59.000Z
A transient heat balance model was developed to assess the impact of a Submersible Mixer Pump (SMP) on waste temperature during the process of waste mixing and removal for the Type-I Savannah River Site (SRS) tanks. The model results will be mainly used to determine the SMP design impacts on the waste tank temperature during operations and to develop a specification for a new SMP design to replace existing long-shaft mixer pumps used during waste removal. The model will also be used to provide input to the operation planning. This planning will be used as input to pump run duration in order to maintain temperature requirements within the tank during SMP operation. The analysis model took a parametric approach. A series of the modeling analyses was performed to examine how submersible mixer pumps affect tank temperature during waste removal operation in the Type-I tank. The model domain included radioactive decay heat load, two SMP's, and one Submersible Transfer Pump (STP) as heat source terms. The present model was benchmarked against the test data obtained by the tank measurement to examine the quantitative thermal response of the tank and to establish the reference conditions of the operating variables under no SMP operation. The results showed that the model predictions agreed with the test data of the waste temperatures within about 10%. Transient modeling calculations for two potential scenarios of sludge mixing and removal operations have been made to estimate transient waste temperatures within a Type-I waste tank. When two 200-HP submersible mixers and 12 active cooling coils are continuously operated in 100-in tank level and 40 C initial temperature for 40 days since the initiation of mixing operation, waste temperature rises about 9 C in 48 hours at a maximum. Sensitivity studies for the key operating variables were performed. The sensitivity results showed that the chromate cooling coil system provided the primary cooling mechanism to remove process heat from the tank during operation.
International Conference on Computational Heat and Mass Transfer Paper Number 135
Khandekar, Sameer
of heat transfer enhancement in sodium heat exchangers used in the fast breeder nuclear reactor [6 and liquid metals (Sodium, Potassium and Mercury) are utilized in the simulation. The critical sizes
Extensions and enhancements to the iLab heat transfer project site
Saylor, David P. (David Patrick)
2005-01-01T23:59:59.000Z
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 ...
Buongiorno, Jacopo
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 ...
Application Of A Spherical-Radial Heat Transfer Model To Calculate...
Spherical-Radial Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Jump to: navigation, search OpenEI Reference LibraryAdd to library...
Heat transfer through horizontal films of liquids evaporating under high vacuum
Stiles, Graham Bill
1961-01-01T23:59:59.000Z
). . . . . . . 17 6. 7 ~ 9. 10 ~ 12 ' 13 ' 14 ' Effect of Liquid Depth on the Heat Transfer Coefficient (Natural Convection') . . . . . . . . 27 Effect of Liquid Depth on the Heat Transfer Coefficient (Nucleate Boiling, 875 BTU/Hr. Ft... of boiling was first discussed by Nukiyama (22). Three main types exist. They are natural convection, nucleate boiling and fi. lm boiling (6, 17, 20). Natural convection occurs when the liquid heated at the heating surface is hotter than that above...
Heat Transfer Research 44(1), 130 (2013) ENTROPY GENERATION ANALYSIS
Zhang, Yuwen
Heat Transfer Research 44(1), 1Â30 (2013) ENTROPY GENERATION ANALYSIS FOR A PULSATING HEAT, m R gas constant of vapor, g gravity, m/s2 kJ/kgK h(hlsen, hlv) coefficient of convective heat Re, kg/m3 of left vapor plug, W p shear stress, N/m3 Qout,v1 condensation heat transfer rate Subscripts
Heat transfer and pressure drop for air flow through enhanced passages
Obot, N.T.; Esen, E.B.
1992-06-01T23:59:59.000Z
An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.
Heat transfer and pressure drop for air flow through enhanced passages. Final report
Obot, N.T.; Esen, E.B.
1992-06-01T23:59:59.000Z
An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.
Influences of electrical field on boiling-condensation heat transfer system
Yang Jiaxiang; Ding Lijian; Chi Xiaochun; Liu Ji [Harbin Inst. of Electrical Technology (China). Dept. of Electrical Materials Engineering; Yang He [Harbin Inst. of Tech. (China). Dept. of Thermal Energy Engineering
1996-12-31T23:59:59.000Z
In this paper, the influences of electrical field on boiling-condensation heat transfer system have been investigated using a cylinder heat transfer model. Freon-11 is selected as working fluid. The condensation heat transfer coefficient, the boiling heat flux and the saturation pressure are measured in this investigation. According to the experimental results, it is found that the electrical field can influence heat transfer system. The boiling heat transfer is enhanced by the applied voltage, and the saturate vapor of working fluid is condensed on the high voltage electrode directly when the applied voltage is higher than 6 kv. The experimental results have been discussed, and it is considered that the high electrical field strength change the thermal properties of working fluid.
TOPAZ2D heat transfer code users manual and thermal property data base
Shapiro, A.B.; Edwards, A.L.
1990-05-01T23:59:59.000Z
TOPAZ2D is a two dimensional implicit finite element computer code for heat transfer analysis. This user's manual provides information on the structure of a TOPAZ2D input file. Also included is a material thermal property data base. This manual is supplemented with The TOPAZ2D Theoretical Manual and the TOPAZ2D Verification Manual. TOPAZ2D has been implemented on the CRAY, SUN, and VAX computers. TOPAZ2D can be used to solve for the steady state or transient temperature field on two dimensional planar or axisymmetric geometries. Material properties may be temperature dependent and either isotropic or orthotropic. A variety of time and temperature dependent boundary conditions can be specified including temperature, flux, convection, and radiation. Time or temperature dependent internal heat generation can be defined locally be element or globally by material. TOPAZ2D can solve problems of diffuse and specular band radiation in an enclosure coupled with conduction in material surrounding the enclosure. Additional features include thermally controlled reactive chemical mixtures, thermal contact resistance across an interface, bulk fluid flow, phase change, and energy balances. Thermal stresses can be calculated using the solid mechanics code NIKE2D which reads the temperature state data calculated by TOPAZ2D. A three dimensional version of the code, TOPAZ3D is available. The material thermal property data base, Chapter 4, included in this manual was originally published in 1969 by Art Edwards for use with his TRUMP finite difference heat transfer code. The format of the data has been altered to be compatible with TOPAZ2D. Bob Bailey is responsible for adding the high explosive thermal property data.
Thermoacoustic sensor for nuclear fuel temperaturemonitoring and heat transfer enhancement
James A. Smith; Dale K. Kotter; Randall A. Alli; Steven L. Garrett
2013-05-01T23:59:59.000Z
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.
Pulsifer, John
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
A new method for solving radiative heat problems in glass
Eindhoven, Technische Universiteit
RANA 9906 A new method for solving radiative heat problems in glass B.J. van der Linden --- R, The Netherlands email: linden@win.tue.nl 15th May 2000 #12; Abstract In the production of glass, temperature Conclusion 25 2 #12; Chapter 1 Introduction The production of glass belongs to the oldest forms of human
A new method for solving radiative heat problems in glass
Eindhoven, Technische Universiteit
RANA 99-06 A new method for solving radiative heat problems in glass B.J. van der Linden -- R, The Netherlands e-mail: linden@win.tue.nl 15th May 2000 #12;Abstract In the production of glass, temperature plays Conclusion 25 2 #12;Chapter 1 Introduction The production of glass belongs to the oldest forms of human
Temperature measurements using multicolor pyrometry in thermal radiation heating environments
Fu, Tairan, E-mail: trfu@mail.tsinghua.edu.cn [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China) [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China); Beijing Key Laboratory of CO2 Utilization and Reduction Technology, Beijing 100084 (China); Liu, Jiangfan; Duan, Minghao; Zong, Anzhou [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)] [Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)
2014-04-15T23:59:59.000Z
Temperature measurements are important for thermal-structural experiments in the thermal radiation heating environments such as used for thermal-structural stress analyses. This paper describes the use of multicolor pyrometry for the measurements of diffuse surfaces in thermal radiation environments that eliminates the effects of background radiation reflections and unknown emissivities based on a least-squares algorithm. The near-infrared multicolor pyrometer had a spectral range of 1100–2400 nm, spectrum resolution of 6 nm, maximum sampling frequency of 2 kHz, working distance of 0.6 m to infinity, temperature range of 700–1700 K. The pyrometer wavelength response, nonlinear intensity response, and spectral response were all calibrated. The temperature of a graphite sample irradiated by quartz lamps was then measured during heating and cooling using the least-squares algorithm based on the calibrated irradiation data. The experiments show that higher temperatures and longer wavelengths are more suitable for the thermal measurements in the quartz lamp radiation heating system. This analysis provides a valuable method for temperature measurements of diffuse surfaces in thermal radiation environments.
Proceedings of HT2007 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference
Ghajar, Afshin J.
to a more complicated data set, forced and mixed convection developing laminar flow in a horizontal tube LAMINAR HEAT TRANSFER IN A HORIZONTAL TUBE USING ARTIFICIAL NEURAL NETWORK L. M. Tam (1) Department variables on our forced convective turbulent heat transfer data in a horizontal tube (Ghajar and Tam, 1994
JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 19, No. 1, JanuaryMarch 2005
Al-Qahtani, Mohammad
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
Thole, Karen A.
Elsevier Inc. All rights reserved. Keywords: Duct flow; Ribbed channels; LES 1. Introduction In an effortExperimental validation of large eddy simulations of flow and heat transfer in a stationary ribbed Abstract Accurate prediction of ribbed duct flow and heat transfer is of importance to the gas turbine
Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater
Zheng, H.; Fan, X.; Li, A.
2006-01-01T23:59:59.000Z
. 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...
Bibliography of US patents on augmentation of convective heat and mass transfer-II
Webb, R.L.; Bergles, A.E.; Junkhan, G.H.
1983-12-01T23:59:59.000Z
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).
Effect of surface conditions on boiling heat transfer of refrigerants in shell-and-tube evaporators
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
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.
Abdou, Mohamed
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), a number of blanket design options with molten salt (FLiBe or FLiNaBe) as the tritium breeder/coolant have
Molten salt as heat transfer fluid for a 500 m2 dish concentrator
Molten salt as heat transfer fluid for a 500 m2 dish concentrator Nicolás del Pozo 1 , Rebecca Dunn salt based thermal storage system with the ANU SG4 500 m2 dish solar concentrator was performed. Specifically, the objective was to research the behaviour of molten salt as a heat transfer fluid for the SG4
Heat Transfer in Buildings: Application to Solar Air Collector and Trombe Wall Design
Paris-Sud XI, Université de
11 Heat Transfer in Buildings: Application to Solar Air Collector and Trombe Wall Design H. Boyer applications are finally discussed. One concerns the modeling of a flat plate air collector and the second focuses on the modeling of Trombe solar walls. In each case, detailed modeling of heat transfer allows
Heat Transfer Performance and Piping Strategy Study for Chilled Water Systems at Low Cooling Loads
Li, Nanxi 1986-
2012-12-05T23:59:59.000Z
cooling loads, it may lead to the laminar flow of the chilled water in the cooling coils. The main objective of this thesis is to explain the heat transfer performance of the cooling coils under low cooling loads. The water side and air side heat transfer...
Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater
Zheng, H.; Fan, X.; Li, A.
2006-01-01T23:59:59.000Z
. 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...
Dehumidification heat transfer on copper surfaces Abhay Varghese Thomas, Nikhil Koratkar, Yoav Peles
Peles, Yoav
and Background When a cooled surface is placed in an air-steam mixture, liquid water droplets or film form Heat transfer Condensation Humid air a b s t r a c t Heat transfer during dehumidification on the surface if its temperature is sufficiently low. In this dehumidification process, the ambient airsteam
1 Copyright 2012 by ASME Proceedings of the ASME 2012 Summer Heat Transfer Conference
Bahrami, Majid
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
Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow
Kostic, Milivoje M.
Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE M of nanofluids in tube flow has been developed, instrumented and computerized. It has been calibrated using) nanofluids show peculiar results with substantial friction drag reduction and heat transfer enhancement
Ammerman, C.N.; You, S.M.; Hong, Y.S. [Univ. of Texas, Arlington, TX (United States). Dept. of Mechanical and Aerospace Engineering
1995-12-31T23:59:59.000Z
A recently developed photographic method is used to quantify vapor volumetric flow rate above a boiling wire. The volumetric flow rate is combined with additional analyses to determine the overall contributions to the total heat flux from four nucleate boiling heat transfer mechanisms (latent heat, natural convection, Marangoni flow, and micro-convection). This technique is used to quantify the boiling heat transfer mechanisms versus heat flux for a 510-{micro}m wire immersed in saturated water and in water with a small amount of liquid soap added. These data are compared with similar data taken for a 75-{micro}m wire boiling in saturated FC-72. For all cases, latent heat is the dominant heat transfer mechanism in the fully developed nucleate boiling regime. In addition, the latent heat component is significantly increased by the addition of small amounts of soap (surfactant).
Heat transfer in the trailing edge cooling channels of turbine blades
Kumaran, T. K.
1989-01-01T23:59:59.000Z
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...
Development of a UF{sub 6} cylinder transient heat transfer/stress analysis model
Williams, W.R. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)
1991-12-31T23:59:59.000Z
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.
Asymptotic solution for heat convection-radiation equation
Mabood, Fazle; Ismail, Ahmad Izani Md [School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Khan, Waqar A. [Department of Engineering Sciences, National University of Sciences and Technology, PN Engineering College, Karachi, 75350 (Pakistan)
2014-07-10T23:59:59.000Z
In this paper, we employ a new approximate analytical method called the optimal homotopy asymptotic method (OHAM) to solve steady state heat transfer problem in slabs. The heat transfer problem is modeled using nonlinear two-point boundary value problem. Using OHAM, we obtained the approximate analytical solution for dimensionless temperature with different values of a parameter ?. Further, the OHAM results for dimensionless temperature have been presented graphically and in tabular form. Comparison has been provided with existing results from the use of homotopy perturbation method, perturbation method and numerical method. For numerical results, we used Runge-Kutta Fehlberg fourth-fifth order method. It was found that OHAM produces better approximate analytical solutions than those which are obtained by homotopy perturbation and perturbation methods, in the sense of closer agreement with results obtained from the use of Runge-Kutta Fehlberg fourth-fifth order method.
Micro and nanostructured surfaces for enhanced phase change heat transfer
Chu, Kuang-Han, Ph. D. Massachusetts Institute of Technology
2013-01-01T23:59:59.000Z
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, ...
Theoretical Design of Thermosyphon for Process Heat Transfer from NGNP to Hydrogen Plant
Piyush Sabharwall; Mike Patterson; Fred Gunnerson
2008-09-01T23:59:59.000Z
The Next Generation Nuclear Plant (NGNP) will most likely produce electricity and process heat, with both being considered for hydrogen production. To capture nuclear process heat, and transport it to a distant industrial facility requires a high temperature system of heat exchangers, pumps and/or compressors. The heat transfer system is particularly challenging not only due to the elevated temperatures (up to ~ 1300K) and industrial scale power transport (=50 MW), but also due to a potentially large separation distance between the nuclear and industrial plants (100+m) dictated by safety and licensing mandates. The work reported here is the preliminary analysis of two-phase thermosyphon heat transfer performance with alkali metals. A thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. In contrast to single-phased forced convective heat transfer via ‘pumping a fluid’, a thermosyphon (also called a wickless heat pipe) transfers heat through the vaporization / condensing process. The condensate is further returned to the hot source by gravity, i.e. without any requirement of pumps or compressors. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. Two-phase heat transfer by a thermosyphon has the advantage of high enthalpy transport that includes the sensible heat of the liquid, the latent heat of vaporization, and vapor superheat. In contrast, single-phase forced convection transports only the sensible heat of the fluid. Additionally, vapor-phase velocities within a thermosyphon are much greater than single-phase liquid velocities within a forced convective loop. Thermosyphon performance can be limited by the sonic limit (choking) or vapor flow and/or by condensate entrainment. Proper thermosyphon requires analysis of both.
Forristall, R.
2003-10-01T23:59:59.000Z
This report describes the development, validation, and use of a heat transfer model implemented in Engineering Equation Solver. The model determines the performance of a parabolic trough solar collector's linear receiver, also called a heat collector element. All heat transfer and thermodynamic equations, optical properties, and parameters used in the model are discussed. The modeling assumptions and limitations are also discussed, along with recommendations for model improvement.
Kasagi, Nobuhide
circulation is dominant at high PeT number. A heat transfer model is proposed to analyze and predict the heat
Thole, Karen A.
delta winglets Michael J. Lawson *, Karen A. Thole Mechanical and Nuclear Engineering Department the formation of streamwise vortices and increase heat transfer between a working fluid and the surface on which importance for fuel econ- omy. Advantages to decreasing heat exchanger size include weight savings, as well
Downflow heat transfer in a heated ribbed vertical annulus with a cosine power profile
Anderson, J.L.; Condie, K.G.; Larson, T.K.
1991-10-01T23:59:59.000Z
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.
Dual-circuit embossed-sheet heat-transfer panel
Morgan, G.D.
1982-08-23T23:59:59.000Z
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.
Vibration damping and heat transfer using material phase changes
Kloucek, Petr (Houston, TX); Reynolds, Daniel R. (Oakland, CA)
2009-03-24T23:59:59.000Z
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.
Condensation heat transfer in square, triangular, and semi-circular mini-channels Melanie Derby a
Peles, Yoav
, 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
Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)
1996-11-05T23:59:59.000Z
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.
Hodges, James L. (3 Hilltop Ave., Vernon, CT 06066); Cerkanowicz, Anthony E. (8 Fieldstone Dr., Livingston, NJ 07039)
1983-01-01T23:59:59.000Z
In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.
Hodges, James L. (3 Hilltop Ave., Vernon, CT 06066); Cerkanowicz, Anthony E. (8 Fieldstone Dr., Livingston, NJ 07039)
1982-01-01T23:59:59.000Z
In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.
FireStem2D A Two-Dimensional Heat Transfer Model for Simulating Tree Stem Injury in Fires
FireStem2D A Two-Dimensional Heat Transfer Model for Simulating Tree Stem Injury in Fires, et al. (2013) FireStem2D A Two-Dimensional Heat Transfer Model for Simulating Tree Stem Injury
Achanta, Vamsee Satish
2004-09-30T23:59:59.000Z
In this work, we study the enhanced endwall heat transfer for flow past non conducting pin fin arrays. The aim is to resolve the controversy over the heat transfer that is taking place from the endwall and the pin ...
Ekkad, S.V.; Huang, Y.; Han, J.C. [Texas A and M Univ., College Station, TX (United States)
1996-12-31T23:59:59.000Z
Modern gas turbine blades have internal serpentine passage for providing effective cooling. Rib turbulators are added periodically on the cooling passage surface to enhance heat transfer. Some of the cooling air is ejected out through bleed (or film) holes for external blade film cooling. The presence of periodic rib turbulators and bleed holes creates strong axial and spanwise variations in the heat transfer distributions on the passage surface. Detailed heat transfer coefficient distributions are presented in this study for a two-pass square channel with a 180{degree} turn. One wall of the channel has periodically placed bleed holes. Four different configurations of 90{degree} parallel, 60{degree} parallel, 60{degree} V ribs, and 60{degree} inverted V ribs are studied in conjunction with the effect of bleed holes on the same wall. The surface is coated with a thin layer of thermochromic liquid crystals and a transient test is run to obtain the detailed heat transfer distributions. The 60{degree} parallel, 60{degree} V, and 60{degree} inverted ribbed channels produce similar levels of heat transfer enhancement in the first pass. However, the 60{degree} inverted V ribbed channel produces higher enhancement in the second pass. Regional averaged heat transfer results indicate that a test surface with bleed holes provides similar heat transfer enhancement as that for a test surface without bleed holes although 20--25% of the inlet mass flow exits through the bleed holes.
Paris-Sud XI, Université de
Ratkowsky "square root" model and a simplified two-parameter20 heat transfer model regarding an infinite
Roll Wave Effects on Annular Condensing Heat Transfer in Horizontal PCCS Condenser Tube
Masaya Kondo; Hideo Nakamura; Yoshinari Anoda [Japan Atomic Energy Research Institute, Tokai-mura 319-1195 (Japan); Sadanori Saishu; Hiroyuki Obata; Rumi Shimada [Japan Atomic Power Company (Japan); Shinichi Kawamura [Tokyo Electric Power Company, Incorporated, 1-3, Uchisaiwai-cho 1-chome, Chiyoda-ku, Tokyo, 1008560 (Japan)
2002-07-01T23:59:59.000Z
A horizontal in-tube condensation heat exchanger is under investigation to be used for a passive containment cooling system (PCCS) of a next generation-type BWR. The flow conditions in the horizontal condenser tube were observed both visually and by local void fraction fluctuation. The observed flow regimes at a rated condition were annular flow at the tube inlet, and turned gradually into wavy flow and smooth stratified flow along the length of the tube. It was found further that frequency of the roll waves that appear on the liquid film in the annular flow is closely related to the measured local condensation heat transfer coefficient. Based on the flow observation, the roll wave frequency and measured condensation heat transfer coefficient, a model is proposed which predicts the condensation heat transfer coefficient particularly for annular flows around the tube inlet region. The proposed heat transfer model predicts well the influences of pressure, local gas-phase velocity and film thickness. (authors)
Flow-Induced Deformation of a Flexible Thin Structure as Manifestation of Heat Transfer Enhancement
Soti, Atul Kumar; Sheridan, John
2015-01-01T23:59:59.000Z
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...
Grid-region heat transfer in a gas solid fluidized bed
Wang, R.C.
1986-01-01T23:59:59.000Z
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.
Protat, Alain
Assessment of uncertainty in cloud radiative effects and heating rates through retrieval algorithm. The effect of uncertainty in retrieved quantities on the cloud radiative effect and radiative heating rates translates into sometimes large differences in cloud shortwave radiative effect (CRE) though the majority
Bhashyam, Srikrishna
INDIAN SOCIETY FOR HEAT AND MASS TRANSFER (REGD.) Indian Institute of Technology Madras Campus for Heat and Mass Transfer Department of Mechanical Engineering Indian Institute of Technology Madras Society for Heat and Mass Transfer (Regd.) I/We agree that I/We will be governed by Rules and Regulations
Paris-Sud XI, Université de
specially designed within the framework of this research. A computational heat transfer model is constructed. The developed mean model constitutes the basis of the computational stochastic heat transfer model that has been to the experimental ones. Keywords: computational heat transfer modeling, uncertainties, probabilistic modeling
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
Kandlikar, Satish
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
Maruyama, Shigeo
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
A phase-field method for 3D simulation of two-phase heat transfer , H. Babaee a
Dong, Suchuan "Steven"
A phase-field method for 3D simulation of two-phase heat transfer X. Zheng a , H. Babaee a , S s t r a c t We formulate new multi-phase convective heat transfer equations by combining the three for convergence in time/space including a conjugate heat transfer problem and also for a realistic tran- sient
Li, Zhiyong; Chen, Chao; Luo, Hailiang; Zhang, Ye; Xue, Yaning [College of Architecture and Civil Engineering, Beijing University of Technology, Beijing (China)
2010-08-15T23:59:59.000Z
The aim of this paper is to establish the heat transfer model of all-glass vacuum tube collector used in forced-circulation solar water heating system. In this model, the simplified heat transfer of collector is composed of the natural convection in single glass tube and forced flow in manifold header. Thus the heat balance equation of water in single tube and the heat balance equation of water in manifold header have been established. The flow equation is also built by analyzing the friction and buoyancy in tube. Through solved these equations the relationship between the collector average temperature, the outlet temperature and natural convection flow rate have been obtained. From this relationship and energy balance equation of collector, the collector outlet temperature can be calculated. The validated experiments of this model were carried out in winter of Beijing. (author)
The influence of a magnetic field on turbulent heat transfer of a high Prandtl number fluid
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
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)
New flow boiling heat transfer model for hydrocarbons evaporating inside horizontal tubes
Chen, G. F.; Gong, M. Q.; Wu, J. F.; Zou, X. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, 35, Beijing, 100190 (China); Wang, S. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, 35, Beijing, 100190 (China); University of Chinese Academy of Science, No. 19 YuQuan Road, Beijing, 100049 (China)
2014-01-29T23:59:59.000Z
Hydrocarbons have high thermodynamic performances, belong to the group of natural refrigerants, and they are the main components in mixture Joule-Thomson low temperature refrigerators (MJTR). New evaluations of nucleate boiling contribution and nucleate boiling suppression factor in flow boiling heat transfer have been proposed for hydrocarbons. A forced convection heat transfer enhancement factor correlation incorporating liquid velocity has also been proposed. In addition, the comparisons of the new model and other classic models were made to evaluate its accuracy in heat transfer prediction.
Heat transfer coefficients in two-dimensional Yukawa systems (numerical simulations)
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
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.
Howard Barker; Jason Cole
2012-05-17T23:59:59.000Z
Utilization of cloud-resolving models and multi-dimensional radiative transfer models to investigate the importance of 3D radiation effects on the numerical simulation of cloud fields and their properties.
Transition boiling heat transfer from a horizontal surface
Berenson Paul Jerome
1960-01-01T23:59:59.000Z
An experiment, utilising a condensing fluid as the heat source, was performed to determine the heat flux vs. temperature difference curve for transition pool boiling from a horisontal surface. The boiling cure was determined ...
Hogan, Robin
Incorporating the Effects of 3D Radiative Transfer in the Presence of Clouds into Two. The 3D effect on shortwave cloud radiative forcing varies between around 225% and around 1100. Therefore, cumulus clouds are of particular im- portance when considering 3D radiative effects: although
Augmentation of condensation heat transfer with electrohydrodynamics on vertical enhanced tubes
Motte, Edouard
1994-01-01T23:59:59.000Z
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...
Dependency of Heat Transfer Rate on the Brinkman Number in Microchannels
H. S. Park
2008-01-07T23:59:59.000Z
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.
Heat and mass transfer in the gas tungsten and gas metal arc welding processes
Watkins, A.D; Smartt, H.B.; Einerson, C.J.; Watkins, J.A.
1990-01-01T23:59:59.000Z
The heat transferred from an electrode negative, argon gas tungsten arc to an anode was measured for a wide range of conditions suitable for mechanized welding. The results are given as (1) the arc efficiency and (2) the anode heat and current input distributions for various anode materials over a range of current and voltage. The nominal arc is Gaussian, {approximately}4 mm in diameter, with {approximately}75{percent}heat transfer efficiency. Variations from these values are discussed in terms of the electrical and thermal energy transport mechanisms. Heat transferred to the workpiece (cathode) during direct current, electrode positive gas metal arc welding (GMAW) was measured for various parameters applicable to machine welding. The results are presented as a function of electrode speed for changing voltages and contact tip to workpiece distances. The total heat transfer efficiency was nominally 85{percent} for a 0.89 mm diameter steel electrode using an argon-2{percent} oxygen shielding gas; the nominal heat transfer efficiency of the droplet component was 40{percent}. The average droplet temperatures ranged from 2400 to 3100 K, depending on the process parameters. A new method of measuring the heat transferred from the arc to the workpiece, using a boiling liquid nitrogen calorimeter, has been developed that gives rapid, accurate values. 20 refs., 8 figs., 2 tabs.
Fresnel Effect in Radiation Transfer in Biological Tissues Kyunghan Kim and Zhixiong Guo*
Guo, Zhixiong "James"
Fresnel Effect in Radiation Transfer in Biological Tissues Kyunghan Kim and Zhixiong Guo* MAE Method (DOM) to incorporate Fresnel's boundary in laser radiation transport in biological tissues is calculated by the use of Snell's law and Fresnel's equation. The radiation fields, including the radiative
Danilova, G.N.; Reznikov, V.I.
1988-01-01T23:59:59.000Z
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.
Bankston, C.P.; Back, L.H.
1982-02-01T23:59:59.000Z
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.
Convective heat-transfer predictions and experiments in an IC engine
Yang, J.
1988-01-01T23:59:59.000Z
Knowledge of heat transfer in engines is critical to engine efficiency, hydrocarbon and particulate emissions, engine-component thermal stress analysis, as well as engine cycle simulation accuracy. However, the relationship between pressure, heat-release rate, turbulent flow, and the heat transfer is not known. Previous engine heat-transfer models, including the law-of-the-wall used for multi-dimensional calculations, are based on a steady-state incompressible flow which is not the case in engines. A new heat-transfer model was developed which is based on an approximate solution of the linearized and normalized one-dimensional energy equation. An empirical turbulent viscosity relation has been used to include the effects of turbulence. The response of this equation to a unit step function was acquired by multi-parameter fit to the numerical solution. The effects of initial thermal boundary layer formed before compression were also considered. The proposed heat-transfer model was extended to include the effects of combustion. Thus, the relationship between pressure variation, spatially-resolved heat-release rate, local flow condition, initial thermal boundary layer, and the surface heat flux and temperature profile was developed.
Critical thickness of an optimum extended surface characterized by uniform heat transfer coefficient
Leontiou, Theodoros
2015-01-01T23:59:59.000Z
We consider the heat transfer problem associated with a periodic array of extended surfaces (fins) subjected to convection heat transfer with a uniform heat transfer coefficient. Our analysis differs from the classical approach as (i) we consider two-dimensional heat conduction and (ii) the base of the fin is included in the heat transfer process. The problem is modeled as an arbitrary two-dimensional channel whose upper surface is flat and isothermal, while the lower surface has a periodic array of extensions/fins which are subjected to heat convection with a uniform heat transfer coefficient. Using the generalized Schwarz-Christoffel transformation the domain is mapped onto a straight channel where the heat conduction problem is solved using the boundary element method. The boundary element solution is subsequently used to pose a shape optimization problem, i.e. an inverse problem, where the objective function is the normalized Shape Factor and the variables of the optimization are the parameters of the Sch...
Passive heat-transfer means for nuclear reactors. [LMFBR
Burelbach, J.P.
1982-06-10T23:59:59.000Z
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.
Heat transfer issues in high-heat-load synchrotron x-ray beams
Khounsary, A.M.; Mills, D.M.
1994-09-01T23:59:59.000Z
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.
ASME 2008 Summer Heat transfer Conference August 10-14, 2008, Jacksonville, FL., USA
Bahrami, Majid
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
Schwaenen, Markus
2012-07-16T23:59:59.000Z
. . . . . . . . . . . . . . . . . 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...
Tabares Velasco, P. C.
2011-04-01T23:59:59.000Z
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.'
Quasiballistic heat transfer studied using the frequency-dependent Boltzmann transport equation
Chen, Gang
Quasiballistic heat transfer occurs when there is a temperature gradient over length scales comparable to phonon mean free paths (MFPs). This regime has been of interest recently because observation of quasiballistic ...
Mechanism and behavior of nucleate boiling heat transfer to the alkalai liquid metals
Deane, Charles William
1969-01-01T23:59:59.000Z
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 ...
Immersion Condensation on Oil-Infused Heterogeneous Surfaces for Enhanced Heat Transfer
Xiao, Rong
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 ...
Wetting and phase-change phenomena on micro/nanostructures for enhanced heat transfer
Xiao, Rong, Ph. D. Massachusetts Institute of Technology
2013-01-01T23:59:59.000Z
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 ...
Moon, Sung-Won
1999-01-01T23:59:59.000Z
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...
Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis
Zhang, C.; Wu, R.; Li, G.; Li, X.; Huang, L.; Sun, D.
2006-01-01T23:59:59.000Z
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...
6th World Conference on Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics
Kasagi, Nobuhide
in order to avoid the effect of interaction of channels in multi-microchannels. Finally, a heat transfer model based on empirical correlations should be established for engineering applications. 2
Heat and mass transfer in bubble column dehumidifiers for HDH desalination
Tow, Emily W
2014-01-01T23:59:59.000Z
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 ...
Traviss, Donald P.
1971-01-01T23:59:59.000Z
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 ...
Forced-convection surface-boiling heat transfer and burnout in tubes of small diameters
Bergles A. E.
1962-01-01T23:59:59.000Z
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. ...
Convective Heat Transfer Enhancement in Nanofluids: Real Anomaly or Analysis Artifact?
Prabhat, Naveen
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 ...
Yu, Jiwon 1982-
2012-12-03T23:59:59.000Z
Experiments were performed to study forced convective heat transfer of de-ionized water (DI water) and aqueous nanofluids flowing in a microchannel. An array of temperature nanosensors, called “Thin Film Thermocouples (TFT)”, was utilized...
Numerical and analytical modeling of heat transfer between fluid and fractured rocks
Li, Wei, S.M. Massachusetts Institute of Technology
2014-01-01T23:59:59.000Z
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 ...