Lenert, Andrej
2012-01-01
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 ...
Heat Transfer in Complex Fluids
Mehrdad Massoudi
2012-01-01
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
Heat Transfer Fluids for Solar Water Heating Systems | Department...
Broader source: Energy.gov (indexed) [DOE]
Illustration of a solar water heater. Illustration of a solar water heater. Heat-transfer fluids carry heat through solar collectors and a heat exchanger to the heat storage tanks...
"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
2008-06-12
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
High Operating Temperature Heat Transfer Fluids for Solar Thermal...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
High Operating Temperature Heat Transfer Fluids for Solar Thermal Power Generation FY13 Q1 High Operating Temperature Heat Transfer Fluids for Solar Thermal Power Generation FY13...
Nanoparticle enhanced ionic liquid heat transfer fluids
Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.; Gray, Joshua R.; Garcia-Diaz, Brenda L.
2014-08-12
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.
Heat Transfer Fluids for Solar Water Heating Systems | Department...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
commonly used as the heat transfer fluid in refrigerators, air conditioners, and heat pumps. They generally have a low boiling point and a high heat capacity. This enables a...
Project Profile: Dual-Purpose Heat Transfer Fluids for CSP
Broader source: Energy.gov [DOE]
Argonne National Laboratory, under an ARRA CSP Award, is developing advanced heat transfer fluids (HTFs) by incorporating multifunctional engineered nanoparticles in heat transfer applications and thermal energy storage.
Low-melting point heat transfer fluid
Cordaro, Joseph Gabriel (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)
2010-11-09
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.
Phenylnaphthalene Derivatives as Heat Transfer Fluids for Concentratin...
Office of Scientific and Technical Information (OSTI)
Report: Phenylnaphthalene Derivatives as Heat Transfer Fluids for Concentrating Solar Power: Loop Experiments and Final Report Citation Details In-Document Search Title:...
Phenylnaphthalene as a Heat Transfer Fluid for Concentrating...
Office of Scientific and Technical Information (OSTI)
Technical Report: Phenylnaphthalene as a Heat Transfer Fluid for Concentrating Solar Power: High-Temperature Static Experiments Citation Details In-Document Search Title:...
Low-melting point heat transfer fluid
Cordaro, Joseph G. (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)
2011-04-12
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.
The Advantages of Sealless Pumps in Heat Transfer Fluid Services
Smith, M. D.
1999-01-01
OF SEALLESS PUMPS IN HEAT TRANSFER FLUID SERVICES Michael D. Smith Engineering Manager Sundstrand Fluid Handling Arvada, CO ABSTRACT The expectations for heat transfer fluid (HTF) system safety and reliability are continuing to increase... mechanical seals. In addition, one type of sealless pump, the canned motor pump, raises the thermal efficiency of HTF systems. Waste heat from the drive motors of m'ost pumps is dissipated to the air. A shaft driven fan wastes additional energy...
Heat Transfer Fluids for Solar Water Heating Systems | Department...
Broader source: Energy.gov (indexed) [DOE]
a high boiling point. Viscosity and thermal capacity determine the amount of pumping energy required. A fluid with low viscosity and high specific heat is easier to pump, because...
Local heat transfer measurement and thermo-fluid characterization of a pulsating heat pipe
Khandekar, Sameer
and possibly future specific requirements from electronics cooling [6,7], heat recovery [8,9] and passiveLocal heat transfer measurement and thermo-fluid characterization of a pulsating heat pipe Mauro 2013 Accepted 29 July 2013 Available online Keywords: Pulsating Heat Pipes Local heat transfer Pressure
Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids
Raade, Justin; Roark, Thomas; Vaughn, John; Bradshaw, Robert
2013-07-22
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.
Project Profile: Polyaromatic Naphthalene Derivatives as Solar Heat Transfer Fluids
Office of Energy Efficiency and Renewable Energy (EERE)
Oak Ridge National Laboratory, under an ARRA CSP Award, is addressing the need for heat transfer fluids (HTFs) for solar power generation that are stable to temperatures approaching 600°C, have good thermal characteristics, and do not react with the vessels in which they are contained.
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
Heat-Traced Fluid Transfer Lines
Schilling, R. E.
1984-01-01
or chemical), to maintain uniform fluid viscosity independent of ambient temperature, to establish uniform temperature above the dew point, and to maintain uniform temperature and prevent component dropout. water freeze protection is needed when a steam... of the parameters. A change in viscosity prJVides false readings and therefore results in unre iable process control. Viscosity control also helps provide uni form flow rates over a wide ran e of ambient temperatures, and in addition, pumps need not be oversized...
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 the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. [2]. Our results
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
Low-melting point inorganic nitrate salt heat transfer fluid
Bradshaw, Robert W. (Livermore, CA); Brosseau, Douglas A. (Albuquerque, NM)
2009-09-15
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.
Heat Transfer Fluids Containing Nanoparticles | Argonne National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-DoseOptions for AccidentalHealth,Heat Transfer Fluids
Molten salt as a heat transfer fluid for heating a subsurface formation
Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)
2010-11-16
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.
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
Project Profile: Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids
Broader source: Energy.gov [DOE]
Halotechnics, under the Thermal Storage FOA, is conducting high-throughput, combinatorial research and development of salt formulations for use as highly efficient heat transfer fluids (HTFs).
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 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
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
DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2
Not Available
1992-06-01
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.
White, Bruce
, Sacramento, 1999 TURBULENT TRANSPORT CHARACTERISTICS IN A LOW-SPEED BOUNDARY LAYER SUBJECTED TO ADVERSE of the 36th Heat Transfer and Fluid Mechanics Institute, California State University, Sacramento, 1999
Numerical and analytical modeling of heat transfer between fluid and fractured rocks
Li, Wei, S.M. Massachusetts Institute of Technology
2014-01-01
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 ...
Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts for CSP Generation
Broader source: Energy.gov [DOE]
In 2008, DOE issued the Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts for Concentrating Solar Power (CSP) Generation funding opportunity announcement (FOA) managed by the SunShot Initiative. The following projects were selected under this competitive solicitation.
THERMOPHYSICAL PROPERTIES OF NANOPARTICLE-ENHANCED IONIC LIQUIDS HEAT TRANSFER FLUIDS
Fox, E.
2013-04-15
An experimental investigation was completed on nanoparticle enhanced ionic liquid heat transfer fluids as an alternative to conventional organic based heat transfer fluids (HTFs). These nanoparticle-based HTFs have the potential to deliver higher thermal conductivity than the base fluid without a significant increase in viscosity at elevated temperatures. The effect of nanoparticle morphology and chemistry on thermophysical properties was examined. Whisker shaped nanomaterials were found to have the largest thermal conductivity temperature dependence and were also less likely to agglomerate in the base fluid than spherical shaped nanomaterials.
Lopez, Jose M; Avila, Marc
2015-01-01
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...
HEAT TRANSFER IN POROUS MEDIA WITH FLUID PHASE CHANGES
Su, Ho-Jeen.
2010-01-01
Cotter, T. P. : "Theory of Heat Pipe," Report No. LA-3246-L. : "Two Component Heat Pipes, It Propress in Astronauticsthe successful. The 'heat pipe ph periments were quite
The deterioration in heat transfer to fluids at supercritical pressure and high heat fluxes
Shiralkar, B. S.
1968-01-01
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 ...
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
Non-intrusive characterization of heat transfer fluid aerosol formation
Krishna, Kiran
2001-01-01
in process equipment. Predictive models relating the aerosol formation distances, aerosol droplet size, and volume concentrations to bulk liquid pressure, temperature, fluid properties, leak size and ambient conditions are developed. These models will be used...
High Operating Temperature Liquid Metal Heat Transfer Fluids...
that the metal alloys identified can meet all the needs of a concentrating solar power plant. A successful candidate fluid would allow for the reduction of the levelized cost...
7th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics
Abdou, Mohamed
, under construction by an international consortium in Cadarache, France, and the 19 #12;7th Worldi #12;ExHFT-7 7th World Conference on Experimental Heat Transfer, Fluid Mechanics FOR HUMANITY M. A. Abdou Center for Energy Science and Technology Advanced Research (CESTAR), Los Angeles, USA
Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Material Modular Thermal Energy Storage System Acciona Solar: Sensible Heat, Direct, Dual-Media Thermal Energy Storage Module City College of New York: A Novel Storage Method...
High Operating Temperature Liquid Metal Heat Transfer Fluids (Fact Sheet)
Not Available
2012-12-01
The University of California, Los Angeles, the University of California, Berkeley, and Yale University is one of the 2012 SunShot CSP R&D awardees for their Multidisciplinary University Research Initiative (MURI): High Operating Temperature (HOT) Fluids. This fact sheet explains the motivation, description, and impact of the project.
Effects of operating conditions on a heat transfer fluid aerosol
Sukmarg, Passaporn
2000-01-01
fluids are used as hot liquids at elevated pressures. If loss of containment does occur, the liquid will leak under pressure and may disperse as a fine aerosol mist. Though it has been recognized that aerosol mists can explode, very little is known about...
Jackson, J. D. [Univ. of Manchester, Manchester (United Kingdom); Jiang, P. X.; Liu, B. [Tsinghua Univ., Thermal Engineering Dept., Beijing (China)
2012-07-01
This paper is concerned with buoyancy-influenced turbulent convective heat transfer in vertical tubes for conditions where the physical properties vary strongly with temperature as in fluids at supercritical pressure in the pseudocritical temperature region. An extended physically-based, semi-empirical model is described which has been developed to account for the extreme non-uniformity of properties which can be present in such fluids and lead to strong influences of buoyancy which cause the mean flow and turbulence fields to be modified in such a manner that has a very profound effect on heat transfer. Data for both upward and downward flow from experiments using carbon dioxide at supercritical pressure (8.80, MPa, p/pc=1.19) in a uniformly heated tube of internal diameter 2 mm and length 290 mm, obtained under conditions of strong non-uniformity of fluid properties, are being correlated and fitted using an approach based on the model. It provides a framework for describing the complex heat transfer behaviour which can be encountered in such experiments by means of an equation of simple form. Buoyancy-induced impairment and enhancement of heat transfer is successfully reproduced by the model. Similar studies are in progress using experimental data for both carbon dioxide and water from other sources. The aim is to obtain an in-depth understanding of the mechanisms by which deterioration of heat transfer might arise in sensitive applications involving supercritical pressure fluids, such as high pressure, water-cooled reactors operating above the critical pressure. (authors)
Direct numerical simulations of fluid flow, heat transfer and phase changes
Juric, D.; Tryggvason, G.; Han, J.
1997-04-01
Direct numerical simulations of fluid flow, heat transfer, and phase changes are presented. The simulations are made possible by a recently developed finite difference/front tracking method based on the one-field formulation of the governing equations where a single set of conservation equations is written for all the phases involved. The conservation equations are solved on a fixed rectangular grid, but the phase boundaries are kept sharp by tracking them explicitly by a moving grid of lower dimension. The method is discussed and applications to boiling heat transfer and the solidification of drops colliding with a wall are shown.
Forrest, Eric Christopher
2009-01-01
Surface effects on pool boiling heat transfer and the critical heat flux are well documented but poorly understood. This study investigates the pool boiling characteristics of various fluids, and demonstrates that surface ...
Tumuluri, Kalpana
2011-08-08
The present research work aims to develop a new heat transfer fluid by combining multiwalled carbon nanotubes (MWCNT) and microencapsulated phase change materials (MPCMs). Stable nanofluids have been prepared using different sizes of multiwalled...
Gas Turbine/Solar Parabolic Trough Hybrid Design Using Molten Salt Heat Transfer Fluid: Preprint
Turchi, C. S.; Ma, Z.
2011-08-01
Parabolic trough power plants can provide reliable power by incorporating either thermal energy storage (TES) or backup heat from fossil fuels. This paper describes a gas turbine / parabolic trough hybrid design that combines a solar contribution greater than 50% with gas heat rates that rival those of natural gas combined-cycle plants. Previous work illustrated benefits of integrating gas turbines with conventional oil heat-transfer-fluid (HTF) troughs running at 390?C. This work extends that analysis to examine the integration of gas turbines with salt-HTF troughs running at 450 degrees C and including TES. Using gas turbine waste heat to supplement the TES system provides greater operating flexibility while enhancing the efficiency of gas utilization. The analysis indicates that the hybrid plant design produces solar-derived electricity and gas-derived electricity at lower cost than either system operating alone.
Virginia Tech
Heat Transfer - 1 You are given the following information for a fluid with thermal conductivity the flow is laminar near the wall. a) (30 points) Determine the corresponding heat transfer coefficient the heat transfer coefficient as a function of x. c) (25 points) Determine the average heat transfer
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhang, Le; Luo, Feng; Xu, Ruina; Jiang, Peixue; Liu, Huihai
2014-12-31
The heat transfer and fluid transport of supercritical CO2 in enhanced geothermal system (EGS) is studied numerically with local thermal non-equilibrium model, which accounts for the temperature difference between solid matrix and fluid components in porous media and uses two energy equations to describe heat transfer in the solid matrix and in the fluid, respectively. As compared with the previous results of our research group, the effect of local thermal non-equilibrium mainly depends on the volumetric heat transfer coefficient ah, which has a significant effect on the production temperature at reservoir outlet and thermal breakthrough time. The uniformity of volumetricmore »heat transfer coefficient ah has little influence on the thermal breakthrough time, but the temperature difference become more obvious with time after thermal breakthrough with this simulation model. The thermal breakthrough time reduces and the effect of local thermal non-equilibrium becomes significant with decreasing ah.« less
Tao, Y.B.; He, Y.L.
2010-10-15
A unified two-dimensional numerical model was developed for the coupled heat transfer process in parabolic solar collector tube, which includes nature convection, forced convection, heat conduction and fluid-solid conjugate problem. The effects of Rayleigh number (Ra), tube diameter ratio and thermal conductivity of the tube wall on the heat transfer and fluid flow performance were numerically analyzed. The distributions of flow field, temperature field, local Nu and local temperature gradient were examined. The results show that when Ra is larger than 10{sup 5}, the effects of nature convection must be taken into account. With the increase of tube diameter ratio, the Nusselt number in inner tube (Nu{sub 1}) increases and the Nusselt number in annuli space (Nu{sub 2}) decreases. With the increase of tube wall thermal conductivity, Nu{sub 1} decreases and Nu{sub 2} increases. When thermal conductivity is larger than 200 W/(m K), it would have little effects on Nu and average temperatures. Due to the effect of the nature convection, along the circumferential direction (from top to down), the temperature in the cross-section decreases and the temperature gradient on inner tube surface increases at first. Then, the temperature and temperature gradients would present a converse variation at {theta} near {pi}. The local Nu on inner tube outer surface increases along circumferential direction until it reaches a maximum value then it decreases again. (author)
The flow and heat transfer in a viscous fluid over an unsteady stretching surface
Ene, Remus-Daniel; Marinca, Bogdan
2015-01-01
In this paper we have studied the flow and heat transfer in a viscous fluid by a horizontal sheet. The stretching rate and temperature of the sheet vary with time. The governing equations for momentum and thermal energy are reduced to ordinary differential equations by means of similarity transformation. These equations are solved approximately by means of the Optimal Homotopy Asymptotic Method (OHAM) which provides us with a convenient way to control the convergence of approximation solutions and adjust convergence rigorous when necessary. Some examples are given and the results obtained reveal that the proposed method is effective and easy to use.
International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics 14 16 July 2014
Ghajar, Afshin J.
pipe systems. To explore and enhance the general understanding of heat transfer in non-boiling two in inclination of the pipe in downward direction causes the two phase heat transfer coefficient to decrease in the heat transfer in two phase air-water flow when pipe is inclined slightly upward from the near
International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics 14 16 July 2014
Ghajar, Afshin J.
. The current experiments analyses the two phase heat transfer in a pipe of diameter 12.5 mm and the results experiments show that the heat transfer coefficient also depends on the pipe diameter along with flow pattern and pipe inclination. The experimental data from these investigations can be used to develop heat transfer
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
Fox, Elise B; Kendrick, Sarah E.; Visser, Ann E.; Bridges, Nicholas J.
2012-10-15
The purpose of this study was to investigate the effect of long-term aging on the thermal stability and chemical structure of seven different ILs so as to explore their suitability for use as a heat transfer fluid. This was accomplished by heating the ILs for 15 weeks at 200?C in an oxidizing environment and performing subsequent analyses on the aged chemicals.
Enhanced heat transfer using nanofluids
Choi, Stephen U. S. (Lisle, IL); Eastman, Jeffrey A. (Naperville, IL)
2001-01-01
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.
Heat Transfer Fluids for Solar Water Heating Systems | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative Fuelsof Energy ServicesContracting OversightEMS Policy HQDepartmentHeat
HEAT TRANSFER DURING THE SHOCK-INDUCED IGNITION OF AN EXPOLSIVE GAS
Heperkan, H.
2013-01-01
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
Gustavsen, Arlid
2008-01-01
be used to calculate radiation heat transfer. The convectionat about 5×10 -10 ). Radiation heat transfer was included inof rays in the radiation heat-transfer algorithm of the CFD
Kumar, Rakesh
2015-01-01
This investigation deals with the analysis of stagnation point heat transfer and corresponding flow features of hydromagnetic viscous incompressible fluid over a vertical shrinking sheet. The considered sheet is assumed to be permeable and subject to addition of stagnation point to control the generated vorticity in the boundary layer. The sheet is placed on the right side of the fluid saturated porous medium which is having permeability of specified form. Nonlinear convection waves in the flow field are realized due to the envisaged nonlinear relation between density and temperature. The equations governing the nonlinear convection boundary layer flow are modeled and simplified using similarity transformations. The economized equations are solved for numerical solutions by employing the implicit finite difference scheme also known as Keller-box method. The influence of the associated parameters of the problem on velocity and temperature distributions, skin friction and rate of heat transfer are presented thr...
Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff
2006-10-10
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.
Bennion, Kevin; Moreno, Gilberto
2015-09-29
Thermal management for electric machines (motors/ generators) is important as the automotive industry continues to transition to more electrically dominant vehicle propulsion systems. Cooling of the electric machine(s) in some electric vehicle traction drive applications is accomplished by impinging automatic transmission fluid (ATF) jets onto the machine's copper windings. In this study, we provide the results of experiments characterizing the thermal performance of ATF jets on surfaces representative of windings, using Ford's Mercon LV ATF. Experiments were carried out at various ATF temperatures and jet velocities to quantify the influence of these parameters on heat transfer coefficients. Fluid temperatures were varied from 50 degrees C to 90 degrees C to encompass potential operating temperatures within an automotive transaxle environment. The jet nozzle velocities were varied from 0.5 to 10 m/s. The experimental ATF heat transfer coefficient results provided in this report are a useful resource for understanding factors that influence the performance of ATF-based cooling systems for electric machines.
Not Available
1980-03-07
A heat transfer system for a nuclear reactor is described. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.
McGuire, Joseph C. (Richland, WA)
1982-01-01
A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.
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
Proceedings of HTFED04 2004 ASME Heat Transfer/ Fluids Engineering Summer Conference
McDonough, James M.
DURING FEMTOSECOND LASER HEATING OF NANO-FILMS USING 3-D DUAL PHASE LAG MODEL Illayathambi Kunadian , J the Dual Phase Lag (DPL) model and consider laser heating at different locations on the metal film Fourier's law. When Eq. (4) is coupled with the energy Eq. (2) we obtain hyperbolic heat conduction
Zhang, Hao; Trias, F Xavier; Yu, Aibing; Tan, Yuanqiang; Oliva, Assensi
2015-01-01
In our recent work [H. Zhang, F.X. Trias, A. Oliva, D. Yang, Y. Tan, Y. Sheng. PIBM: Particulate immersed boundary method for fluid-particle interaction problems. Powder Technology. 272(2015), 1-13.], a particulate immersed boundary method (PIBM) for simulating fluid-particle multiphase flow was proposed and assessed in both two- and three-dimensional applications. In this study, the PIBM was extended to solve thermal interaction problems between spherical particles and fluid. The Lattice Boltzmann Method (LBM) was adopted to solve the fluid flow and temperature fields, the PIBM was responsible for the non-slip velocity and temperature boundary conditions at the particle surface, and the kinematics and trajectory of the solid particles were evaluated by the Discrete Element Method (DEM). Four case studies were implemented to demonstrate the capability of the current coupling scheme. Firstly, numerical simulation of natural convection in a two-dimensional square cavity with an isothermal concentric annulus was...
Kondle, Satyanarayana
2011-10-21
the geometry shape, solid and fluid materials used, and surface roughness, among others. Many configurations of microchannels have been studied with various materials and compared for their effectiveness in heat removal. However, there is little research done...
Kandlikar, Satish
, the effect of structured roughness elements on incompress- ible laminar fluid flow is analyzedA numerical study on the effects of 2d structured sinusoidal elements on fluid flow and heat flow Structured roughness elements Laminar flow a b s t r a c t Better understanding of laminar flow
Low-Temperature Enhanced Geothermal System using Carbon Dioxide as the Heat-Transfer Fluid
Eastman, Alan D.
2014-07-24
This report describes work toward a supercritical CO_{2}-based EGS system at the St. Johns Dome in Eastern Arizona, including a comprehensive literature search on CO_{2}-based geothermal technologies, background seismic study, geological information, and a study of the possible use of metal oxide heat carriers to enhance the heat capacity of sCO_{2}. It also includes cost estimates for the project, and the reasons why the project would probably not be cost effective at the proposed location.
Grogan, Dylan C. P.
2013-08-15
Executive Summary This Final Report for the "Development of Molten-Salt Heat Transfer Fluid (HTF) Technology for Parabolic Trough Solar Power Plants” describes the overall project accomplishments, results and conclusions. Phase 1 analyzed the feasibility, cost and performance of a parabolic trough solar power plant with a molten salt heat transfer fluid (HTF); researched and/or developed feasible component options, detailed cost estimates and workable operating procedures; and developed hourly performance models. As a result, a molten salt plant with 6 hours of storage was shown to reduce Thermal Energy Storage (TES) cost by 43.2%, solar field cost by 14.8%, and levelized cost of energy (LCOE) by 9.8% - 14.5% relative to a similar state-of-the-art baseline plant. The LCOE savings range met the project’s Go/No Go criteria of 10% LCOE reduction. Another primary focus of Phase 1 and 2 was risk mitigation. The large risk areas associated with a molten salt parabolic trough plant were addressed in both Phases, such as; HTF freeze prevention and recovery, collector components and piping connections, and complex component interactions. Phase 2 analyzed in more detail the technical and economic feasibility of a 140 MWe,gross molten-salt CSP plant with 6 hours of TES. Phase 2 accomplishments included developing technical solutions to the above mentioned risk areas, such as freeze protection/recovery, corrosion effects of applicable molten salts, collector design improvements for molten salt, and developing plant operating strategies for maximized plant performance and freeze risk mitigation. Phase 2 accomplishments also included developing and thoroughly analyzing a molten salt, Parabolic Trough power plant performance model, in order to achieve the project cost and performance targets. The plant performance model and an extensive basic Engineering, Procurement, and Construction (EPC) quote were used to calculate a real levelized cost of energy (LCOE) of 11.50¢/kWhe , which achieved the Phase 2 Go/No Go target of less than 0.12¢/kWhe. Abengoa Solar has high confidence that the primary risk areas have been addressed in the project and a commercial plant utilizing molten salt is economically and technically feasible. The strong results from the Phase 1 and 2 research, testing, and analyses, summarized in this report, led Abengoa Solar to recommend that the project proceed to Phase 3. However, a commercially viable collector interconnection was not fully validated by the end of Phase 2, combined with the uncertainty in the federal budget, forced the DOE and Abengoa Solar to close the project. Thus the resources required to construct and operate a molten salt pilot plant will be solely supplied by Abengoa Solar.
Study of Laminar Flow Forced Convection Heat Transfer Behavior of a Phase Change Material Fluid
Ravi, Gurunarayana
2010-01-14
takes into account the melting point and latent heat of fusion of the PCM as shown in Eq. (14) and (15). () ( ) ( ) b sl m p m f 1 2 Cp Cp c Cp 1 c Cp for T T== +? (19) () ( m emf 1 21 cL Cp 1 c Cp for T < T < T (T...
Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference
Kandlikar, Satish
Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference Las Vegas, Nevada, USA July 21-23, 2003 HT2003-47449 HEAT TRANSFER FROM A MOVING AND EVAPORATING MENISCUS ON A HEATED SURFACE meniscus with complete evaporation of water without any meniscus break-up. The experimental heat transfer
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, ...
Heat transfer and heat exchangers reference handbook
Not Available
1991-01-15
The purpose of this handbook is to provide Rocky Flats personnel with an understanding of the basic concepts of heat transfer and the operation of heat exchangers.
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 surfaces in laboratories to obtain the heat transfer coefficient data. In many process applications however, a fluid stream is employed as the heating medium. The heat transfer data generated with the electrically
HEAT AND MOISTURE TRANSFER THROUGH CLOTHING
Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie
2009-01-01
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
2009-01-01
R. C. Eberhart (ed), Heat transfer in medicine and biology.Convective and radiative heat transfer coefficients forbetween convective heat transfer and mass transfer
Heat transfer to impacting drops and post critical heat flux dispersed flow
Kendall, Gail E.
1978-01-01
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 ...
Phase Change Heat Transfer Device for Process Heat Applications
Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson
2010-10-01
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 approx.1300 K) and industrial scale power transport (=50MW), 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 thermal 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) of vapor flow and/or by condensate entrainment. Proper thermosyphon requires analysis of both.
5. Heat transfer Ron Zevenhoven
Zevenhoven, Ron
Three heat transfer mechanisms Conduction Convection Radiation 2/120 Pic: BÖ88 Åbo Akademi University1/120 5. Heat transfer Ron Zevenhoven Åbo Akademi University Thermal and Flow Engineering / Värme | Thermal and Flow Engineering | 20500 Turku | Finland #12;3/120 5.1 Conductive heat transfer Åbo Akademi
Heat Transfer Study of Polymer Solutions with Different Rigidities
Huang, Yao
2014-05-08
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...
Modeling of fuel-to-steel heat transfer in core disruptive accidents
Smith, Russell Charles
1980-01-01
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 ...
Kim, Ho-Young
transfer between fluids, and many types of heat exchangers are used to enhance the heat transfer efficiency.elsevier.com/locate/apthermeng #12;shell-and-tube heat exchanger is generally used for its relatively low pressure drop in the system far, to promote the heat transfer in heat exchangers of the system, either the heat transfer area
Fluid-cooled heat sink with improved fin areas and efficiencies...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
VARIOUS DEVICES Abstract: The disclosure provides a fluid-cooled heat sink having a heat transfer base and a plurality of heat transfer fins in thermal communication with the...
of roomsurface-to-air heat transmission is dependentonan accurateestimateof the filmcoefficient. Forty- eight4065 (RP-664) Convective Energy and Heat Transfer Thermal Load in Building Calculations Daniel E convection film coefficients significantly underpredict the rate of surface convective heat 'transfer
Examination of Liquid Fluoride Salt Heat Transfer
Yoder Jr, Graydon L
2014-01-01
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.
Kafengauz, N.L.; Borovitskii, A.B.
1986-04-01
It is established experimentally that solid carbon deposits formed in heat transfer to kerosene in small-bore tubes induce self-excited thermoacoustic oscillations.
Heat pump/refrigerator using liquid working fluid
Wheatley, John C. (Del Mar, CA); Paulson, Douglas N. (Del Mar, CA); Allen, Paul C. (Solana Beach, CA); Knight, William R. (Corvallis, OR); Warkentin, Paul A. (San Diego, CA)
1982-01-01
A heat transfer device is described that can be operated as a heat pump or refrigerator, which utilizes a working fluid that is continuously in a liquid state and which has a high temperature-coefficient of expansion near room temperature, to provide a compact and high efficiency heat transfer device for relatively small temperature differences as are encountered in heating or cooling rooms or the like. The heat transfer device includes a pair of heat exchangers that may be coupled respectively to the outdoor and indoor environments, a regenerator connecting the two heat exchangers, a displacer that can move the liquid working fluid through the heat exchangers via the regenerator, and a means for alternately increasing and decreasing the pressure of the working fluid. The liquid working fluid enables efficient heat transfer in a compact unit, and leads to an explosion-proof smooth and quiet machine characteristic of hydraulics. The device enables efficient heat transfer as the indoor-outdoor temperature difference approaches zero, and enables simple conversion from heat pumping to refrigeration as by merely reversing the direction of a motor that powers the device.
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
Urban Sewage Delivery Heat Transfer System (2): Heat Transfer
Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.
2006-01-01
analysis of above flow resistance and energy cost, we know that the economy flux ratio of transfer heat-transfer means is between 0.54 and 0.85, namely sewage flux is smaller, and minC Cr min wwCVc?= . It is necessary to point out that though depending... efficiency of contranatant two pass thimble: ()213 1 11 21wwNn wz tt Cr tt 1n? ?? ?==?+ ? (1) Fig.1 Reverse-flow heat efficiency of TDHTS Contranatant single pass heat-transfer efficiency: ( ) ()1 1exp (1 ) 1exp (1)n Cr NTU Cr? = ?? ? ? Put...
Virginia Tech
Spring 2014 1 Heat Transfer - 1 Consider a cylindrical nuclear fuel rod of length L and diameter df and the tube at a rate m , and the outer surface of the tube is well insulated. Heat generation occurs within. The specific heat of water pc , and the thermal conductivity of the fuel rod fk are constants. The system
Not Available
2012-12-01
The University of Arizona, Arizona Statue University (ASU), and Georgia Institute of Technology is one of the 2012 SunShot CSP R&D awardees for their Multidisciplinary University Research Initiative (MURI): High Operating Temperature (HOT) Fluids. This fact sheet explains the motivation, description, and impact of the project.
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)
1998-07-21
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Phillips, B.A.; Zawacki, T.S.
1998-07-21
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.
Robert E. Spall; Barton Smith; Thomas Hauser
2008-12-08
Nationwide, the demand for electricity due to population and industrial growth is on the rise. However, climate change and air quality issues raise serious questions about the wisdom of addressing these shortages through the construction of additional fossil fueled power plants. In 1997, the President's Committee of Advisors on Science and Technology Energy Research and Development Panel determined that restoring a viable nuclear energy option was essential and that the DOE should implement a R&D effort to address principal obstacles to achieving this option. This work has addressed the need for improved thermal/fluid analysis capabilities, through the use of computational fluid dynamics, which are necessary to support the design of generation IV gas-cooled and supercritical water reactors.
Gerardi, Craig Douglas
2009-01-01
A high-speed video and infrared thermography based technique has been used to obtain detailed and fundamental time- and space-resolved information on pool boiling heat transfer. The work is enabled by recent advances in ...
MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER
Lahey, Richard T.
MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts
Electrohydrodynamically enhanced condensation heat transfer
Wawzyniak, Markus
1993-01-01
In a condenser the thickness of the liquid condensate film covering the cooled surface constitutes a resistance to the heat transfer. By establishing a non uniform electric field in the vicinity of the condensation surface the extraction of liquid...
Devices with extended area structures for mass transfer processing of fluids
TeGrotenhuis, Ward E. (Kennewick, WA); Wegeng, Robert S. (Richland, WA); Whyatt, Greg A. (West Richland, WA); King, David L. (Richland, WA); Brooks, Kriston P. (Kennewick, WA); Stenkamp, Victoria S. (Richland, WA)
2009-04-21
A microchannel device includes several mass transfer microchannels to receive a fluid media for processing at least one heat transfer microchannel in fluid communication with a heat transfer fluid defined by a thermally conductive wall, and at several thermally conductive fins each connected to the wall and extending therefrom to separate the mass transfer microchannels from one another. In one form, the device may optionally include another heat transfer microchannel and corresponding wall that is positioned opposite the first wall and has the fins and the mass transfer microchannels extending therebetween.
Submersible pumping system with heat transfer mechanism
Hunt, Daniel Francis Alan; Prenger, F. Coyne; Hill, Dallas D; Jankowski, Todd Andrew
2014-04-15
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.
Lefevre, M. R.
1984-01-01
Almost every industrial process needs some form of cooling. Water is still the most extensively used fluid for cooling, but the days when plenty of it was available are gone forever. Water conservation is currently achieved by the use of evaporative...
Nanoscale heat transfer - from computation to experiment
Luo, Tengfei
2013-04-09
Heat transfer can differ distinctly at the nanoscale from that at the macroscale. Recent advancement in
Microchannel crossflow fluid heat exchanger and method for its fabrication
Swift, G.W.; Migliori, A.; Wheatley, J.C.
1982-08-31
A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance.
Microchannel crossflow fluid heat exchanger and method for its fabrication
Swift, G.W.; Migliori, A.; Wheatley, J.C.
1985-05-14
A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance. 9 figs.
Microchannel crossflow fluid heat exchanger and method for its fabrication
Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM); Wheatley, John C. (Los Alamos, NM)
1985-01-01
A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance.
Fluid-cooled heat sink with improved fin areas and efficiencies for use in cooling various devices
Bharathan, Desikan; Bennion, Kevin; Kelly, Kenneth; Narumanchi, Sreekant
2015-04-21
The disclosure provides a fluid-cooled heat sink having a heat transfer base and a plurality of heat transfer fins in thermal communication with the heat transfer base, where the heat transfer base and the heat transfer fins form a central fluid channel through which a forced or free cooling fluid may flow. The heat transfer pins are arranged around the central fluid channel with a flow space provided between adjacent pins, allowing for some portion of the central fluid channel flow to divert through the flow space. The arrangement reduces the pressure drop of the flow through the fins, optimizes average heat transfer coefficients, reduces contact and fin-pin resistances, and reduces the physical footprint of the heat sink in an operating environment.
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
Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal...
Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...
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
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
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
Code Number :.............. HEAT TRANSFER QUALIFYING EXAM
Feeny, Brian
is at 40 °C, estimate the heat transfer per unit length by radiation and convection between the twoCode Number :.............. HEAT TRANSFER QUALIFYING EXAM January 2010 OPEN BOOK (only one book) The heat transfer coefficient c) The length of pipe needed for a 35 °C increase in mean temperature d
ME 519: THEORY OF HEAT TRANSFER Instructor
Lin, Xi
ME 519: THEORY OF HEAT TRANSFER Fall 2014 Instructor: Class time: Classroom: Office Hours: Prof Tuesday 45pm or by appointment Class description This course will cover the fundamentals of heat transfer. An introductory course in heat transfer (ME 419 or equivalent) is pre-requisite. Grading 20% Homework 25% Exam 1
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01
and J.R. Howell, Thermal radiation heat transfer, Hemispheremade: 1. The heat, mass, and radiation transfer are treatedOne- dimensional heat, mass, and radiation transfers were
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01
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. ,
Heat transfer via dropwise condensation on hydrophobic microstructured surfaces
Ruleman, Karlen E. (Karlen Elizabeth)
2009-01-01
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 ...
Acoustically Enhanced Boiling Heat Transfer
Z. W. Douglas; M. K. Smith; A. Glezer
2008-01-07
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 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
Heat exchanger device and method for heat removal or transfer
Koplow, Jeffrey P. (San Ramon, CA)
2012-07-24
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.
2015-12-08
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
2013-12-10
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.
Advances in refrigeration and heat transfer engineering
Bansal, Pradeep [ORNL; Cremaschi, Prof. Lorenzo [Oklahoma State University
2015-01-01
This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO2 may perhaps have been the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).
Development of Molten-Salt Heat Trasfer Fluid Technology for...
Development of Molten-Salt Heat Trasfer Fluid Technology for Parabolic Trough Solar Power Plants Development of Molten-Salt Heat Trasfer Fluid Technology for Parabolic Trough Solar...
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
Control system for fluid heated steam generator
Boland, J.F.; Koenig, J.F.
1984-05-29
A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.
Control system for fluid heated steam generator
Boland, James F. (Bonneville County, ID); Koenig, John F. (Idaho Falls, ID)
1985-01-01
A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.
Extreme pressure fluid sample transfer pump
Halverson, Justin E. (Grovertown, GA); Bowman, Wilfred W. (North Augusta, SC)
1990-01-01
A transfer pump for samples of fluids at very low or very high pressures comprising a cylinder having a piston sealed with an O-ring, the piston defining forward and back chambers, an inlet and exit port and valve arrangement for the fluid to enter and leave the forward chamber, and a port and valve arrangement in the back chamber for adjusting the pressure across the piston so that the pressure differential across the piston is essentially zero and approximately equal to the pressure of the fluid so that the O-ring seals against leakage of the fluid and the piston can be easily moved, regardless of the pressure of the fluid. The piston may be actuated by a means external to the cylinder with a piston rod extending through a hole in the cylinder sealed with a bellows attached to the piston head and the interior of the back chamber.
Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger
Singh, K. P.
1979-01-01
CHARACTERISTICS OF A GENERALIZED DIVIDED FLrnJ HEAT EXCHANGER KRISHNA P. SINGH, CHIEF ENGINEER JOSEPH OAT CORPORATION 2500 Broadway, Camden, New Jersey 08104 ,l\\bstract The concept of a "Di vi ded-fl O~I" heat exchanger is general i zed by 1oca t i n...-Pass Split-Flow Shell Trans. of the ASME, Journal of Heat Transfer, pp 408-416, Aug. 1964. (4) Singh, K. P. and Holtz, ~I.J., "Generalization of the Split Flow Heat Exchanger - Geometry for Enhanced Heat Transfer", 18th National ASME/AICHE Heat Transfer...
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
Check Heat Transfer Services; Industrial Technologies Program...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
the result of: * Low air:fuel ratios * Improper fuel preparation * Malfunctioning burners * Oxidation of heat transfer surfaces in high temperature applications * Corrosive...
HEAT TRANSFER ANALYSIS OF A PULSE DETONATION
Texas at Arlington, University of
HEAT TRANSFER ANALYSIS OF A PULSE DETONATION ENGINE by NEELIMA KALIDINDI Presented to the Faculty support. November 23, 2009 #12;iv ABSTRACT HEAT TRANSFER ANALYSIS OF A PULSE DETONATION ENGINE NEELIMA thermal conductivity. The study showed a slow temperature rise along the walls of the combustion chamber
Indirect Heat Transfer Technology For Waste Heat Recovery Can Save You Money
Beyrau, J. A.; Bogel, N. G.; Seifert, W. F.; Wuelpern, L. E.
1984-01-01
Il'IflImiUIf ~L t::::..;~~= N2---b!<)-L-, FSL Flow Mitch 10 HS Hone! lW~ch PI Pr_UJ1I indlc.uw Pi Preaurw trarwntaer 30 ~s " ""c:: 26 U d 20 n Flue-gas bypass ductwork, damper (" ...... and bypass control valve g~ 16 \\ o~ \\ ~~ 10... ? ? I ? I I I : I - - 1 Heat?transfer l fluid ... INDIRECT HEAT TRANSFER TECHNOLOGY FOR WASTE HEAT RECOVERY CAN SAVE YOU MONEY John A. Beyrau, Gallie N. Bogel, Walter F. Seifert, Louis E. Wuelpern The Dow Chemical Company Midland, Michigan...
Radiative heat transfer between dielectric bodies
Svend-Age Biehs
2011-03-16
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.
Micro/Nanoscale Heat Transfer: Interfacial Effects Dominate the
Kostic, Milivoje M.
conduction 2. Convective heat transfer 3. Thermal radiation 4. Conclusions 1.1 Thermal conductivity3/15/2012 1 Micro/Nanoscale Heat Transfer: Interfacial Effects Dominate the Heat Transfer 1 Xing/nanoscale heat transfer becomes critical. What is the dominant factor in micro/nanosclae heat transfer
Heat and mass transfer considerations in advanced heat pump systems
Panchal, C.B.; Bell, K.J.
1992-08-01
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.
1992-01-01
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.
Dynamics of heat transfer between nano systems
Svend-Age Biehs; Girish S. Agarwal
2012-10-18
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.
Wang, Yuan
2011-11-22
Heat management in high thermal-density systems such as CPU chips, nuclear reactors and compact heat exchangers is confronting rising challenges due to ever more miniaturized and intensified processes. While searching ...
Heat transfer pathways in underfloor air distribution (UFAD) systems
Bauman, F.; Jin, H.; Webster, T.
2006-01-01
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
Passive heat transfer means for nuclear reactors
Burelbach, James P. (Glen Ellyn, IL)
1984-01-01
An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. Means such as shrouding normally isolated the secondary condensing section from effective heat transfer with the heat sink, but a sensor responds to overheat conditions of the reactor to open the shrouding, which thereby increases the cooling capacity of the heat pipe. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.
Analysis of Heat Transfer in Metal Hydride Based Hydrogen Separation
Fleming, W.H. Jr.
1999-10-20
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.
Industrial Steam System Heat-Transfer Solutions | Department...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Industrial Steam System Heat-Transfer Solutions Industrial Steam System Heat-Transfer Solutions This brief provides an overview of considerations for selecting the best...
Heat Transfer Enhancement: Second Generation Technology
Bergles, A. E.; Webb, R. L.
1984-01-01
This paper reviews current activity in the field of enhanced heat transfer, with the aim of illustrating the technology and typical applications. Guidelines for application of enhanced surfaces are given, and practical concerns and economics...
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
Hodges, James L. (3 Hilltop Ave., Vernon, CT 06066); Cerkanowicz, Anthony E. (8 Fieldstone Dr., Livingston, NJ 07039)
1982-01-01
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)
1983-01-01
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.
Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants
Mathur, Anoop
2013-08-14
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.
Indirect evaporative coolers with enhanced heat transfer
Kozubal, Eric; Woods, Jason; Judkoff, Ron
2015-09-22
A separator plate assembly for use in an indirect evaporative cooler (IEC) with an air-to-air heat exchanger. The assembly includes a separator plate with a first surface defining a dry channel and a second surface defining a wet channel. The assembly includes heat transfer enhancements provided on the first surface for increasing heat transfer rates. The heat transfer enhancements may include slit fins with bodies extending outward from the first surface of separator plate or may take other forms including vortex generators, offset strip fins, and wavy fins. In slit fin implementations, the separator plate has holes proximate to each of the slit fins, and the separator plate assembly may include a sealing layer applied to the second surface of the separator plate to block air flow through the holes. The sealing layer can be a thickness of adhesive, and a layer of wicking material is applied to the adhesive.
Friction-Induced Fluid Heating in Nanoscale Helium Flows
Li Zhigang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)
2010-05-21
We investigate the mechanism of friction-induced fluid heating in nanoconfinements. Molecular dynamics simulations are used to study the temperature variations of liquid helium in nanoscale Poiseuille flows. It is found that the fluid heating is dominated by different sources of friction as the external driving force is changed. For small external force, the fluid heating is mainly caused by the internal viscous friction in the fluid. When the external force is large and causes fluid slip at the surfaces of channel walls, the friction at the fluid-solid interface dominates over the internal friction in the fluid and is the major contribution to fluid heating. An asymmetric temperature gradient in the fluid is developed in the case of nonidentical walls and the general temperature gradient may change sign as the dominant heating factor changes from internal to interfacial friction with increasing external force.
Radiative Heat Transfer between Neighboring Particles
Alejandro Manjavacas; F. Javier Garcia de Abajo
2012-01-26
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.
Inr J Heat Mass Transfer. Vol. 39. No. 15, pp. 3165-3173, 1996 Copyright 0 1996 Elsevier Science Ltd
Zhang, Yuwen
storage system is the shell- and-tube heat exchanger. In this exchanger, the PCM fills the annular shell space around the tube, while the transfer fluid flows within the tube. This type of latent heat storagePergamon Inr J Heat Mass Transfer. Vol. 39. No. 15, pp. 3165-3173, 1996 Copyright 0 1996 Elsevier
Analysis of heat transfer in unlooped and looped pulsating
Zhang, Yuwen
to the exchange of sensible heat. Higher surface tension results in a slight increase in the total heat transfer into turns. There are two types of PHPs: the looped pulsating heat pipe and the unlooped pulsating heat pipeAnalysis of heat transfer in unlooped and looped pulsating heat pipes M.B. Sha®i and A. Faghri
Cooperative heat transfer and ground coupled storage system
Metz, Philip D. (Rocky Point, NY)
1982-01-01
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.
Self supporting heat transfer element
Story, Grosvenor Cook (Livermore, CA); Baldonado, Ray Orico (Livermore, CA)
2002-01-01
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.
Power systems utilizing the heat of produced formation fluid
Lambirth, Gene Richard (Houston, TX)
2011-01-11
Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method includes treating a hydrocarbon containing formation. The method may include providing heat to the formation; producing heated fluid from the formation; and generating electricity from at least a portion of the heated fluid using a Kalina cycle.
Buoyancy-driven heat transfer and flow between a wetted heat source and an isothermal cube
Close, D.J.; Peck, M.K.; White, R.F.; Mahoney, K.J. )
1991-05-01
This paper describes flow visualization and heat transfer experiments conducted with a heat source inside an isothermal cube filled with a saturated or near-saturated gas/vapor mixture. The mixture was formed by vaporizing liquid from the surface of the heat source, and allowing it to condense on the surfaces of the cube, which was initially filled with a noncondensing gas. Visualization studies showed that for air and ethanol below 35C, and for air and water, the flow patterns were similar with the hot plume rising from the source. For air and ethanol above 35C the flow pattern reversed with the hot plume flowing downward. For temperatures spanning 35C, which is the zero buoyancy temperature for the ethanol/water azeotrope and air, no distinct pattern was observed. Using water, liquid droplets fell like rain throughout the cube. Using ethanol, a fog of droplets moved with the fluid flow. Heat transfer experiments were made with water and air, and conductances between plate and cube of around 580 W{center dot}m{sup {minus}2}{center dot}K{sup {minus}1} measured. Agreement between the similarity theory developed for saturated gas/vapor mixtures, and correlations for single component fluids only, was very good. Together with qualitative support from the visualization experiments, the theory developed in a earlier paper deriving a similarity relationship between single fluids and gas/vapor mixtures has been validated.
Heat and Mass Transfer Wrme-und Stoffbertragung
Guo, Zhixiong "James"
Transfer (2013) 49:405-412 DOI 10.1007/s00231-012-1077-8 Natural convection and radiation heat transfer 12 months after publication. #12;ORIGINAL Natural convection and radiation heat transfer wall temperature, both the natural convection and radiation heat transfer are enhanced
Code Number HEAT TRANSFER QUALIFYING EXAM
Feeny, Brian
is a device that uses inadiation from the sun to heat water. A solar collector is insulated on the bottom the rate of energy transfer to the water ifthe solar collector has a temperature of 45°C and ifthe sun.e. that all the energy received is radiated back in space. #12;Question #4) A water solar collector
Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference
Guo, Zhixiong "James"
, USA HT2009-88261 SIMULATION OF FOCUSED RADIATION PROPAGATION AND TRANSIENT HEAT TRANSFER IN TURBID-dependent radiation and conduction bio-heat transfer model. Ultrashort pulsed radiation transport in the cylindrical dissipation and the heat-affected zone. Two characteristics in ultrafast radiation heat transfer are worth
Convective Heat Transfer Augmentation by Flexible fins in Laminar Channel Pulsating flow
Joshi, Rakshitha U; Bhardwaj, Rajneesh
2015-01-01
Fluid-structure interaction (FSI) of thin flexible fins coupled with convective heat transfer has applications in energy harvesting and in understanding functioning of several biological systems. We numerically investigate FSI of the thin flexible fins involving large-scale flow-induced deformation as a potential 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. We consider twin flexible fins in a heated channel with laminar pulsating cross flow. The vortex ring past the fin sweep higher sources of vorticity generated on the channel walls out into the downstream - promoting the mixing of the fluid. The moving fin assists in convective mixing, augmenting convection in bulk and at the walls; and thereby reducing thermal boundary layer thickness and improving heat transfer at the channel walls. The thermal augmentation is...
Kornhuber, Ralf
Coupled fluid transport processes and numerical examples The expression "coupled fluid processes" refers to the central role of groundwater in transferring energy (i.e. heat) mass (i.e. solutes) over #12;Stability criteria TdK RaT Solutal Rayleigh number Thermal Rayleigh number d sat s D CdK CC Ra
Heat Transfer between Graphene and Amorphous SiO2
B. N. J. Persson; H. Ueba
2010-07-22
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.
Flow and heat transfer in vertical annuli
Ulke, A.; Goldberg, I.
1993-11-01
In shell-side boiling heat exchangers narrow crevices that are formed between the tubes and the tube support structure provide areas for local conditions which differ significantly from the bulk fluid conditions. A quasi-two-dimensional model which was developed to describe the local phenomena in a vertical, cylindrical crevice was described previously. The present work compares experimentally obtained flow and tube temperature distributions to those predicted by the model. The results confirm the characteristic ``W`` shape of the tube temperature profile centered at the line contact between a heated tube and tube support.
Experimental characterization of heat transfer in non-boiling spray cooling with two nozzles
Guo, Zhixiong "James"
found that adding a surfactant to the working fluid with an appropriate concentration will further to a heated surface is established for the cooling of high-power devices. The effects of the liquid volume flow rate, the nozzle-to-surface distance and the liquid inlet temperature on the heat transfer
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
Boiling heat transfer in a hydrofoil-based micro pin fin heat sink
Peles, Yoav
Boiling heat transfer in a hydrofoil-based micro pin fin heat sink Ali Kosßar, Yoav Peles-based micro pin fin heat sink was investigated. Average two-phase heat transfer coefficients were obtained intermittent and spray-annular flows. Heat transfer coefficient trends and flow morphologies were used to infer
A meshless method for modeling convective heat transfer
Carrington, David B
2010-01-01
A meshless method is used in a projection-based approach to solve the primitive equations for fluid flow with heat transfer. The method is easy to implement in a MATLAB format. Radial basis functions are used to solve two benchmark test cases: natural convection in a square enclosure and flow with forced convection over a backward facing step. The results are compared with two popular and widely used commercial codes: COMSOL, a finite element model, and FLUENT, a finite volume-based model.
Nanoparticles for heat transfer and thermal energy storage
Singh, Dileep; Cingarapu, Sreeram; Timofeeva, Elena V.; Moravek, Michael
2015-07-14
An article of manufacture and method of preparation thereof. The article of manufacture and method of making the article includes an eutectic salt solution suspensions and a plurality of nanocrystalline phase change material particles having a coating disposed thereon and the particles capable of undergoing the phase change which provides increase in thermal energy storage. In addition, other articles of manufacture can include a nanofluid additive comprised of nanometer-sized particles consisting of copper decorated graphene particles that provide advanced thermal conductivity to heat transfer fluids.
Flexible profile approach to the conjugate heat transfer problem
M. -N. Sabry
2008-01-07
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.
Buoyancy effects on conjugate heat transfer due to a laminar impinging jet: Preliminary results
Altieri, G.; De Luca, V.; Ruocco, G.
1999-07-01
A numerical analysis for fluid flow and conjugate conduction/convection heat transfer from a laminar, planar gas jet impingement (JI) on a finite thickness, discretely heated substrate is performed, which includes the effect of buoyancy. The competition between transfer of heat by conduction in the plate and by convection in the fluid is examined. A combination of assisting or opposing mixed convection is modeled, and the related flow field as well as local heat transfer rate is studied as a function of the mixed convection parameter, the Richardson number, for a given geometry and a thermal-fluid base-case. Preliminary evaluations of the heat transfer rate are presented as local Nusselt number distributions, for nonbuoyant, assisted and opposed impinging jets, along the impinged substrate. The complex, non-monotonic progresses of these results justify the inclusion of the conduction mechanism in the substrate, in order to correctly quantify the driving parameters for the heat transfer control. The presented calculations are in fair accordance with existing literature which is limited to pure fluid jet impingement. The inclusion of the conduction mechanism confirms the absence of the conjugate effect when an opposing cooling jet configuration is realized.
Conjugate heat transfer analysis using the Calore and Fuego codes.
Francis, Nicholas Donald, Jr.
2007-09-01
Full coupling of the Calore and Fuego codes has been exercised in this report. This is done to allow solution of general conjugate heat transfer applications that require more than a fluid flow analysis with a very simple conduction region (solved using Fuego alone) or more than a complex conduction/radiation analysis using a simple Newton's law of cooling boundary condition (solved using Calore alone). Code coupling allows for solution of both complex fluid and solid regions, with or without thermal radiation, either participating or non-participating. A coupled physics model is developed to compare to data taken from a horizontal concentric cylinder arrangement using the Penlight heating apparatus located at the thermal test complex (TTC) at Sandia National Laboratories. The experimental set-up requires use of a conjugate heat transfer analysis including conduction, nonparticipating thermal radiation, and internal natural convection. The fluids domain in the model is complex and can be characterized by stagnant fluid regions, laminar circulation, a transition regime, and low-level turbulent regions, all in the same domain. Subsequently, the fluids region requires a refined mesh near the wall so that numerical resolution is achieved. Near the wall, buoyancy exhibits its strongest influence on turbulence (i.e., where turbulence conditions exist). Because low-Reynolds number effects are important in anisotropic natural convective flows of this type, the {ovr {nu}{sup 2}}-f turbulence model in Fuego is selected and compared to results of laminar flow only. Coupled code predictions are compared to temperature measurements made both in the solid regions and a fluid region. Turbulent and laminar flow predictions are nearly identical for both regions. Predicted temperatures in the solid regions compare well to data. The largest discrepancies occur at the bottom of the annulus. Predicted temperatures in the fluid region, for the most part, compare well to data. As before, the largest discrepancies occur at the bottom of the annulus where the flow transitions to or is a low-level turbulent flow.
Radial heat transfer from a moving plasma
Johnson, James Randall
1966-01-01
devices are presently being con- sideredd both f r propulsion and attitude control. For the gener'ation of electrical power - the future, the controlled thermonuclear pro- cess or, , uclear fusion holds great promise. Whether the e. ergy created in.... this process is removed in the form of heat or some other means, the fusion gas will exist as a plasma. Also, chemical processing at pre- sent appears to be another area for future application of plasma jets '". which heat transfer data will be needed...
Heat transfer during film condensation of potassium vapor
Kroger, Detlev Gustav
1966-01-01
The object of this work is to investigate theoretically and experimentally the following two phases of heat transfer during condensation of potassium vapore, a. Heat transfer during film condensation of pure saturated ...
Modeling of Heat and Mass Transfer in Fusion Welding (Book) ...
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Book: Modeling of Heat and Mass Transfer in Fusion Welding Citation Details In-Document Search Title: Modeling of Heat and Mass Transfer in Fusion Welding In fusion welding, parts...
Heat transfer pathways in underfloor air distribution (UFAD) systems
Bauman, F.; Jin, H.; Webster, T.
2006-01-01
radiative heat transfer, since radiation was neglectedradiation striking the floor makes up the majority of the total heat transferheat transfer processes: conduction through the slab and floor panels and into the supply plenum via convection; radiation
Hydrodynamics, heat transfer and flow boiling instabilities in microchannels
Barber, Jacqueline Claire
2010-01-01
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 ...
Fort, James A.; Cuta, Judith M.; Bajwa, C.; Baglietto, E.
2010-07-18
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.
Situ soil sampling probe system with heated transfer line
Robbat, Jr., Albert (Andover, MA)
2002-01-01
The present invention is directed both to an improved in situ penetrometer probe and to a heated, flexible transfer line. The line and probe may be implemented together in a penetrometer system in which the transfer line is used to connect the probe to a collector/analyzer at the surface. The probe comprises a heater that controls a temperature of a geologic medium surrounding the probe. At least one carrier gas port and vapor collection port are located on an external side wall of the probe. The carrier gas port provides a carrier gas into the geologic medium, and the collection port captures vapors from the geologic medium for analysis. In the transfer line, a flexible collection line that conveys a collected fluid, i.e., vapor, sample to a collector/analyzer. A flexible carrier gas line conveys a carrier gas to facilitate the collection of the sample. A system heating the collection line is also provided. Preferably the collection line is electrically conductive so that an electrical power source can generate a current through it so that the internal resistance generates heat.
Theoretical Design of Thermosyphon for Process Heat Transfer from NGNP to Hydrogen Plant
Piyush Sabharwall; Mike Patterson; Fred Gunnerson
2008-09-01
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.
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 in inhomogeneous, nongray, and anisotropically scattering media
Guo, Zhixiong "James"
Radiative heat transfer in inhomogeneous, nongray, and anisotropically scattering media Zhixiong Radiative heat transfer in three-dimensional inhomogeneous, nongray and anisotropically scattering of an application of engineering interest, radiative heat transfer in a boiler model with non-isothermal, nongray
RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1
Paris-Sud XI, Université de
509 RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1 C. JOHANNES Service de Recherches Appliquées, L boiling, forced convection heat transfer. Relations between critical nucleate flux and some parameters confronted with the problem of calculating the heat transfer from the helium to the superconducting material
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
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 16.2.2 Heat Transfer and Airflow Near a Vertical Plate..................................................448 16.2.3 Heat Transfer and Airflow in Empty Closed Cavity
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
Gustavsen, Arild
2009-01-01
of convection and radiation heat transfer and developconvection and radiation heat transfer in three dimensionsaccount for 3- D radiation heat transfer on indoor surfaces.
DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION
Yee, G.
2010-01-01
DEVELOpiNG FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS9092 Developing Flow and Heat Transfer in Strongly CurvedForced Convection Heat Transfer in Curved Rectangular
Gustavsen, Arild
2009-01-01
free convection. In: Heat Transfer and Turbulent Buoyantof convection heat transfer and develop correlations.and radiation heat transfer and develop correlations for
Heat Transfer Operators Associated with Quantum Operations
Ç. Aksak; S. Turgut
2011-04-14
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.
Optimization of Phase Change Heat Transfer in Biporous Media
Reilly, Sean
2013-01-01
transfer analysis of a loop heat pipe with biporous wicks”.Planes”. Frontiers in Heat Pipes Journal 1, 013001 (2010).in Evaporator of Loop Heat Pipe. ” Journal of Thermophysics
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
Journal of Enhanced Heat Transfer, 19 (5): 457476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT
Ghajar, Afshin J.
2012-01-01
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 ¯ux 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
Heat Transfer Boundary Conditions in the RELAP5-3D Code
Richard A. Riemke; Cliff B. Davis; Richard R. Schultz
2008-05-01
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.
Flow-Induced Deformation of a Flexible Thin Structure as Manifestation of Heat Transfer Enhancement
Soti, Atul Kumar; Sheridan, John
2015-01-01
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...
Heat recirculating cooler for fluid stream pollutant removal
Richards, George A. (Morgantown, WV); Berry, David A. (Morgantown, WV)
2008-10-28
A process by which heat is removed from a reactant fluid to reach the operating temperature of a known pollutant removal method and said heat is recirculated to raise the temperature of the product fluid. The process can be utilized whenever an intermediate step reaction requires a lower reaction temperature than the prior and next steps. The benefits of a heat-recirculating cooler include the ability to use known pollutant removal methods and increased thermal efficiency of the system.
Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers
Thole, Karen A.
Abstract The louvered fin heat exchanger, a type of compact heat exchanger, has been used heavilyEffects 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
Heat transfer in a pulsating heat pipe with open end Yuwen Zhang 1
Zhang, Yuwen
Heat transfer in a pulsating heat pipe with open end Yuwen Zhang 1 , Amir Faghri * Department and condenser sections of a pulsating heat pipe (PHP) with open end is modeled by analyzing thin ®lm evaporation and condensation. The heat transfer solutions are applied to the thermal model of the pulsating heat pipe
Enhanced Geothermal Systems (EGS) comparing water with CO2 as heat transmission fluids
Pruess, Karsten
2007-01-01
Supercritical CO 2 as Heat Transmission Fluid in the EGSof Using Supercritical CO2 as Heat Transmission Fluid in an2 instead of water as heat transmission fluid (D.W. Brown,
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
Heat transfer assembly for a fluorescent lamp and fixture
Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.
1992-12-29
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.
Heat transfer assembly for a fluorescent lamp and fixture
Siminovitch, Michael J. (Richmond, CA); Rubenstein, Francis M. (Berkeley, CA); Whitman, Richard E. (Richmond, CA)
1992-01-01
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.
Proceedings of HTSC 2005: Heat Transfer Summer Conference
Guo, Zhixiong "James"
for describing radiation transfer and heat transfer in the micro/nanoscale devices is presented firstProceedings of HTSC 2005: Heat Transfer Summer Conference San Francisco, CA, July 17-22, 2005 HT's equations which govern the propagation of electromagnetic field and the radiation energy transport
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
High flux heat transfer in a target environment
McDonald, Kirk
Valid for: Consider turbulent heat transfer in a 1.5mm diameter pipe Dittus Boelter correlationHigh flux heat transfer in a target environment T. Davenne High Power Targets Group Rutherford · Radiation Cooling · Forced Convection · Nucleate Boiling · Critical Heat Flux · Other ideas · Summary #12
Micro/Nanoscale Heat Transfer: Interfacial Effects Dominate the
Kostic, Milivoje M.
-probe method Pump laser is externally modulated and heats the sample Probe beam detects the transient3/15/2012 1 Micro/Nanoscale Heat Transfer: Interfacial Effects Dominate the Heat Transfer 1 Xing nanotransistors. Nanotechnology has been described as a new industrial revolution M. Chu, et al. Annu. Rev. Mater
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
Transient critical heat flux and blowdown heat-transfer studies
Leung, J.C.
1980-05-01
Objective of this study is to give a best-estimate prediction of transient critical heat flux (CHF) during reactor transients and hypothetical accidents. To accomplish this task, a predictional method has been developed. Basically it involves the thermal-hydraulic calculation of the heated core with boundary conditions supplied from experimental measurements. CHF predictions were based on the instantaneous ''local-conditions'' hypothesis, and eight correlations (consisting of round-tube, rod-bundle, and transient correlations) were tested against most recent blowdown heat-transfer test data obtained in major US facilities. The prediction results are summarized in a table in which both CISE and Biasi correlations are found to be capable of predicting the early CHF of approx. 1 s. The Griffith-Zuber correlation is credited for its prediction of the delay CHF that occurs in a more tranquil state with slowly decaying mass velocity. In many instances, the early CHF can be well correlated by the x = 1.0 criterion; this is certainly indicative of an annular-flow dryout-type crisis. The delay CHF occurred at near or above 80% void fraction, and the success of the modified Zuber pool-boiling correlation suggests that this CHF is caused by flooding and pool-boiling type hydrodynamic crisis.
Augmentation of condensation heat transfer with electrohydrodynamics on vertical enhanced tubes
Motte, Edouard
1994-01-01
condensation heat transfer performance on the outside surface of enhanced tubes. R-1 13 is the working fluid. Korodense (3.81 cm O.D.) and Turbo CIII (1.905 cm O.D.) enhanced tubes were tested. Smooth tubes (3.81 cm and 1.905 cm O.D.) served as the basis...
Sensitivity Analysis of the Gap Heat Transfer Model in BISON.
Swiler, Laura Painton; Schmidt, Rodney C.; Williamson, Richard; Perez, Danielle
2014-10-01
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.
IntroductiontoProcessEngineering(PTG) 5. Heat transfer
Zevenhoven, Ron
#5/6 IntroductiontoProcessEngineering(PTG) VST rz13 1/114 5. Heat transfer Ron Zevenhoven ÅboProcessEngineering(PTG) VST rz13 Three heat transfer mechanisms Conduction Convection Radiation 2/114 Pic: BÖ88 #12;#5/6 IntroductiontoProcessEngineering(PTG) VST rz13 3/114 5.1 Conductive heat transfer #5/6 Introductionto
Steam Technical Brief: Industrial Steam System Heat-Transfer Solutions
None
2010-06-25
This BestPractices Steam Technical Brief provides an overview of considerations for selecting the best heat-transfer solution for various applications.
Characterization and Development of Advanced Heat Transfer Technologies (Presentation)
Kelly, K.
2009-05-01
This presentation gives an overview of the status and FY09 accomplishments for the NREL thermal management research project 'Characterization and Development of Advanced Heat Transfer Technologies'.
Effects of solar photovoltaic panels on roof heat transfer
Dominguez, Anthony; Kleissl, Jan; Luvall, Jeffrey C
2011-01-01
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
Characterization and Development of Advanced Heat Transfer Technologie...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
and Development of Advanced Heat Transfer Technologies Advanced Power Electronics and Electric Machines Compact, Light-Weight, Single-Phase, Liquid-Cooled Cold Plate...
Clean Firetube Boiler Waterside Heat Transfer Surfaces, Energy...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
7 Clean Firetube Boiler Waterside Heat Transfer Surfaces The prevention of scale formation in firetube boilers can result in substantial energy savings. Scale deposits occur when...
Heat transfer and pressure drop in tape generated swirl flow
Lopina, Robert F.
1967-01-01
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 ...
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 ...
ME 360N Intermediate Heat Transfer ABET EC2000 syllabus
Ben-Yakar, Adela
and Internal), Heat Exchangers (1) 3. Heat Exchanger Analysis (1) 4. Radiation (Intro) (Properties, Surface (1) 22. Nat'l. Conv. (1) 23. Intro Heat Exchangers & Energy Balances (1) 24. Overall H.T. Coeff Intermediate Heat Transfer Page 2 ABET EC2000 syllabus Class/Laboratory Schedule (Type, number and duration
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
Geb, David; Zhou, Feng; Catton, Ivan
2012-01-01
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)
1996-12-03
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.
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)
1994-11-29
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.
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
Low GWP Working Fluid for High Temperature Heat Pumps
Oak Ridge National Laboratory
Low GWP Working Fluid for High Temperature Heat Pumps: DR-2 Chemical Stability at High Temperatures Temp Heat Pumps: DR-2 Very Low GWP AND Non-Flammable HFC-245fa DR-2 Chemical Formula CF3CH2CHF2 HFO 171.3 Pcr [MPa] 3.65 2.9 Kontomaris-DuPont; European Heat Pump Summit, Nuremberg, October 15th, 2013
Broader source: Energy.gov [DOE]
A hybrid heat exchanger is designed to keep highly stressed materials around the working fluid at a moderate temperature so that it can operate at higher working fluid pressure.
Convective Heat Transport in Compressible Fluids
Akira Furukawa; Akira Onuki
2002-02-01
We present hydrodynamic equations of compressible fluids in gravity as a generalization of those in the Boussinesq approximation used for nearly incompressible fluids. They account for adiabatic processes taking place throughout the cell (the piston effect) and those taking place within plumes (the adiabatic temperature gradient effect). Performing two-dimensional numerical analysis, we reveal some unique features of plume generation and convection in transient and steady states of compressible fluids. As the critical point is approached, overall temperature changes induced by plume arrivals at the boundary walls are amplified, giving rise to overshoot behavior in transient states and significant noises of the temperature in steady states. The velocity field is suggested to assume a logarithmic profile within boundary layers. Random reversal of macroscopic shear flow is examined in a cell with unit aspect ratio. We also present a simple scaling theory for moderate Rayleigh numbers.
Proceedings of HT2003 2003 ASME Summer Heat Transfer Conference
McDonough, James M.
Proceedings of HT2003 2003 ASME Summer Heat Transfer Conference July 21-23, 2003, Las Vegas, Nevada School Lexington, Kentucky 40513 ABSTRACT In this study the commercial flow code STAR-CD has been used 2003 by ASME Proceedings of HT2003 ASME Summer Heat Transfer Conference July 21-23, 2003, Las Vegas
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
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
2012-03-07
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.
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 ...
Gas heat transfer in a heated vertical channel under deteriorated turbulent heat transfer regime
Lee, Jeongik
2007-01-01
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 ...
Ultrasonic effect on the bubble nucleation and heat transfer of oscillating nanofluid
Zhao, Nannan; Fu, Benwei; Ma, H. B.
2014-06-30
Ultrasonic sound effect on bubble nucleation, oscillating motion activated by bubble formation, and its heat transfer enhancement of nanofluid was experimentally investigated. Nanofluid consists of distilled water and dysprosium (III) oxide (Dy{sub 2}O{sub 3}) nanoparticles with an average size of 98?nm and a mass ratio of 0.5%. Visualization results demonstrate that when the nanoparticles are added in the fluid influenced by the ultrasonic sound, bubble nucleation can be significantly enhanced. The oscillating motion initiated by the bubble formation of nanofluid under the influence of ultrasonic sound can significantly enhance heat transfer of nanofluid in an interconnected capillary loop.
Heat transfer between elastic solids with randomly rough surfaces
B. N. J. Persson; B. Lorenz; A. I. Volokitin
2009-08-27
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.
Method and apparatus for improving heat transfer in a fluidized bed
Lessor, Delbert L. (Richland, WA); Robertus, Robert J. (Richland, WA)
1990-01-01
An apparatus contains a fluidized bed that includes particles of different triboelectrical types, each particle type acquiring an opposite polarity upon contact. The contact may occur between particles of the two types or between particles of etiher type and structure or fluid present in the apparatus. A fluidizing gas flow is passed through the particles to produce the fluidized bed. Immersed within the bed are electrodes. An alternating EMF source connected to the electrodes applies an alternating electric field across the fluidized bed to cause particles of the first type to move relative to particles of the second type and relative to the gas flow. In a heat exchanger incorporating the apparatus, the electrodes are conduits conveying a fluid to be heated. The two particle types alternately contact each conduit to transfer heat from a hot gas flow to the second fluid within the conduit.
Heat transfer and film cooling with steam injection
Conklin, Gary Eugene
1982-01-01
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...
Dual circuit embossed sheet heat transfer panel
Morgan, G.D.
1984-02-21
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.
Grossmann, Ignacio E.
Forced convective heat transfer Solar radiation heat transfer Atmospheric radiation Natural convective number #12;Solar radiation heat transfer Heat transfer at the wall of the shipping container Direct solarHeat transfer model of large shipping containers 1Chemical Engineering Department - Carnegie Mellon
Enhanced two phase flow in heat transfer systems
Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D
2013-12-03
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.
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))
1991-01-01
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.
Intermediate Heat Transfer Loop Study for High Temperature Gas-Cooled Reactor
C. H. Oh; C. Davis; S. Sherman
2008-08-01
A number of possible configurations for a system that transfers heat between the nuclear reactor and the hydrogen and/or electrical generation plants were identified. These configurations included both direct and indirect cycles for the production of electricity. Both helium and liquid salts were considered as the working fluid in the intermediate heat transport loop. Methods were developed to perform thermal-hydraulic and cycleefficiency evaluations of the different configurations and coolants. The thermal-hydraulic evaluations estimated the sizes of various components in the intermediate heat transport loop for the different configurations. This paper also includes a portion of stress analyses performed on pipe configurations.
Nano-engineering the boiling surface for optimal heat transfer rate and critical heat flux
Phillips, Bren Andrew
2011-01-01
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
2012-02-14
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
2014-01-01
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 ...
Local, instantaneous heat transfer in pulse-stabilized fluidization
Pence, D.V. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Mechanical Engineering and Applied Mechanics; Beasley, D.E. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering
1996-12-31
The Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed, has technical advantages in energy efficiency and emissions. The present study examines the effect of an opposing oscillatory flow on the local, instantaneous heat transfer in a laboratory scale bubbling gas-fluidized bed. This opposing secondary flow consisted of a steady mean component and an oscillating component thereby modeling the flow in the tailpipe of a pulsed combustor. Spectral and contact time analyses of local, instantaneous heat flux measurements from a heated, submerged horizontal cylinder clearly indicate that the bed hydrodynamics were significantly altered by the opposing secondary flow. These heat flux measurements were accomplished by employing an isothermal platinum film heat flux gage. For the present investigation, data were acquired for a monodisperse distribution of particles with a mean diameter of 345 {micro}m and total fluidization ratios ranging from 1.1 through 2.7. Heat transfer observed under conditions of secondary flows with a superimposed waveform exhibit characteristics of globally dominated, as opposed to locally dominated, hydrodynamics. For low primary and secondary flow rates and a forcing frequency of 5 Hz, a substantial enhancement in heat transfer was observed. Increases in the bubble phase and emulsion phase heat transfer coefficients were identified as the primary contributors to the observed increases in time-averaged local heat transfer coefficients.
Modeling of Heat Transfer in Geothermal Heat Exchangers
Cui, P.; Man, Y.; Fang, Z.
2006-01-01
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...
Downflow heat transfer in a heated ribbed vertical annulus with a cosine power profile
Anderson, J.L.; Condie, K.G.; Larson, T.K.
1991-10-01
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.
Analytical and numerical solution of one- and two-dimensional steady heat transfer in a coldplate
Jones, G.F.; Bennett, G.A.; Bultman, D.H.
1987-01-01
We develop analytical models for steady-state, one- and two-dimensional heat transfer in a single-material, flat-plate coldplate. Discrete heat sources are mounted on one side of the plate and heat transfer to a flowing fluid occurs on the other. The models are validated numerically using finite differences. We propose a simple procedure for estimating maximum coldplate temperature at the location of each heat source which includes thermal interaction among the sources. Results from one model are compared with data obtained for a composite coldplate operated in the laboratory. We demonstrate the utility of the models as diagnostic tools to be used for predicting the existence and extent of void volumes and delaminations in the composite material that can occur with coldplates of this type. Based on our findings, recommendations for effective coldplate design are given.
Neirotti, Juan Pablo
a range of advanced modern heat transfer and turbo- machinery problems and systems. Module Learning Outcomes: The students will have developed an understanding of a range of advanced heat transfer and turbo-machinery thermo-fluid principles to a wide range of engineering and design problems. #12;Ability to develop
Qu, Weilin
Experimental and numerical study of pressure drop and heat transfer in a single-phase micro Received 6 July 2001; received in revised form 26 October 2001 Abstract The pressure drop and heat transfer-dimensional heat transfer characteristics of the heat sink were analyzed numerically by solving the conjugate heat
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)
2014-07-10
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.
Survey and evaluation of techniques to augment convective heat transfer
Bergles A. E.
1965-01-01
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 ...
Influence of Infrared Radiation on Attic Heat Transfer
Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.
1985-01-01
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 Transfer Enhancement in Rectangular Channel with Compound Cooling Techniques
Krad, Belal
2013-11-27
to analyze heat transfer and pressure loss characteristics to determine which configuration had the overall best performance. Two different flow configurations were considered, a uniform channel flow setup as well as a jet impingement setup. There were a...
Enhancement of Pool Boiling Heat Transfer in Confined Space
Hsu, Chia-Hsiang
2014-05-05
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...
Heat transfer enhancement resulting from induction electrohydrodynamic pumping
Margo, Bryan David
1992-01-01
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...
Mpemba effect, Newton cooling law and heat transfer equation
Vladan Pankovic; Darko V. Kapor
2012-12-11
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).
Guo, Zhixiong "James"
Global heat transfer analysis in Czochralski silicon furnace with radiation on curved specular method are adopted to solve the global heat transfer and the radiative heat exchange, respectively rate QJ diffuse radiation heat transfer rate QX net rate of radiative heat loss QT heat generation rate
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
Kandlikar, Satish
Controlling bubble motion over heated surface through evaporation momentum force to enhance pool://apl.aip.org/about/rights_and_permissions #12;Controlling bubble motion over heated surface through evaporation momentum force to enhance pool on the basis of this hypothesis to control the bubble trajectory for (i) enhancing the heat transfer
Error Analysis of Heat Transfer for Finned-Tube Heat-Exchanger Text-Board
Chen, Y.; Zhang, J.
2006-01-01
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...
M. Bahrami ENSC 388 (F09) Forced Convection Heat Transfer 1 Forced Convection Heat Transfer
Bahrami, Majid
surface, and the type of the fluid flow (laminar or turbulent). Fig. 1: Forced convection fluid. Whereas in forced convection, the fluid is forced to flow over a surface or in a tube Boundary Layer Consider the flow of a fluid over a flat plate, the velocity and the temperature
Active heat transfer enhancement in integrated fan heat sinks
Staats, Wayne Lawrence
2012-01-01
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 ...
Project Profile: Heat Transfer and Latent Heat Storage in Inorganic...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
energy storage capacity of a thermocline. The PCM-based TES uses the latent heat of fusion of inorganic salt mixtures for storing thermal energy. The concepts being applied by...
Pool boiling heat transfer characteristics of nanofluids
Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology
2007-01-01
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 ...
Boyer, Edmond
Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated. It has been applied to measure heat transfer coefficients of water flowing in a round tube and in a multiport-flat tube. Models were developed to deduce heat transfer coefficient from wall temperature
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
Size-dependant heating rates of iron oxide nanoparticles for magnetic fluid hyperthermia
Krishnan, Kannan M.
Size-dependant heating rates of iron oxide nanoparticles for magnetic fluid hyperthermia Marcela. & 2008 Published by Elsevier B.V. 1. Introduction Increased heating rates of magnetic fluids in magnetic fluid hyperthermia (MFH). Possible approaches to increase heating rates of super- paramagnetic
Abdou, Mohamed
Characterization of the effect of Froude number on surface waves and heat transfer in inclined describes wave/heat transfer phenomena in inclined turbulent open surface water flows. The experiments were. These changes lead to a heat transfer improvement, enough to double the heat transfer coefficient
ME 544 Advanced Heat Transfer Spring 2013 Time: 2pm-3pm MWF
Connors, Daniel A.
and engineering applications of heat transfer including conduction, convection, and radiation. Course Learning, convection, and radiation heat transfer modes. 2. Determine the dominant modes of heat transfer, and apply fields. The last part of the course is concerned with radiation heat transfer, specifically radiation
Demonstration of Strong Near-Field Radiative Heat Transfer between Integrated Nanostructures
Lipson, Michal
Demonstration of Strong Near-Field Radiative Heat Transfer between Integrated Nanostructures-polariton Recently, there has been a growing interest in controlling radiative heat transfer in the near-field,1 ultrahigh contrast rectification of heat transfer.27 Here we show strong near-field radiative heat transfer
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-tube and 1000m micro-tube. In the single-phase heat transfer experiments, the fully-developed flow heat transfer were also measured using thermocouples (TC). The results showed that the heat transfer coefficient
Heat SET 2005 Heat Transfer in Components and Systems
Hidrovo, Carlos H.
Engineering Stanford University, Stanford, CA 94305 USA jbstein@stanford.edu ABSTRACT Polymer Electrolyte and mass transfer and axial pressure gradients. INTRODUCTION The Polymer Electrolyte Membrane (PEM) fuel be evacuated quickly. Furthermore, in small channels surface tension dominates and can lead to flooding
Heat Transfer Laboratory | Argonne National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFESOpportunitiesNERSCGrid-based29HaiWhy IsHealth Period:HeatHeat
Research on Convective Heat Transfer and Mass Transfer of the Evaporator in Micro/Mini-Channel
Su, J.; Li, J.
2006-01-01
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...
Wellbore Heat Transfer Model for Wax Deposition in Permafrost Region
Cui, Xiaoting
2012-05-31
based on energy balances for heat exchange between the producing fluids and production string as well as the formation/permafrost. To simplify the calculation, oil and gas were assumed well mixed as one single-phase in the tubing. Furthermore, Singh...
A 2-D Test Problem for CFD Modeling Heat Transfer in Spent Fuel Transfer Cask Neutron Shields
Zigh, Ghani; Solis, Jorge; Fort, James A.
2011-01-14
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
Instantaneous pressure and heat transfer in pulse-stabilized fluidization
Beasley, D.E.; Postle, M.C. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering; Pence, D.V. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Mechanical Engineering and Applied Mechanics
1996-12-31
A hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed was developed by Manufacturing Technology Conversion International, Inc. (MTCI, Inc.) and licensed to Thermo-Chem, Inc. This Pulsed Atmospheric Fluidized Bed technology has technical advantages in energy efficiency and emissions and is currently in pilot scale demonstration on the campus of Clemson University. The present study examines the effect of an opposing oscillatory flow on the pressure and overall heat transfer in a bubbling gas-fluidized bed. This opposing flow models the flow in the tailpipe of a pulsed combustor. Pressure measurements at the wall and on a submerged horizontal cylinder clearly indicate that the bed hydrodynamics are significantly altered by the opposing secondary flow. Under operating conditions of low secondary flow rates and pulse frequencies, the dominant frequency of the pressure fluctuations measured in the bed shifts from the natural, unforced response of the bed to the imposed frequency. For higher fluidization and secondary flow rates both the natural and forced response of the bed are present. Overall and time-averaged local heat transfer measurements from a submerged horizontal cylinder clearly indicate that the heat transfer rates are significantly altered by the opposing secondary flow. The most dramatic increases in heat transfer, on the order of 12%, were identified with operating conditions with low primary and secondary flow rates and pulse frequencies near the natural frequency of the bed. The local heat transfer was most significantly altered at the stagnation point. A modified form of the Strouhal number is shown to effectively describe the effect of pulse stabilization on overall heat transfer.
Flow visualization study of inverted annular flow of post dryout heat transfer region. [PWR; BWR
Ishii, M.; De Jarlais, G.
1985-01-01
The inverted annular flow is important in the area of LWR accident analysis in terms of the maximum cladding temperature and effectiveness of the emergency core cooling. However, the inverted annular flow thermal-hydraulics is not well understood due to its special heat transfer condition of film boiling. The review of existing data indicates further research is needed in the areas of basic hydrodynamics related to liquid core disintegration mechanisms, slug and droplet formation, entrainment, and droplet size distributions. In view of this, the inverted flow is studied in detail experimentally. A new experimental apparatus has been constructed in which film boiling heat transfer can be established in a transparent test section. The test section consists of two coaxial quartz tubes. The annular gap between these two tubes is filled with a hot, clear fluid (syltherm 800) so as to maintain film boiling temperatures and heat transfer rates at the inner quartz tube wall. Data on liquid core stability, core break-up mechanism, and dispersed-core liquid slug and droplet sizes are obtained using F 113 as a test fluid. Both high speed movies and flash photographs (3 ..mu..sec) are used.
Lee, C.M.; Schock, H.J.
1988-01-01
Currently, the heat transfer equation used in the rotary combustion engine (RCE) simulation model is taken from piston engine studies. These relations have been empirically developed by the experimental input coming from piston engines whose geometry differs considerably from that of the RCE. The objective of this work was to derive equations to estimate heat transfer coefficients in the combustion chamber of an RCE. This was accomplished by making detailed temperature and pressure measurements in a direct injection stratified charge (DISC) RCE under a range of conditions. For each specific measurement point, the local gas velocity was assumed equal to the local rotor tip speed. Local physical properties of the fluids were then calculated. Two types of correlation equations were derived and are described in this paper. The first correlation expresses the Nusselt number as a function of the Prandtl number, Reynolds number, and characteristic temperature ratio; the second correlation expresses the forced convection heat transfer coefficient as a function of fluid temperature, pressure and velocity. 10 references.
Convective heat transfer inside passive solar buildings
Jones, R.W.; Balcomb, J.D.; Yamaguchi, K.
1983-11-01
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.
Convective heat transfer inside passive solar buildings
Jones, R.W.; Balcomb, J.D.; Yamaguchi, K.
1983-01-01
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.
Radiative heat transfer in 2D Dirac materials
Pablo Rodriguez-Lopez; Wang-Kong Tse; Diego A. R. Dalvit
2015-02-02
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.
Combined heat and mass transfer device for improving separation process
Tran, Thanh Nhon (Flossmoor, IL)
1999-01-01
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.
1999-08-24
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.
Matthias Krüger; Giuseppe Bimonte; Thorsten Emig; Mehran Kardar
2012-07-16
We present a detailed derivation of heat radiation, heat transfer and (Casimir) interactions for N arbitrary objects in the framework of fluctuational electrodynamics in thermal non-equilibrium. The results can be expressed as basis-independent trace formulae in terms of the scattering operators of the individual objects. We prove that heat radiation of a single object is positive, and that heat transfer (for two arbitrary passive objects) is from the hotter to a colder body. The heat transferred is also symmetric, exactly reversed if the two temperatures are exchanged. Introducing partial wave-expansions, we transform the results for radiation, transfer and forces into traces of matrices that can be evaluated in any basis, analogous to the equilibrium Casimir force. The method is illustrated by (re)deriving the heat radiation of a plate, a sphere and a cylinder. We analyze the radiation of a sphere for different materials, emphasizing that a simplification often employed for metallic nano-spheres is typically invalid. We derive asymptotic formulae for heat transfer and non-equilibrium interactions for the cases of a sphere in front a plate and for two spheres, extending previous results. As an example, we show that a hot nano-sphere can levitate above a plate with the repulsive non-equilibrium force overcoming gravity -- an effect that is not due to radiation pressure.
Low heat transfer, high strength window materials
Berlad, Abraham L. (Stony Brook, NY); Salzano, Francis J. (Patchogue, NY); Batey, John E. (Stony Brook, NY)
1978-01-01
A multi-pane window with improved insulating qualities; comprising a plurality of transparent or translucent panes held in an essentially parallel, spaced-apart relationship by a frame. Between at least one pair of panes is a convection defeating means comprising an array of parallel slats or cells so designed as to prevent convection currents from developing in the space between the two panes. The convection defeating structures may have reflective surfaces so as to improve the collection and transmittance of the incident radiant energy. These same means may be used to control (increase or decrease) the transmittance of solar energy as well as to decouple the radiative transfer between the interior surfaces of the transparent panes.
Cheeti, Satish K.R.
1993-01-01
and the average heat transfer coefficients and hence the Nusselt numbers were determined in the range of Rayleigh numbers from 9 x 10' to 4 x 10'. The nature of the free convection flow over the heated surface was inferred from the local and average Nusselt...
A Small Artery Heat Transfer Model for Self-Heated Thermistor Measurements of Perfusion in the
of interlobular arteries in kidney cortex (1/cm2) n(r) number of blood vessels in a shell of tissue at radius r P) r radial distance from the center of the thermistor (cm) S kidney cortex cross sectional area (cm2A Small Artery Heat Transfer Model for Self-Heated Thermistor Measurements of Perfusion
Optimization of Magnetic Refrigerators by Tuning the Heat Transfer Medium and Operating Conditions
Ghahremani, Mohammadreza; Bennett, Lawrence H; Della Torre, Edward
2015-01-01
A new experimental test bed has been designed, built, and tested to evaluate the effect of the systems parameters on a reciprocating Active Magnetic Regenerator (AMR) near room temperature. Bulk gadolinium was used as the refrigerant, silicon oil as the heat transfer medium, and a magnetic field of 1.3 T was cycled. This study focuses on the methodology of single stage AMR operation conditions to get a higher temperature span near room temperature. Herein, the main objective is not to report the absolute maximum attainable temperature span seen in an AMR system, but rather to find the systems optimal operating conditions to reach that maximum span. The results of this research show that there is a optimal operating frequency, heat transfer fluid flow rate, flow duration, and displaced volume ratio in an AMR system. By optimizing these parameters the refrigeration performance increased by 24%. It is expected that such optimization will permit the design of a more efficient magnetic refrigeration system.
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)
2002-01-01
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.
Method of measuring heat influx of a cryogenic transfer system
Niemann, Ralph C. (Downers Grove, IL); Zelipsky, Steven A. (Tinley Park, IL); Rezmer, Ronald R. (Lisle, IL); Smelser, Peter (Bruner, MO)
1981-01-01
A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.
Two-dimensional heat transfer from earth-sheltered buildings
Krarti, M. (Steven Winter Associates, Inc., Norwalk, CT (US)); Claridge, D.E. (Texas A and M Univ., College Station, TX (USA). Dept. of Mechanical Engineering)
1990-02-01
This paper describes use of the interzone temperature profile estimation (or ITPE) technique, an analytical calculation procedure to predict heat transfer within earth in contact with a structure. The solutions governing steady-state and steady-periodic heat conduction are derived for rectangular earth-sheltered buildings. The procedure accepts continuously variable values of geometric dimensions, insulation levels, and constant soil thermal characteristics and considers the presence of a finite water table level. Soil temperature profiles are shown for both steady-state and steady periodic conditions. The effects of insulation and water table depth on the heat losses from an earth-sheltered building envelope are discussed.
Waste Heat Recovery by Organic Fluid Rankine Cycle
Verneau, A.
1979-01-01
RECOVERY BY ORGANIC FLUID RANKINE CYCLE Alain VERNEAU Civil Mining Engineer Licenciate of the E.N.S.P.M. Societe BERTIN & Cie Versailles, France SUMMARY The use of Organic Rankin~Cycle for waste heat recovery presents several characteristics which... Energy Technology Conference Houston, TX, April 22-25, 1979 Ternperoturll I Tn-i- 1 Water and alcohol mi)(f:url2S SIEntropy) RII FBS 5 max --- R 113 R 114 ~gene:rator ~ s T llemptrature) T~ralurt T Liquid. vapor liquid ! Ji /li 2oo?C I...
Zevenhoven, Ron
= Q34 = h4 h3 = 2173,3 kJ/kg d. Heat input = Q15 = h1 h5 = h1 h4 + 4 (pump power) = 2831,0 kPTG exam 9 April 2014 short answers 123. Heat given off = surface * heat transfer coefficient * temperature = A * h * T Heat transfer coefficient from Nunumber, which for natural convection
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
Integration of Heat Transfer, Stress, and Particle Trajectory Simulation
Thuc Bui; Michael Read; Lawrence ives
2012-05-17
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.
MODELLING OF CAVITY RECEIVER HEAT TRANSFER COMPACT LINEAR FRESNEL REFLECTOR
MODELLING OF CAVITY RECEIVER HEAT TRANSFER FOR THE COMPACT LINEAR FRESNEL REFLECTOR John D Pye receiver for the Compact Linear Fresnel Reflector is presented. Response to changes in ambient temperature equations are provided. 1. BACKGROUND The Compact Linear Fresnel Reflector (CLFR), shown in Figure 1
Heat transfer in inertial confinement fusion reactor systems
Hovingh, J.
1980-04-23
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.
A CONVECTIVE HEAT TRANSFER MODEL FOR SIMULATION OF ROOMS WITH
Quest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, MI 48106-1346 by ProQuest Information and Learning Company. #12;II A CONVECTIVE HEAT TRANSFER MODEL FOR SIMULATION OF ROOMS. Seeing him grow gave me a new level of energy and hope. Without a doubt, my family members have been
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
Numerical Passage from Radiative Heat Transfer to Nonlinear Diffusion Models \\Lambda
Schmeiser, Christian
Numerical Passage from Radiative Heat Transfer to Nonlinear Diffusion Models \\Lambda A. Klar y C. Schmeiser z Abstract Radiative heat transfer equations including heat conduction are considÂ ered situations are presented. Keywords. radiative heat transfer, asymptotic analysis, nonlinear diffusion limit
A Study of Heat Transfer for Two Layered Composite Inclined Plate Crotch Absorbers
Kemner, Ken
1S-143 M. Choi Nov., 1989 A Study of Heat Transfer for Two Layered Composite Inclined Plate Crotch used in CESR. They analyzed the heat transfer problem numerically for the case of a vertically located to the inclined photon beam penetration heating. An analytical solution for heat transfer is obtained for a full
Temperature distribution in a flowing fluid heated in a microwave resonant cavity
Thomas, J.R. Jr. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Nelson, E.M.; Kares, R.J.; Stringfield, R.M. [Los Alamos National Lab., NM (United States)
1996-04-01
This paper presents results of an analytical study of microwave heating of a fluid flowing through a tube situated along the axis of a cylindrical microwave applicator. The interaction of the microwave field pattern and the fluid velocity profiles is illustrated for both laminar and turbulent flow. Resulting temperature profiles are compared with those generated by conventional heating through a surface heat flux. It is found that microwave heating offers several advantages over conventional heating.
Shugo Yasuda; Ryoichi Yamamoto
2014-07-16
The synchronized molecular dynamics simulation via macroscopic heat and momentum transfer is proposed for the non-isothermal flow behaviors of complex fluids. In this method, the molecular dynamics simulations are assigned to small fluid elements to calculate the local stresses and temperatures and are synchronized at certain time intervals to satisfy the macroscopic heat- and momentum- transport equations. This method is applied to the lubrication of a polymeric liquid composed of short chains with ten beads between parallel plates. The rheological properties and conformation of polymer chains coupled with the local viscous heating are investigated with a non-dimensional parameter, i.e., the Nahme-Griffith number, which is defined by the ratio of the viscous heating to the thermal conduction at the characteristic temperature required to sufficiently change the viscosity. The present simulation demonstrates that strong shear thinning and transitional behavior of the conformation of the polymer chains occur with a rapid temperature rise when the Nahme-Griffith number exceeds unity. The results also clarify that the reentrant transition of the linear stress-optical relation occurs for large shear stresses due to the coupling of the conformation of polymer chains and heat generation under shear flows.
Bullock, James H.; Youchison, Dennis Lee; Ulrickson, Michael Andrew
2010-11-01
Several commercial computational fluid dynamics (CFD) codes now have the capability to analyze Eulerian two-phase flow using the Rohsenow nucleate boiling model. Analysis of boiling due to one-sided heating in plasma facing components (pfcs) is now receiving attention during the design of water-cooled first wall panels for ITER that may encounter heat fluxes as high as 5 MW/m2. Empirical thermalhydraulic design correlations developed for long fission reactor channels are not reliable when applied to pfcs because fully developed flow conditions seldom exist. Star-CCM+ is one of the commercial CFD codes that can model two-phase flows. Like others, it implements the RPI model for nucleate boiling, but it also seamlessly transitions to a volume-of-fluid model for film boiling. By benchmarking the results of our 3d models against recent experiments on critical heat flux for both smooth rectangular channels and hypervapotrons, we determined the six unique input parameters that accurately characterize the boiling physics for ITER flow conditions under a wide range of absorbed heat flux. We can now exploit this capability to predict the onset of critical heat flux in these components. In addition, the results clearly illustrate the production and transport of vapor and its effect on heat transfer in pfcs from nucleate boiling through transition to film boiling. This article describes the boiling physics implemented in CCM+ and compares the computational results to the benchmark experiments carried out independently in the United States and Russia. Temperature distributions agreed to within 10 C for a wide range of heat fluxes from 3 MW/m2 to 10 MW/m2 and flow velocities from 1 m/s to 10 m/s in these devices. Although the analysis is incapable of capturing the stochastic nature of critical heat flux (i.e., time and location may depend on a local materials defect or turbulence phenomenon), it is highly reliable in determining the heat flux where boiling instabilities begin to dominate. Beyond this threshold, higher heat fluxes lead to the boiling crisis and eventual burnout. This predictive capability is essential in determining the critical heat flux margin for the design of complex 3d components.
A simplified model for heat transfer in heat exchangers and stack plates for thermoacoustic devices
Chen, Y.; Herman, C.
1999-07-01
A simplified model of heat transfer in heat exchangers and stack plates of thermoacoustic devices was developed. The model took advantage of previous results regarding the thermal behavior of the thermoacoustic core for investigations of the performance of heat exchangers attached to the core. Geometrical and operational parameters as well as thermophysical properties of the heat exchangers, the plate, and the working medium were organized into dimensionless groups that allowed to account for their impact on the performance of the heat exchangers. Numerical simulations with the model were carried out. Nonlinear temperature distributions and heat fluxes near the edge of the stack plate were observed. Effects of different parameters on the thermal performance of the heat exchangers were investigated.
ASME Journal of Heat Transfer Vol.118, pp.592-598, 1996
Zhao, Tianshou
ASME Journal of Heat Transfer Vol.118, pp.592-598, 1996 OSCILLATORY HEAT TRANSFER IN A PIPE for laminar forced convection in a long pipe heated by uniform heat flux and subjected to a reciprocating flow for the numerical simulation of the hydrodynamically and thermally developing reciprocating flow in the heated pipe
Heating systems for heating subsurface formations
Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)
2011-04-26
Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.
Zhijie Xu
2012-07-01
We introduce a new method of solution for the convective heat transfer under forced laminar flow that is confined by two parallel plates with a distance of 2a or by a circular tube with a radius of a. The advection-conduction equation is first mapped onto the boundary. The original problem of solving the unknown field T(x,r,t) is reduced to seek the solutions of T at the boundary (r = a or r = 0, r is the distance from the centerline shown in Fig. 1), i.e., the boundary functions T{sub a}(x,t) {triple_bond} T(x,r=a,t) and/or T{sub 0}(x,t) {triple_bond} T(x,r=0,t). In this manner, the original problem is significantly simplified by reducing the problem dimensionality from 3 to 2. The unknown field T(x,r,t) can be eventually solved in terms of these boundary functions. The method is applied to the convective heat transfer with uniform wall temperature boundary condition and with heat exchange between flowing fluids and its surroundings that is relevant to the geothermal applications. Analytical solutions are presented and validated for the steady-state problem using the proposed method.
Xu, Zhijie
2012-07-01
We introduce a method of solution for the convective heat transfer under forced laminar flow that is confined by two parallel plates with a distance of 2a or by a circular tube with a radius of a. The advection-conduction equation is first mapped onto the boundary. The original problem of solving the unknown field is reduced to seek the solutions of T at the boundary (r=a or r=0, r is the distance from the centerline shown in Fig. 1), i.e. the boundary functions and/or . In this manner, the original problem is significantly simplified by reducing the problem dimensionality from 3 to 2. The unknown field can be eventually solved in terms of these boundary functions. The method is applied to the convective heat transfer with uniform wall temperature boundary condition and with heat exchange between flowing fluids and its surroundings that is relevant to the geothermal applications. Analytical solutions are presented and validated for the steady state problem using the proposed method.
RELAP5-3D Modeling of Heat Transfer Components (Intermediate...
Office of Scientific and Technical Information (OSTI)
reactor that could generate both electricity and process heat for the production of hydrogen. The heat from the high-temperature primary loop must be transferred via an...
Simulation of a Heat Transfer in Porous Media
Juergen Geiser
2012-05-11
We are motivated to model a heat transfer to a multiple layer regime and their optimization for heat energy resources. Such a problem can be modeled by a porous media with different phases (liquid and solid). The idea arose of a geothermal energy reservoir which can be used by cities, e.g. Berlin. While hot ground areas are covered to most high populated cites, the energy resources are important and a shift to use such resources are enormous. We design a model of the heat transport via the flow of water through the heterogeneous layer of the underlying earth sediments. We discuss a multiple layer model, based on mobile and immobile zones. Such numerical simulations help to economize on expensive physical experiments and obtain control mechanisms for the delicate heating process.
Transient PVT measurements and model predictions for vessel heat transfer. Part II.
Felver, Todd G.; Paradiso, Nicholas Joseph; Winters, William S., Jr.; Evans, Gregory Herbert; Rice, Steven F.
2010-07-01
Part I of this report focused on the acquisition and presentation of transient PVT data sets that can be used to validate gas transfer models. Here in Part II we focus primarily on describing models and validating these models using the data sets. Our models are intended to describe the high speed transport of compressible gases in arbitrary arrangements of vessels, tubing, valving and flow branches. Our models fall into three categories: (1) network flow models in which flow paths are modeled as one-dimensional flow and vessels are modeled as single control volumes, (2) CFD (Computational Fluid Dynamics) models in which flow in and between vessels is modeled in three dimensions and (3) coupled network/CFD models in which vessels are modeled using CFD and flows between vessels are modeled using a network flow code. In our work we utilized NETFLOW as our network flow code and FUEGO for our CFD code. Since network flow models lack three-dimensional resolution, correlations for heat transfer and tube frictional pressure drop are required to resolve important physics not being captured by the model. Here we describe how vessel heat transfer correlations were improved using the data and present direct model-data comparisons for all tests documented in Part I. Our results show that our network flow models have been substantially improved. The CFD modeling presented here describes the complex nature of vessel heat transfer and for the first time demonstrates that flow and heat transfer in vessels can be modeled directly without the need for correlations.
A Site-Scale Model For Fluid And Heat Flow In The Unsaturated...
multicomponent fluid and heat flow through porous and fractured rock. Fracture and matrix flow is treated using both dual-permeability and effective-continuum modeling...
Enhanced Geothermal Systems (EGS) with CO2as Heat Transmission Fluid
Broader source: Energy.gov [DOE]
The overall objective of the research is to explore the feasibility of operating enhanced geothermal systems (EGS) with CO2as heat transmission fluid.
Kimura, Shigeo; Darie, Emanuel; Kiwata, Takahiro; Okajima, Atsushi
1999-07-01
A simple one-dimensional theory regarding the heat transfer through a thermally conductive partition that separates two fluid reservoirs at different temperatures has been developed. According to the theory a unique nondimensional (Biot number-like) parameter to characterize the problem is identified; the parameter is defined by the geometric aspect ratio of the partition, the fluid-to-partition thermal conductivity ratio and the Rayleigh number based on the temperature difference between the two reservoirs. The theory predicts the average temperatures of both sides of the partition and the overall Nusselt number. The theory has the strength due to its simplicity and the fact that the unique Biot number-like parameter contains all the conditions necessary to describe the problem. In order to test the proposed one-dimensional theory a series of experiments have been conducted using an apparatus that consists of two water chambers and a partition separating the two. The one chamber, which is filled with water, is heated by electric heaters and the other is cooled by a serpentine copper pipe. Three different materials, i.e., copper, stainless steel and ceramics, are employed for the partition. The heat transfer rates across the partition are measured by the electric power dissipated at the heaters. The reservoir temperatures and the partition temperatures are monitored by thermocouples. The Rayleigh number defined by the partition height and the temperature difference of the two reservoirs is around 10{sup 8}. a pH indicator method to visualize convecting flows shows a presence of velocity boundary layers along both sides of the vertical partition. The temperature measurements in the reservoirs show a strong temperature stratification in the core region, where the water is largely stagnant and sandwiched by two counter-advancing horizontal jets at the top and bottom. The experimentally-obtained average heat transfer rates and partition surface temperatures are well compared with the theoretical predictions.
Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures
Lu, Ming-Chang
2010-01-01
transfer coefficient models in pool boiling In summary, highlength effect on nucleate pool boiling heat transfer AnnalsTheory of The Peak and Minimum Pool Boiling Heat Fluxes, CR-
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, ...
Heat transfer rates for filmwise, dropwise, and superhydrophobic condensation on silicon substrates
Hery, Travis M
2011-01-01
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 ...
Jet impingement heat transfer in two-pass rotating rectangular channels
Zhang, Yuming
1996-01-01
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
1996-01-01
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...
Ghorbani, N. [School of Mechanical Engineering, University of Leeds, Leeds, England (United Kingdom); Taherian, H. [Department of Engineering Technology and Industrial Distribution, Texas A and M University, College Station, TX (United States); Gorji, M. [Department of Mechanical Engineering, Babol Noushirvani University of Technology, Babol (Iran); Mirgolbabaei, H. [Department of Mechanical Engineering, Islamic Azad University, Jouybar branch, Jouybar (Iran)
2010-10-15
In this study the mixed convection heat transfer in a coil-in-shell heat exchanger for various Reynolds numbers, various tube-to-coil diameter ratios and different dimensionless coil pitch was experimentally investigated. The experiments were conducted for both laminar and turbulent flow inside coil. Effects of coil pitch and tube diameters on shell-side heat transfer coefficient of the heat exchanger were studied. Different characteristic lengths were used in various Nusselt number calculations to determine which length best fits the data and several equations were proposed. The particular difference in this study in comparison with the other similar studies was the boundary conditions for the helical coils. The results indicate that the equivalent diameter of shell is the best characteristic length. (author)
Increasing LTC Engine Efficiency by Reducing Pressure-Oscillation-Related Heat Transfer Losses
Broader source: Energy.gov [DOE]
This research discusses how reducing heat-transfer losses from pressure oscillation can increase low-temperature combustion engine efficiency.
Local Mass and Heat Transfer on a Turbine Blade Tip
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Jin, P.; Goldstein, R. J.
2003-01-01
Local mass and heat transfer measurements on a simulated high-pressure turbine blade-tip surface are conducted in a linear cascade with a nonmoving tip endwall, using a naphthalene sublimation technique. The effects of tip clearance (0.86–6.90% of chord) are investigated at various exit Reynolds numbers (4–7 × 10 5 ) and turbulence intensities (0.2 and 12.0%). The mass transfer on the tip surface is significant along its pressure edge at the smallest tip clearance. At the two largest tip clearances, the separation bubble on the tip surface can cover the wholemore »width of the tip on the second half of the tip surface. The average mass-transfer rate is highest at a tip clearance of 1.72% of chord. The average mass-transfer rate on the tip surface is four and six times as high as on the suction and the pressure surface, respectively. A high mainstream turbulence level of 12.0% reduces average mass-transfer rates on the tip surface, while the higher mainstream Reynolds number generates higher local and average mass-transfer rates on the tip surface.« less
Makhkamov, K.K.; Ingham, D.B.
1998-07-01
In this paper the {kappa}-{var{underscore}epsilon} turbulent model for the incompressible fluid flow has been used to describe the heat transfer and gas dynamical processes on the external circuit of a Stirling Engine as used on a Solar Dish/Stirling System. The problem considered, in this work for a cavity-type heat receiver of the Stirling Engine, is that of the heat transfer in the body of the shell of the heat exchangers of the engine due to the thermal conductivity, the convective heat transfer between the working fluid and the walls of the engine internal gas circuit and the heat transfer due to the forced convection of the air in the cavity and in the attached air domain. The boundary conditions employed on the engines internal circuit were obtained using the developed one-dimensional second level mathematical model of the engine working cycle. Physical models for the distribution of the solar insolation on the bottom and side walls of the heat receiver have been taken into account and the temperature fields for the heat receiver and the air velocity have been obtained for the case when the heat receiver is affected by wind. The numerical results show that it is in the region of the boundary of the input window of the heat receiver where there is the largest reduction in the temperature in the shell of the heat exchangers and this is due to the convection of the air.
Convective heat transfer in buildings: recent research results. Rev
Bauman, F.; Gadgil, A.; Kammerud, R.; Altmayer, E.; Nansteel, M.W.
1982-10-01
Recent experimental and numerical studies of convective heat transfer in buildings are described, and important results are presented. The experimental work has been performed on small-scale, water-filled enclosures; the numerical analysis results have been produced by a computer program based on a finite-difference scheme. The convective processes investigated in this research are: (1) natural convective heat transfer between room surfaces and the adjacent air, (2) natural convective heat transfer between adjacent rooms through a doorway or other openings, and (3) forced convection between the building and its external environment (such as wind-driven ventilation through windows, doors, or other openings). Results obtained at Lawrence Berkeley Laboratory (LBL) for surface convection coefficients are compared with existing ASHRAE correlations, and differences can have a significant impact on the accuracy of building energy analysis computer simulations. Interzone coupling correlations obtained from experimental work are in reasonable agreement with recently published experimental results and with earlier published work. Numerical simulations of wind-driven natural ventilation are presented. They exhibit good qualitative agreement with published wind-tunnel data.
Unsteady laminar flow and convective heat transfer in a sharp 180 bend
Chung, Yongmann M.
Unsteady laminar flow and convective heat transfer in a sharp 180° bend Yongmann M. Chung a , Paul Unsteady laminar flow and heat transfer in a sharp 180° bend is studied numerically to investigate to be strong. Ó 2002 Elsevier Science Inc. All rights reserved. Keywords: Laminar; Unsteady; Heat transfer
1 Copyright 2012 by ASME Proceedings of the ASME 2012 Summer Heat Transfer Conference
Ghajar, Afshin J.
OF NON-BOILING GAS-LIQUID TWO PHASE HEAT TRANSFER IN VERTICAL DOWNWARD PIPE ORIENTATION Swanand M of the non-boiling two phase heat transfer phenomenon for this pipe orientation, experimental investigation1 Copyright © 2012 by ASME Proceedings of the ASME 2012 Summer Heat Transfer Conference HT2012 July
340 Technical Notes heat transfer in helically coiled tubes. A.J.Cli.E. JI 17,
Zhang, Yuwen
340 Technical Notes heat transfer in helically coiled tubes. A.J.Cli.E. JI 17, 1114-1122 (1971). 2 vcctivc heat transfer in helical coiled tubes. /111. J. H. Acharya. Experimental and numerical investigation of heat transfer enhancement in coiled tubes bv chaotic
Control and Estimation of the Boundary Heat Transfer Function in Stefan Problems
Ring, Wolfgang
Control and Estimation of the Boundary Heat Transfer Function in Stefan Problems V. Barbu Institute. The class of admissible heat transfer functions or feedback control laws is chosen to be A = f = @j : with j procedure for the identi cation of a nonlinear bound- ary heat transfer function in a one phase Stefan
TWO-DIMENSIONAL TRANSIENT RADIATIVE HEAT TRANSFER USING DISCRETE ORDINATES METHOD
Guo, Zhixiong "James"
TWO-DIMENSIONAL TRANSIENT RADIATIVE HEAT TRANSFER USING DISCRETE ORDINATES METHOD Zhixiong Guo for the first time to solve transient radiative heat transfer in a two-dimensional rectangular enclosure of solution method of radiative heat transfer in participating media in recent decades. However, the analysis
Dual-scale 3-D approach for modeling radiative heat transfer in fibrous insulations
Tafreshi, Hooman Vahedi
Dual-scale 3-D approach for modeling radiative heat transfer in fibrous insulations R. Arambakam 2013 Keywords: Radiative heat transfer Dual-scale modeling Insulation media Fibrous media a b s t r a c a fiber diameter for which radiation heat transfer through a fibrous media is min- imal, ranging between 3
Tafreshi, Hooman Vahedi
Modeling the role of microstructural parameters in radiative heat transfer through disordered high-tempera- tures. Traditional studies of radiative heat transfer in fibrous materials have been the performance of fibrous materials used as radiative heat transfer insulation media. Although effective
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 models for thermophysical and transport properties and heat, mass, and radiation transfer in glass foams. In addition, the new results on simulation of combined conduction and radiation heat transfer in glass foams
Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application
New York at Stoney Brook, State University of
Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application to Crystal University of New York at Stony Brook Stony Brook N.Y. 11794 ABSTRACT Radiative heat transfer plays simulating radiative heat transfer in the crystal and in the region above the melt containing gas under
Near-Field Radiative Heat Transfer between Macroscopic Planar Surfaces R. S. Ottens,1
Tanner, David B.
Near-Field Radiative Heat Transfer between Macroscopic Planar Surfaces R. S. Ottens,1 V. Quetschke-field, blackbody radiation. Although heat transfer via near-field effects has been discussed for many years.014301 PACS numbers: 44.40.+a, 78.20.Ci Humans knew of radiative heat transfer at least as early
An Investigation of the Radiative Heat Transfer through Nonwoven Fibrous Materials
Tafreshi, Hooman Vahedi
An Investigation of the Radiative Heat Transfer through Nonwoven Fibrous Materials Imad Qashou1 of the Fluent CFD code is used to investigate the response of a fibrous material to the radiative heat transfer in agreement with our experimental study. INTRODUCTION Radiative heat transfer through fibrous media has been
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. Radiative heat transfer in this class of material is nonlocalized in the optically thick limit
and the basic rate equations for conduction, convection, and radiation. 2. Analyze conduction heat transfer the appropriate correlation for convective heat transfer process. 6. Analyze radiation exchange within methods for 2-D conduction 4. Forced Convection 5. Natural/Free Convection 6. Radiation Heat Transfer #12
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, 29(9):793804, 2008 Copyright C Taylor and Francis Group, LLC
Ghajar, Afshin J.
Heat Transfer Engineering, 29(9):793804, 2008 Copyright C Taylor and Francis Group, LLC ISSN: 0145 for Laminar and Turbulent Flow Convection Heat Transfer in a Horizontal Tube Using Artificial Neural Network was used to develop empirical correlations for laminar and turbulent heat transfer in a horizontal tube
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
MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA "BUILDINGS" LIBRARY
MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA "BUILDINGS" LIBRARY Michael Wetter, Wangda Zuo describes the implementation of the room heat transfer model in the free open-source Modelica "Buildings the model is de- composed into submodels for the individual heat transfer phenomena. We also discuss
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
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
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@niu.edu * www.kostic.niu.edu Abstract: - An apparatus for exploring friction and heat transfer characteristics flow. Initial turbulent friction and heat transfer measurements for silica and carbon nanotube (CNT
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
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 of the concept is that the flows in the FW channels are turbulent to provide a high heat transfer coefficient
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
The Influence of Heat Transfer Irreversibilities on the Optimal Performance of Diabatic
Salamon, Peter
The Influence of Heat Transfer Irreversibilities on the Optimal Performance of Diabatic is only slightly dependent on the heat transfer law considered. In the limit of an infinite number of trays even this column with resistance to transfer of heat becomes reversible. 1 #12;Keywords Diabatic
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 Lefèvre Laboratoire d three heat transfer modes with experimental data and modeling. We conclude that the three modes in "International Journal of Heat and Mass Transfer 49, 1-2 (2006) 251-258" DOI : 10.1016/j.ijheatmasstransfer.2005
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
on the total window heat transfer rates may be much larger. This effect is even greater in low on a literature review and an evaluation of current methods of modeling heat transfer through window frames, we evaluating heat transfer through the low-conductance frames. We conclude that the near-term priorities
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
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
Heat transfer from multiple row arrays of low aspect ratio pin fins Seth A. Lawson a,
Thole, Karen A.
Heat transfer from multiple row arrays of low aspect ratio pin fins Seth A. Lawson a, , Alan A 18 March 2011 Available online 5 May 2011 Keywords: Pin fins Heat transfer augmentation Array to enhance heat transfer. In modern gas turbines, for exam- ple, airfoils are designed with sophisticated
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 or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers-dimensional numerical simulation of the heat transfers through the double skin reveals the most important parameters
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
Wright, Lance Cole
1996-01-01
The effect of unsteady periodic wakes on heat transfer and boundary layer transition was investigated on a constant curvature heat transfer curved plate in a subsonic wind tunnel facility. The local heat transfer coefficient ...
Kandlikar, Satish
Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure online 4 May 2013 Keywords: Pool boiling Heat transfer enhancement Open microchannels Cylindrical tube boiling heat transfer over enhanced cylindrical microchannel test surfaces with water at atmospheric
Nottrott, A.; Onomura, S.; Inagaki, A.; Kanda, M.; Kleissl, J.
2011-01-01
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,
Yuen, W W
2006-01-01
the effect of radiation heat transfer in multi-dimensionaleffects of the radiation heat transfer, particularly in3-D Surface Radiation Calculation”, Numerical heat Transfer,
Modeling of Heat and Mass Transfer in Fusion Welding
Zhang, Wei [ORNL
2011-01-01
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.
Experimental and numerical study of laminar forced convection heat transfer for a dimpled heat sink
Park, Do Seo
2009-05-15
of the copper plate. The outer surface of the test section consisted of fiberglass to reduce heat loss to the outside surroundings. The blower was turned on and air was forced through the test setup. The flow rate through the test section was controlled... 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...
Heat transfer characteristics of a two-pass trapezoidal channel and a novel heat pipe
Lee, Sang Won
2009-06-02
and roughened two-pass trapezoidal channels with a 180° turn over a range of Reynolds numbers between about 10,000 and 60,000. The naphthalene sublimation technique and the heat and mass transfer analogy were applied. The results showed that there was a very...
Fainman, Yeshaiahu
to heat transfer in ducts and external boundary layers. Introduction to heat conduction and radiation and radiative heat transfer 1.2 Students will be able to recognize applications in which heat transfer transfer by radiation Objective 3 3.1 Students will demonstrate the ability to analyze heat exchangers 3
Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger
Im, Kwan H. (Naperville, IL); Ahluwalia, Rajesh K. (Burr Ridge, IL)
1994-01-01
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.
1994-10-18
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.
Edwards, Bronwyn K
2009-01-01
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 ...
Recent Heat Transfer Improvements to the RELAP5-3D Code
Riemke, Richard A; Davis, Cliff B; Oh, Chang
2007-05-01
The heat transfer section of the RELAP5-3D computer program has been recently improved. The improvements are as follows: (1) the general cladding rupture model was modified (more than one heat structure segment connected to the hydrodynamic volume and heat structure geometry’s internal gap pressure), (2) the cladding rupture model was modified for reflood, and (3) the heat transfer minor edits/plots were extended to include radiation/enclosure heat flux and generation (internal heat source).
Conceptual Design of Forced Convection Molten Salt Heat Transfer Testing Loop
Manohar S. Sohal; Piyush Sabharwall; Pattrick Calderoni; Alan K. Wertsching; S. Brandon Grover
2010-09-01
This report develops a proposal to design and construct a forced convection test loop. A detailed test plan will then be conducted to obtain data on heat transfer, thermodynamic, and corrosion characteristics of the molten salts and fluid-solid interaction. In particular, this report outlines an experimental research and development test plan. The most important initial requirement for heat transfer test of molten salt systems is the establishment of reference coolant materials to use in the experiments. An earlier report produced within the same project highlighted how thermophysical properties of the materials that directly impact the heat transfer behavior are strongly correlated to the composition and impurities concentration of the melt. It is therefore essential to establish laboratory techniques that can measure the melt composition, and to develop purification methods that would allow the production of large quantities of coolant with the desired purity. A companion report describes the options available to reach such objectives. In particular, that report outlines an experimental research and development test plan that would include following steps: •Molten Salts: The candidate molten salts for investigation will be selected. •Materials of Construction: Materials of construction for the test loop, heat exchangers, and fluid-solid corrosion tests in the test loop will also be selected. •Scaling Analysis: Scaling analysis to design the test loop will be performed. •Test Plan: A comprehensive test plan to include all the tests that are being planned in the short and long term time frame will be developed. •Design the Test Loop: The forced convection test loop will be designed including extensive mechanical design, instrument selection, data acquisition system, safety requirements, and related precautionary measures. •Fabricate the Test Loop. •Perform the Tests. •Uncertainty Analysis: As a part of the data collection, uncertainty analysis will be performed to develop probability of confidence in what is measured in the test loop. Overall, the testing loop will allow development of needed heat transfer related thermophysical parameters for all the salts, validate existing correlations, validate measuring instruments under harsh environment, and have extensive corrosion testing of materials of construction.
Thole, Karen A.
acceptable increases in pressure losses. Increases in efficiency allow for louvered fin heat exchang- ersHeat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical surface of louvered fin heat exchangers. It is shown that delta winglets placed on louvered fins produce
Reimann, Robert C. (Lafayette, NY); Root, Richard A. (Spokane, WA)
1986-01-01
A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.
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)
2013-06-15
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.
The Impact of Heat Transfer Enhancement Techniques on Energy Savings in the U.S. Industry
Rebello, W. J.; Peterson, G. R.; Sohal, M.
1988-01-01
hydrocarbons in kettle reboilers in refineries. Finned tubing is now available in corrosion resistant materials, such as, titanium, Inconel, Hastelloy and stain less steel. In the past, finning techniques were developed for ductile, easy... and Internally Finned Tubes", J.of Heat Transfer vlOO, nl,Feb. 1978. 12. R. L. Webb, "Performance Evalu tion Criteria for Use of Enhanced Heat Transfer Surfaces in Heat Exchanger Design", International Journal of Heat and Mass Transfer, v24, n4, pp715, 1981...
Grid-independent Issue in Numerical Heat Transfer
Yao Wei; Wang Jian; Liao Guangxuan
2006-09-26
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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journalvivo Low-DoseOptions for AccidentalHealth,Heat Transfer
Heat transfer to a fluid flowing in an annulus
Logan, Earl
1958-01-01
. Zntegra ting equation (5) yields e r hAg (ts-tf)de = qse - mc(ts-tl), 0 where tl is--ths initial tempez'aturs of the central pipe e The quantity f(t -tf)de was determined graphically fzom a curve similar to Pigurs g, The ooefficisnt h was not found...
HEAT TRANSFER IN POROUS MEDIA WITH FLUID PHASE CHANGES
Su, Ho-Jeen.
2010-01-01
mass flux capillary pressure vapor pressure water pressureW. N. : "The Effect of Vapor-Pressure Lowering Upon Pressurethat both the water pressure and the vapor pressure at
Base fluid and temperature effects on the heat transfer characteristic...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Type Journal Article Year of Publication 2011 Authors Timofeeva, EV, Yu, W, France, DM, Singh, D, Routbort, JL Journal Journal of Applied Physics Volume 109 Start Page 014914...
Molten Salt Heat Transfer Fluid (HTF) - Energy Innovation Portal
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High Operating Temperature Liquid Metal Heat Transfer Fluids | Department
Broader source: Energy.gov (indexed) [DOE]
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Molten salt heat transfer fluids and thermal storage technology.
Office of Scientific and Technical Information (OSTI)
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Phenylnaphthalene Derivatives as Heat Transfer Fluids for Concentrating
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Phenylnaphthalene Derivatives as Heat Transfer Fluids for Concentrating
Office of Scientific and Technical Information (OSTI)
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Phenylnaphthalene as a Heat Transfer Fluid for Concentrating Solar Power:
Office of Scientific and Technical Information (OSTI)
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Phenylnaphthalene as a Heat Transfer Fluid for Concentrating Solar Power:
Office of Scientific and Technical Information (OSTI)
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Heat Transfer Fluids Containing Nanoparticles (08-066) - Energy Innovation
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Thermal System Design Thermal/Fluids
Kostic, Milivoje M.
of thermodynamics, heat transfer, and fluid mechanics ? Hardware: fans, pumps, compressors, engines, heat exchangers, fluids transport, and food, chemical, and process industries #12;3 Basic Course Topics ? Analysis networks ? Thermodynamics: modeling and optimization of a refrigeration system ? Heat Transfer: design
Enhanced convective and film boiling heat transfer by surface gas injection
Duignan, M.R.; Greene, G.A. ); Irvine, T.F., Jr. . Dept. of Mechanical Engineering)
1992-04-01
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.; Irvine, T.F., Jr.
1992-04-01
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.
Pruess, K.
2010-01-01
Supercritical CO 2 as Heat Transmission Fluid in the EGSof Using Supercritical CO2 as Heat Transmission Fluid in anEGS) with CO 2 as Heat Transmission Fluid - A Scheme for
ACHILLES: Heat Transfer in PWR Core During LOCA Reflood Phase
2013-11-01
1. NAME AND TITLE OF DATA LIBRARY ACHILLES -Heat Transfer in PWR Core During LOCA Reflood Phase. 2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS N/A 3. CONTRIBUTOR AEA Technology, Winfrith Technology Centre, Dorchester DT2 8DH United Kingdom through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France. 4. DESCRIPTION OF TEST FACILITY The most important features of the Achilles rig were the shroud vessel, which contained the test section, and the downcomer. These may be thought of as representing the core barrel and the annular downcomer in the reactor pressure vessel. The test section comprises a cluster of 69 rods in a square array within a circular shroud vessel. The rod diameter and pitch (9.5 mm and 12.6 mm) were typical of PWR dimensions. The internal diameter of the shroud vessel was 128 mm. Each rod was electrically heated over a length of 3.66 m, which is typical of the nuclear heated length in a PWR fuel rod, and each contained 6 internal thermocouples. These were arranged in one of 8 groupings which concentrated the thermocouples in different axial zones. The spacer grids were at prototypic PWR locations. Each grid had two thermocouples attached to its trailing edge at radial locations. The axial power profile along the rods was an 11 step approximation to a "chopped cosine". The shroud vessel had 5 heating zones whose power could be independently controlled. 5. DESCRIPTION OF TESTS The Achilles experiments investigated the heat transfer in the core of a Pressurized Water Reactor during the re-flood phase of a postulated large break loss of coolant accident. The results provided data to validate codes and to improve modeling. Different types of experiments were carried out which included single phase cooling, re-flood under low flow conditions, level swell and re-flood under high flow conditions. Three series of experiments were performed. The first and the third used the same test section but the second used another test section, similar in all respects except that it contained a partial blockage formed by attaching sleeves (or "balloons") to some of the rods. 6. SOURCE AND SCOPE OF DATA Phenomena Tested - Heat transfer in the core of a PWR during a re-flood phase of postulated large break LOCA. Test Designation - Achilles Rig. The programme includes the following types of experiments: - on an unballooned cluster: -- single phase air flow -- low pressure level swell -- low flooding rate re-flood -- high flooding rate re-flood - on a ballooned cluster containing 80% blockage formed by 16 balloon sleeves -- single phase air flow -- low flooding rate re-flood 7. DISCUSSION OF THE DATA RETRIEVAL PROGRAM N/A 8. DATA FORMAT AND COMPUTER Many Computers (M00019MNYCP00). 9. TYPICAL RUNNING TIME N/A 11. CONTENTS OF LIBRARY The ACHILLES package contains test data and associated data processing software as well as the documentation listed above. 12. DATE OF ABSTRACT November 2013. KEYWORDS: DATABASES, BENCHMARKS, HEAT TRANSFER, LOSS-OF-COLLANT ACCIDENT, PWR REACTORS, REFLOODING
Raghavan, Srinivasa
Photoreversible Micellar Solution as a Smart Drag-Reducing Fluid for Use in District Heating solution is developed as a promising working fluid for district heating/cooling systems (DHCs). It can systems. A promising application of DR fluids is in district heating/ cooling systems (DHCs)9
Interaction and heat exchange in two-component relativistic fluid
Ernst Trojan; George V. Vlasov
2011-08-12
A model of two-component relativistic fluid is considered, and the thermal nature of coupling between the fluid constituents is outlined. This thermal coupling is responsible for non-ideality of the fluid composite where the components are not fully independent. The interaction between particles is reflected only in the equation of state of each component, but it deals nothing with the coupling between the fluid components and does not influence the hydrodynamic motion. A general form of two-fluid decomposition is formulated for arbitrary interacting system.
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
Chen, Binjiao; Wang, Xin; Zeng, Ruolang; Zhang, Yinping; Di, Hongfa [Department of Building Science, Tsinghua University, Beijing 100084 (China); Wang, Xichun; Niu, Jianlei [Department of Building Service Engineering, The Hong Kong Polytechnic University, Hong Kong (China); Li, Yi [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China)
2008-09-15
By contrast with the conventional heat transfer fluid (water), the microencapsulated phase change material (MPCM) suspension, with a small temperature difference between storing and releasing heat, is of much larger apparent specific heat and much higher thermal energy storage capacity. It has been suggested to serve as a dual-functional medium for thermal energy transport and/or storage. The heat transfer characteristics of a kind of MPCM suspension, formed by microencapsulating industrial-grade 1-bromohexadecane (C{sub 16}H{sub 33}Br) as phase change material, were experimentally studied for laminar flow in a circular tube under constant heat flux. A new expression of Ste is put forward in the paper, according to the physical definition of Stefan number. The results in the experiments show: (a) the dimensionless internal wall temperature of the MPCM suspension is lower than pure water, and the decrease can be up to 30% of that of water; (b) the heat transfer enhancement ratio can be 1.42 times of that of water at x{sup +} = 4.2 x 10{sup -2} for 15.8 wt% MPCM suspension, which is not as much as in some references; and (c) the pump consumption of the MPCM suspension system decrease greatly for the larger heat transfer rate compared with water, due to phase change, the decrease can be up to 67.5% of that of water at q = 750 W (15.8 wt%). The kind of MPCM suspension has good application feasibility in practice. (author)
Thermoacoustic sensor for nuclear fuel temperaturemonitoring and heat transfer enhancement
James A. Smith; Dale K. Kotter; Randall A. Alli; Steven L. Garrett
2013-05-01
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.
Flow regimes and heat transfer in vertical narrow annuli
Ulke, A.; Goldberg, I.
1993-11-01
In shell side boiling heat exchangers narrow crevices that are formed between the tubes and the tube support structure provide areas for local thermal-hydraulic conditions which differ significantly from bulk fluid conditions. Understanding of the processes of boiling and dryout in flow restricted crevices can help in designing of tube support geometries to minimize the likelihood of tube support plate and tube corrosion observed in commercial power plant steam generators. This paper describes a one dimensional thermal-hydraulic model of a vertical crevice between a tube and a support plate with cylindrical holes. The annulus formed by the support plate hole and an eccentrically located tube has been represented by vertical strips. The formation, growth and collapse of a steam bubble in each strip has been determined. Based on the bubble history, and flow regimes characterized by ``isolated`` bubbles, ``coalesced`` bubbles and liquid deficient regions have been defined.
J. Yang; F. B. Cheung; J. L. Rempe; K. Y. Suh; S. B. Kim
2005-07-01
Four types of steady-state boiling experiments were conducted to investigate the efficacy of two distinctly different heat transfer enhancement methods for external reactor vessel cooling under severe accident conditions. One method involved the use of a thin vessel coating and the other involved the use of an enhanced insulation structure. By comparing the results obtained in the four types of experiments, the separate and integral effect of vessel coating and insulation structure were determined. Correlation equations were obtained for the nucleate boiling heat transfer and the critical heat flux. It was found that both enhancement methods were quite effective. Depending on the angular location, the local critical heat flux could be enhanced by 1.4 to 2.5 times using vessel coating alone whereas it could be enhanced by 1.8 to 3.0 times using an enhanced insulation structure alone. When both vessel coating and insulation structure were used simultaneously, the integral effect on the enhancement was found much less than the product of the two separate effects, indicating possible competing mechanisms (i.e., interference) between the two enhancement methods.
Garg, Paritosh
2009-05-15
thermal 6 conductivity and convective heat transfer as compared to the base fluid [1-5]. These nanoparticles could be either metal oxides of copper, copper oxide, aluminium, alumina, titania, or they could be non-metals like carbon. In this work, we...
Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology
2009-01-01
A nanofluid is a colloidal suspension of nano-scale particles in water, or other base fluids. Previous pool boiling studies have shown that nanofluids can improve the critical heat flux (CHF) by as much as 200%. In this ...
Fluid Circulation and Heat Extraction from Engineered Geothermal...
in less-confined reservoirs. Under such conditions, a downhole production-well pump may be employed to increase productivity by recovering more of the injected fluid at...
A method of correlating heat transfer data for surface boiling of liquids
Rohsenow, Warren M.
1951-01-01
A method based an a logical uxplanation of the meani of beat transfer associated with the boiling process is presented for correlating heat transfer data for nucleate boiling of liquids for the case of pool boiling. Tbe ...
TRANSIENT HEAT TRANSFER MODEL FOR SRS WASTE TANK OPERATIONS
Lee, S; Richard Dimenna, R
2007-03-27
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.
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
Fluid Bed Waste Heat Boiler Operating Experience in Dirty Gas Streams
Kreeger, A. H.
1986-01-01
BOILER OPERATING EXPERIENCE IN DIRTY GAS STREAMS Alan H. Kreeger. Aerojet Energy Conversion Company. Sacramento. California ABSTRACT The first industrial fluid bed waste heat boiler in the U. S. is operating on an aluminium melting furnace...
Design and Operation of Fluid Beds for Heating, Cooling and Quenching Operations
Kemp, W. E.
1981-01-01
A commercial foundry has been established which makes extensive use of fluid beds in the production of heat treated alloy steel castings. The castings are cooled immediately after solidification by fluidizing the mold sand in which they were cast...
Pressure drop and heat transfer characteristics of boiling water in sub-hundred micron channel
Bhide, R.R.; Singh, S.G.; Sridharan, Arunkumar; Duttagupta, S.P.; Agrawal, Amit [Department of Mechanical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India)
2009-09-15
The current work focuses on the pressure drop, heat transfer and stability in two phase flow in microchannels with hydraulic diameter of less than one hundred microns. Experiments were conducted in smooth microchannels of hydraulic diameter of 45, 65 {mu}m, and a rough microchannel of hydraulic diameter of 70 {mu}m, with deionised water as the working fluid. The local saturation pressure and temperature vary substantially over the length of the channel. In order to correctly predict the local saturation temperature and subsequently the heat transfer characteristics, numerical techniques have been used in conjunction with the conventional two phase pressure drop models. The Lockhart-Martinelli (liquid-laminar, vapour-laminar) model is found to predict the two phase pressure drop data within 20%. The instability in two phase flow is quantified; it is found that microchannels of smaller hydraulic diameter have lesser instabilities as compared to their larger counterparts. The experiments also suggest that surface characteristics strongly affect flow stability in the two phase flow regime. The effect of hydraulic diameter and surface characteristics on the flow characteristics and stability in two phase flow is seldom reported, and is of considerable practical relevance. (author)
A modified lattice Bhatnagar-Gross-Krook model for convection heat transfer in porous media
Wang, Liang; Guo, Zhaoli
2015-01-01
The lattice Bhatnagar-Gross-Krook (LBGK) model has become the most popular one in the lattice Boltzmann method for simulating the convection heat transfer in porous media. However, the LBGK model generally suffers from numerical instability at low fluid viscosities and effective thermal diffusivities. In this paper, a modified LBGK model is developed for incompressible thermal flows in porous media at the representative elementary volume scale, in which the shear rate and temperature gradient are incorporated into the equilibrium distribution functions. With two additional parameters, the relaxation times in the collision process can be fixed at a proper value invariable to the viscosity and the effective thermal diffusivity. In addition, by constructing a modified equilibrium distribution function and a source term in the evolution equation of temperature field, the present model can recover the macroscopic equations correctly through the Chapman-Enskog analysis, which is another key point different from pre...
Application Of A Spherical-Radial Heat Transfer Model To Calculate...
Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...
HEAT AND MASS TRANSFER IN A FAULT-CONTROLLED GEOTHERMAL RESERVOIR CHARGED AT CONSTANT PRESSURE
Goyal, K.P.
2013-01-01
in Hydrothermal Systems, Geothermal Resources (eds. L.1975. Heat Transfer in Geothermal Systems, 11 in Advances inI. G. , The Simulation of Geothermal Systems with a Simple
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
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 ...
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01
with lamp heating than with furnace heating and (2) hydrogensilica tube and heated in a furnace or by an incandescentan incandescent lamp than within furnace. Here, sample and
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01
the same heat input, the maximum release rate from samplesThe same heat (a) Normalized hydrogen release rate Numericalrelease rate under otherwise identical heat input. 5. Lamp
RELAP5 MODEL OF THE DIVERTOR PRIMARY HEAT TRANSFER SYSTEM
Popov, Emilian L [ORNL; Yoder Jr, Graydon L [ORNL; Kim, Seokho H [ORNL
2010-08-01
This report describes the RELAP5 model that has been developed for the divertor primary heat transfer system (PHTS). The model is intended to be used to examine the transient performance of the divertor PHTS and evaluate control schemes necessary to maintain parameters within acceptable limits during transients. Some preliminary results are presented to show the maturity of the model and examine general divertor PHTS transient behavior. The model can be used as a starting point for developing transient modeling capability, including control system modeling, safety evaluations, etc., and is not intended to represent the final divertor PHTS design. Preliminary calculations using the models indicate that during normal pulsed operation, present pressurizer controls may not be sufficient to keep system pressures within their desired range. Additional divertor PHTS and control system design efforts may be required to ensure system pressure fluctuation during normal operation remains within specified limits.
Near field radiative heat transfer between two nonlocal dielectrics
Singer, F; Joulain, Karl
2015-01-01
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...
378 Solutions Manual x Fluid Mechanics, Fifth Edition where heat flow, J/s
Bahrami, Majid
378 Solutions Manual x Fluid Mechanics, Fifth Edition where heat flow, J/s A surface area, m Q 2 'T Ans. L V VV U PU § ·' : 3 3 3 3 ¨ ¸ © ¹ 5.18 Under laminar conditions, the volume flow Q through temperature difference, K The dimensionless form of h, called the Stanton number, is a combination of h, fluid
Improved time-space method for 3-D heat transfer problems including global warming
Saitoh, T.S.; Wakashima, Shinichiro
1999-07-01
In this paper, the Time-Space Method (TSM) which has been proposed for solving general heat transfer and fluid flow problems was improved in order to cover global and urban warming. The TSM is effective in almost all-transient heat transfer and fluid flow problems, and has been already applied to the 2-D melting problems (or moving boundary problems). The computer running time will be reduced to only 1/100th--1/1000th of the existing schemes for 2-D and 3-D problems. However, in order to apply to much larger-scale problems, for example, global warming, urban warming and general ocean circulation, the SOR method (or other iterative methods) in four dimensions is somewhat tedious and provokingly slow. Motivated by the above situation, the authors improved the speed of iteration of the previous TSM by introducing the following ideas: (1) Timewise chopping: Time domain is chopped into small peaches to save memory requirement; (2) Adaptive iteration: Converged region is eliminated for further iteration; (3) Internal selective iteration: Equation with slow iteration speed in iterative procedure is selectively iterated to accelerate entire convergence; and (4) False transient integration: False transient term is added to the Poisson-type equation and the relevant solution is regarded as a parabolic equation. By adopting the above improvements, the higher-order finite different schemes and the hybrid mesh, the computer running time for the TSM is reduced to some 1/4600th of the conventional explicit method for a typical 3-D natural convection problem in a closed cavity. The proposed TSM will be more efficacious for large-scale environmental problems, such as global warming, urban warming and general ocean circulation, in which a tremendous computing time would be required.
Zhao, Tianshou
- channels is important for the design and optimization of heat pipes and capillary pumped loops (CPL), which of micro heat pipes. Khrustalev and Faghri [3] developed a detailed mathematical model to examine the heat and mass transfer processes in a micro heat pipe. The liquid flow in the triangular-shaped corners
Heat Transfer Engineering, 29(1):2044, 2008 Copyright C Taylor and Francis Group, LLC
Zhang, Yuwen
, Connecticut, USA Pulsating (or oscillating) heat pipes (PHP or OHP) are new two-phase heat transfer devices turns. The unique feature of PHPs, compared with conventional heat pipes, is that there is no wick are discussed. INTRODUCTION Evolution in the design of the heat pipe--a type of passive two-phase thermal
DOE Webinar ? Residential Geothermal Heat Pump Retrofits (Presentatio...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
to the heating fluid or air handler Heat is transferred to the room by radiant floor heating or air distribution system Refrigerant expands causing it to cool Heat Pump...
Natural convection heat transfer within horizontal spent nuclear fuel assemblies
Canaan, R.E.
1995-12-01
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.
Zhang, M.; Ibekwe, S.; Li, G.; Pang, S.S.; and Lian, K.
2006-07-01
The Pressurized Water Reactors (PWRs in Figure 1) were originally developed for naval propulsion purposes, and then adapted to land-based applications. It has three parts: the reactor coolant system, the steam generator and the condenser. The Steam generator (a yellow area in Figure 1) is a shell and tube heat exchanger with high-pressure primary water passing through the tube side and lower pressure secondary feed water as well as steam passing through the shell side. Therefore, a key issue in increasing the efficiency of heat exchanger is to improve the design of steam generator, which is directly translated into economic benefits. The past research works show that the presence of a pin-fin array in a channel enhances the heat transfer significantly. Hence, using microfabrication techniques, such as LIGA, micro-molding or electroplating, some special microstructures can be fabricated around the tubes in the heat exchanger to increase the heat-exchanging efficiency and reduce the overall size of the heat-exchanger for the given heat transfer rates. In this paper, micro-pin fins of different densities made of SU-8 photoresist are fabricated and studied to evaluate overall heat transfer efficiency. The results show that there is an optimized micro pin-fin configuration that has the best overall heat transfer effects.
TOPAZ2D heat transfer code users manual and thermal property data base
Shapiro, A.B.; Edwards, A.L.
1990-05-01
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.
Forming liquid sprays in compressed-gas energy storage systems for effective heat exchange
McBride, Troy O.; Bell, Alexander; Bollinger, Benjamin R.
2012-08-07
In various embodiments, efficiency of energy storage and recovery systems compressing and expanding gas is improved via heat exchange between the gas and a heat-transfer fluid.
Forming liquid sprays in compressed-gas energy storage systems for effective heat exchange
McBride, Troy O; Bell, Alexander; Bollinger, Benjamin R; Shang, Andrew; Chmiel, David; Richter, Horst; Magari, Patrick; Cameron, Benjamin
2013-07-02
In various embodiments, efficiency of energy storage and recovery systems compressing and expanding gas is improved via heat exchange between the gas and a heat-transfer fluid.
Single nozzle spray cooling heat transfer mechanisms Bohumil Horacek, Kenneth T. Kiger, Jungho Kim *
Kim, Jungho
Single nozzle spray cooling heat transfer mechanisms Bohumil Horacek, Kenneth T. Kiger, Jungho Kim Abstract An investigation into single nozzle spray cooling heat transfer mechanisms with varying amounts the effective subcooling of the liquid, and shifted the spray cooling curves to higher wall temperatures
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
JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 13, No. 4, OctoberDecember 1999
Xu, Xianfan
, it has been proposed that nanometer-sizedparticles could be suspended in industrial heat transfer uidsJOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 13, No. 4, OctoberDecember 1999 Thermal in water, vacuum pump uid, engine oil, and ethylene glycol. Experimental results show that the thermal
NOMENCLATURE (Journal of Heat Transfer, Vol. 121, No. 4. pp 770-773, November 1999)
NOMENCLATURE (Journal of Heat Transfer, Vol. 121, No. 4. pp 770-773, November 1999) QUANTITY SYMBOL (constant v or p) molar (constant v or p) ratio cp/cv C pcvc , pcvc , J/K J/kg K J/kmol K Heat Transfer COHERENT SI UNIT Absorptivity (radiation) Absorption Coefficient (radiation) m-1 Activation Energy
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
Bibliography of US patents on augmentation of convective heat and mass transfer-II
Webb, R.L.; Bergles, A.E.; Junkhan, G.H.
1983-12-01
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).
Ammerman, C.N.; You, S.M.; Hong, Y.S. [Univ. of Texas, Arlington, TX (United States). Dept. of Mechanical and Aerospace Engineering
1995-12-31
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).
The effect of undrained heating on a fluid-saturated hardened cement paste
Ghabezloo, Siavash; Saint-Marc, Jérémie
2008-01-01
The effect of undrained heating on volume change and induced pore pressure increase is an important point to properly understand the behaviour and evaluate the integrity of an oil well cement sheath submitted to rapid temperature changes. This thermal pressurization of the pore fluid is due to the discrepancy between the thermal expansion coefficients of the pore fluid and of the solid matrix. The equations governing the undrained thermo-hydro-mechanical response of a porous material are presented and the effect of undrained heating is studied experimentally for a saturated hardened cement paste. The measured value of the thermal pressurization coefficient is equal to 0.6MPa/'C. The drained and undrained thermal expansion coefficients of the hardened cement paste are also measured in the heating tests. The anomalous thermal behaviour of cement pore fluid is back analysed from the results of the undrained heating test.
Molecular Dynamics Simulations of Heat Transfer In Nanoscale Liquid Films
Kim, Bo Hung
2010-07-14
Molecular Dynamics (MD) simulations of nano-scale flows typically utilize fixed lattice crystal interactions between the fluid and stationary wall molecules. This approach cannot properly model thermal interactions at the wall-fluid interface...
Greene, G.A.; Irvine, T.F. Jr.
1988-01-01
The modeling of molten core debris in the CORCON and VANESA computer codes as overlying, immiscible liquid layers is discussed as it relates to the transfer of heat and mass between the layers. This initial structure is identified and possible configurations are discussed. The stratified, gas-sparged configuration that is presently employed in CORCON and VANESA is examined and the existing literature for interlayer heat transfer is assessed. An experiment which was designed to measure interlayer heat transfer with gas sparging is described. The results are presented and compared to previously existing models. A dimensionless correlation for stratified, interlayer heat transfer with gas sparging is developed. This relationship is recommended for inclusion in CORCON-MOD2 for heat transfer between stratified, molten liquid layers. 12 refs., 6 figs., 3 tabs.
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)
1991-12-31
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.
A vectorized heat transfer model for solid reactor cores
Rider, W.J.; Cappiello, M.W.; Liles, D.R.
1990-01-01
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.
Micro and nanostructured surfaces for enhanced phase change heat transfer
Chu, Kuang-Han, Ph. D. Massachusetts Institute of Technology
2013-01-01
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, ...
ON CONVECTIVE HEAT TRANSFER IN BUILDING ENERGY ANALYSIS
Gadgil, Ashok Jagannath
2013-01-01
an ement of fluid in a steady laminar flow, can be used tolaminar, the f1uid flows along streamli defined by *For steady flow~ fluid particles flowlaminar boundary layer thickness, L v'Re RECIRCULATING FLOW INDUCED IN A FLUID
Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid
Attard, Phil
Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid March 2005; accepted 4 May 2005; published online 28 June 2005 A statistical mechanical theory for heat distribution for heat flow down an imposed thermal gradient is tested with simulations of a Lennard-Jones fluid
Characterization of Fuego for laminar and turbulent natural convection heat transfer.
Francis, Nicholas Donald, Jr. (,; .)
2005-08-01
A computational fluid dynamics (CFD) analysis is conducted for internal natural convection heat transfer using the low Mach number code Fuego. The flow conditions under investigation are primarily laminar, transitional, or low-intensity level turbulent flows. In the case of turbulent boundary layers at low-level turbulence or transitional Reynolds numbers, the use of standard wall functions no longer applies, in general, for wall-bounded flows. One must integrate all the way to the wall in order to account for gradients in the dependent variables in the viscous sublayer. Fuego provides two turbulence models in which resolution of the near-wall region is appropriate. These models are the v2-f turbulence model and a Launder-Sharma, low-Reynolds number turbulence model. Two standard geometries are considered: the annulus formed between horizontal concentric cylinders and a square enclosure. Each geometry emphasizes wall shear flow and complexities associated with turbulent or near turbulent boundary layers in contact with a motionless core fluid. Overall, the Fuego simulations for both laminar and turbulent flows compared well to measured data, for both geometries under investigation, and to a widely accepted commercial CFD code (FLUENT).
Dual manifold system and method for fluid transfer
Doktycz, Mitchel J. (Knoxville, TN); Bryan, William Louis (Knoxville, TN); Kress, Reid (Oak Ridge, TN)
2003-05-27
A dual-manifold assembly is provided for the rapid, parallel transfer of liquid reagents from a microtiter plate to a solid state microelectronic device having biological sensors integrated thereon. The assembly includes aspiration and dispense manifolds connected by a plurality of conduits. In operation, the aspiration manifold is actuated such that the aspiration manifold is seated onto an array of reagent-filled wells of the microtiter plate. The wells are pressurized to force reagent through conduits toward the dispense manifold. A pressure pulse provided by a standard ink-jet printhead ejects nanoliter-to-picoliter droplets of reagent through an array of printhead orifices and onto test sites on the surface of the microelectronic device.
Dual manifold system and method for fluid transfer
Doktycz, Mitchel J.; Bryan, William Louis; Kress, Reid
2003-09-30
A dual-manifold assembly is provided for the rapid, parallel transfer of liquid reagents from a microtiter plate to a solid state microelectronic device having biological sensors integrated thereon. The assembly includes aspiration and dispense manifolds connected by a plurality of conduits. In operation, the aspiration manifold is actuated such that the aspiration manifold is seated onto an array of reagent-filled wells of the microtiter plate. The wells are pressurized to force reagent through conduits toward the dispense manifold. A pressure pulse provided by a standard ink-jet printhead ejects nanoliter-to-picoliter droplets of reagent through an array of printhead orifices and onto test sites on the surface of the microelectronic device.
A PC simulation of heat transfer and temperature distribution in a circulating wellbore
Pierce, Robert Duane
1987-01-01
-Wold (Chair of Committee) James E. Russell (Member) Earl R. Hoskins (Member) D, Von Gonton (H ad of Department) December 1987 ABSTRACT A PC Simulation of Heat Transfer and Temperature Distribution in a Circulating Wellbore (December 1987) Robert... SUPPLEMENTAL SOURCES CONSULTED APPENDIX A: MATHEMATICAL MODEL AND TREATMENT 103 108 APPENDIX B: DERIVATION OF RAMEY'SS WELLBORE HEAT TRANSMISSION SOLUTION 112 APPENDIX C: RHEOLOGICAL PRESSURE LOSS MODEL CALCULATIONS APPENDIX D: OVER-ALL HEAT TRANSFER...
Vibration damping and heat transfer using material phase changes
Kloucek, Petr (Houston, TX); Reynolds, Daniel R. (Oakland, CA)
2009-03-24
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.
Dual-circuit embossed-sheet heat-transfer panel
Morgan, G.D.
1982-08-23
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.
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)
2014-09-07
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.
Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)
1996-11-05
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.
Optimization of Phase Change Heat Transfer in Biporous Media
Reilly, Sean
2013-01-01
demand for efficient evaporators for heat pipes and spreaders will increase in kind. Sintered copper
Thiagarajan, S. J.; Wang, W.; Yang, R.; Narumanchi, S.; King, C.
2010-09-01
The DOE National Renewable Energy Laboratory (NREL) is leading a national effort to develop next-generation cooling technologies for hybrid vehicle electronics. The goal is to reduce the size, weight, and cost of power electronic modules that convert direct current from batteries to alternating current for the motor, and vice versa. Aggressive thermal management techniques help to increase power density and reduce weight and volume, while keeping chip temperatures within acceptable limits. The viability of aggressive cooling schemes such as spray and jet impingement in conjunction with enhanced surfaces is being explored. Here, we present results from a series of experiments with pool and spray boiling on enhanced surfaces, such as a microporous layer of copper and copper nanowires, using HFE-7100 as the working fluid. Spray impingement on the microporous coated surface showed an enhancement of 100%-300% in the heat transfer coefficient at a given wall superheat with respect to spray impingement on a plain surface under similar operating conditions. Critical heat flux also increased by 7%-20%, depending on flow rates.
Achanta, Vamsee Satish
2004-09-30
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 ...
Lee, Sang Won
2002-01-01
influence the velocity profiles, therefore, the heat transfer performance. Location of the hole of the upstream blockage significantly changes the velocity profiles; therefore, heat transfer results. The jets through the holes of the upstream blockage...
In situ heat treatment process utilizing a closed loop heating system
Vinegar, Harold J. (Bellaire, TX); Nguyen, Scott Vinh (Houston, TX)
2010-12-07
Systems and methods for an in situ heat treatment process that utilizes a circulation system to heat one or more treatment areas are described herein. The circulation system may use a heated liquid heat transfer fluid that passes through piping in the formation to transfer heat to the formation. In some embodiments, the piping may be positioned in at least two of the wellbores.
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
Low temperature barriers with heat interceptor wells for in situ processes
McKinzie, II, Billy John (Houston, TX)
2008-10-14
A system for reducing heat load applied to a frozen barrier by a heated formation is described. The system includes heat interceptor wells positioned between the heated formation and the frozen barrier. Fluid is positioned in the heat interceptor wells. Heat transfers from the formation to the fluid to reduce the heat load applied to the frozen barrier.
Haihua Zhao; Hongbin Zhang; Samuel E. Bays
2009-05-01
The sodium intermediate heat transfer loop is used in existing sodium cooled fast reactor (SFR) plant design as a necessary safety measure to separate the radioactive primary loop sodium from the water of the steam Rankine power cycle. However, the intermediate heat transfer loop significantly increases the SFR plant cost and decreases the plant reliability due to the relatively high possibility of sodium leakage. A previous study shows that helium Brayton cycles with multiple reheat and intercooling for SFRs with reactor outlet temperature in the range of 510°C to 650°C can achieve thermal efficiencies comparable to or higher than steam cycles or recently proposed supercritical CO2 cycles. Use of inert helium as the power conversion working fluid provides major advantages over steam or CO2 by removing the requirement for safety systems to prevent and mitigate the sodium-water or sodium-CO2 reactions. A helium Brayton cycle power conversion system therefore makes the elimination of the intermediate heat transfer loop possible. This paper presents a pre-conceptual design of multiple reheat helium Brayton cycle for an advanced loop type SFR. This design widely refers the new horizontal shaft distributed PBMR helium power conversion design features. For a loop type SFR with reactor outlet temperature 550°C, the design achieves 42.4% thermal efficiency with favorable power density comparing with high temperature gas cooled reactors.
Hogue, Christopher William
2011-01-01
topic, and researchers all over the world began reworking classical convection correlations to better model heat transfer
New flow boiling heat transfer model for hydrocarbons evaporating inside horizontal tubes
Chen, G. F.; Gong, M. Q.; Wu, J. F.; Zou, X.; Wang, S.
2014-01-29
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.
Tafreshi, Hooman Vahedi
Analytical Monte Carlo Ray Tracing simulation of radiative heat transfer through bimodal fibrous-state radiative heat transfer through fibrous insulation materials. The simulations are conducted in 3-D disor radiation and conduc- tion to be the only modes of heat transfer in fibrous insulation materials
Phung, Kim-dang.- Le Laboratoire de MathÃ©matiques
I: Heat equation II: SchrÃ¶dinger equation III: Wave equation IV: Radiative transfer equation;I: Heat equation II: SchrÃ¶dinger equation III: Wave equation IV: Radiative transfer equation QUCP: Heat equation II: SchrÃ¶dinger equation III: Wave equation IV: Radiative transfer equation QUCP
Paris-Sud XI, Université de
and the convective heat transfer2 coefficient on bacterial growth3 4 H. Ben Yaghlenea,b* , I. Leguerinela , M. Hamdib Ratkowsky "square root" model and a simplified two-parameter20 heat transfer model regarding an infinite air temperature, the convective heat transfer22 coefficient and the growth parameters of the micro
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
Fusion Engineering and Design 81 (2006) 549553 Numerical analysis of MHD flow and heat transfer in a
Abdou, Mohamed
2006-01-01
Fusion Engineering and Design 81 (2006) 549553 Numerical analysis of MHD flow and heat transfer January 2006 Abstract MHD flow and heat transfer have been analyzed for a front poloidal channel blanket; Magnetohydrodynamics; Heat transfer 1. Introduction Using flow channel inserts (FCIs) made
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
Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)
1992-01-01
An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.
Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference
Hidrovo, Carlos H.
, TX, USA Carlos H. Hidrovo The University of Texas at Austin Austin, TX, USA ABSTRACT Heat pipes in a heat pipe is done passively by means of a wicking structure that induces capillary-driven flow from measurements of baseline mesh wicks and nanowicks. Since the thermal performance of most heat pipes is usually
Grant L. Hawkes; James E. O'Brien; Greg Tao
2011-11-01
A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in an internally manifolded planar solid oxide electrolysis cell (SOEC) stack. This design is being evaluated at the Idaho National Laboratory for hydrogen production from nuclear power and process heat. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, operating potential, steam-electrode gas composition, oxygen-electrode gas composition, current density and hydrogen production over a range of stack operating conditions. Single-cell and five-cell results will be presented. Flow distribution through both models is discussed. Flow enters from the bottom, distributes through the inlet plenum, flows across the cells, gathers in the outlet plenum and flows downward making an upside-down ''U'' shaped flow pattern. Flow and concentration variations exist downstream of the inlet holes. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, oxygen-electrode and steam-electrode current density, and contact resistance from the base case are presented. Contour plots of local electrolyte temperature, current density, and Nernst potential indicate the effects of heat transfer, reaction cooling/heating, and change in local gas composition. Results are discussed for using this design in the electrolysis mode. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production, cell thermal efficiency, cell electrical efficiency, and Gibbs free energy are discussed and reported herein.
Dependency of Heat Transfer Rate on the Brinkman Number in Microchannels
H. S. Park
2008-01-07
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.
Passive heat-transfer means for nuclear reactors. [LMFBR
Burelbach, J.P.
1982-06-10
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.
Critical thickness of an optimum extended surface characterized by uniform heat transfer coefficient
Leontiou, Theodoros
2015-01-01
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...
MEC E 230 Introduction to thermo-fluid sciences
Flynn, Morris R.
. Introduction to fluid mechanics. Fluid properties. Fluid statics. Use of control volumes. Internal flows. Pre in mechanical engineering. The physics of heat transfer and fluid mechanics are introduced. · Understand tension in calculating pressure in a fluid · Calculate static pressure and forces on immersed objects
Study of the Effects of Surface Morphology and Droplet Growth Dynamics on Condensation Heat Transfer
Yao, Chun-Wei
2014-04-23
Condensation heat transfer has recently received a lot of renewed attention due to the development and use of surfaces with micro- and nano-scale features. Most of the new surfaces tend to promote drop-wise condensation, ...
Forced-convection surface-boiling heat transfer and burnout in tubes of small diameters
Bergles A. E.
1962-01-01
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. ...
Traviss, Donald P.
1971-01-01
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 ...
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 ...
Industrial Steam System Heat-Transfer SolutionsL: A BestPractices...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
least 18 inches or more from the heat-transfer unit. The horizontal distance from the vertical drop-leg to the steam trap should never be more than 8 inches. Any length more...
Heat and mass transfer in bubble column dehumidifiers for HDH desalination
Tow, Emily W
2014-01-01
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 ...
Condensation heat transfer in square, triangular, and semi-circular mini-channels Melanie Derby a
Peles, Yoav
Condensation heat transfer in square, triangular, and semi-circular mini-channels Melanie Derby a , Hee Joon Lee a,b , Yoav Peles a , Michael K. Jensen a, a Department of Mechanical, Aerospace
Clean Boiler Water-side Heat Transfer Surfaces - Steam Tip Sheet #7
2012-01-31
This revised AMO 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.
Tabares Velasco, P. C.
2011-04-01
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.'
Moon, Sung-Won
1999-01-01
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...
Yu, Jiwon 1982-
2012-12-03
of convective heat transfer involving suspensions of nanoparticles in coolants (or nanofluids). Flow visualization and quantitative estimation of near-wall temperature profiles were performed using quantum dots and fluorescent dyes. This non-contact measurement...
Mechanism and behavior of nucleate boiling heat transfer to the alkalai liquid metals
Deane, Charles William
1969-01-01
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 ...
Bian, David (David Wei)
2015-01-01
This thesis investigates the role of mass flux on flow boiling heat transfer in microchannels with surface micropillar arrays. The motivation for this investigation was to determine the general trends of the optimal ...
Residential Slab-On-Grade Heat Transfer in Hot Humid Climates
Clark, E.; Ascolese, M.; Collins, W.
1989-01-01
Heat transfer through an uninsulated slab on grade is calculated using a simple method developed by Kusuda. The seasonal and annual slab loads are graphed as a function of annual average soil temperature, Tm, for a variety of floor system...
Mhetras, Shantanu Prakash
2002-01-01
Jet impingement has been shown to be an effective method for enhancing convective heat transfer. There are a variety of applications of impinging jets in industry, including tempering and shaping of glass, annealing of metal and plastic sheets...