Development of a Heat Transfer Model for the Integrated Facade Heating
Gong, X.; Archer, D. H.; Claridge, D. E.
2007-01-01T23:59:59.000Z
the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts...
Development of a Heat Transfer Model for the Integrated Facade Heating
Gong, X.; Archer, D. H.; Claridge, D. E.
2007-01-01T23:59:59.000Z
the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts...
A CONVECTIVE HEAT TRANSFER MODEL FOR SIMULATION OF ROOMS WITH
A CONVECTIVE HEAT TRANSFER MODEL FOR SIMULATION OF ROOMS WITH ATTACHED WALL JETS By WEIXIU KONGQuest Information and Learning Company. #12;II A CONVECTIVE HEAT TRANSFER MODEL FOR SIMULATION OF ROOMS
Sensitivity Analysis of the Gap Heat Transfer Model in BISON.
Swiler, Laura Painton; Schmidt, Rodney C.; Williamson, Richard (INL); Perez, Danielle (INL)
2014-10-01T23:59:59.000Z
This report summarizes the result of a NEAMS project focused on sensitivity analysis of the heat transfer model in the gap between the fuel rod and the cladding used in the BISON fuel performance code of Idaho National Laboratory. Using the gap heat transfer models in BISON, the sensitivity of the modeling parameters and the associated responses is investigated. The study results in a quantitative assessment of the role of various parameters in the analysis of gap heat transfer in nuclear fuel.
Modeling of Heat Transfer in Geothermal Heat Exchangers
Cui, P.; Man, Y.; Fang, Z.
2006-01-01T23:59:59.000Z
for heat transfer inside boreholes. The transient 2-D temperature response in a semi-infinite medium with a line-source of finite length has also been derived for heat conduction outside boreholes. In order to investigate the impact of groundwater advection...
Wellbore Heat Transfer Model for Wax Deposition in Permafrost Region
Cui, Xiaoting
2012-05-31T23:59:59.000Z
Producing waxy oil in arctic area may cause wax deposited on the well wall. Since wax deposition is strongly thermal related, accurate heat transfer model is necessary in predicting and preventing wax depostion. A mathematical model was derived...
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
Heat transfer and oil displacement models for tar sands reservoirs
Ward, C.E.; Ward, G.D.
1984-09-01T23:59:59.000Z
A convective heat transfer model and one dimensional displacement model applicable to tar sands and heavy oils for use with a microcomputer are presented. The convective heat transfer model describes the temperature profiles in a thermal operation. The displacement model offers insight into the effect of process variables on the steam/oil or air/oil ratio of thermal operations. A method is presented for predicting the fuel burn in a fireflood.
Heat transfer model of above and underground insulated piping systems
Kwon, K.C.
1998-07-01T23:59:59.000Z
A simplified heat transfer model of above and underground insulated piping systems was developed to perform iterative calculations for fluid temperatures along the entire pipe length. It is applicable to gas, liquid, fluid flow with no phase change. Spreadsheet computer programs of the model have been developed and used extensively to perform the above calculations for thermal resistance, heat loss and core fluid temperature.
Modeling of Heat Transfer in Rooms in the Modelica Buildings Library
Wetter, Michael
2013-01-01T23:59:59.000Z
of the room heat transfer model in the free open-sourcea layer-by-layer heat transfer model that computes infrared
Grossmann, Ignacio E.
Heat transfer model of large shipping containers 1Chemical Engineering Department - Carnegie Mellon to the inside air 3. Heat transfer at the cargo on the pallets I. The heat transfer model Outline: II. Case
A Small Artery Heat Transfer Model for Self-Heated Thermistor Measurements of Perfusion in the
A Small Artery Heat Transfer Model for Self-Heated Thermistor Measurements of Perfusion model (SAM) for self-heated thermistor measurements of perfusion in the canine kidney is developed based clinical method to quantify perfusion for a majority of applications. Self-heated thermistor techniques
Modelling of heat transfer and crystallation kinetics in thermoplastic pultrusion
Carlsson, A.; Astroem, B.T. [Royal Institute of Technology, Stockholm (Sweden)
1996-12-31T23:59:59.000Z
While pultrusion with thermoset resins has been widely analyses, there is a scarcity of knowledge about pultrusion with thermoplastic resins. The objective of the present study is to develop a realistic heat transfer model for the entire thermoplastic pultrusion process, from room temperature prepreg, through preheater and dies, to room temperature composite. The aim is to determine dominating heat transfer mechanisms and to be able to predict residual stresses and crystallinity, which depend on the thermal history of the composite. A complete heat transfer model including crystallization kinetics is presented. Results show reasonably good agreement with experimental data and the model thus provides a tool for process simulations with a variety of processing parameters.
Mass and heat transfer model of Tubular Solar Still
Ahsan, Amimul [University Putra Malaysia, Dept. Civil Engineering, Faculty of Engineering, 43400 UPM Serdang, Selangor (Malaysia); Fukuhara, Teruyuki [University of Fukui, Graduate School of Engineering, 3-9-1 Bunkyo, Fukui 910-8507 (Japan)
2010-07-15T23:59:59.000Z
In this paper, a new mass and heat transfer model of a Tubular Solar Still (TSS) was proposed incorporating various mass and heat transfer coefficients taking account of the humid air properties inside the still. The heat balance of the humid air and the mass balance of the water vapor in the humid air were formulized for the first time. As a result, the proposed model enabled to calculate the diurnal variations of the temperature, water vapor density and relative humidity of the humid air, and to predict the hourly condensation flux besides the temperatures of the water, cover and trough, and the hourly evaporation flux. The validity of the proposed model was verified using the field experimental results carried out in Fukui, Japan and Muscat, Oman in 2008. The diurnal variations of the calculated temperatures and water vapor densities had a good agreement with the observed ones. Furthermore, the proposed model can predict the daily and hourly production flux precisely. (author)
Modeling of Heat Transfer in Geothermal Heat Exchangers
Cui, P.; Man, Y.; Fang, Z.
2006-01-01T23:59:59.000Z
Ground-coupled heat pump (GCHP) systems have been gaining increasing popularity for space conditioning in residential and commercial buildings. The geothermal heat exchanger (GHE) is devised for extraction or injection of thermal energy from...
Heat Transfer Modeling and Use of Distributed Temperature Measurements to Predict Rate
Hashmi, Gibran Mushtaq
2014-07-08T23:59:59.000Z
Heat transfer modeling is important in many fields of engineering. In petroleum engineering, heat transfer modeling has many applications. One such application that this study focused on is flow rate estimation. In this work, two different models...
Heat transfer modeling of dry spent nuclear fuel storage facilities
Lee, S.Y.
1999-07-01T23:59:59.000Z
The present work was undertaken to provide heat transfer model that accurately predicts the thermal performance of dry spent nuclear fuel storage facilities. One of the storage configurations being considered for DOE Aluminum-clad Spent Nuclear Fuel (Al-SNF), such as the Material and Testing Reactor (MTR) fuel, is in a dry storage facility. To support design studies of storage options a computational and experimental program has been conducted at the Savannah River Site (SRS). The main objective is to develop heat transfer models including natural convection effects internal to an interim dry storage canister and to geologic codisposal Waste Package (WP). Calculated temperatures will be used to demonstrate engineering viability of a dry storage option in enclosed interim storage and geologic repository WP and to assess the chemical and physical behaviors of the Al-SNF in the dry storage facilities. The current paper describes the modeling approaches and presents the computational results along with the experimental data.
Heat Transfer Modeling of Dry Spent Nuclear Fuel Storage Facilities
Lee, S.Y.
1999-01-13T23:59:59.000Z
The present work was undertaken to provide heat transfer model that accurately predicts the thermal performance of dry spent nuclear fuel storage facilities. One of the storage configurations being considered for DOE Aluminum-clad Spent Nuclear Fuel (Al-SNF), such as the Material and Testing Reactor (MTR) fuel, is in a dry storage facility. To support design studies of storage options a computational and experimental program has been conducted at the Savannah River Site (SRS). The main objective is to develop heat transfer models including natural convection effects internal to an interim dry storage canister and to geological codisposal Waste Package (WP). Calculated temperatures will be used to demonstrate engineering viability of a dry storage option in enclosed interim storage and geological repository WP and to assess the chemical and physical behaviors of the Al-SNF in the dry storage facilities. The current paper describes the modeling approaches and presents the computational results along with the experimental data.
Modeling of fuel-to-steel heat transfer in core disruptive accidents
Smith, Russell Charles
1980-01-01T23:59:59.000Z
A mathematical model for direct-contact boiling heat transfer between immiscible fluids was developed and tested experimentally. The model describes heat transfer from a hot fluid bath to an ensemble of droplets of a cooler ...
MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA "BUILDINGS" LIBRARY
describes the implementation of the room heat transfer model in the free open-source Modelica "Buildings
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
Chen, Du; Bogy, David B.
2010-01-01T23:59:59.000Z
Bogy, D.B. : A heat transfer model for thermal ?uctuation inA phenomenological heat transfer model for the molecular gasA generalized heat transfer model for thin ?lm bearings at
Coupled Reactor Kinetics and Heat Transfer Model for Heat Pipe Cooled Reactors
WRIGHT,STEVEN A.; HOUTS,MICHAEL
2000-11-22T23:59:59.000Z
Heat pipes are often proposed as cooling system components for small fission reactors. SAFE-300 and STAR-C are two reactor concepts that use heat pipes as an integral part of the cooling system. Heat pipes have been used in reactors to cool components within radiation tests (Deverall, 1973); however, no reactor has been built or tested that uses heat pipes solely as the primary cooling system. Heat pipe cooled reactors will likely require the development of a test reactor to determine the main differences in operational behavior from forced cooled reactors. The purpose of this paper is to describe the results of a systems code capable of modeling the coupling between the reactor kinetics and heat pipe controlled heat transport. Heat transport in heat pipe reactors is complex and highly system dependent. Nevertheless, in general terms it relies on heat flowing from the fuel pins through the heat pipe, to the heat exchanger, and then ultimately into the power conversion system and heat sink. A system model is described that is capable of modeling coupled reactor kinetics phenomena, heat transfer dynamics within the fuel pins, and the transient behavior of heat pipes (including the melting of the working fluid). The paper focuses primarily on the coupling effects caused by reactor feedback and compares the observations with forced cooled reactors. A number of reactor startup transients have been modeled, and issues such as power peaking, and power-to-flow mismatches, and loading transients were examined, including the possibility of heat flow from the heat exchanger back into the reactor. This system model is envisioned as a tool to be used for screening various heat pipe cooled reactor concepts, for designing and developing test facility requirements, for use in safety evaluations, and for developing test criteria for in-pile and out-of-pile test facilities.
A meshless method for modeling convective heat transfer
Carrington, David B [Los Alamos National Laboratory
2010-01-01T23:59:59.000Z
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.
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
RELAP5 MODEL OF THE DIVERTOR PRIMARY HEAT TRANSFER SYSTEM
Popov, Emilian L [ORNL; Yoder Jr, Graydon L [ORNL; Kim, Seokho H [ORNL
2010-08-01T23:59:59.000Z
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.
Fluid flow and heat transfer modeling for castings
Domanus, H.M.; Liu, Y.Y.; Sha, W.T.
1986-01-01T23:59:59.000Z
Casting is fundamental to manufacturing of many types of equipment and products. Although casting is a very old technology that has been in existence for hundreds of years, it remains a highly empirical technology, and production of new castings requires an expensive and time-consuming trial-and-error approach. In recent years, mathematical modeling of casting has received increasing attention; however, a majority of the modeling work has been in the area of heat transfer and solidification. Very little work has been done in modeling fluid flow of the liquid melt. This paper presents a model of fluid flow coupled with heat transfer of a liquid melt for casting processes. The model to be described in this paper is an extension of the COMMIX code and is capable of handling castings with any shape, size, and material. A feature of this model is the ability to track the liquid/gas interface and liquid/solid interface. The flow of liquid melt through the sprue and runners and into the mold cavity is calculated as well as three-dimensional temperature and velocity distributions of the liquid melt throughout the casting process. 14 refs., 13 figs.
TRANSIENT HEAT TRANSFER MODEL FOR SRS WASTE TANK OPERATIONS
Lee, S; Richard Dimenna, R
2007-03-27T23:59:59.000Z
A transient heat balance model was developed to assess the impact of a Submersible Mixer Pump (SMP) on waste temperature during the process of waste mixing and removal for the Type-I Savannah River Site (SRS) tanks. The model results will be mainly used to determine the SMP design impacts on the waste tank temperature during operations and to develop a specification for a new SMP design to replace existing long-shaft mixer pumps used during waste removal. The model will also be used to provide input to the operation planning. This planning will be used as input to pump run duration in order to maintain temperature requirements within the tank during SMP operation. The analysis model took a parametric approach. A series of the modeling analyses was performed to examine how submersible mixer pumps affect tank temperature during waste removal operation in the Type-I tank. The model domain included radioactive decay heat load, two SMP's, and one Submersible Transfer Pump (STP) as heat source terms. The present model was benchmarked against the test data obtained by the tank measurement to examine the quantitative thermal response of the tank and to establish the reference conditions of the operating variables under no SMP operation. The results showed that the model predictions agreed with the test data of the waste temperatures within about 10%. Transient modeling calculations for two potential scenarios of sludge mixing and removal operations have been made to estimate transient waste temperatures within a Type-I waste tank. When two 200-HP submersible mixers and 12 active cooling coils are continuously operated in 100-in tank level and 40 C initial temperature for 40 days since the initiation of mixing operation, waste temperature rises about 9 C in 48 hours at a maximum. Sensitivity studies for the key operating variables were performed. The sensitivity results showed that the chromate cooling coil system provided the primary cooling mechanism to remove process heat from the tank during operation.
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
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
AN EXPERIMENTAL INVESTIGATION OF THE HEAT TRANSFER FROM A BUOYANT GAS PLUME TO A
Winfree, Erik
Temperature E. Heat Transfer Model 1. Determining the Ceiling Heat Transfer 2. Ceiling Heat Transfer
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S modeling of the turbulent flow in a rotor-stator cavity subjected to a superimposed throughflow with heat the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial
Application Of A Spherical-Radial Heat Transfer Model To Calculate...
Spherical-Radial Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Jump to: navigation, search OpenEI Reference LibraryAdd to library...
A vectorized heat transfer model for solid reactor cores
Rider, W.J.; Cappiello, M.W.; Liles, D.R.
1990-01-01T23:59:59.000Z
The new generation of nuclear reactors includes designs that are significantly different from light water reactors. Among these new reactor designs is the Modular High-Temperature Gas-Cooled Reactor (MHTGR). In addition, nuclear thermal rockets share a number of similarities with terrestrial HTGRs and would be amenable to similar types of analyses. In these reactors, the heat transfer in the solid core mass is of primary interest in design and safety assessment. One significant safety feature of these reactors is the capability to withstand a loss of pressure and forced cooling in the primary system and still maintain peak fuel temperatures below the safe threshold for retaining the fission products. To accurately assess the performance of gas-cooled reactors during these types of transients, a Helium/Hydrogen Cooled Reactor Analysis (HERA) computer code has been developed. HERA has the ability to model arbitrary geometries in three dimensions, which allows the user to easily analyze reactor cores constructed of prismatic graphite elements. The code accounts for heat generation in the fuel, control rods and other structures; conduction and radiation across gaps; convection to the coolant; and a variety of boundary conditions. The numerical solution scheme has been optimized for vector computers, making long transient analyses economical. Time integration is either explicit or implicit, which allows the use of the model to accurately calculate both short- or long-term transients with an efficient use of computer time. Both the basic spatial and temporal integration schemes have been benchmarked against analytical solutions. Also, HERA has been used to analyze a depressurized loss of forced cooling transient in a HTGR with a very detailed three-dimensional input model. The results compare favorably with other means of analysis and provide further validation of the models and methods. 18 refs., 11 figs.
Forristall, R.
2003-10-01T23:59:59.000Z
This report describes the development, validation, and use of a heat transfer model implemented in Engineering Equation Solver. The model determines the performance of a parabolic trough solar collector's linear receiver, also called a heat collector element. All heat transfer and thermodynamic equations, optical properties, and parameters used in the model are discussed. The modeling assumptions and limitations are also discussed, along with recommendations for model improvement.
Development of a UF{sub 6} cylinder transient heat transfer/stress analysis model
Williams, W.R. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)
1991-12-31T23:59:59.000Z
A heat transfer/stress analysis model is being developed to simulate the heating to a point of rupture of a cylinder containing UF{sub 6} when it is exposed to a fire. The assumptions underlying the heat transfer portion of the model, which has been the focus of work to date, will be discussed. A key aspect of this model is a lumped parameter approach to modeling heat transfer. Preliminary results and future efforts to develop an integrated thermal/stress model will be outlined.
Paris-Sud XI, Université de
Ratkowsky "square root" model and a simplified two-parameter20 heat transfer model regarding an infinite
Paris-Sud XI, Université de
specially designed within the framework of this research. A computational heat transfer model is constructed. The developed mean model constitutes the basis of the computational stochastic heat transfer model that has been to the experimental ones. Keywords: computational heat transfer modeling, uncertainties, probabilistic modeling
FireStem2D A Two-Dimensional Heat Transfer Model for Simulating Tree Stem Injury in Fires
FireStem2D A Two-Dimensional Heat Transfer Model for Simulating Tree Stem Injury in Fires, et al. (2013) FireStem2D A Two-Dimensional Heat Transfer Model for Simulating Tree Stem Injury
Lenert, Andrej
2012-01-01T23:59:59.000Z
The choice of heat transfer fluids has significant effects on the performance, cost, and reliability of solar thermal systems. In this chapter, we evaluate existing heat transfer fluids such as oils and molten salts based ...
Intra-channel mass and heat-transfer modeling in diesel oxidation catalysts
Tennessee, University of
02FCC-140 Intra-channel mass and heat-transfer modeling in diesel oxidation catalysts Kalyana transfer in modeling the performance of diesel oxidation catalysts. Many modeling studies have assumed experimental measurements of CO and hydrocarbon oxidation in diesel exhaust re- veal that actual mass
Not Available
1980-03-07T23:59:59.000Z
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)
1982-01-01T23:59:59.000Z
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
New flow boiling heat transfer model for hydrocarbons evaporating inside horizontal tubes
Chen, G. F.; Gong, M. Q.; Wu, J. F.; Zou, X. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, 35, Beijing, 100190 (China); Wang, S. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, 35, Beijing, 100190 (China); University of Chinese Academy of Science, No. 19 YuQuan Road, Beijing, 100049 (China)
2014-01-29T23:59:59.000Z
Hydrocarbons have high thermodynamic performances, belong to the group of natural refrigerants, and they are the main components in mixture Joule-Thomson low temperature refrigerators (MJTR). New evaluations of nucleate boiling contribution and nucleate boiling suppression factor in flow boiling heat transfer have been proposed for hydrocarbons. A forced convection heat transfer enhancement factor correlation incorporating liquid velocity has also been proposed. In addition, the comparisons of the new model and other classic models were made to evaluate its accuracy in heat transfer prediction.
Numerical and analytical modeling of heat transfer between fluid and fractured rocks
Li, Wei, S.M. Massachusetts Institute of Technology
2014-01-01T23:59:59.000Z
Modeling of heat transfer between fluid and fractured rocks is of particular importance for energy extraction analysis in EGS, and therefore represents a critical component of EGS design and performance evaluation. In ...
Tabares Velasco, P. C.
2011-04-01T23:59:59.000Z
This presentation discusses estimating heat and mass transfer processes in green roof systems: current modeling capabilities and limitations. Green roofs are 'specialized roofing systems that support vegetation growth on rooftops.'
Analysis of heat transfer in unlooped and looped pulsating
Zhang, Yuwen
, Tubing Abstract An advanced heat transfer model for both unlooped and looped Pulsating Heat Pipes (PHPs
Temperature profile and heat transfer model for a chemical wastewater treatment plant
Brown, E.V. (CH2M HILL, Atlanta, GA (United States)); Enzminger, J.D. (CH2M HILL, Parsippany, NJ (United States))
1991-08-01T23:59:59.000Z
This paper presents a heat transfer model for equalization, activated sludge, and trickling filter unit processes than can be used to assess the effect of operating temperature on unit process selection, materials of construction selection, and heat retention and cooling requirements. In developing this model, the individual variables that affect the operating temperature of biological systems were first identified. Mathematical relationships were then developed to describe system behavior, based on conservation laws and rate equations. The heat transfer models were then used to developed a temperature profile of the two alternative WWTP configurations.
Li, Zhiyong; Chen, Chao; Luo, Hailiang; Zhang, Ye; Xue, Yaning [College of Architecture and Civil Engineering, Beijing University of Technology, Beijing (China)
2010-08-15T23:59:59.000Z
The aim of this paper is to establish the heat transfer model of all-glass vacuum tube collector used in forced-circulation solar water heating system. In this model, the simplified heat transfer of collector is composed of the natural convection in single glass tube and forced flow in manifold header. Thus the heat balance equation of water in single tube and the heat balance equation of water in manifold header have been established. The flow equation is also built by analyzing the friction and buoyancy in tube. Through solved these equations the relationship between the collector average temperature, the outlet temperature and natural convection flow rate have been obtained. From this relationship and energy balance equation of collector, the collector outlet temperature can be calculated. The validated experiments of this model were carried out in winter of Beijing. (author)
Models for Metal Hydride Particle Shape, Packing, and Heat Transfer
Kyle C. Smith; Timothy S. Fisher
2012-05-04T23:59:59.000Z
A multiphysics modeling approach for heat conduction in metal hydride powders is presented, including particle shape distribution, size distribution, granular packing structure, and effective thermal conductivity. A statistical geometric model is presented that replicates features of particle size and shape distributions observed experimentally that result from cyclic hydride decreptitation. The quasi-static dense packing of a sample set of these particles is simulated via energy-based structural optimization methods. These particles jam (i.e., solidify) at a density (solid volume fraction) of 0.665+/-0.015 - higher than prior experimental estimates. Effective thermal conductivity of the jammed system is simulated and found to follow the behavior predicted by granular effective medium theory. Finally, a theory is presented that links the properties of bi-porous cohesive powders to the present systems based on recent experimental observations of jammed packings of fine powder. This theory produces quantitative experimental agreement with metal hydride powders of various compositions.
Nawaz, Waqas
2014-04-25T23:59:59.000Z
on the role of evaporation and convection phenomena on the cryogenic pool temperature and its vaporization rate. Various models describing heat transfer by evaporation were compared. The models differ from each other in terms of mass transfer coefficient...
A convective-radiative heat transfer model for gas core reactors
Chen, G.; Anghaie, S. [Univ. of Florida, Gainesville, FL (United States)
1995-12-31T23:59:59.000Z
A convective-radiative heat transfer model is developed and used to predict the temperature distribution in gaseous fuel nuclear reactor cores. The axisymmetric, thin layer Navier-Stokes equations with diffusive radiation source term are the basis for this modeling approach. An algebraic turbulence model is used to calculate the eddy viscosity. The Rosseland diffusion approximation is used to model the radiative heat transfer. A hybrid implicit-explicit numerical scheme with Gauss-Seidel iterative process and a highly stretched grid system near wall is employed to solve the governing equations. Several cases with different internal heat generation rates are modeled and analyzed. Results of the temperature distribution, wall heat flux and the associated Nusselt number are presented. The influence of the internal heat generation rate and the wall temperature on the radiative and convective wall heat fluxes are discussed. At gas and wall temperatures close to 3,500 K and 1,600 K, respectively, the radiative and convective heat transfer rates have similar values.
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.
2010-07-01T23:59:59.000Z
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.
Effective-medium model of wire metamaterials in the problems of radiative heat transfer
Mirmoosa, M. S., E-mail: mohammad.mirmoosa@aalto.fi; Nefedov, I. S., E-mail: igor.nefedov@aalto.fi; Simovski, C. R., E-mail: konstantin.simovski@aalto.fi [Department of Radio Science and Engineering, School of Electrical Engineering, Aalto University, P. O. Box 13000, 00076 Aalto (Finland); Rüting, F., E-mail: felix.ruting@uam.es [Departamento de Física Teorica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autonoma de Madrid, E-28049 (Spain)
2014-06-21T23:59:59.000Z
In the present work, we check the applicability of the effective medium model (EMM) to the problems of radiative heat transfer (RHT) through so-called wire metamaterials (WMMs)—composites comprising parallel arrays of metal nanowires. It is explained why this problem is so important for the development of prospective thermophotovoltaic (TPV) systems. Previous studies of the applicability of EMM for WMMs were targeted by the imaging applications of WMMs. The analogous study referring to the transfer of radiative heat is a separate problem that deserves extended investigations. We show that WMMs with practically realizable design parameters transmit the radiative heat as effectively homogeneous media. Existing EMM is an adequate tool for qualitative prediction of the magnitude of transferred radiative heat and of its effective frequency band.
Ganapathy, V.
1982-01-01T23:59:59.000Z
Heat transfer principles are discussed with emphasis on the practical aspects of the problems. Correlations for heat transfer and pressure drop from several worldwide sources for flow inside and outside of tubes, including finned tubes are presented, along with design and performance calculations of heat exchangers economizers, air heaters, condensers, waste-heat boilers, fired heaters, superheaters, and boiler furnaces. Vibration analysis for tube bundles and heat exchangers are also discussed, as are estimating gas-mixture properties at atmospheric and elevated pressures and life-cycle costing techniques. (JMT)
Jia, S.; Chung, B.T.F. [Univ. of Akron, OH (United States). Dept. of Mechanical Engineering
1996-12-31T23:59:59.000Z
Based on a previously proposed non-linear turbulence model, a turbulent heat transfer model is formulated in the present study using the concept of Generalized Gradient Diffusion (GGD) hypothesis. Under this hypothesis, an anisotropic thermal diffusivity can be obtained through the proposed non-linear turbulent model which is applied to the turbulent flow and heat transfer in a sudden expansion pipe with a constant heat flux through the pipe wall. The numerical results are compared with the available experimental data for both turbulent and thermal quantities, with an emphasis on the non-linear heat transfer predictions. The improved results are obtained for the bulk temperature distribution showing that the present non-linear heat transfer model is capable of predicting the anisotropic turbulent heat transfer for the pipe expansion flow. Some limits of the proposed model are also identified and discussed.
On exact and perturbation solutions to nonlinear equations for heat transfer models
Francisco M. Fernández
2009-11-03T23:59:59.000Z
We analyze some exact and approximate solutions to nonlinear equations for heat transfer models. We prove that recent results derived from a method based on Lie algebras are either trivial or wrong. We test a simple analytical expression based on the hypervirial theorem and also discuss earlier perturbation results.
Heat and Mass Transfer Modeling of Dry Gases in the Cathode of PEM Fuel Cells
Stockie, John
Heat and Mass Transfer Modeling of Dry Gases in the Cathode of PEM Fuel Cells M.J. Kermani1 J and N2, through the cathode of a proton exchange membrane (PEM) fuel cell is studied numerically) an energy equation, written in a form that has enthalpy as the dependent variable. Keywords: PEM fuel cells
Application of a transient heat transfer model for bundled, multiphase pipelines
Brown, T.S.; Clapham, J.; Danielson, T.J.; Harris, R.G.; Erickson, D.D.
1996-12-31T23:59:59.000Z
A computer model has been developed which accurately describes transient heat transfer in pipeline bundles. An arbitrary number of internal pipelines containing different fluids, flowing in either direction along with the input of heat to one or more of the fluids can be accommodated. The model is coupled to the transient, multiphase flow simulator OLGA. The lines containing the multiphase production fluids are modeled by OLGA, and the heat transfer between the internal lines, carrier pipe, and surroundings is handled by the bundle model. The model has been applied extensively to the design of a subsea, heated bundle system for the Britannia gas condensate field in the North Sea. The 15-km bundle system contains a 14{double_prime} production line, an 8{double_prime} test line, a 3{double_prime} methanol line, and a 12{double_prime} internal heating medium line within a 37.25{double_prime} carrier. The heating medium (water) flows in the internal heating medium line and in the annulus at 82,500 BPD. The primary purpose of the bundle system is to avoid the formation of hydrates. A secondary purpose is to avoid the deposition of paraffin. The bundle model was used to (1) compare the merits of two coaxial lines vs. a single bundle; (2) optimize the insulation levels on the carrier and internal lines; (3) determine the minimum time required to heat up the bundle; (4) determine heat input requirements to avoid hydrates throughout the field life, (5) determine temperature profiles along the lines for a range of production rates; (6) study ruptures of the production line into the bundle annulus; (7) determine minimum temperatures during depressurization; and (8) determine cool-down times. The results of these studies were used to size lines, select insulation levels, assess erosion potential, design for thermal expansion-induced stresses, and to select materials of construction.
Greendyke, Robert Brian
1988-01-01T23:59:59.000Z
will examine the radiance model and various step models in order to determine their appropriateness to the flight regime of the AOTV. The final area to be investigated will be the effect of nonequilibrium corrections on the radiative heat transfer models... of T and e T will be valid as long as there is a reasonable amount vNs of nitrogen molecules in the flow. Radiative Heat Transfer Models For this study, four radiative heat transfer models were examined. One of these models is an optically thin radiance...
Deru, M.; Judkoff, R.; Neymark, J.
2002-08-01T23:59:59.000Z
A three-dimensional, finite-element, heat-transfer computer program was developed to study ground-coupled heat transfer from buildings. It was used in conjunction with the SUNREL whole-building energy simulation program to analyze ground-coupled heat transfer from buildings, and the results were compared with the simple ground-coupled heat transfer models used in whole-building energy simulation programs. The detailed model provides another method of testing and refining the simple models and analyzing complex problems. This work is part of an effort to improve the analysis of the ground-coupled heat transfer in building energy simulation programs. The output from this detailed model and several others will form a set of reference results for use with the BESTEST diagnostic procedure. We anticipate that the results from the work will be incorporated into ANSI/ASHRAE 140-2001, Standard Method of Test for the Evaluation of Building Energy Analysis Computer Programs.
HEAT AND MOISTURE TRANSFER THROUGH CLOTHING
Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie
2009-01-01T23:59:59.000Z
R. C. Eberhart (ed), Heat transfer in medicine and biology.between convective heat transfer and mass transferConvective and radiative heat transfer coefficients for
Heat and moisture transfer through clothing
Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie
2009-01-01T23:59:59.000Z
R. C. Eberhart (ed), Heat transfer in medicine and biology.Convective and radiative heat transfer coefficients forbetween convective heat transfer and mass transfer
A Heat Transfer Model for a Stratified Corium-Metal Pool in the Lower Plenum of a Nuclear Reactor
M. S. Sohal; L. J. Siefken
1999-08-01T23:59:59.000Z
This preliminary design report describes a model for heat transfer in a corium-metal stratified pool. It was decided to make use of the existing COUPLE model. Currently available correlations for natural convection heat transfer in a pool with and without internal heat generation were obtained. The appropriate correlations will be incorporated in the existing COUPLE model. Heat conduction and solidification modeling will be done with existing algorithms in the COUPLE. Assessment of the new model will be done by simple energy conservation problems.
A Heat Transfer Model for a Stratified Corium-metal Pool in the Lower Plenum of a Nuclear Reactor
Sohal, Manohar Singh; Siefken, Larry James
1999-08-01T23:59:59.000Z
This preliminary design report describes a model for heat transfer in a corium-metal stratified pool. It was decided to make use of the existing COUPLE model. Currently available correlations for natural convection heat transfer in a pool with and without internal heat generation were obtained. The appropriate correlations will be incorporated in the existing COUPLE model. Heat conduction and solidification modeling will be done with existing algorithms in the COUPLE. Assessment of the new model will be done by simple energy conservation problems.
Analysis of Heat Transfer in Metal Hydride Based Hydrogen Separation
Fleming, W.H. Jr.
1999-10-20T23:59:59.000Z
This thesis presents a transient heat transfer analysis to model the heat transfer in the Pd/k packed column, and the impact of adding metallic foam.
Minnesota, University of
Design and Testing of a Heat Transfer Model of a Raccon (Procyon Lotor) in a Closed Tree Den Author. http://www.jstor.org #12;Ecology (1974) 55: pp. 29-39 DESIGN AND TESTING OF A HEAT TRANSFER MODEL
Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference
Guo, Zhixiong "James"
-dependent radiation and conduction bio-heat transfer model. Ultrashort pulsed radiation transport in the cylindrical a combined transient heat transfer and Pennes bio-heat transfer model is developed to simulate the heat transfer models; and concluded that the Pennes model is still the most practical for fast prediction
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
Greendyke, Robert Brian
1988-01-01T23:59:59.000Z
A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN GREENDYKE Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1988 Major Subject: Aerospace Engineering A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN...
ON THE ROLE OF THERMOELECTRIC HEAT TRANSFER IN THE DESIGN OF SMA ACTUATORS: THEORETICAL MODELING theoretical/experimentalstudy of the heat transferin thermoelectricShape Memory Alloy (SMA) actuators is undertaken in this paper. A one-dimensional model of a thermoelectric unit cell with a SMA junction
Application of an EASM model for turbulent convective heat transfer in ribbed duct
Saidi, A.; Sunden, B.
1999-07-01T23:59:59.000Z
A numerical investigation is performed to predict local and mean thermal-hydraulic characteristics in rib-roughened ducts. The Navier-Stokes and energy equations, and a low-Re number {kappa}-{epsilon} turbulence model are solved with two methods for determination of the Reynolds stresses, eddy viscosity model (EVM) and explicit algebraic stress model (EASM). The numerical solution procedure uses a collocated grid, and the pressure-velocity coupling is handled by the SIMPLEC algorithm. The assumption of fully developed periodic conditions is applied. The calculated mean and local heat transfer enhancement values are compared with experimental data and fairly good agreement on mean Nu numbers is achieved. The prediction capabilities of the two turbulence models (EVM and EASM) are discussed. Both models have similar ability to predict the mean Nusselt numbers but the EASM model is superior in description of the flow field structure.
Nottrott, A.; Onomura, S.; Inagaki, A.; Kanda, M.; Kleissl, J.
2011-01-01T23:59:59.000Z
Vortex structure and heat transfer in turbulent flow over asurface, Proc. 5 th Int. Heat Transfer Conf. 3 (1974) 129-a vertical plate, J. Heat Transfer 109(1) [13] K. Patel,
Modeling the heat transfer in geometrically complex media with a volume source
Gurevich, M. I., E-mail: gur.m@mail.ru; Tel’kovskaya, O. V.; Chukbar, B. K.; Shkarovskiy, D. A. [National Research Center Kurchatov Institute (Russian Federation)
2014-12-15T23:59:59.000Z
Fuel elements produced from spent fuel are porous media with spatially varying characteristics. A hierarchical discrete structure for the numerical modeling of heat-transfer processes in media with an anisotropic geometry that is characterized by both the microscopic voids and macroscopic changes in the parameters is proposed. The basic unit of the structure at its lower level is a cell that represents the local properties of the medium. The cells have a standard interface that allows one to form three-dimensional networks of such cells. Different types of cells in the network represent macroscopic changes. The potential for parallel processing is analyzed.
July 2008 Mold heat transfer in continuous casting
Thomas, Brian G.
with the 1-D heat transfer model, CON1D. To account for the multi- dimensional thermal behavior around speeds and new mold designs. COND Model Description The heat transfer model CON1D1 models sev- eral
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhang, Le; Luo, Feng; Xu, Ruina; Jiang, Peixue; Liu, Huihai
2014-12-31T23:59:59.000Z
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
Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff
2006-10-10T23:59:59.000Z
Apparatuses, systems, methods, and computer code for, among other things, monitoring the health of samples such as the brain while providing local cooling or heating. A representative device is a heat transfer probe, which includes an inner channel, a tip, a concentric outer channel, a first temperature sensor, and a second temperature sensor. The inner channel is configured to transport working fluid from an inner inlet to an inner outlet. The tip is configured to receive at least a portion of the working fluid from the inner outlet. The concentric outer channel is configured to transport the working fluid from the inner outlet to an outer outlet. The first temperature sensor is coupled to the tip, and the second temperature sensor spaced apart from the first temperature sensor.
A modified lattice Bhatnagar-Gross-Krook model for convection heat transfer in porous media
Wang, Liang; Guo, Zhaoli
2015-01-01T23:59:59.000Z
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...
Grant L. Hawkes; James E. O'Brien; Greg Tao
2011-11-01T23:59:59.000Z
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.
About convective heat transfer in geothermal systems
Pashkevich, R.I. [Kamchatsky Complex Department of NIPIgeotherm Institute, Petropavlovsk-Kamchatsky (Russian Federation)
1996-12-31T23:59:59.000Z
The interphase fluid-rock heat exchange in convective beat transfer in geothermal systems is investigated Nonlinear model of interphase heat exchange is suggested. Calculation for one dimension case and comparison with known Anzelius-Schumann solution is presented Generalized type block heat transfer model is formulated. The model is adequate for case of geothermal systems and reservoir when a rock block size is comparable with filtration path length. Criterion equations for nonstationary coefficients of interphase heat exchange we presented these equations were obtained in laboratory experiments with diorites.
Investigating Mould Heat Transfer in Thin Slab Casting with CON1D Begoa Santillana
Thomas, Brian G.
. Heat transfer in the thin slab casting mould is being investigated with the 1-D heat transfer model MODEL DESCRIPTION The heat transfer model, CON1D1 , models several aspects of the continuous casting
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
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
Urban Sewage Delivery Heat Transfer System (2): Heat Transfer
Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.
2006-01-01T23:59:59.000Z
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...
"Nanotechnology Enabled Advanced Industrial Heat Transfer Fluids"
Dr. Ganesh Skandan; Dr. Amit Singhal; Mr. Kenneth Eberts; Mr. Damian Sobrevilla; Prof. Jerry Shan; Stephen Tse; Toby Rossmann
2008-06-12T23:59:59.000Z
ABSTRACT Nanotechnology Enabled Advanced industrial Heat Transfer Fluids” Improving the efficiency of Industrial Heat Exchangers offers a great opportunity to improve overall process efficiencies in diverse industries such as pharmaceutical, materials manufacturing and food processing. The higher efficiencies can come in part from improved heat transfer during both cooling and heating of the material being processed. Additionally, there is great interest in enhancing the performance and reducing the weight of heat exchangers used in automotives in order to increase fuel efficiency. The goal of the Phase I program was to develop nanoparticle containing heat transfer fluids (e.g., antifreeze, water, silicone and hydrocarbon-based oils) that are used in transportation and in the chemical industry for heating, cooling and recovering waste heat. Much work has been done to date at investigating the potential use of nanoparticle-enhanced thermal fluids to improve heat transfer in heat exchangers. In most cases the effect in a commercial heat transfer fluid has been marginal at best. In the Phase I work, we demonstrated that the thermal conductivity, and hence heat transfer, of a fluid containing nanoparticles can be dramatically increased when subjected to an external influence. The increase in thermal conductivity was significantly larger than what is predicted by commonly used thermal models for two-phase materials. Additionally, the surface of the nanoparticles was engineered so as to have a minimal influence on the viscosity of the fluid. As a result, a nanoparticle-laden fluid was successfully developed that can lead to enhanced heat transfer in both industrial and automotive heat exchangers
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
Vasilyev, Oleg V.
HTDVol.335, Proceedings of hte ASME Heat Transfer Division Volume 4 ASME 1996 THERMOACOUSTIC WAVE ABSTRACT Thermoacoustic wave propagation in a twodimensional rectan gular cavity is studied numerically. The thermoacoustic waves are generated by raising the temperature locally at the walls. The waves, which decay
Dynamics of heat transfer between nano systems
Svend-Age Biehs; Girish S. Agarwal
2012-10-18T23:59:59.000Z
We develop a dynamical theory of heat transfer between two nano systems. In particular, we consider the resonant heat transfer between two nanoparticles due to the coupling of localized surface modes having a finite spectral width. We model the coupled nanosystem by two coupled quantum mechanical oscillators, each interacting with its own heat bath, and obtain a master equation for the dynamics of heat transfer. The damping rates in the master equation are related to the lifetimes of localized plasmons in the nanoparticles. We study the dynamics towards the steady state and establish connection with the standard theory of heat transfer in steady state. For strongly coupled nano particles we predict Rabi oscillations in the mean occupation number of surface plasmons in each nano particle.
Analytical modeling for the heat transfer in sheared flows of nanofluids
Ferrari, Claudio; L'vov, Victor S; Procaccia, Itamar; Rudenko, Oleksii; Boonkkamp, J H M ten Thije; Toschi, Federico
2012-01-01T23:59:59.000Z
We developed a model for the enhancement of the heat flux by spherical and elongated nano- particles in sheared laminar flows of nano-fluids. Besides the heat flux carried by the nanoparticles the model accounts for the contribution of their rotation to the heat flux inside and outside the particles. The rotation of the nanoparticles has a twofold effect, it induces a fluid advection around the particle and it strongly influences the statistical distribution of particle orientations. These dynamical effects, which were not included in existing thermal models, are responsible for changing the thermal properties of flowing fluids as compared to quiescent fluids. The proposed model is strongly supported by extensive numerical simulations, demonstrating a potential increase of the heat flux far beyond the Maxwell-Garnet limit for the spherical nanoparticles. The road ahead which should lead towards robust predictive models of heat flux enhancement is discussed.
Analytical modeling for the heat transfer in sheared flows of nanofluids
Claudio Ferrari; Badr Kaoui; Victor S. L'vov; Itamar Procaccia; Oleksii Rudenko; J. H. M. ten Thije Boonkkamp; Federico Toschi
2012-04-12T23:59:59.000Z
We developed a model for the enhancement of the heat flux by spherical and elongated nano- particles in sheared laminar flows of nano-fluids. Besides the heat flux carried by the nanoparticles the model accounts for the contribution of their rotation to the heat flux inside and outside the particles. The rotation of the nanoparticles has a twofold effect, it induces a fluid advection around the particle and it strongly influences the statistical distribution of particle orientations. These dynamical effects, which were not included in existing thermal models, are responsible for changing the thermal properties of flowing fluids as compared to quiescent fluids. The proposed model is strongly supported by extensive numerical simulations, demonstrating a potential increase of the heat flux far beyond the Maxwell-Garnet limit for the spherical nanoparticles. The road ahead which should lead towards robust predictive models of heat flux enhancement is discussed.
Electrohydrodynamically enhanced condensation heat transfer
Wawzyniak, Markus
1993-01-01T23:59:59.000Z
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...
Demazière, Christophe
transport) and a heat transfer model (describing heat transfer between the fuel and the coolant). All
Winters, W.S.
1984-01-01T23:59:59.000Z
An overview of the computer code TOPAZ (Transient-One-Dimensional Pipe Flow Analyzer) is presented. TOPAZ models the flow of compressible and incompressible fluids through complex and arbitrary arrangements of pipes, valves, flow branches and vessels. Heat transfer to and from the fluid containment structures (i.e. vessel and pipe walls) can also be modeled. This document includes discussions of the fluid flow equations and containment heat conduction equations. The modeling philosophy, numerical integration technique, code architecture, and methods for generating the computational mesh are also discussed.
Kiryukhin, A.V.; Sugrobov, V.M.
1986-01-21T23:59:59.000Z
The application of the two-dimensional numerical heat-transfer model to the Pauzhetka hydrothermal system allowed us to establish that: (1) a shallow magma body with the anomalous temperature of 700-1000 C and with a volume of 20-30 km{sup 3} may be a heat source for the formation of the Pauzhetka hydrothermal system. (2) The water feeding source of the Pauzhetka hydrothermal system may be meteoric waters which are infiltrated at an average rate of 5-10 kg/s {center_dot} km{sup 2}. The coupling of the numerical heat-transfer model with hydroisotopic data (D,T,{sup 18}O) obtained from the results of testing of exploitation wells, rivers and springs is the basis to understand more clearly the position of recharge areas and the structure of water flows in the hydrothermal system.
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 heat transfer using nanofluids
Choi, Stephen U. S. (Lisle, IL); Eastman, Jeffrey A. (Naperville, IL)
2001-01-01T23:59:59.000Z
This invention is directed to a method of and apparatus for enhancing heat transfer in fluids such as deionized water. ethylene glycol, or oil by dispersing nanocrystalline particles of substances such as copper, copper oxide, aluminum oxide, or the like in the fluids. Nanocrystalline particles are produced and dispersed in the fluid by heating the substance to be dispersed in a vacuum while passing a thin film of the fluid near the heated substance. The fluid is cooled to control its vapor pressure.
Medina, M. A.
A transient heat and mass transfer model was developed to predict ceiling heat gain/loss through the attic space in residences and to accurately estimate savings in cooling and heating loads produced by the use of radiant barriers. The model...
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
Heat Transfer Fluids for Solar Water Heating Systems | Department...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
heater. Illustration of a solar water heater. Heat-transfer fluids carry heat through solar collectors and a heat exchanger to the heat storage tanks in solar water heating...
Nanoscale heat transfer - from computation to experiment
Luo, Tengfei
2013-04-09T23:59:59.000Z
Heat transfer can differ distinctly at the nanoscale from that at the macroscale. Recent advancement in
HEAT TRANSFER IN UNDERGROUND HEATING EXPERIMENTS IN GRANITE, STRIPA, SWEDEN
Chan, T.
2010-01-01T23:59:59.000Z
Session on Heat Transfer in Nuclear Waste Disposal, C'.heat transfer processes associated with underground nuclear wasteheat transfer and related processes in an un derground environment similar to that expected in a mined nuclear waste
Zhao, Tianshou
Simplified model and lattice Boltzmann algorithm for microscale electro-osmotic flows and heat The extremely small length scale of the electric double layer (EDL) of electro-osmotic flows (EOF and temperature as the velocity-slip and temperature-jump boundary conditions, form a simple model for the electro-osmotic
De Castro, Carlos Armando
2011-01-01T23:59:59.000Z
In this paper is developed a simple mathematical model of transient heat transfer under soil with plastic mulch in order to determine with numerical studies the influence of different plastic mulches on the soil temperature and the evolutions of temperatures at different depths with time. The governing differential equations are solved by a Galerkin Finite Element Model, taking into account the nonlinearities due to radiative heat exchange between the soil surface, the plastic mulch and the atmosphere. The model was validated experimentally giving good approximation of the model to the measured data. Simulations were run with the validated model in order to determine the optimal combination of mulch optical properties to maximize the soil temperature with a Taguchi's analysis, proving that the material most used nowadays in Colombia is not the optimal and giving quantitative results of the properties the optimal mulch must possess.
Virginia Tech
Spring 2014 1 Heat Transfer - 1 Consider a cylindrical nuclear fuel rod of length L and diameter df the fuel rod, and the volumetric generation rate is known to vary sinusoidally with distance along the rod to exist between the surface of the rod and the water. Axial conduction can be neglected in rod and fluid
Modeling of Heat Transfer in Rooms in the Modelica Buildings Library
Wetter, Michael
2013-01-01T23:59:59.000Z
for building heating, ventilation and air-conditioningfor Building Heating, Ventilation and Air- Conditioning
Analysis of radial fin assembly heat transfer with dehumidification
Rosario, L.; Rahman, M.M. [Univ. of South Florida, Tampa, FL (United States). Dept. of Mechanical Engineering
1996-12-31T23:59:59.000Z
The aim of this paper is the analysis of heat transfer in a radial fin assembly during the process of dehumidification. An individual finned tube geometry is a reasonable representation of heat exchangers used in air conditioning. The condensation process involves both heat and mass transfer and the cooling takes place by the removal of sensible as well as latent heat. The ratio of sensible to total heat is an important quantity that defines the heat transfer process during a dehumidifier operation. A one-dimensional model for heat transfer in the fin and the heat exchanger block is developed to study the effects of condensation on the fin surface. The combined heat and mass transfer process is modeled by incorporating the ratio of sensible to total heat in the formulation. The augmentation of heat transfer due to fin was established by comparing heat transfer rate with and without fins under the same operating conditions. Numerical calculations were carried out to study the effects of relative humidity and dry bulb temperature of the incoming air, and cold fluid temperature inside the coil on the performance of the heat exchanger. Results were compared to those published for rectangular fin under humid condition showed excellent agreement when the present model was used to compute that limiting condition. It was found that the heat transfer rate increased with increment in both dry bulb temperature and relative humidity of the air. The augmentation factor, however, decreased with increment in relative humidity and the dry bulb temperature.
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
Effects of solar photovoltaic panels on roof heat transfer
Dominguez, Anthony; Kleissl, Jan; Luvall, Jeffrey C
2011-01-01T23:59:59.000Z
the energy performance of photovoltaic roofs, ASHRAE Trans A thermal model for photovoltaic systems, Solar Energy, Effects of Solar Photovoltaic Panels on Roof Heat Transfer
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
Convective heat transfer in rotating, circular channels
Hogan, Brenna Elizabeth
2012-01-01T23:59:59.000Z
Nusselt number values for flow in a rotating reference frame are obtained through computational fluid dynamic (CFD) analysis for Rossby numbers Ro ~1-4 and Reynolds numbers Re ~1,000-2,000. The heat-transfer model is first ...
Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger
Singh, K. P.
1979-01-01T23:59:59.000Z
in such an exchanger are derived and solved leading to an optimization problem. In this problem, the optimal subdivision of heat transfer surface to minimize required overall heat transfer surface, under certain restricted conditions, is sought. It is shown...
MODELING COUPLED PROCESSES OF MULTIPHASE FLOW AND HEAT TRANSFER IN UNSATURATED FRACTURED ROCK
Y. Wu; S. Mukhopadhyay; K. Zhang; G.S. Bodvarsson
2006-02-28T23:59:59.000Z
A mountain-scale, thermal-hydrologic (TH) numerical model is developed for investigating unsaturated flow behavior in response to decay heat from the radioactive waste repository at Yucca Mountain, Nevada, USA. The TH model, consisting of three-dimensional (3-D) representations of the unsaturated zone, is based on the current repository design, drift layout, and thermal loading scenario under estimated current and future climate conditions. More specifically, the TH model implements the current geological framework and hydrogeological conceptual models, and incorporates the most updated, best-estimated input parameters. This mountain-scale TH model simulates the coupled TH processes related to mountain-scale multiphase fluid flow, and evaluates the impact of radioactive waste heat on the hydrogeological system, including thermally perturbed liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature elevations, as well as the changes in water flux driven by evaporation/condensation processes and drainage between drifts. For a better description of the ambient geothermal condition of the unsaturated zone system, the TH model is first calibrated against measured borehole temperature data. The ambient temperature calibration provides the necessary surface and water table boundary as well as initial conditions. Then, the TH model is used to obtain scientific understanding of TH processes in the Yucca Mountain unsaturated zone under the designed schedule of repository thermal load.
Heat Transfer Enhancement: Second Generation Technology
Bergles, A. E.; Webb, R. L.
1984-01-01T23:59:59.000Z
feature of national and interna tional conferences on heat transfer. This paper reviews current activity in the field of enhanced heat transfer, with the aim of illustrating the technology and typical applications. 300...
Heat Transfer in Complex Fluids
Mehrdad Massoudi
2012-01-01T23:59:59.000Z
Amongst the most important constitutive relations in Mechanics, when characterizing the behavior of complex materials, one can identify the stress tensor T, the heat flux vector q (related to heat conduction) and the radiant heating (related to the radiation term in the energy equation). Of course, the expression 'complex materials' is not new. In fact, at least since the publication of the paper by Rivlin & Ericksen (1955), who discussed fluids of complexity (Truesdell & Noll, 1992), to the recently published books (Deshpande et al., 2010), the term complex fluids refers in general to fluid-like materials whose response, namely the stress tensor, is 'non-linear' in some fashion. This non-linearity can manifest itself in variety of forms such as memory effects, yield stress, creep or relaxation, normal-stress differences, etc. The emphasis in this chapter, while focusing on the constitutive modeling of complex fluids, is on granular materials (such as coal) and non-linear fluids (such as coal-slurries). One of the main areas of interest in energy related processes, such as power plants, atomization, alternative fuels, etc., is the use of slurries, specifically coal-water or coal-oil slurries, as the primary fuel. Some studies indicate that the viscosity of coal-water mixtures depends not only on the volume fraction of solids, and the mean size and the size distribution of the coal, but also on the shear rate, since the slurry behaves as shear-rate dependent fluid. There are also studies which indicate that preheating the fuel results in better performance, and as a result of such heating, the viscosity changes. Constitutive modeling of these non-linear fluids, commonly referred to as non-Newtonian fluids, has received much attention. Most of the naturally occurring and synthetic fluids are non-linear fluids, for example, polymer melts, suspensions, blood, coal-water slurries, drilling fluids, mud, etc. It should be noted that sometimes these fluids show Newtonian (linear) behavior for a given range of parameters or geometries; there are many empirical or semi-empirical constitutive equations suggested for these fluids. There have also been many non-linear constitutive relations which have been derived based on the techniques of continuum mechanics. The non-linearities oftentimes appear due to higher gradient terms or time derivatives. When thermal and or chemical effects are also important, the (coupled) momentum and energy equations can give rise to a variety of interesting problems, such as instability, for example the phenomenon of double-diffusive convection in a fluid layer. In Conclusion, we have studied the flow of a compressible (density gradient type) non-linear fluid down an inclined plane, subject to radiation boundary condition. The heat transfer is also considered where a source term, similar to the Arrhenius type reaction, is included. The non-dimensional forms of the equations are solved numerically and the competing effects of conduction, dissipation, heat generation and radiation are discussed. It is observed that the velocity increases rapidly in the region near the inclined surface and is slower in the region near the free surface. Since R{sub 7} is a measure of the heat generation due to chemical reaction, when the reaction is frozen (R{sub 7}=0.0) the temperature distributions would depend only on R{sub 1}, and R{sub 2}, representing the effects of the pressure force developed in the material due to the distribution, R{sub 3} and R{sub 4} viscous dissipation, R{sub 5} the normal stress coefficient, R{sub 6} the measure of the emissivity of the particles to the thermal conductivity, etc. When the flow is not frozen (RP{sub 7} > 0) the temperature inside the flow domain is much higher than those at the inclined and free surfaces. As a result, heat is transferred away from the flow toward both the inclined surface and the free surface with a rate that increases as R{sub 7} increases. For a given temperature, an increase in {zeta} implies that the activation energy is smaller and thus, the reaction ra
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 ...
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
Kaviany and B.P. Singh, “Radiative heat transfer in porousmedia”, Advances in Heat Transfer, vol. 23, no. 23, pp. 133–Thermal radiation heat transfer, Hemisphere Publishing Co. ,
Heat transfer via dropwise condensation on hydrophobic microstructured surfaces
Ruleman, Karlen E. (Karlen Elizabeth)
2009-01-01T23:59:59.000Z
Dropwise condensation has the potential to greatly increase heat transfer rates. Heat transfer coefficients by dropwise condensation and film condensation on microstructured silicon chips were compared. Heat transfer ...
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
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
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
On the design of heat-transfer probes
Brich, M.A.; Ganzha, V.L.; Saxena, S.C. [Univ. of Illinois, Chicago, IL (United States)] [Univ. of Illinois, Chicago, IL (United States)
1997-03-01T23:59:59.000Z
Saxena and coworkers have reported heat-transfer coefficient values for magnetofluidized beds using electrically heated heat-transfer probes. Here, a two-dimensional heat-transfer model is employed to investigate the influence of significant design features on measured parameters. Numerical calculations reveal that the thermal conductivity of the probe material has an insignificant contribution but the material of end caps and relative sizes and locations of the probe and heater appreciably influence the heat-transfer rates through end-conduction.
Modelling for post-dryout heat transfer and droplet sizes at low pressure and low flow conditions
Jeong, H.Y.; No, H.C. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Nuclear Engineering] [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Nuclear Engineering
1996-10-01T23:59:59.000Z
A correlation describing the initial droplet size just after the CHF position at low mass flux is suggested through regression analysis. The history-dependent post-dryout model of Varone and Rohsenow replaced by the Webb-Chen model for wall-vapor heat transfer is used as a reference model in the analysis. In the post-dryout region at low pressure and low flow, it is found that the suggested one-dimensional mechanistic model is valid only in the churn-turbulent flow regime (j*{sub g} = 0.5 {approximately} 4.5). It is also suggested that the droplet size generated from the churn-turbulent surface is dependent not only on the pressure but also on the vapor velocity. It turns out that the present model can predict the measured cladding and vapor temperatures within 20% and 15%, respectively.
Acoustically Enhanced Boiling Heat Transfer
Z. W. Douglas; M. K. Smith; A. Glezer
2008-01-07T23:59:59.000Z
An acoustic field is used to increase the critical heat flux (CHF) of a flat-boiling-heat-transfer surface. The increase is a result of the acoustic effects on the vapor bubbles. Experiments are performed to explore the effects of an acoustic field on vapor bubbles in the vicinity of a rigid-heated wall. Work includes the construction of a novel heater used to produce a single vapor bubble of a prescribed size and at a prescribed location on a flatboiling surface for better study of an individual vapor bubble's reaction to the acoustic field. Work also includes application of the results from the single-bubble heater to a calibrated-copper heater used for quantifying the improvements in CHF.
Heat exchanger device and method for heat removal or transfer
Koplow, Jeffrey P. (San Ramon, CA)
2012-07-24T23:59:59.000Z
Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.
Heat exchanger device and method for heat removal or transfer
Koplow, Jeffrey P
2013-12-10T23:59:59.000Z
Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.
Heat 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 The present paper deals with the experimental aero-heat transfer studies performed in rotating turbine research facilities. Turbine heat transfer research had significant progress in the last few decades. Since
Modeling multiphase heat and mass transfer in consolidated, fractured, porous media
Bixler, N.E.; Eaton, R.R.
1987-12-31T23:59:59.000Z
A number of potential transport mechanisms are considered in this paper: Darcy flow due to pressure and density gradients in the liquid and gas phases; Knudsen diffusion in the gas phase; binary diffusion in the gas phase; heat conduction; energy convection; and evaporation/condensation and its associated latent heat effects. Most of these mechanisms are highly nonlinear, especially Darcy flow, where relative permeabilities often vary by orders of magnitude depending on local saturation, and evaporation/condensation, which depends strongly on local temperature, gas pressure, and saturation. As a consequence of the nonlinearities, it is essential to employ numerical methods if realistic modeling is to be performed. Here, the numerical model is of the standard Galerkin/finite element variety, which is convenient for handling irregular domains and a wide variety of boundary conditions. This numerical model is used to examine the relative effectiveness of each of the transport mechanisms in several one-dimensional and simple two-dimensional multiphase flows in fractured and unfractured porous materials. The importance of fracture orientation is also studied. Predictions are compared with experimental measurements for imbibition and drying of fractured volcanic tuff.
Modeling of Heat and Mass Transfer in Fusion Welding (Book) | SciTech
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect Journal Article:UsingMeson to a J/PsiReactionConnect Book: Modeling of Heat and Mass
Heat transfer analysis capabilities of the scale computational system
Parks, C.V.; Giles, G.E.; Childs, K.W.; Bryan, C.B.
1986-01-01T23:59:59.000Z
The heat transfer capabilities within the modular SCALE computational system are centered about the HEATING6 functional module. This paper reviews the features and modeling capabilities of HEATING6, discusses the supportive plotting capabilities of REGPLOT6 and HEATPLOT-S, and finally provides a general description of the Heat Transfer Analysis Sequence No.1 (HTASI) available in SCALE for performing thermal analyses of transport casks via HEATING6. The HTASI control module is an easy-to-use tool that allows an inexperienced HEATING6 user to obtain reliable thermal analysis results. A summary of the recent verification efforts undertaken for HEATING6 is also provided. 16 refs., 14 figs.
Carbajal, Luis
2015-01-01T23:59:59.000Z
Heat build-up in prosthetic sockets is a significant problem experienced by many amputees in America, with no central solution in sight. Heat and discomfort accounts for over 70% of problems experienced by lower limb ...
"Developing novel heat transfer diagnostics for nanosystems."
Acton, Scott
become an increasingly popular technology for waste heat recovery in the last few years. The efficiency"Developing novel heat transfer diagnostics for nanosystems." Patrick Hopkins Assistant Professor Young Investigator Award for heat transfer across solid/fluid interfaces · 2013 AFOSR Young Investigator
A WSRC-MS-g8-00318 Heat Transfer Model of Above and Underground...
Office of Scientific and Technical Information (OSTI)
of the surrounding air to prevent condensation. Most of city water, sewage and liquid waste are usually transferred through single or double underground pipe lines. The...
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
Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal...
depends on various factors, such as permeability, temperature gradient and fluid properties. The features of heat transfer are different for single or two-phase flow....
Grant Hawkes; James E. O'Brien
2008-10-01T23:59:59.000Z
A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in a new novel integrated planar porous-tube supported solid oxide electrolysis cell (SOEC). The model is of several integrated planar cells attached to a ceramic support tube. This design is being evaluated with modeling at the Idaho National Laboratory. 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, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean per-cell area-specific-resistance (ASR) values decrease with increasing current density. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, cathode and anode exchange current density, and contact resistance from the base case are presented. Contour plots of local electrolyte temperature, current density, and Nernst potential indicated 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.
Study on the heat transfer of heat exchangers for the Stirling Engine
Kanzaka, M. (Nagasaki Research and Development Center (JP)); Iwabuchi, M. (Advanced Technology Research Center, Mitsubishi Heavy Industries, Ltd. (JP))
1991-01-01T23:59:59.000Z
This paper reports that heat-transfer characteristics in heated tubes under periodically reversing flow conditions have been investigated experimentally using a test apparatus that simulates the heat exchangers for the actual Sterling engine. It was shown that the heat-transfer characteristics under these conditions were greatly affected by the piston phase-angle difference that generates the reversing flow of the working gas, and this phenomenon was proper to the heat transfer under the periodically reversing flow and was different from conventional heat transfer in steady flow. The experimental correlation considering the influence of the piston phase-angle difference for the heat-transfer coefficient has been induced by the use of the working gas velocity evaluated from the Schmidt cycle model which is one of the ideal Sterling cycles.
Zhang, Yuwen
transfer Non-equilibrium Dual-phase lag a b s t r a c t Based on a nonequilibrium heat transfer model
Kandlikar, Satish
. (2004) developed three- zone flow boiling heat transfer model to describe evaporation of elongated
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
MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER
Lahey, Richard T.
MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL AND CHAOS THEORY" RICHARD T. LAHEY, JR. Center for Multiphase Research Rensselaer Polytechnic Institute Troy and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts
A Numerical Study of a 3D Bioheat Transfer Problem with Different Spatial Heating \\Lambda
Zhang, Jun
, and thermal parameter estimation. 1 #12; 2 Heat Transfer Model Figure 1 reflects a typical cancer hyperthermia
Calculating Radiative Heat Transfer in an Axisymmetric Closed Chamber: An Application
New York at Stoney Brook, State University of
the parallelization of the radiative heat transfer model introduced by Naraghi and Nunes of Manhattan College [8
Radiative heat transfer between dielectric bodies
Svend-Age Biehs
2011-03-16T23:59:59.000Z
The recent development of a scanning thermal microscope (SThM) has led to measurements of radiative heat transfer between a heated sensor and a cooled sample down to the nanometer range. This allows for comparision of the known theoretical description of radiative heat transfer, which is based on fluctuating electrodynamics, with experiment. The theory itself is a macroscopic theory, which can be expected to break down at distances much smaller than 10-8m. Against this background it seems to be reasonable to revisit the known macroscopic theory of fluctuating electrodynamics and of radiative heat transfer.
Heat Transfer Calculations for a Fixed CST Bed Column
Lee, S.Y.
2001-03-28T23:59:59.000Z
In support of the crystalline silicotitanate (CST) ion exchange project of High-Level Waste (HLW) Process Engineering, a transient two-dimensional heat transfer model that includes the conduction process neglecting the convection cooling mechanism inside the CST column has been constructed and heat transfer calculations made for the present design configurations. For this situation, a no process flow condition through the column was assumed as one of the reference conditions for the simulation of a loss-of-flow accident. The modeling and calculations were performed using a computational heat transfer approach.
Phase Change Heat Transfer Device for Process Heat Applications
Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson
2010-10-01T23:59:59.000Z
The next generation nuclear plant (NGNP) will most likely produce electricity and process heat, with both being considered for hydrogen production. To capture nuclear process heat, and transport it to a distant industrial facility requires a high temperature system of heat exchangers, pumps and/or compressors. The heat transfer system is particularly challenging not only due to the elevated temperatures (up to 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.
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
Enhanced heat transfer in partially-saturated hydrothermal systems
Bixler, N.E.; Carrigan, C.R.
1986-01-01T23:59:59.000Z
The role of capillarity is potentially important for determining heat transfer in hydrothermal regions. Capillarity allows mixing of phases in liquid/vapor systems and results in enhanced two-phase convection. Comparisons involving a numerical model with capillarity and analytical models without indicate that heat transfer can be enhanced by about an order of magnitude. Whether capillarity can be important for a particular hydrothermal region will depend on the nature of mineral precipitation as well as pore and fracture size distributions.
Heat Transfer Modeling and Use of Distributed Temperature Measurements to Predict Rate
Hashmi, Gibran Mushtaq
2014-07-08T23:59:59.000Z
/(lbf/ft2) cp Tubing fluid heat capacity, Btu/lbm °F CT Thermal storage parameter, dimensionless d𝑝/d𝑧 Tubing pressure gradient, psi/ft g Gravitational acceleration, ft/sec2 gc Conversion factor, 32.17 (lbm-ft)/lbf/sec2 gG Geothermal gradient, °F... by 𝑄 = ? 2𝜋𝑘𝑒 𝑇𝐷(𝑡𝐷) (𝑇𝑓 ? 𝑇𝑒𝑖) (4) In Eq. 4, we assume the geothermal gradient to be linear with depth, i.e., 𝑇𝑒𝑖 = 𝑇𝑒𝑖𝑏? ? 𝑔𝐺(𝐿 ? 𝑧) (5) The dimensionless temperature, TD(tD ), is a function of dimensionless time...
Modeling of Heat Transfer in Rooms in the Modelica Buildings Library
Wetter, Michael
2013-01-01T23:59:59.000Z
Multizone Air- flow Model in Modelica. ” Edited by ChristianRecent developments of the Modelica buildings library forof the 8-th International Modelica Conference. Modelica
Order Reduction of the Radiative Heat Transfer Model for the Simulation of Plasma Arcs
Fagiano, Lorenzo
2015-01-01T23:59:59.000Z
An approach to derive low-complexity models describing thermal radiation for the sake of simulating the behavior of electric arcs in switchgear systems is presented. The idea is to approximate the (high dimensional) full-order equations, modeling the propagation of the radiated intensity in space, with a model of much lower dimension, whose parameters are identified by means of nonlinear system identification techniques. The low-order model preserves the main structural aspects of the full-order one, and its parameters can be straightforwardly used in arc simulation tools based on computational fluid dynamics. In particular, the model parameters can be used together with the common approaches to resolve radiation in magnetohydrodynamic simulations, including the discrete-ordinate method, the P-N methods and photohydrodynamics. The proposed order reduction approach is able to systematically compute the partitioning of the electromagnetic spectrum in frequency bands, and the related absorption coefficients, tha...
Advances in refrigeration and heat transfer engineering
Bansal, Pradeep [ORNL; Cremaschi, Prof. Lorenzo [Oklahoma State University
2015-01-01T23:59:59.000Z
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).
Heat transfer pathways in underfloor air distribution (UFAD) systems
Bauman, F.; Jin, H.; Webster, T.
2006-01-01T23:59:59.000Z
is little radiative heat transfer and little impact on thereturn air extrac- tion and heat transfer to the plenum. ItUFAD is often used and heat transfer out of the room through
Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures
Lu, Ming-Chang
2010-01-01T23:59:59.000Z
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-
Passive heat transfer means for nuclear reactors
Burelbach, James P. (Glen Ellyn, IL)
1984-01-01T23:59:59.000Z
An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. 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.
HEAT TRANSFER DURING THE SHOCK-INDUCED IGNITION OF AN EXPOLSIVE GAS
Heperkan, H.
2013-01-01T23:59:59.000Z
Proceedings of the 1963 Heat Transfer and Fluid Mechanicsto the Journal of Heat Transfer HEAT TRANSFER DURING THETechniques for Heat Transfer and Force Measurements in a
Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts...
Broader source: Energy.gov (indexed) [DOE]
Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts for CSP Generation In 2008, DOE issued the Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts for...
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...
EXPERIMENTAL MEASUREMENT OF RADIATION HEAT TRANSFER FROM COMPLEX
EXPERIMENTAL MEASUREMENT OF RADIATION HEAT TRANSFER FROM COMPLEX FENESTRATION SYSTEMS By BARRY OF RADIATION HEAT TRANSFER FROM COMPLEX FENESTRATION SYSTEMS Thesis Approved: Dr. Dan Fisher Thesis Adviser Dr
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
Nanoparticle enhanced ionic liquid heat transfer fluids
Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.; Gray, Joshua R.; Garcia-Diaz, Brenda L.
2014-08-12T23:59:59.000Z
A heat transfer fluid created from nanoparticles that are dispersed into an ionic liquid is provided. Small volumes of nanoparticles are created from e.g., metals or metal oxides and/or alloys of such materials are dispersed into ionic liquids to create a heat transfer fluid. The nanoparticles can be dispersed directly into the ionic liquid during nanoparticle formation or the nanoparticles can be formed and then, in a subsequent step, dispersed into the ionic liquid using e.g., agitation.
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
1996-12-31T23:59:59.000Z
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.
Nawaz, Waqas
2014-04-25T23:59:59.000Z
initially stays at its boiling temperature, for models using linear driving force, such indicating the prevalence of boiling on the overall vaporization rate. Subsequently, the temperature of the cryogenic pool drops down, as the heat taken by evaporation...
Literature survey of heat transfer enhancement techniques in refrigeration applications
Jensen, M.K.; Shome, B. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Mechanical Engineering, Aeronautical Engineering and Mechanics
1994-05-01T23:59:59.000Z
A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.
Examination of Liquid Fluoride Salt Heat Transfer
Yoder Jr, Graydon L [ORNL] [ORNL
2014-01-01T23:59:59.000Z
The need for high efficiency power conversion and energy transport systems is increasing as world energy use continues to increase, petroleum supplies decrease, and global warming concerns become more prevalent. There are few heat transport fluids capable of operating above about 600oC that do not require operation at extremely high pressures. Liquid fluoride salts are an exception to that limitation. Fluoride salts have very high boiling points, can operate at high temperatures and low pressures and have very good heat transfer properties. They have been proposed as coolants for next generation fission reactor systems, as coolants for fusion reactor blankets, and as thermal storage media for solar power systems. In each case, these salts are used to either extract or deliver heat through heat exchange equipment, and in order to design this equipment, liquid salt heat transfer must be predicted. This paper discusses the heat transfer characteristics of liquid fluoride salts. Historically, heat transfer in fluoride salts has been assumed to be consistent with that of conventional fluids (air, water, etc.), and correlations used for predicting heat transfer performance of all fluoride salts have been the same or similar to those used for water conventional fluids an, water, etc). A review of existing liquid salt heat transfer data is presented, summarized, and evaluated on a consistent basis. Less than 10 experimental data sets have been found in the literature, with varying degrees of experimental detail and measured parameters provided. The data has been digitized and a limited database has been assembled and compared to existing heat transfer correlations. Results vary as well, with some data sets following traditional correlations; in others the comparisons are less conclusive. This is especially the case for less common salt/materials combinations, and suggests that additional heat transfer data may be needed when using specific salt eutectics in heat transfer equipment designs. All of the data discussed above were taken under forced convective conditions (both laminar and turbulent). Some recent data taken at ORNL under free convection conditions are also presented and results discussed. This data was taken using a simple crucible experiment with an instrumented nickel heater inserted in the salt to induce natural circulation within the crucible. The data was taken over a temperature range of 550oC to 650oC in FLiNaK salt. This data covers both laminar and turbulent natural convection conditions, and is compared to existing forms of natural circulation correlations.
O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert
2002-08-01T23:59:59.000Z
A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numerical modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.
Heat transfer in gas tungsten arc welding
Smartt, H.B.; Stewart, J.A.; Einerson, C.J.
1986-05-01T23:59:59.000Z
The heat transferred from an electrode negative, argon gas tungsten arc to an anode has been measured for a wide range of conditions suitable for mechanized welding applications. The results are given as (1) the arc efficiency; and (2) the anode heat and current input distribution functional shapes and radii for various anode materials and groove shapes over a wide range of current and voltage, using different electrode geometries, as well as both He and Ar-He shielding gases. The nominal arc is Gaussian with a diameter of about 4 mm and a heat transfer efficiency to the anode of about 75%. Variations from these values are discussed in terms of current knowledge of the electrical and thermal energy transport mechanisms. A new method of measuring the heat transferred from the arc to the anode, using a boiling liquid nitrogen calorimeter, has been developed which gives rapid, accurate values.
Heat and mass transfer analysis of a desiccant dehumidifier matrix
Pesaran, A.A.
1986-07-01T23:59:59.000Z
This report documents the SERI Single-Blow Test Facility's design, fabrication, and testing for characterizing desiccant dehumidifiers for solar cooling applications. The first test article, a silica-gel parallel-plate dehumidifier with highly uniform passages, was designed and fabricated. Transient heat and mass transfer data and pressure drop data across the dehumidifier were obtained. Available heat and mass transfer models were extended to the parallel-place geometry, and the experimental data were compared with model predictions. Pressure drop measurements were also compared with model predictions of the fully developed laminar flow theory. The comparisons between the lumped-capacitance model and the experimental data were satisfactory. The pressure drop data compared satisfactorily with the theory (within 15%). A solid-side resistance model that is more detailed and does not assume symmetrical diffusion in particles was recommended for performance. This study has increased our understanding of the heat and mass transfer in silica gel parallel-plate dehumidifiers.
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
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
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
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
Recent Heat Transfer Improvements to the RELAP5-3D Code
Riemke, Richard A; Davis, Cliff B; Oh, Chang
2007-05-01T23:59:59.000Z
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).
George A. Zyvoloski; Bruce A. Robinson; Zora V. Dash; Lynn L. Trease
1997-07-01T23:59:59.000Z
The mathematical models and numerical methods employed by the FEHM application, a finite-element heat- and mass-transfer computer code that can simulate nonisothermal multiphase multi-component flow in porous media, are described. The use of this code is applicable to natural-state studies of geothermal systems and groundwater flow. A primary use of the FEHM application will be to assist in the understanding of flow fields and mass transport in the saturated and unsaturated zones below the proposed Yucca Mountain nuclear waste repository in Nevada. The component models of FEHM are discussed. The first major component, Flow- and Energy-Transport Equations, deals with heat conduction; heat and mass transfer with pressure- and temperature-dependent properties, relative permeabilities and capillary pressures; isothermal air-water transport; and heat and mass transfer with noncondensible gas. The second component, Dual-Porosity and Double-Porosity/Double-Permeability Formulation, is designed for problems dominated by fracture flow. Another component, The Solute-Transport Models, includes both a reactive-transport model that simulates transport of multiple solutes with chemical reaction and a particle-tracking model. Finally, the component, Constitutive Relationships, deals with pressure- and temperature-dependent fluid/air/gas properties, relative permeabilities and capillary pressures, stress dependencies, and reactive and sorbing solutes. Each of these components is discussed in detail, including purpose, assumptions and limitations, derivation, applications, numerical method type, derivation of numerical model, location in the FEHM code flow, numerical stability and accuracy, and alternative approaches to modeling the component.
Indirect Heat Transfer Technology For Waste Heat Recovery Can Save You Money
Beyrau, J. A.; Bogel, N. G.; Seifert, W. F.; Wuelpern, L. E.
1984-01-01T23:59:59.000Z
constraints of an existing installation makes the conventional flue gas to air energy recovery technology impractical to employ. A successful alternative is the transfer of waste heat to an intermediate heat transfer fluid (i.e., DOWTHERM Heat Transfer Fluid...
Heat transfer 1990. Proceedings of the ninth international heat transfer conference
Hetsroni, G.
1990-01-01T23:59:59.000Z
This book contains the proceedings of the Ninth International Heat Transfer Conference. Included in Volume 6 are the following chapters: Local void fraction measurements in finned tube bundles, Unsteady heat and mass transfer in low two-phase flows and The effect of physical properties on drop size in annular flow.
Radiative Heat Transfer between Neighboring Particles
Alejandro Manjavacas; F. Javier Garcia de Abajo
2012-01-26T23:59:59.000Z
The near-field interaction between two neighboring particles is known to produce enhanced radiative heat transfer. We advance in the understanding of this phenomenon by including the full electromagnetic particle response, heat exchange with the environment, and important radiative corrections both in the distance dependence of the fields and in the particle absorption coefficients. We find that crossed terms of electric and magnetic interactions dominate the transfer rate between gold and SiC particles, whereas radiative corrections reduce it by several orders of magnitude even at small separations. Radiation away from the dimer can be strongly suppressed or enhanced at low and high temperatures, respectively. These effects must be taken into account for an accurate description of radiative heat transfer in nanostructured environments.
5. Heat transfer Ron Zevenhoven
Zevenhoven, Ron
) Heat conductance as Gheat =1/Rheat = Q/T (unit: W/K or W/°C) For a plane material with thickness L (m) and conductivity (W/mK): Gheat = ·A/L Rheat = L/(·A) . . . Åbo Akademi University | Thermal and Flow Engineering rate Q through a cross-sectional area A (m2). If is a constant: with thermal conductivity , unit: W
Cooperative heat transfer and ground coupled storage system
Metz, Philip D. (Rocky Point, NY)
1982-01-01T23:59:59.000Z
A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.
Self supporting heat transfer element
Story, Grosvenor Cook (Livermore, CA); Baldonado, Ray Orico (Livermore, CA)
2002-01-01T23:59:59.000Z
The present invention provides an improved internal heat exchange element arranged so as to traverse the inside diameter of a container vessel such that it makes good mechanical contact with the interior wall of that vessel. The mechanical element is fabricated from a material having a coefficient of thermal conductivity above about 0.8 W cm.sup.-1.degree. K.sup.-1 and is designed to function as a simple spring member when that member has been cooled to reduce its diameter to just below that of a cylindrical container or vessel into which it is placed and then allowed to warm to room temperature. A particularly important application of this invention is directed to a providing a simple compartmented storage container for accommodating a hydrogen absorbing alloy.
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
Kasagi, Nobuhide
circulation is dominant at high PeT number. A heat transfer model is proposed to analyze and predict the heat
Heat Transfer between Graphene and Amorphous SiO2
B. N. J. Persson; H. Ueba
2010-07-22T23:59:59.000Z
We study the heat transfer between graphene and amorphous SiO2. We include both the heat transfer from the area of real contact, and between the surfaces in the non-contact region. We consider the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies, and the heat transfer by the gas in the non-contact region. We find that the dominant contribution to the heat transfer result from the area of real contact, and the calculated value of the heat transfer coefficient is in good agreement with the value deduced from experimental data.
Boiling heat transfer in a hydrofoil-based micro pin fin heat sink
Peles, Yoav
transfer in a horizontal tube bundle and reported an increase in local heat transfer coefficient boiling heat transfer of water in small horizontal tube bundles at low velocities. How- ever, the dataBoiling heat transfer in a hydrofoil-based micro pin fin heat sink Ali Kosßar, Yoav Peles
Nasal, J.R.; Deaver, R.
1995-12-31T23:59:59.000Z
In response to an increasing demand for operational tools that benefit both efficiency and environmental compliance, General Physics Corporation (GP) has developed and installed a unique aid to optimize sootblowing at Delmarva Power`s Edge Moor Unit No. 5. By combining expert system techniques with a rigorous mathematical model, a robust and reliable indication of boiler section(s) cleanliness is graphically presented to the control room operators on a minute-to-minute basis. The overall approach used in the heat transfer model is based upon technology developed in the former Soviet Union while the expert system component acts as an independent {open_quotes}cross-check{close_quotes} of the values calculated in the math model. This paper presents an overview of the general engineering approach used in developing the boiler cleanliness module as an integral part of a power plant`s performance monitoring system. It includes graphical displays of the user interface and describes the concepts behind the heat transfer model as well as typical expert system rules used to verify the accuracy of the model. The paper concludes with {open_quotes}lessons learned{close_quotes} and a comparison of empirical data versus calculated cleanliness values for the various boiler sections over a wide capacity range of the boiler.
Nasal, J.R.; DesJardins, R.R.; Deaver, R.
1996-05-01T23:59:59.000Z
In response to an increasing demand for operational tools that benefit both efficiency and environmental compliance, General Physics Corporation (GP) has developed and installed a unique aid to optimize sootblowing at Delmarva Power`s Edge Moor Unit No. 5. By combining expert system techniques with a rigorous mathematical model, a robust and reliable indication of boiler section(s) cleanliness is graphically presented to the control room operators on a minute-to-minute basis. The overall approach used in the heat transfer model is based upon technology developed in the former Soviet Union while the expert system component acts as an independent {open_quotes}cross-check{close_quotes} of the values calculated in the math model. This paper presents an overview of the general engineering approach used in developing the boiler cleanliness module as an integral part of a power plant`s, performance monitoring system. It includes graphical displays of the user interface and describes the concepts behind the heat transfer model as well as typical expert system rules used to verify the accuracy of the model. The paper concludes with {open_quotes}lessons learned{close_quotes} and a comparison of empirical data versus calculated cleanliness values for the various boiler sections over a wide capacity range of the boiler.
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
Enhanced convective and film boiling heat transfer by surface gas injection
Duignan, M.R.; Greene, G.A. [Brookhaven National Lab., Upton, NY (United States); Irvine, T.F., Jr. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Mechanical Engineering
1992-04-01T23:59:59.000Z
Heat transfer measurements were made for stable film boiling of water over a horizontal, flat stainless steel plate from the minimum film boiling point temperature, T{sub SURFACE} {approximately}500K, to T{sub SURFACE} {approximately}950K. The pressure at the plate was approximately 1 atmosphere and the temperature of the water pool was maintained at saturation. The data were compared to the Berenson film-boiling model, which was developed for minimum film-boiling-point conditions. The model accurately represented the data near the minimum film-boiling point and at the highest temperatures measured, as long it was corrected for the heat transferred by radiation. On the average, the experimental data lay within {plus_minus}7% of the model. Measurements of heat transfer were made without film boiling for nitrogen jetting into an overlying pool of water from nine 1-mm- diameter holes, drilled in the heat transfer plate. The heat flux was maintained constant at approximately 26.4 kW/m{sup 2}. For water-pool heights of less than 6cm the heat transfer coefficient deceased linearly with a decrease in heights. Above 6cm the heat transfer coefficient was unaffected. For the entire range of gas velocities measured [0 to 8.5 cm/s], the magnitude of the magnitude of the heat transfer coefficient only changed by approximately 20%. The heat transfer data bound the Konsetov model for turbulent pool heat transfer which was developed for vertical heat transfer surfaces. This agreement suggests that surface orientation may not be important when the gas jets do not locally affect the surface heat transfer. Finally, a database was developed for heat transfer from the plate with both film boiling and gas jetting occurring simultaneously, in a pool of water maintained at its saturation temperature. The effect of passing nitrogen through established film boiling is to increase the heat transfer from that surface. 60 refs.
Enhanced convective and film boiling heat transfer by surface gas injection
Duignan, M.R.; Greene, G.A. (Brookhaven National Lab., Upton, NY (United States)); Irvine, T.F., Jr. (State Univ. of New York, Stony Brook, NY (United States). Dept. of Mechanical Engineering)
1992-04-01T23:59:59.000Z
Heat transfer measurements were made for stable film boiling of water over a horizontal, flat stainless steel plate from the minimum film boiling point temperature, T{sub SURFACE} {approximately}500K, to T{sub SURFACE} {approximately}950K. The pressure at the plate was approximately 1 atmosphere and the temperature of the water pool was maintained at saturation. The data were compared to the Berenson film-boiling model, which was developed for minimum film-boiling-point conditions. The model accurately represented the data near the minimum film-boiling point and at the highest temperatures measured, as long it was corrected for the heat transferred by radiation. On the average, the experimental data lay within {plus minus}7% of the model. Measurements of heat transfer were made without film boiling for nitrogen jetting into an overlying pool of water from nine 1-mm- diameter holes, drilled in the heat transfer plate. The heat flux was maintained constant at approximately 26.4 kW/m{sup 2}. For water-pool heights of less than 6cm the heat transfer coefficient deceased linearly with a decrease in heights. Above 6cm the heat transfer coefficient was unaffected. For the entire range of gas velocities measured (0 to 8.5 cm/s), the magnitude of the magnitude of the heat transfer coefficient only changed by approximately 20%. The heat transfer data bound the Konsetov model for turbulent pool heat transfer which was developed for vertical heat transfer surfaces. This agreement suggests that surface orientation may not be important when the gas jets do not locally affect the surface heat transfer. Finally, a database was developed for heat transfer from the plate with both film boiling and gas jetting occurring simultaneously, in a pool of water maintained at its saturation temperature. The effect of passing nitrogen through established film boiling is to increase the heat transfer from that surface. 60 refs.
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
Measurement and analysis of gas turbine blade endwall heat transfer
Lee, Joon Ho
2001-01-01T23:59:59.000Z
and calibrated for heat transfer and flow measurement. The vane used in this study is a 2 dimensional model of a first stage gas turbine vane with an endwall profile of an aircraft gas turbine engine. The flow condition in the test cascade corresponds...
Nanofluid heat transfer enhancement for nuclear reactor applications
Buongiorno, Jacopo
Colloidal dispersions of nanoparticles are known as `nanofluids'. Such engineered fluids offer the potential for enhancing heat transfer, particularly boiling heat transfer, while avoiding the drawbacks (i.e., erosion, ...
Experimental evaluation of heat transfer characteristics of silica nanofluid
Zhang, Zihao, S.B. Massachusetts Institute of Technology
2010-01-01T23:59:59.000Z
The laminar convective heat transfer characteristics were investigated for silica nanofluid. An experimental loop was built to obtain heat transfer coefficients for single-phase nanofluids in a circular conduit in laminar ...
Hydrodynamics, heat transfer and flow boiling instabilities in microchannels
Barber, Jacqueline Claire
2010-01-01T23:59:59.000Z
Boiling in microchannels is a very efficient mode of heat transfer with high heat and mass transfer coefficients achieved. Less pumping power is required for two-phase flows than for single-phase liquid flows to achieve ...
Heat transfer pathways in underfloor air distribution (UFAD) systems
Bauman, F.; Jin, H.; Webster, T.
2006-01-01T23:59:59.000Z
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
Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet)
Not Available
2010-08-01T23:59:59.000Z
Fact sheet describing NREL CSP Program capabilities in the area of thermal storage and advanced heat transfer fluids: measuring thermophysical properties, measuring fluid flow and heat transfer, and simulating flow of thermal energy and fluid.
Heat transfer during film condensation of potassium vapor
Kroger, Detlev Gustav
1966-01-01T23:59:59.000Z
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 ...
Radial heat transfer from a moving plasma
Johnson, James Randall
1966-01-01T23:59:59.000Z
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...
Young Jin Lee; Bub Dong Chung [Korea Atomic Energy Research Institute, P.O. Box 105, Dukjin-Dong, Yuseong-Gu, Daejeon, 305-600 (Korea, Republic of); Jong Chull Jo; Hho Jung Kim [Korea Institute of Nuclear Safety, 19 Gusong-Dong, Yuseong-Gu, Daejeon, 305-338 (Korea, Republic of); Un Chul Lee [Department of Nuclear Engineering, Seoul National University, San 56-1 Sillim-Dong, Kwanak-Gu, Seoul, 151-742 (Korea, Republic of)
2004-07-01T23:59:59.000Z
SMART is a medium sized integral type advanced pressurized water reactor currently under development at KAERI. The steam generators of SMART are designed with helically coiled tubes and these are designed to produce superheated steam. The helical shape of the tubes can induce strong centrifugal effect on the secondary coolant as it flows inside the tubes. The presence of centrifugal effect is expected to enhance the formation of cross-sectional circulation flows within the tubes that will increase the overall heat transfer. Furthermore, the centrifugal effect is expected to enhance the moisture separation and thus make it easier to produce superheated steam. MARS is a best-estimate thermal-hydraulic systems analysis code with multi-phase, multi-dimensional analysis capability. The MARS code was produced by restructuring and merging the RELAP5 and the COBRA-TF codes. However, MARS as well as most other best-estimate systems analysis codes in current use lack the detailed models needed to describe the thermal hydraulics of helically coiled tubes. In this study, the heat transfer characteristics and relevant correlations for both the tube and shell sides of helical tubes have been investigated, and the appropriate models have been incorporated into the MARS code. The newly incorporated helical tube heat transfer package is available to the MARS users via selection of the appropriate option in the input. A performance analysis on the steam generator of SMART under full power operation was carried out using the modified MARS code. The results of the analysis indicate that there is a significant improvement in the code predictability. (authors)
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
Low-melting point heat transfer fluid
Cordaro, Joseph Gabriel (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)
2010-11-09T23:59:59.000Z
A low-melting point, heat transfer fluid made of a mixture of five inorganic salts including about 29.1-33.5 mol % LiNO.sub.3, 0-3.9 mol % NaNO.sub.3, 2.4-8.2 mol % KNO.sub.3, 18.6-19.9 mol % NaNO.sub.2, and 40-45.6 mol % KNO.sub.2. These compositions can have liquidus temperatures below 80.degree. C. for some compositions.
DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION
Yee, G.
2010-01-01T23:59:59.000Z
DEVELOpiNG FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS9092 Developing Flow and Heat Transfer in Strongly CurvedForced Convection Heat Transfer in Curved Rectangular
Gustavsen, Arild
2009-01-01T23:59:59.000Z
free convection. In: Heat Transfer and Turbulent Buoyantof convection heat transfer and develop correlations.and radiation heat transfer and develop correlations for
Gustavsen, Arild
2009-01-01T23:59:59.000Z
of convection and radiation heat transfer and developconvection and radiation heat transfer in three dimensionsaccount for 3- D radiation heat transfer on indoor surfaces.
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
1996-12-31T23:59:59.000Z
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.
Dt2boool2> Nora Heat Transfer Correlations
Dt2boool2> Nora Heat Transfer Correlations in Nuclear Reactor Safety Calculations VW ÉAiiattÉaii #12;fcflison cufiMiMltt lor yhdyiifci aomicantfgy RIS0-M-25O4 6«.*). HEAT TRANSFER of work 26 3. PRESENT KNOWLEDGE 27 3.1. General considerations 27 3.2. Heat transfer in different flow
Proceeding of the 1st International Forum on Heat Transfer
Maruyama, Shigeo
Proceeding of the 1st International Forum on Heat Transfer November 24-26, 2004, Kyoto, Japan Paper No. HEAT TRANSFER PROBLEMS RELATED WITH CARBON NANOTUBES BY MOLECULAR DYNAMICS-BASED SIMULATIONS Dynamics Simulation, Thermal Conductance ABSTRACT Several heat transfer problems related to single
Proceedings of NHTC'00: 34 th National Heat Transfer Conference
Kandlikar, Satish
Proceedings of NHTC'00: 34 th National Heat Transfer Conference Pittsburgh, Pennsylvania, August 20 ON SINGLE- AND TWO-PHASE HEAT TRANSFER CHARACTERISTICS IN A MICROCHANNEL Michael S June Graduate Student study investigates the heat transfer characteristics of single and two-phase flows in a 200 m wide
ULTRAFAST RADIATION HEAT TRANSFER IN LASER TISSUE WELDING AND SOLDERING
Guo, Zhixiong "James"
ULTRAFAST RADIATION HEAT TRANSFER IN LASER TISSUE WELDING AND SOLDERING Kyunghan Kim and Zhixiong. The transient radiation heat transfer in the picosecond time scale is numerically investigated for the first surface. Comparisons of radiation heat transfer are made between the spatially square- variance
Heat transfer of finned tube bundles in crossflow
Stasiulevicius, J.; Skrinska, A.; Zukauskas, A.
1988-01-01T23:59:59.000Z
This volume correlates findings on heat transfer and hydraulic drag of bundles of finned tubes in crossflow at Reynolds numbers from 10/sup 4/ to 10/sup 6/. These studies illustrate fin, local, and mean heat transfer coefficients; effects of geometric parameters of the fins; effect of tube location within the bundle on heat transfer and hydraulic drag; and resistance of finned tube bundles.
Heat Transfer Operators Associated with Quantum Operations
Ç. Aksak; S. Turgut
2011-04-14T23:59:59.000Z
Any quantum operation applied on a physical system is performed as a unitary transformation on a larger extended system. If the extension used is a heat bath in thermal equilibrium, the concomitant change in the state of the bath necessarily implies a heat exchange with it. The dependence of the average heat transferred to the bath on the initial state of the system can then be found from the expectation value of a hermitian operator, which is named as the heat transfer operator (HTO). The purpose of this article is the investigation of the relation between the HTOs and the associated quantum operations. Since, any given quantum operation on a system can be realized by different baths and unitaries, many different HTOs are possible for each quantum operation. On the other hand, there are also strong restrictions on the HTOs which arise from the unitarity of the transformations. The most important of these is the Landauer erasure principle. This article is concerned with the question of finding a complete set of restrictions on the HTOs that are associated with a given quantum operation. An answer to this question has been found only for a subset of quantum operations. For erasure operations, these characterizations are equivalent to the generalized Landauer erasure principle. For the case of generic quantum operations however, it appears that the HTOs obey further restrictions which cannot be obtained from the entropic restrictions of the generalized Landauer erasure principle.
Journal of Enhanced Heat Transfer, 19 (5): 457476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT
Ghajar, Afshin J.
2012-01-01T23:59:59.000Z
Journal of Enhanced Heat Transfer, 19 (5): 457476 (2012) EXPERIMENTAL INVESTIGATION OF HEAT microfin tubes, most of the heat transfer and friction factor studies were focused on the turbulent region. However, there is a lack of information about the heat transfer and friction factor behavior of microfin
Optimization of Phase Change Heat Transfer in Biporous Media
Reilly, Sean
2013-01-01T23:59:59.000Z
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
Daurelle, J.V.; Topin, F.; Occelli, R. [IUSTI, Marseille (France)
1998-01-01T23:59:59.000Z
The physical model is based on balance equations at the representative elementary volume. The considered medium has three phases (liquid, solid, and gas). The gas phase includes two components (air and vapor). The authors use the mass balance equations on air and water (liquid and steam) as well as the heat equation in order to describe the phenomena. The system of equations is closed via classical relations in these media, which leads to a three-equation system with coupled nonlinear partial derivatives. The authors have applied this model to superheated steam drying. A solution model of the coupled nonlinear equation system based on the finite element method in a two-dimensional configuration was developed and validated. This approach allows one to determine all the variables of the problem. It is a complementary tool of analysis that opens access to nonmeasurable variables, such as the phase change rate. This computation model was applied to a configuration studied experimentally. The numerical and experimental results agree in nondimensional time. This double approach has enabled them to point out and evaluate new mechanisms typical of this drying method.
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
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
Near-field heat transfer between gold nanoparticle arrays
Phan, Anh D., E-mail: anhphan@mail.usf.edu [Department of Physics, University of South Florida, Tampa, Florida 33620 (United States); Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Ba Dinh, Hanoi 10000 (Viet Nam); Phan, The-Long, E-mail: ptlong2512@yahoo.com [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Woods, Lilia M. [Department of Physics, University of South Florida, Tampa, Florida 33620 (United States)
2013-12-07T23:59:59.000Z
The radiative heat transfer between gold nanoparticle layers is presented using the coupled dipole method. Gold nanoparticles are modelled as effective electric and magnetic dipoles interacting via electromagnetic fluctuations. The effect of higher-order multipoles is implemented in the expression of electric polarizability to calculate the interactions at short distances. Our findings show that the near-field radiation reduces as the radius of the nanoparticles is increased. Also, the magnetic dipole contribution to the heat exchange becomes more important for larger particles. When one layer is displayed in parallel with respect to the other layer, the near-field heat transfer exhibits oscillatory-like features due to the influence of the individual nanostructures. Further details about the effect of the nanoparticles size are also discussed.
Boiling Heat Transfer on Superhydrophilic, Superhydrophobic, and Superbiphilic Surfaces
Betz, Amy Rachel; Kim, Chang-Jin 'CJ'; Attinger, Daniel
2012-01-01T23:59:59.000Z
With recent advances in micro- and nanofabrication, superhydrophilic and superhydrophobic surfaces have been developed. The statics and dynamics of fluids on these surfaces have been well characterized. However, few investigations have been made into the potential of these surfaces to control and enhance other transport phenomena. In this article, we characterize pool boiling on surfaces with wettabilities varied from superhydrophobic to superhydrophilic, and provide nucleation measurements. The most interesting result of our measurements is that the largest heat transfer coefficients are reached not on surfaces with spatially uniform wettability, but on biphilic surfaces, which juxtapose hydrophilic and hydrophobic regions. We develop an analytical model that describes how biphilic surfaces effectively manage the vapor and liquid transport, delaying critical heat flux and maximizing the heat transfer coefficient. Finally, we manufacture and test the first superbiphilic surfaces (juxtaposing superhydrophobic ...
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
Integration of Heat Transfer, Stress, and Particle Trajectory Simulation
Thuc Bui; Michael Read; Lawrence ives
2012-05-17T23:59:59.000Z
Calabazas Creek Research, Inc. developed and currently markets Beam Optics Analyzer (BOA) in the United States and abroad. BOA is a 3D, charged particle optics code that solves the electric and magnetic fields with and without the presence of particles. It includes automatic and adaptive meshing to resolve spatial scales ranging from a few millimeters to meters. It is fully integrated with CAD packages, such as SolidWorks, allowing seamless geometry updates. The code includes iterative procedures for optimization, including a fully functional, graphical user interface. Recently, time dependent, particle in cell capability was added, pushing particles synchronically under quasistatic electromagnetic fields to obtain particle bunching under RF conditions. A heat transfer solver was added during this Phase I program. Completed tasks include: (1) Added a 3D finite element heat transfer solver with adaptivity; (2) Determined the accuracy of the linear heat transfer field solver to provide the basis for development of higher order solvers in Phase II; (3) Provided more accurate and smoother power density fields; and (4) Defined the geometry using the same CAD model, while maintaining different meshes, and interfacing the power density field between the particle simulator and heat transfer solvers. These objectives were achieved using modern programming techniques and algorithms. All programming was in C++ and parallelization in OpenMP, utilizing state-of-the-art multi-core technology. Both x86 and x64 versions are supported. The GUI design and implementation used Microsoft Foundation Class.
Heat Transfer Analysis for a Fixed CST Column
Lee, S.Y.
2004-02-19T23:59:59.000Z
In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, a transient two-dimensional heat transfer model that includes the conduction process neglecting the convection cooling mechanism inside the crystalline silicotitanate (CST) column has been constructed and heat transfer calculations made for the present design configurations. For this situation, a no process flow condition through the column was assumed as one of the reference conditions for the simulation of a loss-of-flow accident. A series of the modeling calculations has been performed using a computational heat transfer approach. Results for the baseline model indicate that transit times to reach 130 degrees Celsius maximum temperature of the CST-salt solution column are about 96 hours when the 20-in CST column with 300 Ci/liter heat generation source and 25 degrees Celsius initial column temperature is cooled by natural convection of external air as a primary heat transfer mechanism. The modeling results for the 28-in column equipped with water jacket systems on the external wall surface of the column and water coolant pipe at the center of the CST column demonstrate that the column loaded with 300 Ci/liter heat source can be maintained non-boiling indefinitely. Sensitivity calculations for several alternate column sizes, heat loads of the packed column, engineered cooling systems, and various ambient conditions at the exterior wall of the column have been performed under the reference conditions of the CST-salt solution to assess the impact of those parameters on the peak temperatures of the packed column for a given transient time. The results indicate that a water-coolant pipe at the center of the CST column filled with salt solution is the most effective one among the potential design parameters related to the thermal energy dissipation of decay heat load. It is noted that the cooling mechanism at the wall boundary of the column has significant impact on maximum and wall temperatures of the column. In addition, the results computed by the present model were verified by the theoretical results. The analysis results will provide quantitative information associated with the process heat control and management of the CST base design. For example, transient responses of the CST system under a loss-of-flow accident condition will provide safety design information for an emergency cooling system of the column.
HEAT TRANSFER ANALYSIS FOR NUCLEAR WASTE SOLIDIFICATION CONTAINER
Lee, S.
2009-06-01T23:59:59.000Z
The Nuclear Nonproliferation Programs Design Authority is in the design stage of the Waste Solidification Building (WSB) for the treatment and solidification of the radioactive liquid waste streams generated by the Pit Disassembly and Conversion Facility (PDCF) and Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The waste streams will be mixed with a cementitious dry mix in a 55-gallon waste container. Savannah River National Laboratory (SRNL) has been performing the testing and evaluations to support technical decisions for the WSB. Engineering Modeling & Simulation Group was requested to evaluate the thermal performance of the 55-gallon drum containing hydration heat source associated with the current baseline cement waste form. A transient axi-symmetric heat transfer model for the drum partially filled with waste form cement has been developed and heat transfer calculations performed for the baseline design configurations. For this case, 65 percent of the drum volume was assumed to be filled with the waste form, which has transient hydration heat source, as one of the baseline conditions. A series of modeling calculations has been performed using a computational heat transfer approach. The baseline modeling results show that the time to reach the maximum temperature of the 65 percent filled drum is about 32 hours when a 43 C initial cement temperature is assumed to be cooled by natural convection with 27 C external air. In addition, the results computed by the present model were compared with analytical solutions. The modeling results will be benchmarked against the prototypic test results. The verified model will be used for the evaluation of the thermal performance for the WSB drum. Detailed results and the cases considered in the calculations will be discussed here.
Outside heat transfer coefficients for atmospheric coolers
George, David Mark
1950-01-01T23:59:59.000Z
? the equation in integral form becomes for both steady state conditions and a constant cross sectional area A, ~c ~J? -KA t, (3) $ = K A(f-f )/( , g g ) If (tl - t2' is called 4t, the temperature difference asso- ciated with the heat transferred, and (x2.... th as that for the ma)or equipment First, ths 90 pound steam to the U tube bundle is ini- tially controlled by a 1-1/g inch master valve and then by either a 3/4. inch of 1A inch valve, Figure 9. Two valves of this size are necessary at this point...
Heat Transfer Laboratory | Argonne National Laboratory
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirt DocumentationSitesWeather6Environmental1Grandson of EnolaHanfordHeat Transfer Laboratory Materials in
Heat transfer to impacting drops and post critical heat flux dispersed flow
Kendall, Gail E.
1978-01-01T23:59:59.000Z
Heat transfer to drops impacting on a hot surface is examined in context of dispersions of flowing, boiling fluids. The liquid contribution to heat transfer from a hot tube to a two-phase dispersion is formulated in terms ...
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, Michael J. (Richmond, CA); Rubenstein, Francis M. (Berkeley, CA); Whitman, Richard E. (Richmond, CA)
1992-01-01T23:59:59.000Z
In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure.
Heat transfer assembly for a fluorescent lamp and fixture
Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.
1992-12-29T23:59:59.000Z
In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure. 11 figs.
Flow and heat transfer in vertical annuli
Ulke, A.; Goldberg, I.
1993-11-01T23:59:59.000Z
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.
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
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
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
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
Effect of surface conditions on boiling heat transfer of refrigerants in shell-and-tube evaporators
Danilova, G.N.; Dyundin, V.A.; Borishanskaya, A.V.; Soloviyov, A.G.; Vol'nykh, Y.A.; Kozyrev, A.A.
1990-01-01T23:59:59.000Z
Experimental results are presented for the boiling heat transfer performance of R 22 and R 717 on surfaces with porous metallized coatings. A calculational-theoretical model is given for predicting the heat transfer of refrigerants boiling on a bundle of finned tubes.
Winiarski, David Walter
1992-01-01T23:59:59.000Z
day of year, fraction of cloud cover Nusselt number heat flow heat flux radiant barrier time temperature truss radiant barrier width radiative matrix thermal diffusivity, solar absorptivity thermal expansivity surface azimuth angle gamma..., latitude radiative constant kinematic viscosity Superscripts time step Subscripts c cond conv d dp eff f h, hor iJ, k cloud conductive convective diffuse dew point effective forced horizontal numerical subscript spatial node...
Mechanism and behavior of nucleate boiling heat transfer to the alkalai liquid metals
Deane, Charles William
1969-01-01T23:59:59.000Z
A model of boiling heat transfer to the alkali liquid metals is postulated from an examination of the events and phases of the nucleate boiling cycle. The model includes the important effect of microlayer evaporation which ...
Heat transfer in bundles of finned tubes in crossflow
Stasiulevicius, J.; Skrinska, A.; Zukauskas, A.; Hewitt, G.F.
1986-01-01T23:59:59.000Z
This book provides correlations of heat transfer and hydraulic data for bundles of finned tubes in crossflow at high Reynolds numbers. Results of studies of the effectiveness of the fin, local, and mean heat transfer coefficients are presented. The effect of geometric parameters of the fins and of the location of tubes in the bundle on heat transfer and hydraulic drag are described. The resistance of the finned tube bundles under study and other factors are examined.
Influences of electrical field on boiling-condensation heat transfer system
Yang Jiaxiang; Ding Lijian; Chi Xiaochun; Liu Ji [Harbin Inst. of Electrical Technology (China). Dept. of Electrical Materials Engineering; Yang He [Harbin Inst. of Tech. (China). Dept. of Thermal Energy Engineering
1996-12-31T23:59:59.000Z
In this paper, the influences of electrical field on boiling-condensation heat transfer system have been investigated using a cylinder heat transfer model. Freon-11 is selected as working fluid. The condensation heat transfer coefficient, the boiling heat flux and the saturation pressure are measured in this investigation. According to the experimental results, it is found that the electrical field can influence heat transfer system. The boiling heat transfer is enhanced by the applied voltage, and the saturate vapor of working fluid is condensed on the high voltage electrode directly when the applied voltage is higher than 6 kv. The experimental results have been discussed, and it is considered that the high electrical field strength change the thermal properties of working fluid.
Heat Transfer Study of Polymer Solutions with Different Rigidities
Huang, Yao
2014-05-08T23:59:59.000Z
The heat transfer behaviors of non-Newtonian fluids under laminar flow conditions in circular tubes are presented in this study. The constant wall heat flux is considered as a boundary condition for dilute polymer solutions with different polymer...
Heat transfer and pressure drop in tape generated swirl flow
Lopina, Robert F.
1967-01-01T23:59:59.000Z
The heat transfer and pressure drop characteristics of water in tape generated swirl flow were investigated. The test sections were electrically heated small diameter nickel tubes with tight fitting full length Inconel ...
Flexible profile approach to the conjugate heat transfer problem
M. -N. Sabry
2008-01-07T23:59:59.000Z
The flexible profile approach proposed earlier to create CTM (compact or reduced order thermal models) is extended to cover the area of conjugate heat transfer. The flexible profile approach is a methodology that allows building a highly boundary conditions independent CTM, with any desired degree of accuracy, that may adequately replace detailed 3D models for the whole spectrum of applications in which the modeled object may be used. The extension to conjugate problems radically solves the problem of interfacing two different domains. Each domain, fluid or solid, can be "compacted" independently creating two CTM that can be joined together to produce reliable results for any arbitrary set of external boundary conditions.
Steam Technical Brief: Industrial Steam System Heat-Transfer Solutions
None
2010-06-25T23:59:59.000Z
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 Technologie...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
May 18-22, 2009 -- Washington D.C. ape11kelly.pdf More Documents & Publications Characterization and Development of Advanced Heat Transfer Technologies Advanced Power Electronics...
Tracer Testing for Estimating Heat Transfer Area in Fractured Reservoirs
Pruess, Karsten; van Heel, Ton; Shan, Chao
2004-01-01T23:59:59.000Z
Heat Flow in Fractured Reservoirs, SPE Advanced TechnologyTransfer Area in Fractured Reservoirs Karsten Pruess 1 , Tonbehavior arises in fractured reservoirs. As cold injected
Low-melting point heat transfer fluid
Cordaro, Joseph G. (Oakland, CA); Bradshaw, Robert W. (Livermore, CA)
2011-04-12T23:59:59.000Z
A low-melting point, heat transfer fluid comprising a mixture of LiNO.sub.3, NaNO.sub.3, KNO.sub.3, NaNO.sub.2 and KNO.sub.2 salts where the Li, Na and K cations are present in amounts of about 20-33.5 mol % Li, about 18.6-40 mol % Na, and about 40-50.3 mol % K and where the nitrate and nitrite anions are present in amounts of about 36-50 mol % NO.sub.3, and about 50-62.5 mol % NO.sub.2. These compositions can have liquidus temperatures between 70.degree. C. and 80.degree. C. for some compositions.
Nanofluids for heat transfer : an engineering approach.
Timofeeva, E. V.; Yu, W.; France, D. M.; Singh, D.; Routbort, J. L. (Energy Systems); ( NE); (Univ. of Illinois at Chicago)
2011-02-28T23:59:59.000Z
An overview of systematic studies that address the complexity of nanofluid systems and advance the understanding of nanoscale contributions to viscosity, thermal conductivity, and cooling efficiency of nanofluids is presented. A nanoparticle suspension is considered as a three-phase system including the solid phase (nanoparticles), the liquid phase (fluid media), and the interfacial phase, which contributes significantly to the system properties because of its extremely high surface-to-volume ratio in nanofluids. The systems engineering approach was applied to nanofluid design resulting in a detailed assessment of various parameters in the multivariable nanofluid systems. The relative importance of nanofluid parameters for heat transfer evaluated in this article allows engineering nanofluids with desired set of properties.
Submersible pumping system with heat transfer mechanism
Hunt, Daniel Francis Alan; Prenger, F. Coyne; Hill, Dallas D; Jankowski, Todd Andrew
2014-04-15T23:59:59.000Z
A submersible pumping system for downhole use in extracting fluids containing hydrocarbons from a well. In one embodiment, the pumping system comprises a rotary induction motor, a motor casing, one or more pump stages, and a cooling system. The rotary induction motor rotates a shaft about a longitudinal axis of rotation. The motor casing houses the rotary induction motor such that the rotary induction motor is held in fluid isolation from the fluid being extracted. The pump stages are attached to the shaft outside of the motor casing, and are configured to impart fluid being extracted from the well with an increased pressure. The cooling system is disposed at least partially within the motor casing, and transfers heat generated by operation of the rotary induction motor out of the motor casing.
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
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)
1996-12-03T23:59:59.000Z
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI); Marsala, Joseph (Glen Ellyn, IL)
1994-11-29T23:59:59.000Z
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.
Geb, David; Zhou, Feng; Catton, Ivan
2012-01-01T23:59:59.000Z
the Hydraulic Drag and Heat Transfer Coefficients in Porous5] Locke, G. L. , 1950, “Heat Transfer and Flow FrictionA. P. , 1993, “Heat Transfer and Hydraulic Resistance in
Heat Transfer Enhancement: Second Generation Technology
Bergles, A. E.; Webb, R. L.
1984-01-01T23:59:59.000Z
are discussed. Special attention is directed toward use of enhanced surfaces in industrial process heat exchangers and heat recovery equipment....
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
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
2012-03-07T23:59:59.000Z
We compute the radiative heat transfer between nanostructured gold plates in the framework of the scattering theory. We predict an enhancement of the heat transfer as we increase the depth of the corrugations while keeping the distance of closest approach fixed. We interpret this effect in terms of the evolution of plasmonic and guided modes as a function of the grating's geometry.
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
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
2007-01-01T23:59:59.000Z
Passive cooling via natural circulation of gas after a loss of coolant (LOCA) accident is one of the major goals of the Gas-cooled Fast Reactor (GFR). Due to its high surface heat flux and low coolant velocities under ...
Error Analysis of Heat Transfer for Finned-Tube Heat-Exchanger Text-Board
Chen, Y.; Zhang, J.
2006-01-01T23:59:59.000Z
influences heat transfer in air side. Finally, this paper indicates that the key problem of reducing heat transfer in water side is water temperature measurement of the in-out pipe of heat-exchanger, and wet bulb temperature difference is a key to decrease...
Siewert, Charles E.
-grey heat transfer model is that of SIMMONS and FERZIGER(~)who used the normal modes(4) of the equation
Heat transfer between elastic solids with randomly rough surfaces
B. N. J. Persson; B. Lorenz; A. I. Volokitin
2009-08-27T23:59:59.000Z
We study the heat transfer between elastic solids with randomly rough surfaces. We include both the heat transfer from the area of real contact, and the heat transfer between the surfaces in the noncontact regions. We apply a recently developed contact mechanics theory, which accounts for the hierarchical nature of the contact between solids with roughness on many different length scales. For elastic contact, at the highest (atomic) resolution the area of real contact typically consists of atomic (nanometer) sized regions, and we discuss the implications of this for the heat transfer. For solids with very smooth surfaces, as is typical in many modern engineering applications, the interfacial separation in the non-contact regions will be very small, and for this case we show the importance of the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies.
An upgraded heat transfer fluid eliminates odors and leaks
NONE
1995-10-01T23:59:59.000Z
At Morton, persistent leakage of an aromatics-based heat transfer fluid left its mark--a black, oxidized residue at flange and valve locations. By switching to a high-purity fluid from a paraffinic hydrocarbon base stock, the firm eliminated odors and sticky residue, and improved heat transfer. After four years of operation with the paraffinic heat transfer fluid, Morton continues to have no odor problems and virtually no flange or packing leakage. As an added bonus, the heat transfer coefficient of the new fluid allows Morton to operate the systems 10--15 F cooler than when the company used the traditional, aromatic fluid. This has cut fuel use and reduced the potential for thermal damage to the heat transfer fluid, process fluid and process equipment.
Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.
2005-01-01T23:59:59.000Z
Studies Using the Yucca Mountain Unsaturated Zone Model,Unsaturated Zone at Yucca Mountain, Nevada, to Thermal LoadUnsaturated Zone, Yucca Mountain, Nevada, Water-Resources
Author's personal copy Radiative heat transfer in enhanced hydrogen
Pilon, Laurent
Author's personal copy Radiative heat transfer in enhanced hydrogen outgassing of glass Rei radiation. Combined conduction, radiation, and mass transfer were accounted for by solving the one-dimensional transient mass and energy conservation equations along with the steady-state radiative transfer equation
Roll Wave Effects on Annular Condensing Heat Transfer in Horizontal PCCS Condenser Tube
Masaya Kondo; Hideo Nakamura; Yoshinari Anoda [Japan Atomic Energy Research Institute, Tokai-mura 319-1195 (Japan); Sadanori Saishu; Hiroyuki Obata; Rumi Shimada [Japan Atomic Power Company (Japan); Shinichi Kawamura [Tokyo Electric Power Company, Incorporated, 1-3, Uchisaiwai-cho 1-chome, Chiyoda-ku, Tokyo, 1008560 (Japan)
2002-07-01T23:59:59.000Z
A horizontal in-tube condensation heat exchanger is under investigation to be used for a passive containment cooling system (PCCS) of a next generation-type BWR. The flow conditions in the horizontal condenser tube were observed both visually and by local void fraction fluctuation. The observed flow regimes at a rated condition were annular flow at the tube inlet, and turned gradually into wavy flow and smooth stratified flow along the length of the tube. It was found further that frequency of the roll waves that appear on the liquid film in the annular flow is closely related to the measured local condensation heat transfer coefficient. Based on the flow observation, the roll wave frequency and measured condensation heat transfer coefficient, a model is proposed which predicts the condensation heat transfer coefficient particularly for annular flows around the tube inlet region. The proposed heat transfer model predicts well the influences of pressure, local gas-phase velocity and film thickness. (authors)
Heat transfer and film cooling with steam injection
Conklin, Gary Eugene
1982-01-01T23:59:59.000Z
HEAT TRANSFER AND FILM COOLING WITH STEAM INJECTION A Thesis by GARY EUGENE CONKLIN Submitted to the Graduate College of Texas AIM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1982 Major... Subject: Mechanical Engineering HEAT TRANSFER AND FILM COOLING WITH STEAM INJECTION A Thesis by GARY EUGENE CONKLIN Approved as to style and content by: (Chairm of Committee) (Member) (Memb e r) (Me r (Head Departme ) May 1982 ABSTRACT Heat...
6th World Conference on Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics
Kasagi, Nobuhide
in order to avoid the effect of interaction of channels in multi-microchannels. Finally, a heat transfer model based on empirical correlations should be established for engineering applications. 2
Heat and mass transfer in bubble column dehumidifiers for HDH desalination
Tow, Emily W
2014-01-01T23:59:59.000Z
Heat and mass transfer processes governing the performance of bubble dehumidifier trays are studied in order to develop a predictive model and design rules for efficient and economical design of bubble column dehumidifiers ...
Research on Convective Heat Transfer and Mass Transfer of the Evaporator in Micro/Mini-Channel
Su, J.; Li, J.
2006-01-01T23:59:59.000Z
With the development of science and technology, various heating and cooling equipment have a development trend of micromation. Micro-fabrication processes make it possible to conduct research on condensation heat transfer in micro-channels. Based...
Dual circuit embossed sheet heat transfer panel
Morgan, G.D.
1984-02-21T23:59:59.000Z
A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed to form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet. 6 figs.
Enhanced two phase flow in heat transfer systems
Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D
2013-12-03T23:59:59.000Z
A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.
Natural convection heat transfer from two horizontal cylinders
Reymond, Olivier; Murray, Darina B. [Department of Mechanical and Manufacturing Engineering, Trinity College Dublin (Ireland); O'Donovan, Tadhg S. [School of Engineering and Physical Sciences, Heriot-Watt University, Nasmyth Building, Edinburgh EH14 4AS (United Kingdom)
2008-09-15T23:59:59.000Z
Natural convection heat transfer from a single horizontal cylinder and a pair of vertically aligned horizontal cylinders is investigated. Surface heat transfer distributions around the circumference of the cylinders are presented for Rayleigh numbers of 2 x 10{sup 6}, 4 x 10{sup 6} and 6 x 10{sup 6} and a range of cylinder spacings of 1.5, 2 and 3 diameters. With a cylinder pairing the lower cylinder is unaffected by the presence of the second cylinder; the same is true of the upper cylinder if the lower one is not heated. However, when both cylinders are heated it has been found that a plume rising from the heated lower cylinder interacts with the upper cylinder and significantly affects the surface heat transfer distribution. Spectral analysis of surface heat transfer signals has established the influence of the plume oscillations on the heat transfer. Thus, when the plume from the lower cylinder oscillates out of phase with the flow around the upper cylinder it increases the mixing and results in enhanced heat transfer. (author)
New tube bundle heat transfer correlations and flow regime maps for a Once Through Steam Generator
Blanchat, Thomas Kevin
1988-01-01T23:59:59.000Z
completed which allow the user to input the pitch and tube o. d. for the system. Predicted RELAP5/MOD2 heat transfer coefficients from correlations have been reviewed for single phase liquid convection, subcooled, and saturated nu- cleate boiling... of the OTSG model to determine the "model efFects" prior to changing any thermal ? hydraulic correlations. These studies inves- tigated the effects of hydraulic diameter, tube bundle surface heat transfer area, snd inlet feedwater subcooling, in addition...
Tetreault-Friend, Melanie
2014-01-01T23:59:59.000Z
Predicting the conditions of critical heat flux (CHF) is of considerable importance for safety and economic reasons in heat transfer units, such as in nuclear power plants. It is greatly advantageous to increase this thermal ...
Nano-engineering the boiling surface for optimal heat transfer rate and critical heat flux
Phillips, Bren Andrew
2011-01-01T23:59:59.000Z
The effects on pool boiling characteristics such as critical heat flux and the heat transfer coefficient of different surface characteristics such as surface wettability, roughness, morphology, and porosity are not well ...
Gaskill, Travis
2012-02-14T23:59:59.000Z
The present study has focused on the use of coil heat exchangers (CHEs) with microencapsulated phase change material (MPCM) slurries to understand if CHEs can yield greater rates of heat transfer. An experimental study was conducted using a...
The deterioration in heat transfer to fluids at supercritical pressure and high heat fluxes
Shiralkar, B. S.
1968-01-01T23:59:59.000Z
At slightly supercritical pressure and in the neighborhood of the pseudo-critical temperature (defined as the temperature corresponding to the peak in specific heat at the operating pressure), the heat transfer coefficient ...
Heat transfer near spacer grids in rod bundles
Yoder, G.L.
1985-01-01T23:59:59.000Z
Heat transfer data from several sources have been assembled which show the effect of spacer grids on local heat transfer within a rod bundle. Both single phase (air and steam) data and two phase (steam/water) data show heat transfer augmentation in the grid region. Heat transfer improvement immediately beyond the grid ranges from a few percent to over fifty percent in these experiments, depending on flow conditions. The data are examined using several nondimensional parameters which relate the above effects to known quantities. The relative effect of the grid on local heat transfer is altered by both the Reynolds number and blockage ratio. Twenty to thirty hydraulic diameters are required before the local effect of the grid dissipates. Locally, both the single phase and two phase data show the same trends. Comparison of the single and two phase data also shown some differences. Some film boiling data indicate that an altered heat transfer regime may exist near the grid. High rod heat transfer coefficients at the grid locations indicate either a rewet of the rods or at least a change from film boiling to transition boiling near the spacer. The comparison also indicates that the film boiling data is affected on a global as well as local basis. This is due to the effect of the grid on the liquid distribution.
Impingement cooling and heat transfer measurement using transient liquid crystal technique
Huang, Yizhe
1996-01-01T23:59:59.000Z
is used in this study to obtain the detailed heat transfer coefficient. Results show that a higher Reynolds number increases heat transfer over the entire impingement target surface. The flow exit orientation with crossflow affects the heat transfer...
Heat Transfer Boundary Conditions in the RELAP5-3D Code
Richard A. Riemke; Cliff B. Davis; Richard R. Schultz
2008-05-01T23:59:59.000Z
The heat transfer boundary conditions used in the RELAP5-3D computer program have evolved over the years. Currently, RELAP5-3D has the following options for the heat transfer boundary conditions: (a) heat transfer correlation package option, (b) non-convective option (from radiation/conduction enclosure model or symmetry/insulated conditions), and (c) other options (setting the surface temperature to a volume fraction averaged fluid temperature of the boundary volume, obtaining the surface temperature from a control variable, obtaining the surface temperature from a time-dependent general table, obtaining the heat flux from a time-dependent general table, or obtaining heat transfer coefficients from either a time- or temperature-dependent general table). These options will be discussed, including the more recent ones.
Heat transfer rates in fixed bed catalytic reactors
Levelton, Bruce Harding
1951-01-01T23:59:59.000Z
HEAT TRANSFER RATES IN FIXED BED CATALYTIC REACTORS H EATTRNSFSAIX DB DNCLR YFNOAXa rRJRuSIX nSeR 1951i HssNIJFu FT SI TSBuR FXO LIXSRXS NRLIeeRXOROt HEAT TRANSFER RATES IN FIXED BED CATALYTIC REACTORS H EATTRNSFSAIX BSar DNCLR YFNOAXa r...RJRuSIX June 1951 HEAT TRANSFER RATES IN FIXED BED CATALYTIC REACTORS A Dissertation Submitted to the Faculty of the Agricultural and Mechanical College of Texas in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Major...
Convective heat-transfer predictions and experiments in an IC engine
Yang, J.
1988-01-01T23:59:59.000Z
Knowledge of heat transfer in engines is critical to engine efficiency, hydrocarbon and particulate emissions, engine-component thermal stress analysis, as well as engine cycle simulation accuracy. However, the relationship between pressure, heat-release rate, turbulent flow, and the heat transfer is not known. Previous engine heat-transfer models, including the law-of-the-wall used for multi-dimensional calculations, are based on a steady-state incompressible flow which is not the case in engines. A new heat-transfer model was developed which is based on an approximate solution of the linearized and normalized one-dimensional energy equation. An empirical turbulent viscosity relation has been used to include the effects of turbulence. The response of this equation to a unit step function was acquired by multi-parameter fit to the numerical solution. The effects of initial thermal boundary layer formed before compression were also considered. The proposed heat-transfer model was extended to include the effects of combustion. Thus, the relationship between pressure variation, spatially-resolved heat-release rate, local flow condition, initial thermal boundary layer, and the surface heat flux and temperature profile was developed.
Fourier analysis of conductive heat transfer for glazed roofing materials
Roslan, Nurhana Lyana; Bahaman, Nurfaradila; Almanan, Raja Noorliyana Raja; Ismail, Razidah [Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Zakaria, Nor Zaini [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)
2014-07-10T23:59:59.000Z
For low-rise buildings, roof is the most exposed surface to solar radiation. The main mode of heat transfer from outdoor via the roof is conduction. The rate of heat transfer and the thermal impact is dependent on the thermophysical properties of roofing materials. Thus, it is important to analyze the heat distribution for the various types of roofing materials. The objectives of this paper are to obtain the Fourier series for the conductive heat transfer for two types of glazed roofing materials, namely polycarbonate and polyfilled, and also to determine the relationship between the ambient temperature and the conductive heat transfer for these materials. Ambient and surface temperature data were collected from an empirical field investigation in the campus of Universiti Teknologi MARA Shah Alam. The roofing materials were installed on free-standing structures in natural ventilation. Since the temperature data are generally periodic, Fourier series and numerical harmonic analysis are applied. Based on the 24-point harmonic analysis, the eleventh order harmonics is found to generate an adequate Fourier series expansion for both glazed roofing materials. In addition, there exists a linear relationship between the ambient temperature and the conductive heat transfer for both glazed roofing materials. Based on the gradient of the graphs, lower heat transfer is indicated through polyfilled. Thus polyfilled would have a lower thermal impact compared to polycarbonate.
16 Heat Transfer and Air Flow in a Domestic Refrigerator
Paris-Sud XI, Université de
445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR Génie Industriel...............................................447 16.2.1 Studies in Domestic Refrigerators...................................................................................... 451 16.3 Cold Production System in Domestic Refrigerators
Small distance expansion for radiative heat transfer between curved objects
Golyk, Vladyslav A.
We develop a small distance expansion for the radiative heat transfer between gently curved objects, in terms of the ratio of distance to radius of curvature. A gradient expansion allows us to go beyond the lowest-order ...
Enhancement of Pool Boiling Heat Transfer in Confined Space
Hsu, Chia-Hsiang
2014-05-05T23:59:59.000Z
Pool boiling is an effective method used in many technical applications for a long time. Its highly efficient heat transfer performance results from not only the convection effect but also the phase change process in pool boiling. Pool boiling...
Survey and evaluation of techniques to augment convective heat transfer
Bergles A. E.
1965-01-01T23:59:59.000Z
This report presents a survey and evaluation of the numerous techniques which have been shown to augment convective heat transfer. These techniques are: surface promoters, including roughness and treatment; displaced ...
Numerical Study of Flow and Heat Transfer in Rotating Microchannels
Roy, Pratanu
2014-10-07T23:59:59.000Z
Investigation of fluid flow and heat transfer in rotating microchannels is important for centrifugal microfluidics, which has emerged as an advanced technique in biomedical applications and chemical separations. The centrifugal force...
Influence of Infrared Radiation on Attic Heat Transfer
Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.
1985-01-01T23:59:59.000Z
An experimental study concerned with different modes of heal transfer in fibrous and cellulose insulating material is presented. A series of experiments were conducted using an attic simulator to determine the effects of ventilation on attic heat...
Enhancement of Pool Boiling Heat Transfer in Confined Space
Hsu, Chia-Hsiang
2014-05-05T23:59:59.000Z
Pool boiling is an effective method used in many technical applications for a long time. Its highly efficient heat transfer performance results from not only the convection effect but also the phase change process in pool boiling. Pool boiling...
Heat Transfer Enhancement in Rectangular Channel with Compound Cooling Techniques
Krad, Belal
2013-11-27T23:59:59.000Z
Various compound internal cooling techniques were investigated in this experiment to see which combinations can offer the greatest heat transfer. Combinations of rib turbulators as well as pin0fins were used in different configurations in order...
Samady, Mezhgan Frishta
2011-01-01T23:59:59.000Z
transient the heat transfer model. T h i s required the roofto develop and calibrate heat transfer models to be able toE S station, the heat transfer models described i n sections
Heat transfer enhancement resulting from induction electrohydrodynamic pumping
Margo, Bryan David
1992-01-01T23:59:59.000Z
HEAT TRANSFER ENHANCEMENT RESULTING FROM INDUCTION ELECTROHYDRODYNAMIC PUMPING A Thesis by BRYAN DAVID MARGO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1992 Major Subject: Mechanical Engineering HEAT TRANSFER ENHANCEMENT RESULTING FROM INDUCTION ELECTROHYDRODYNAMIC PUMPING A Thesis by BRYAN DAVID MARGO Approved as to style and content by: Jamal Seyed- Yagoobi (Chair...
Mpemba effect, Newton cooling law and heat transfer equation
Vladan Pankovic; Darko V. Kapor
2012-12-11T23:59:59.000Z
In this work we suggest a simple theoretical solution of the Mpemba effect in full agreement with known experimental data. This solution follows simply as an especial approximation (linearization) of the usual heat (transfer) equation, precisely linearization of the second derivation of the space part of the temperature function (as it is well-known Newton cooling law can be considered as the effective approximation of the heat (transfer) equation for constant space part of the temperature function).
Heat transfer enhancement resulting from induction electrohydrodynamic pumping
Margo, Bryan David
1992-01-01T23:59:59.000Z
HEAT TRANSFER ENHANCEMENT RESULTING FROM INDUCTION ELECTROHYDRODYNAMIC PUMPING A Thesis by BRYAN DAVID MARGO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1992 Major Subject: Mechanical Engineering HEAT TRANSFER ENHANCEMENT RESULTING FROM INDUCTION ELECTROHYDRODYNAMIC PUMPING A Thesis by BRYAN DAVID MARGO Approved as to style and content by: Jamal Seyed- Yagoobi (Chair...
Experimental and numerical study of laminar forced convection heat transfer for a dimpled heat sink
Park, Do Seo
2009-05-15T23:59:59.000Z
heat transfer can be increased. Pin fins, protruding ribs (turbulators), louvered fins, offset-strip fins, slit fins and vortex generators are typical methods. The pattern and placements are suitably chosen based on the required cooling. 3 Heat... concavities- hemispheric and tear drop. Concavities serve as vortex generators to promote turbulent mixing in the bulk flow to enhance the heat transfer at Re H = 10,000 to 50,000, H/d of 0.5, 1.5, 3.0 and ? /d =0.575. Heat transfer enhancement was 2...
Journal ofEnhanced Heat Transfer, 18 (3): 177-190 (2011) THERMALLY-INDUCED OSCILLATORY FLOW AND
Zhang, Yuwen
2011-01-01T23:59:59.000Z
AND HEAT TRANSFER IN AN OSCILLATING HEAT PIPE Wei Shao & Yuwen Zhang* Department ofMechanical and Aerospace - a building block ofan Oscillating Heat Pipe (OHP) - is modeled by analyzing evaporation and condensation flow and by empirical correlationsfor a turbulent liquid flow. KEY WORDS: oscillating heat pipe
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
Finite element analysis of conjugate heat transfer in axisymmetric pipe flows
Fithen, Robert Miller
1987-01-01T23:59:59.000Z
to x=L. In the unheated section of the tube x(0 and x)L, adiabatic condition apply on the tube exterior. A schematic of the heat transfer model is shown in figure l. The energy equation for i'ully developed laminar flow is 2pcrub 1 ? ? = Kf... ? + ? +? Equation (1) expressed in non ? dimensional form where &q Pe ctR' R i)R r R=- Ti 2pcsubri Pe = f (2) u(r) ri nine noded lagrangian element Fig. 1 Heat transfer model for a circular tube for constant heat flux for constant temperature case From...
Heat transfer in the plate heat exchanger of an ammonia-synthesis column
Obolentsev, Y.G.; Chus', M.S.; Norobchanskii, O.A.; Teplitshi, Y.S.; Tovazhnyanskii, L.L.
1983-01-01T23:59:59.000Z
The planning and construction of high-capacity synthetic ammonia plants requires the development and fabrication of unique, high unit-power equipment with high technical and economic characteristics. In foreign and domestic practice, tubular heat exchangers with relatively low heat-transfer coefficients are used. Plate heat exchangers are a promising alternative. They are compact and have a high heat energy efficiency and a relatively small metal content. To make an experimental check of the operating capability of a plate heat exchanger under ammonia production conditions, a welded plate heat exchanger was designed for an ammonia synthesis column 800mm in diameter. On prolonged testing (four years), the device provided an autothermal operating mode in the column and the heat transfer coefficient was practically constant for fixed space velocities. Consequently, the heat exchange surface was not contaminated significantly with catalyst dust, confirmed by visual observation of the heat exchanger after disassembly.
Proceedings of HT2005 2005 ASME Summer Heat Transfer Conference
Aguilar, Guillermo
Proceedings of HT2005 2005 ASME Summer Heat Transfer Conference July 17-22, 2005, San Francisco absorption and increasing the thickness of the protected region. A 2D finite volume numerical code based interface location density (kg m-3 ) 1 Copyright © 2005 by ASME Proceedings of HT2005 2005 ASME Summer Heat
Heat transfer to air-water two-phase flow in slug/churn region
Wadekar, V.V. [AEA Technology, Harwell (United Kingdom). Heat Transfer and Fluid Flow Service; Tuzla, K.; Chen, J.C. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Chemical Engineering
1996-12-31T23:59:59.000Z
Measured heat transfer data for air-water two-phase flow in the slug/churn flow region are reported. The measurements were obtained from a 1.3 m tall, 15.7 mm diameter vertical tube test-section. It is observed that the data exhibit different heat transfer characteristics to those predicted by the standard correlations for the convective component of flow boiling heat transfer. Comparison with the predictions of a slug flow model for evaporation shows a significant overprediction of the data. The reason for the overprediction is attributed to the sensible heating requirement of the gas phase. The slug flow model is therefore suitably modified for non-evaporating two-phase flow. This specially adapted model is found to give reasonably good predictions of the measured data.
INVESTIGATING THE EFFECT OF HEATING METHOD ON POOL BOILING HEAT TRANSFER
Kandlikar, Satish
INVESTIGATING THE EFFECT OF HEATING METHOD ON POOL BOILING HEAT TRANSFER Satish G. Kandlikar Department Rochester Institute of Technology Rochester, NY, USA Phone: (716) 475-6728; Fax: (716) 475-7710 E-mail: SGKEME@RIT.EDU ABSTRACT Pool boiling experiments are generally conducted with electrically heated
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
Near field radiative heat transfer between two nonlocal dielectrics
Singer, F; Joulain, Karl
2015-01-01T23:59:59.000Z
We explore in the present work the near-field radiative heat transfer between two semi-infinite parallel nonlocal dielectric planes by means of fluctuational electrodynamics. We use atheory for the nonlocal dielectric permittivityfunction proposed byHalevi and Fuchs. This theory has the advantage to includedifferent models performed in the literature. According to this theory, the nonlocal dielectric function is described by a Lorenz-Drude like single oscillator model, in which the spatial dispersion effects are represented by an additional term depending on the square of the total wavevector k. The theory takes into account the scattering of the electromagneticexcitation at the surface of the dielectric material, which leads to the need of additional boundary conditions in order to solve Maxwell's equations and treat the electromagnetic transmission problem. The additional boundary conditions appear as additional surface scattering parameters in the expressions of the surface impedances. It is shown that the...
Active heat transfer enhancement in integrated fan heat sinks
Staats, Wayne Lawrence
2012-01-01T23:59:59.000Z
Modern computer processors require significant cooling to achieve their full performance. The "efficiency" of heat sinks is also becoming more important: cooling of electronics consumes 1% of worldwide electricity use by ...
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
Heat transfer to a silicon carbide/water nanofluid.
Yu, W.; France , D. M.; Smith, D. S.; Singh, D.; Timofeeva, E. V.; Routbort, J. L.; Univ. of Illinois at Chicago
2009-07-01T23:59:59.000Z
Heat transfer experiments were performed with a water-based nanofluid containing 170-nm silicon carbide particles at a 3.7% volume concentration and having potential commercial viability. Heat transfer coefficients for the nanofluid are presented for Reynolds numbers ranging from 3300 to 13,000 and are compared to the base fluid water on the bases of constant Reynolds number, constant velocity, and constant pumping power. Results were also compared to predictions from standard liquid correlations and a recently altered nanofluid correlation. The slip mechanisms of Brownian diffusion and thermophoresis postulated in the altered correlation were investigated in a series of heating and cooling experiments.
Critical thickness of an optimum extended surface characterized by uniform heat transfer coefficient
Leontiou, Theodoros
2015-01-01T23:59:59.000Z
We consider the heat transfer problem associated with a periodic array of extended surfaces (fins) subjected to convection heat transfer with a uniform heat transfer coefficient. Our analysis differs from the classical approach as (i) we consider two-dimensional heat conduction and (ii) the base of the fin is included in the heat transfer process. The problem is modeled as an arbitrary two-dimensional channel whose upper surface is flat and isothermal, while the lower surface has a periodic array of extensions/fins which are subjected to heat convection with a uniform heat transfer coefficient. Using the generalized Schwarz-Christoffel transformation the domain is mapped onto a straight channel where the heat conduction problem is solved using the boundary element method. The boundary element solution is subsequently used to pose a shape optimization problem, i.e. an inverse problem, where the objective function is the normalized Shape Factor and the variables of the optimization are the parameters of the Sch...
Pool boiling heat transfer characteristics of nanofluids
Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology
2007-01-01T23:59:59.000Z
Nanofluids are engineered colloidal suspensions of nanoparticles in water, and exhibit a very significant enhancement (up to 200%) of the boiling Critical Heat Flux (CHF) at modest nanoparticle concentrations (50.1% by ...
The influence of multiple tubes on the tube-to-bed heat transfer in a fluidised bed L.M. Armstrong Keywords: CFD Heat transfer Fluidised bed Eulerian a b s t r a c t There have been few studies modelling both flow and heat transfer in fluidised beds. The kinetic theory of granular flow (KTGF) has been used
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Phillips, B.A.; Zawacki, T.S.
1998-07-21T23:59:59.000Z
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.
Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)
1998-07-21T23:59:59.000Z
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.
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
Modeling of pulsating heat pipes.
Givler, Richard C.; Martinez, Mario J.
2009-08-01T23:59:59.000Z
This report summarizes the results of a computer model that describes the behavior of pulsating heat pipes (PHP). The purpose of the project was to develop a highly efficient (as compared to the heat transfer capability of solid copper) thermal groundplane (TGP) using silicon carbide (SiC) as the substrate material and water as the working fluid. The objective of this project is to develop a multi-physics model for this complex phenomenon to assist with an understanding of how PHPs operate and to be able to understand how various parameters (geometry, fill ratio, materials, working fluid, etc.) affect its performance. The physical processes describing a PHP are highly coupled. Understanding its operation is further complicated by the non-equilibrium nature of the interplay between evaporation/condensation, bubble growth and collapse or coalescence, and the coupled response of the multiphase fluid dynamics among the different channels. A comprehensive theory of operation and design tools for PHPs is still an unrealized task. In the following we first analyze, in some detail, a simple model that has been proposed to describe PHP behavior. Although it includes fundamental features of a PHP, it also makes some assumptions to keep the model tractable. In an effort to improve on current modeling practice, we constructed a model for a PHP using some unique features available in FLOW-3D, version 9.2-3 (Flow Science, 2007). We believe that this flow modeling software retains more of the salient features of a PHP and thus, provides a closer representation of its behavior.
Hierarchical Modeling for Population-Based Heat Exchanger Design
Geb, David
2013-01-01T23:59:59.000Z
Catton, I. , 2001, "NON-INTRUSIVE HEAT TRANSFER COEFFICIENTCatton, I. , 2010, "Non- Intrusive Heat Transfer Coefficientthis section, the non-intrusive induction heating transient
Forced convective heat transfer in channels with internal longitudinal fins
Ong, Liang Eng
1987-01-01T23:59:59.000Z
and f in surface temperatures (g ? $b), and the local surface heat flux (q"/Q"). The relative amounts of heat transfer from the exposed channel wall, the surface of the fin along the fin axis, and the fin tip are also calculated individually... heat flux on the tip of the fin. 18 4. RESULTS AND DISCUSSION The results of the computational investigation are presented in this section. They consist of the d istr ibut ions of the d imens ionless temperature (4w ? gb), and the heat flux (q"/Q...
ECI International Conference on Boiling Heat Transfer Florianpolis-SC-Brazil, 3-7 May 2009
Yanikoglu, Berrin
. Recently the study of heat transfer in micro pin fin heat sinks has been extended to flow boiling by Koar and Peles (2006c), who studied boiling heat transfer in a hydrofoil-based micro pin fin heat sinkECI International Conference on Boiling Heat Transfer Florianópolis-SC-Brazil, 3-7 May 2009
Shape factors in conductive heat transfer
Faulkner, Richard Campbell
1954-01-01T23:59:59.000Z
flow bg gonduotion 'between flat parallel plates with insulated edges and a uniform oxoes-seotional area for heat flow. )see Pig. IX) Kx. steady state, -- 0 Shen ? X :, . x a eg Sub st ' tut ills boundary cordi'tionel el (0) e e@ to + ((t...
Heat transfer coefficients for atmospheric coolers
Robinson, Robert McCollum
1950-01-01T23:59:59.000Z
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 1 0 6 kppendixo ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 110 li Heating System. . ~ ~ ~ ~ ~ . ~ . ? ~ ~ ~ ~ Page ~ . ~ 25 2. Cooling System. . . . . . . ~ ~ ~ ~ ~ 28 3. Outside F11m Coeffioient versus... per Minute. . . . 95 6i Outside Film Coeffioient versus Tube Row Depth; Shell Side Rata, 21 Gallons per Minuteo ~ ~ ~ ~ ~ ~ o ~ e ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ I ~ ~ Ii ~ ~ o ~ ~ ~ ~ 96 VS Outside F1lm Coeffioient vers1s Tube Row Depth...
The effect of the number of wavebands used in spectral radiation heat transfer calculations
Chang, S. L.; Golchert, B.; Petrick, M.
2000-05-09T23:59:59.000Z
A spectral radiation heat transfer model that conserves emitted and absorbed energy has been developed and used to model the combustion space of an industrial glass furnace. This comprehensive radiation heat transfer model coupled with a computational fluid dynamics (CFD) code was used to investigate the effect of spectral dependencies on the computed results. The results of this work clearly indicate the need for a spectral approach as opposed to a gray body approach since the gray body approach (one waveband) severely underestimates the energy emitted via radiation.
Indirect Heat Transfer Technology For Waste Heat Recovery Can Save You Money
Beyrau, J. A.; Bogel, N. G.; Seifert, W. F.; Wuelpern, L. E.
1984-01-01T23:59:59.000Z
) that eliminates the large diameter ducting associated with the direct heat transfer technology. This paper presents a method to project, during the preliminary engineering phase of a flue gas energy recovery project, the capital cost and payback period for systems...
Nuclear reactor fuel element having improved heat transfer
Garnier, J.E.; Begej, S.; Williford, R.E.; Christensen, J.A.
1982-03-03T23:59:59.000Z
A nuclear reactor fuel element having improved heat transfer between fuel material and cladding is described. The element consists of an outer cladding tube divided into an upper fuel section containing a central core of fissionable or mixed fissionable and fertile fuel material, slightly smaller in diameter than the inner surface of the cladding tube and a small lower accumulator section, the cladding tube being which is filled with a low molecular weight gas to transfer heat from fuel material to cladding during irradiation. A plurality of essentially vertical grooves in the fuel section extend downward and communicate with the accumulator section. The radial depth of the grooves is sufficient to provide a thermal gradient between the hot fuel surface and the relatively cooler cladding surface to allow thermal segregation to take place between the low molecular weight heat transfer gas and high molecular weight fission product gases produced by the fuel material during irradiation.
Preliminary Heat Transfer Studies for the Double Shell Tanks (DST) Transfer Piping
HECHT, S.L.
2000-02-15T23:59:59.000Z
Heat transfer studies were made to determine the thermal characteristics of double-shell tank transfer piping under both transient and steady-state conditions. A number of design and operation options were evaluated for this piping system which is in its early design phase.
Investigation of spectral radiation heat transfer and NO{sub x} emission in a glass furnace
Golchert, B.; Zhou, C. Q.; Chang, S. L.; Petrick, M.
2000-08-02T23:59:59.000Z
A comprehensive radiation heat transfer model and a reduced NOx kinetics model were coupled with a computational fluid dynamics (CFD) code and then used to investigate the radiation heat transfer, pollutant formation and flow characteristics in a glass furnace. The radiation model solves the spectral radiative transport equation in the combustion space of emitting and absorbing media, i.e., CO{sub 2}, H{sub 2}O, and soot and emission/reflection from the furnace crown. The advanced numerical scheme for calculating the radiation heat transfer is extremely effective in conserving energy between radiation emission and absorption. A parametric study was conducted to investigate the impact of operating conditions on the furnace performance with emphasis on the investigation into the formation of NOx.
Conjugate heat transfer analysis using the Calore and Fuego codes.
Francis, Nicholas Donald, Jr.
2007-09-01T23:59:59.000Z
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.
Radiative heat transfer in 2D Dirac materials
Pablo Rodriguez-Lopez; Wang-Kong Tse; Diego A. R. Dalvit
2015-02-02T23:59:59.000Z
We compute the radiative heat transfer between two sheets of 2D Dirac materials, including topological Chern insulators and graphene, within the framework of the local approximation for the optical response of these materials. In this approximation, which neglects spatial dispersion, we derive both numerically and analytically the short-distance asymptotic of the near-field heat transfer in these systems, and show that it scales as the inverse of the distance between the two sheets. Finally, we discuss the limitations to the validity of this scaling law imposed by spatial dispersion in 2D Dirac materials.
Combined heat and mass transfer device for improving separation process
Tran, Thanh Nhon (Flossmoor, IL)
1999-01-01T23:59:59.000Z
A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area.
Enhanced boiling heat transfer in horizontal test bundles
Trewin, R.R.; Jensen, M.K.; Bergles, A.E.
1994-08-01T23:59:59.000Z
Two-phase flow boiling from bundles of horizontal tubes with smooth and enhanced surfaces has been investigated. Experiments were conducted in pure refrigerant R-113, pure R-11, and mixtures of R-11 and R-113 of approximately 25, 50, and 75% of R-113 by mass. Tests were conducted in two staggered tube bundles consisting of fifteen rows and five columns laid out in equilateral triangular arrays with pitch-to-diameter ratios of 1.17 and 1.5. The enhanced surfaces tested included a knurled surface (Wolverine`s Turbo-B) and a porous surface (Linde`s High Flux). Pool boiling tests were conducted for each surface so that reference values of the heat transfer coefficient could be obtained. Boiling heat transfer experiments in the tube bundles were conducted at pressures of 2 and 6 bar, heat flux values from 5 to 80 kW/m{sup 2}s, and qualities from 0% to 80%, Values of the heat transfer coefficients for the enhanced surfaces were significantly larger than for the smooth tubes and were comparable to the values obtained in pool boiling. It was found that the performance of the enhanced tubes could be predicted using the pool boiling results. The degradation in the smooth tube heat transfer coefficients obtained in fluid mixtures was found to depend on the difference between the molar concentration in the liquid and vapor.
Combined heat and mass transfer device for improving separation process
Tran, T.N.
1999-08-24T23:59:59.000Z
A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area. 12 figs.
Matthias Krüger; Giuseppe Bimonte; Thorsten Emig; Mehran Kardar
2012-07-16T23:59:59.000Z
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.
Natural convection heat transfer within horizontal spent nuclear fuel assemblies
Canaan, R.E.
1995-12-01T23:59:59.000Z
Natural convection heat transfer is experimentally investigated in an enclosed horizontal rod bundle, which characterizes a spent nuclear fuel assembly during dry storage and/or transport conditions. The basic test section consists of a square array of sixty-four stainless steel tubular heaters enclosed within a water-cooled rectangular copper heat exchanger. The heaters are supplied with a uniform power generation per unit length while the surrounding enclosure is maintained at a uniform temperature. The test section resides within a vacuum/pressure chamber in order to subject the assembly to a range of pressure statepoints and various backfill gases. The objective of this experimental study is to obtain convection correlations which can be used in order to easily incorporate convective effects into analytical models of horizontal spent fuel systems, and also to investigate the physical nature of natural convection in enclosed horizontal rod bundles in general. The resulting data consist of: (1) measured temperatures within the assembly as a function of power, pressure, and backfill gas; (2) the relative radiative contribution for the range of observed temperatures; (3) correlations of convective Nusselt number and Rayleigh number for the rod bundle as a whole; and (4) correlations of convective Nusselt number as a function of Rayleigh number for individual rods within the array.
Cheeti, Satish K.R.
1993-01-01T23:59:59.000Z
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...
Nonlocal study of the near field radiative heat transfer between two n-doped semiconductors
Singer, F; Joulain, Karl
2015-01-01T23:59:59.000Z
We study in this work the near-field radiative heat transfer between two semi-infinite parallel planes of highly n-doped semiconductors. Using a nonlocal model of the dielectric permittivity, usually used for the case of metallic planes, we show that the radiative heat transfer coefficientsaturates as the separation distance is reduced for high doping concentration. These results replace the 1/d${}^2$ infinite divergence obtained in the local model case. Different features of the obtained results are shown to relate physically to the parameters of the materials, mainly the doping concentration and the plasmon frequency.
Hauser, S.G.; Kreid, D.K.; Johnson, B.M.
1981-04-01T23:59:59.000Z
This second part of a two-part paper summarizes the experimental evaluation of a plate finned heat exchanger both with and without the surface wetted by a flowing film of water. The results indicate an increase in heat transfer during wet operation of two to five times over that of dry operation for the same meteorological conditions. The deluge model is shown to accurately predict the wet performance using an experimentally determined deluge film coefficient and the dry performance characteristics.
Chiu, Rong-Shi Paul (Glenmont, NY); Hasz, Wayne Charles (Pownal, VT); Johnson, Robert Alan (Simpsonville, SC); Lee, Ching-Pang (Cincinnati, OH); Abuaf, Nesim (Lincoln City, OR)
2002-01-01T23:59:59.000Z
An annular turbine shroud separates a hot gas path from a cooling plenum containing a cooling medium. Bumps are cast in the surface on the cooling side of the shroud. A surface coating overlies the cooling side surface of the shroud, including the bumps, and contains cooling enhancement material. The surface area ratio of the cooling side of the shroud with the bumps and coating is in excess of a surface area ratio of the cooling side surface with bumps without the coating to afford increased heat transfer across the element relative to the heat transfer across the element without the coating.
Modeling, Estimation, and Control of Waste Heat Recovery Systems
Luong, David
2013-01-01T23:59:59.000Z
Kan08] for flow through vertical and horizontal tubes. TheFlow Boiling Heat Transfer Inside Horizontal and Vertical Tubes. ”and thin horizontal tube. 2. Working fluid flow modeled as a
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
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 Transfer Study of Polymer Solutions with Different Rigidities
Huang, Yao
2014-05-08T23:59:59.000Z
Chemical Structure DPS Dilute Polymer Solution MW Molecular Weight RCP Rigidity Changing Parameter viii TABLE OF CONTENTS Page ABSTRACT... ...................................................................... 14 2.4 Intrinsic Viscosity ........................................................................................... 18 ix DESCRIPTION OF DILUTE POLYMER SOLUTION (DPS) FORMULATION AND NUMERICAL HEAT TRANSFER AND FLUID DYNAMICS SIMULATION...
Heat transfer in inertial confinement fusion reactor systems
Hovingh, J.
1980-04-23T23:59:59.000Z
The short time and deposition distance for the energy from inertial fusion products results in local peak power densities on the order of 10/sup 18/ watts/m/sup 3/. This paper presents an overview of the various inertial fusion reactor designs which attempt to reduce these peak power intensities and describes the heat transfer considerations for each design.
RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1
Paris-Sud XI, UniversitÃ© de
509 RECENT ADVANCES IN HEAT TRANSFER TO HELIUM 1 C. JOHANNES Service de Recherches AppliquÃ©es, L'hÃ©lium hypercritique. Abstract. - Conditions of thermal exchange in helium 1 are reviewed. Pool boiling thermosi- phon are given. Use of hypercritical helium. REVUE DE PHYSIQUE APPLIQUÃ?E TOME 6, DÃ?CEMBRE 1971, PAGE Introduction
Evaporation and Condensation Heat Transfer Performance of Flammable Refrigerants in a
Oak Ridge National Laboratory
Evaporation and Condensation Heat Transfer Performance of Flammable Refrigerants in a Brazed Plate and Condensation Heat Transfer Performance of Flammable Refrigerants in a Brazed Plate Heat Exchanger Sheila C ........................................................... 8 3. Average relative difference (%) in calculated heat transfer rates for refrigerants and HTF
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with
Paris-Sud XI, Université de
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial-Newtonian boundary layer flow and heat transfer over an exponentially stretch- ing sheet with partial slip boundary. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed sur
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
Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants
Mathur, Anoop [Terrafore Inc.] [Terrafore Inc.
2013-08-14T23:59:59.000Z
A key technological issue facing the success of future Concentrating Solar Thermal Power (CSP) plants is creating an economical Thermal Energy Storage (TES) system. Current TES systems use either sensible heat in fluids such as oil, or molten salts, or use thermal stratification in a dual-media consisting of a solid and a heat-transfer fluid. However, utilizing the heat of fusion in inorganic molten salt mixtures in addition to sensible heat , as in a Phase change material (PCM)-based TES, can significantly increase the energy density of storage requiring less salt and smaller containers. A major issue that is preventing the commercial use of PCM-based TES is that it is difficult to discharge the latent heat stored in the PCM melt. This is because when heat is extracted, the melt solidifies onto the heat exchanger surface decreasing the heat transfer. Even a few millimeters of thickness of solid material on heat transfer surface results in a large drop in heat transfer due to the low thermal conductivity of solid PCM. Thus, to maintain the desired heat rate, the heat exchange area must be large which increases cost. This project demonstrated that the heat transfer coefficient can be increase ten-fold by using forced convection by pumping a hyper-eutectic salt mixture over specially coated heat exchanger tubes. However,only 15% of the latent heat is used against a goal of 40% resulting in a projected cost savings of only 17% against a goal of 30%. Based on the failure mode effect analysis and experience with pumping salt at near freezing point significant care must be used during operation which can increase the operating costs. Therefore, we conclude the savings are marginal to justify using this concept for PCM-TES over a two-tank TES. The report documents the specialty coatings, the composition and morphology of hypereutectic salt mixtures and the results from the experiment conducted with the active heat exchanger along with the lessons learnt during experimentation.
Gustavsen, Arild; Arasteh, Dariush; Jelle, Bjorn Petter; Curcija, Charlie; Kohler, Christian
2008-09-11T23:59:59.000Z
While window frames typically represent 20-30% of the overall window area, their impact on the total window heat transfer rates may be much larger. This effect is even greater in low-conductance (highly insulating) windows that incorporate very low-conductance glazing. Developing low-conductance window frames requires accurate simulation tools for product research and development. Based on a literature review and an evaluation of current methods of modeling heat transfer through window frames, we conclude that current procedures specified in ISO standards are not sufficiently adequate for accurately evaluating heat transfer through the low-conductance frames. We conclude that the near-term priorities for improving the modeling of heat transfer through low-conductance frames are: (1) Add 2D view-factor radiation to standard modeling and examine the current practice of averaging surface emissivity based on area weighting and the process of making an equivalent rectangular frame cavity. (2) Asses 3D radiation effects in frame cavities and develop recommendation for inclusion into the design fenestration tools. (3) Assess existing correlations for convection in vertical cavities using CFD. (4) Study 2D and 3D natural convection heat transfer in frame cavities for cavities that are proven to be deficient from item 3 above. Recommend improved correlations or full CFD modeling into ISO standards and design fenestration tools, if appropriate. (5) Study 3D hardware short-circuits and propose methods to ensure that these effects are incorporated into ratings. (6) Study the heat transfer effects of ventilated frame cavities and propose updated correlations.
Computational model of miniature pulsating heat pipes.
Martinez, Mario J.; Givler, Richard C.
2013-01-01T23:59:59.000Z
The modeling work described herein represents Sandia National Laboratories (SNL) portion of a collaborative three-year project with Northrop Grumman Electronic Systems (NGES) and the University of Missouri to develop an advanced, thermal ground-plane (TGP), which is a device, of planar configuration, that delivers heat from a source to an ambient environment with high efficiency. Work at all three institutions was funded by DARPA/MTO; Sandia was funded under DARPA/MTO project number 015070924. This is the final report on this project for SNL. This report presents a numerical model of a pulsating heat pipe, a device employing a two phase (liquid and its vapor) working fluid confined in a closed loop channel etched/milled into a serpentine configuration in a solid metal plate. The device delivers heat from an evaporator (hot zone) to a condenser (cold zone). This new model includes key physical processes important to the operation of flat plate pulsating heat pipes (e.g. dynamic bubble nucleation, evaporation and condensation), together with conjugate heat transfer with the solid portion of the device. The model qualitatively and quantitatively predicts performance characteristics and metrics, which was demonstrated by favorable comparisons with experimental results on similar configurations. Application of the model also corroborated many previous performance observations with respect to key parameters such as heat load, fill ratio and orientation.
Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids
Raade, Justin; Roark, Thomas; Vaughn, John; Bradshaw, Robert
2013-07-22T23:59:59.000Z
Concentrating solar power (CSP) facilities are comprised of many miles of fluid-filled pipes arranged in large grids with reflective mirrors used to capture radiation from the sun. Solar radiation heats the fluid which is used to produce steam necessary to power large electricity generation turbines. Currently, organic, oil-based fluid in the pipes has a maximum temperature threshold of 400 °C, allowing for the production of electricity at approximately 15 cents per kilowatt hour. The DOE hopes to foster the development of an advanced heat transfer fluid that can operate within higher temperature ranges. The new heat transfer fluid, when used with other advanced technologies, could significantly decrease solar electricity cost. Lower costs would make solar thermal electricity competitive with gas and coal and would offer a clean, renewable source of energy. Molten salts exhibit many desirable heat transfer qualities within the range of the project objectives. Halotechnics developed advanced heat transfer fluids (HTFs) for application in solar thermal power generation. This project focused on complex mixtures of inorganic salts that exhibited a high thermal stability, a low melting point, and other favorable characteristics. A high-throughput combinatorial research and development program was conducted in order to achieve the project objective. Over 19,000 candidate formulations were screened. The workflow developed to screen various chemical systems to discover salt formulations led to mixtures suitable for use as HTFs in both parabolic trough and heliostat CSP plants. Furthermore, salt mixtures which will not interfere with fertilizer based nitrates were discovered. In addition for use in CSP, the discovered salt mixtures can be applied to electricity storage, heat treatment of alloys and other industrial processes.
Heat Transfer Characteristics of Mark 15 Slugs for Different Bonding Conditions
McAllister, J.E. Jr.
2001-08-13T23:59:59.000Z
A numerical heat transfer model based on the HEATING53 conduction code was developed to analyze poor bonding around the endcap of the outer Mark 15 slug. An analytical model could not be developed because of non-uniform heat generation in the core and the arrangement of the various materials in the cylindrical geometry. Results for air gaps are also included; however, they are not considered reasonable poor bond cases because the 300 area inspection tests can detect slugs with air gaps. This reports discusses the test results.
ME 519: THEORY OF HEAT TRANSFER Instructor
Lin, Xi
encountered engineering problems taken from manufacturing, electronics, consumer products, and energy systems series and chart solutions 4.5 (5.35.5) 10/2 2D and 3D unsteady conduction 4.3 (5.8) 6 10/7 Numerical: superposition 9 10/28 Laplace transforms, thermal waves Handout 10/30 Convection: Bulk flow modeling (7
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
Su, Guanyu, S.M. Massachusetts Institute of Technology
2015-01-01T23:59:59.000Z
Conduction and single-phase convective heat transfer are well understood phenomena: analytical models [1] and empirical correlations [2] allow capturing the thermal behavior of plate-type fuels or heaters in contact with ...
Neymark, J.; Judkoff, R.; Beausoleil-Morrison, I.; Ben-Nakhi, A.; Crowley, M.; Deru, M.; Henninger, R.; Ribberink, H.; Thornton, J.; Wijsman, A.; Witte, M.
2009-06-01T23:59:59.000Z
A set of validation test cases is presented to compare the results of midlevel detailed ground-coupled heat transfer models typically used with whole-building energy simulation software.
Greif, Ralph (University of California, Berkeley, CA); Evans, Gregory Herbert; Kearney, Sean Patrick (Sandia National Laboratories, Albuquerque, NM); Laskowski, Gregory Michael
2006-02-01T23:59:59.000Z
Heat transfer to and from a circular cylinder in a cross-flow of water at low Reynolds number was studied both experimentally and numerically. The experiments were carried out in a high aspect ratio water channel. The test section inflow temperature and velocity, channel lower surface temperature and cylinder surface temperature were controlled to yield either laminar or turbulent flow for a desired Richardson number. When the lower surface was unheated, the temperatures of the lower surface and water upstream of the cylinder were maintained approximately equal and the flow was laminar. When the lower surface was heated, turbulence intensities as high as 20% were measured several cylinder diameters upstream of the cylinder due to turbulent thermal plumes produced by heating the lower surface. Variable property, two-dimensional simulations were undertaken using a variant of the u{sup 2}-f turbulence model with buoyancy production of turbulence accounted for by a simple gradient diffusion model. Predicted and measured heat flux distributions around the cylinder are compared for values of the Richardson number, Gr{sub d}/Re{sub d}{sup 2} from 0.3 to 9.3. For laminar flow, the predicted and measured heat flux results agreed to within the experimental uncertainty. When the lower surface was heated, and the flow was turbulent, there was qualitative agreement between predicted and measured heat flux distributions around the cylinder. However the predicted spatially averaged Nusselt number was from 37% to 53% larger than the measured spatially averaged Nusselt number. Additionally, spatially averaged Nusselt numbers are compared to correlations in the literature for mixed convection heat transfer to/from cylinders in cross-flow. The results presented here are larger than the correlation values. This is believed to be due to the effects of buoyancy-induced turbulence resulting from heating the lower surface and the proximity of the cylinder to that surface.
Jet impingement heat transfer in two-pass rotating rectangular channels
Zhang, Yuming
1996-01-01T23:59:59.000Z
The combined effects of rotation and jet impingement on local heat transfer in a two-pass rotating rectangular channel is studied. The results of an experimental investigation on the surface heat transfer coefficients under a perforated plate...
Impingement cooling and heat transfer measurement using transient liquid crystal technique
Huang, Yizhe
1996-01-01T23:59:59.000Z
A heat transfer study on jet impingement cooling is presented. The study focuses on the effect of impingement jet flow rate, jet angle, and flow exit direction on various target surface heat transfer distributions. A two-channel test section...
Heat transfer rates for filmwise, dropwise, and superhydrophobic condensation on silicon substrates
Hery, Travis M
2011-01-01T23:59:59.000Z
Condensation, a two-phase heat transfer processes, is commonly utilized in industrial systems. Condensation heat transfer can be optimized by using surfaces in which dropwise condensation (DWC) occurs, and even further ...
A visualization comparison of convective flow boiling heat transfer augmentation devices
Lundy, Brian Franklin
1998-01-01T23:59:59.000Z
The qualitative effects of inset-table heat transfer phics. augmentation devices on vertical in-tube convective flow boiling flow regimes, transition mechanisms, and heat transfer are presented in this study. Three twisted tapes with twist ratios...
A visualization comparison of convective flow boiling heat transfer augmentation devices
Lundy, Brian Franklin
1998-01-01T23:59:59.000Z
The qualitative effects of inset-table heat transfer phics. augmentation devices on vertical in-tube convective flow boiling flow regimes, transition mechanisms, and heat transfer are presented in this study. Three twisted tapes with twist ratios...
Heat transfer during film condensation of potassium vapor on a horizontal plate
Meyrial, Paul M.
1968-01-01T23:59:59.000Z
The object of the investigation is to analyze the following two features of heat transfer during condensation of potassium vapor: a. Heat transfer during film condensation of a pure saturated potassium vapor on a horizontal ...
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, ...
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)
2010-10-15T23:59:59.000Z
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)
Modeling regional power transfers
Kavicky, J.A.; Veselka, T.D.
1994-03-01T23:59:59.000Z
The Spot Market Network (SMN) model was used to estimate spot market transactions and prices between various North American Electric Reliability Council (NERC) regions for summer on-peak situations. A preliminary analysis of new or proposed additions to the transmission network was performed. The effects of alternative exempt wholesale generator (EWG) options on spot market transactions and the transmission system are also studied. This paper presents the SMN regional modelling approach and summarizes simulation results. Although the paper focuses on a regional network representation, a discussion of how the SMN model was used to represent a detailed utility-level network is also presented.
An experimental, theoretical and numerical investigation of corona wind heat transfer enhancement
Owsenek, Brian Leonard
1993-01-01T23:59:59.000Z
transfer coefficients with various voltages and needle height of 5 cm 19 Fig. 2.5 Average heat transfer coefficients with various voltages and needle height of 5 cm 19 Fig. 2.6 Local heat transfer coefficients at 10 kV with various needle heights 20... Fig. 2.7 Average heat transfer coefficients at 10 kV with various needle heights 20 Fig. 2.8 Heat transfer and standard error for 10 kV and 15 kV needles 3 cm above surface 22 Fig. 2.9 Relationship between 100 cm^ average heat transfer and the 1...
Jackson, J. D. [Univ. of Manchester, Manchester (United Kingdom); Jiang, P. X.; Liu, B. [Tsinghua Univ., Thermal Engineering Dept., Beijing (China)
2012-07-01T23:59:59.000Z
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)
Heat transfer and pressure drop in an annular channel with downflow
Dolan, F.X.; Crowley, C.J. (Creare, Inc., Hanover, NH (United States)); Qureshi, Z.H. (Westinghouse Savannah River Co., Aiken, SC (United States))
1992-01-01T23:59:59.000Z
The onset of a flow instability (OFI) determines the minimum flow rate for cooling in the flow channels of a nuclear fuel assembly. A test facility was constructed with full-scale models (length and diameter) of annular flow channels incorporating many instruments to measure heat transfer and pressure drop with downflow in the annulus. Tests were performed both with and without axial centering ribs at prototypical values of pressure, flow rate and uniform wall heat flux. The axial ribs have the effect of subdividing the annulus into quadrants, so the problem becomes one of parallel channel flow, unlike previous experiments in tubes (upflow and downflow). Other tests were performed to determine the effects if any of asymmetric and non-uniform circumferential wall heating, operating pressure level and dissolved gas concentration. Data from the tests are compared with models for channel heat transfer and pressure drop profiles in several regimes of wall heating from single-phase forced convection through partially and fully developed nucleate boiling. Minimum stable flow rates were experimentally determined as a function of wall heat flux and heat distribution and compared with the model for the transition to fully developed boiling which is a key criterion in determining the OFI condition in the channel. The heat transfer results in the channel without ribs are in excellent agreement with predictions from a computer model of the flow in the annulus and with empirical correlations developed from similar tests. The test results with centering ribs show that geometrical variations between the channels can lead to differences in subchannel behavior which can make the effect of the ribs and the geometry an important factor when assessing the power level at which the fuel assembly (and the reactor) can be operated to prevent overheating in the event of a loss-of-coolant-accident (LOCA).
Heat transfer and pressure drop in an annular channel with downflow
Dolan, F.X.; Crowley, C.J. [Creare, Inc., Hanover, NH (United States); Qureshi, Z.H. [Westinghouse Savannah River Co., Aiken, SC (United States)
1992-06-01T23:59:59.000Z
The onset of a flow instability (OFI) determines the minimum flow rate for cooling in the flow channels of a nuclear fuel assembly. A test facility was constructed with full-scale models (length and diameter) of annular flow channels incorporating many instruments to measure heat transfer and pressure drop with downflow in the annulus. Tests were performed both with and without axial centering ribs at prototypical values of pressure, flow rate and uniform wall heat flux. The axial ribs have the effect of subdividing the annulus into quadrants, so the problem becomes one of parallel channel flow, unlike previous experiments in tubes (upflow and downflow). Other tests were performed to determine the effects if any of asymmetric and non-uniform circumferential wall heating, operating pressure level and dissolved gas concentration. Data from the tests are compared with models for channel heat transfer and pressure drop profiles in several regimes of wall heating from single-phase forced convection through partially and fully developed nucleate boiling. Minimum stable flow rates were experimentally determined as a function of wall heat flux and heat distribution and compared with the model for the transition to fully developed boiling which is a key criterion in determining the OFI condition in the channel. The heat transfer results in the channel without ribs are in excellent agreement with predictions from a computer model of the flow in the annulus and with empirical correlations developed from similar tests. The test results with centering ribs show that geometrical variations between the channels can lead to differences in subchannel behavior which can make the effect of the ribs and the geometry an important factor when assessing the power level at which the fuel assembly (and the reactor) can be operated to prevent overheating in the event of a loss-of-coolant-accident (LOCA).
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.
2003-01-01T23:59:59.000Z
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 ×105) 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 whole width of the tip on the second half of the tip surface.more »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
Yuen, W W
2006-01-01T23:59:59.000Z
the effect of radiation heat transfer in multi-dimensionaleffects of the radiation heat transfer, particularly in3-D Surface Radiation Calculation”, Numerical heat Transfer,
Wright, Lance Cole
1996-01-01T23:59:59.000Z
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
Gustavsen, Arlid
2008-01-01T23:59:59.000Z
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
Tokyo, University of
of the local heat transfer coefficient. Two types of microchannels were tested: a circular Pyrex glass exchangers [1], and reformers for methane direct micro fuel cells. Convective boiling heat transferVisualization of convective boiling heat transfer in single microchannels with different shaped
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
HEAT TRANSFER ON A HYPERSONIC SPHERE WITH DIFFUSE RAREFIED-GAS INJECTION
Riabov, Vladimir V.
HEAT TRANSFER ON A HYPERSONIC SPHERE WITH DIFFUSE RAREFIED-GAS INJECTION Vladimir V. Riabov* Rivier numbers Re0,R.3-7 Mass injection can be considered as an effective way of the reduction of heat transfer in the case of small Reynolds numbers. Moss12 found that mass injection dramatically reduces heat transfer
Heat Transfer Engineering, 28(6):525540, 2007 Copyright C Taylor and Francis Group, LLC
Ghajar, Afshin J.
Heat Transfer Engineering, 28(6):525540, 2007 Copyright C Taylor and Francis Group, LLC ISSN: 0145-7632 print / 1521-0537 online DOI: 10.1080/01457630701193906 Heat Transfer Measurements, Flow Pattern Maps, Stillwater, Oklahoma, USA Local heat transfer coefficients and flow parameters were measured for air
Heat Transfer Engineering, 27(5):2338, 2006 Copyright C Taylor and Francis Group, LLC
Ghajar, Afshin J.
Heat Transfer Engineering, 27(5):2338, 2006 Copyright C Taylor and Francis Group, LLC ISSN: 0145-7632 print / 1521-0537 online DOI: 10.1080/01457630600559538 Transitional Heat Transfer in Plain Horizontal, Oklahoma, USA In this study, the heat transfer behavior in the transition region for plain horizontal tubes
Flow Boiling Heat Transfer Coefficient In Minichannels Correlation and Trends Satish G. Kandlikar
Kandlikar, Satish
Flow Boiling Heat Transfer Coefficient In Minichannels Correlation and Trends Satish G. Kandlikar York 14623, USA The flow boiling heat transfer in small diameter passages is being applied in many boiling heat transfer coefficient with the correlations developed for conventional channels. It is found
Proceedings of HT2007 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference
Ghajar, Afshin J.
Proceedings of HT2007 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference July 8-12, 2007, Vancouver, British Columbia, CANADA HT2007-32219 VALIDATION OF A GENERAL HEAT TRANSFER, Stillwater, OK 74078, USA E-mail: ghajar@ceat.okstate.edu ABSTRACT A general heat transfer correlation
Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based
Le Roy, Robert J.
Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based Continuous is dedicated to under- standing the fluid flow and heat transfer mechanisms occurring in continuous flow PCR are discussed in detail. The importance of each heat transfer mechanism for different situations is also
Scaling of Heat Transfer Coefficients Along Louvered Fins A. C. Lyman1
Thole, Karen A.
1 Scaling of Heat Transfer Coefficients Along Louvered Fins A. C. Lyman1 , R. A. Stephan2 , and K 23681-2199 #12;2 Abstract Louvered fins provide a method for improving the heat transfer performance for evaluating the spatially-resolved louver heat transfer coefficients using various reference temperatures
SINGLE-PHASE LIQUID HEAT TRANSFER IN PLAIN AND ENHANCED MICROCHANNELS Mark E. Steinke
Kandlikar, Satish
SINGLE-PHASE LIQUID HEAT TRANSFER IN PLAIN AND ENHANCED MICROCHANNELS Mark E. Steinke Systems upon the understanding of the fundamental heat transfer processes that occur in these systems. There have been great advancements in our understanding of the heat transfer and fluid flow mechanisms
Assignment 6: Heat Transfer Page 1 of 8 600.112: Introduction to Programming
Fröhlich, Peter
Assignment 6: Heat Transfer Page 1 of 8 600.112: Introduction to Programming for Scientists and Engineers Assignment 6: Heat Transfer Peter H. Fr¨ohlich phf@cs.jhu.edu Joanne Selinski joanne to Programming for Scientists and Engineers is all about heat transfer and how to simulate it. There are three
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
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
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
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
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law
Boyer, Edmond
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law F transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat-Cattaneo law, heat transfer, magnetic field, magnetization AMS subject classifications: 76N10, 35Q35. 1
Heat transfer 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 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
Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal Thermography
Ghajar, Afshin J.
62 TC02-007 Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal thermography (LCT) method was developed for surface temperature measurements on a horizontal 2000m macro-tube and 1000m micro-tube. In the single-phase heat transfer experiments, the fully-developed flow heat transfer
Heat Transfer Engineering, 29(9):793804, 2008 Copyright C Taylor and Francis Group, LLC
Ghajar, Afshin J.
for Laminar and Turbulent Flow Convection Heat Transfer in a Horizontal Tube Using Artificial Neural Network. INTRODUCTION Heat transfer inside horizontal tubes in the laminar, transi- tional, and turbulent flow regimes was used to develop empirical correlations for laminar and turbulent heat transfer in a horizontal tube
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
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
Int. Symp. on Heat Transfer in Gas Turbine Systems 9 14 August, 2009, Antalya, Turkey
Camci, Cengiz
for turbine aero heat transfer work performed under rotational conditions. A flow coefficient and a loading candidates to generate very realistic gas turbine heat transfer data, the initial investment made generate an accurately measurable amount of heat transfer from the gas side to turbine blades in a linear
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
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
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
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
Convective heat transfer in buildings: recent research results. Rev
Bauman, F.; Gadgil, A.; Kammerud, R.; Altmayer, E.; Nansteel, M.W.
1982-10-01T23:59:59.000Z
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.
Situ soil sampling probe system with heated transfer line
Robbat, Jr., Albert (Andover, MA)
2002-01-01T23:59:59.000Z
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.
Molten salt as a heat transfer fluid for heating a subsurface formation
Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)
2010-11-16T23:59:59.000Z
A heating system for a subsurface formation includes a conduit located in an opening in the subsurface formation. An insulated conductor is located in the conduit. A material is in the conduit between a portion of the insulated conductor and a portion of the conduit. The material may be a salt. The material is a fluid at operating temperature of the heating system. Heat transfers from the insulated conductor to the fluid, from the fluid to the conduit, and from the conduit to the subsurface formation.
Simulation of Strongly Heated Internal Gas Flows Using a Near-Wall Two-Equation Heat Flux Model
Richards, Adam H.; Spall, Robert E. [Utah State University, 1400 Old Main Hill Logan, Utah 84322-1400 (United States)
2006-07-01T23:59:59.000Z
A two-equation k-{omega} model is used to model a strongly heated, low-Mach number gas flowing upward in a vertical tube. Heating causes significant property variation and thickening of the viscous sublayer, consequently a fully developed flow does not evolve. Two-equation turbulence models generally perform poorly under such conditions. Consequently, in the present work, a near-wall two-equation heat transfer model is utilized in conjunction with the k-{omega} model to improve heat transfer predictions. (authors)
Influence of Infrared Radiation on Attic Heat Transfer
Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.
1985-01-01T23:59:59.000Z
roof temperatures. It was found that a radiant barrier such as aluminum foil can reduce the heat flux significantly. Experimental results were compared to a Three-Region approximate solution developed at Oak Ridge National Laboratories (ORNL). The model...
Heat transfer characteristics of a two-pass trapezoidal channel and a novel heat pipe
Lee, Sang Won
2009-06-02T23:59:59.000Z
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...
Triplett, C.E.
1996-12-01T23:59:59.000Z
This thesis presents the results of an experimental investigation of natural convection heat transfer in a staggered array of heated cylinders, oriented horizontally within a rectangular enclosure. The main purpose of this research was to extend the knowledge of heat transfer within enclosed bundles of spent nuclear fuel rods sealed within a shipping or storage container. This research extends Canaan`s investigation of an aligned array of heated cylinders that thermally simulated a boiling water reactor (BWR) spent fuel assembly sealed within a shipping or storage cask. The results are presented in terms of piecewise Nusselt-Rayleigh number correlations of the form Nu = C(Ra){sup n}, where C and n are constants. Correlations are presented both for individual rods within the array and for the array as a whole. The correlations are based only on the convective component of the heat transfer. The radiative component was calculated with a finite-element code that used measured surface temperatures, rod array geometry, and measured surface emissivities as inputs. The correlation results are compared to Canaan`s aligned array results and to other studies of natural convection in horizontal tube arrays.
Edwards, Bronwyn K
2009-01-01T23:59:59.000Z
An experimental study was performed to determine thermal performance and adhesion effects of a combined nanoparticle and polymeric dispersion coating. The critical heat flux (CHF) values and nucleate boiling heat transfer ...
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, K.H.; Ahluwalia, R.K.
1994-10-18T23:59:59.000Z
A radiative heat transfer mechanism in a furnace is described having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits. 7 figs.
Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger
Im, Kwan H. (Naperville, IL); Ahluwalia, Rajesh K. (Burr Ridge, IL)
1994-01-01T23:59:59.000Z
A radiative heat transfer mechanism in a furnace having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits.
An analytical model for the design of in-slab electric heating panels
Ritter, T.L.; Kilkis, B.I. [Heatway, Springfield, MO (United States)
1998-10-01T23:59:59.000Z
In this paper, a steady-state heat transfer model is described for design and sizing of electric radiant panel heating systems embedded in a slab. This model is applicable both for ceiling and floor panels. An approximate panel surface heat output algorithm is also given as a function of size and orientation of the heated space and outdoor exposure.
Measurement and calculation of nozzle guide vane end wall heat transfer
Harvey, N.W.; Rose, M.G.; Coupland, J. [Rolls-Royce plc, Derby (United Kingdom); Jones, T.V. [Univ. of Oxford, Derby (United Kingdom). Dept. of Engineering Science
1999-04-01T23:59:59.000Z
A three-dimensional steady viscous finite volume pressure correction method for the solution of the Reynolds-averaged Navier-Stokes equations has been used to calculate the heat transfer rates on the end walls of a modern High Pressure Turbine first-stage stator. Surface heat transfer rates have been calculated at three conditions and compared with measurements made on a model of the vane tested in annular cascade in the Isentropic Light Piston Facility at DERA, Pyestock. The NGV Mach numbers, Reynolds numbers, and geometry are fully representative of engine conditions. Design condition data have previously been presented by Harvey and Jones (1990). Off-design data are presented here for the first time. In the areas of highest heat transfer, the calculated heat transfer rates are shown to be within 20% of the measured values at all three conditions. Particular emphasis is placed on the use of wall functions in the calculations with which relatively coarse grids (of around 140,000 nodes) can be used to keep computational run times sufficiently low for engine design purposes.
Lopez, Jose M; Avila, Marc
2015-01-01T23:59:59.000Z
The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction, in which cases heat transfer occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. We obtain a simple linear criterion that determines whether the infinite-cylinder assumption can be employed. The curvature of the cylinders enters this linear relationship through the slope and additive constant. For a given length-to-gap aspect ratio there is a critical Rayleigh number beyond which the laminar flow in the finite system is convective and so the behaviour is entirely different from the periodic case. The criterion does not depend on the Pra...
Couette flow regimes with heat transfer in rarefied gas
Abramov, A. A., E-mail: alabr54@mail.ru; Butkovskii, A. V., E-mail: albutkov@mail.ru [Zhukovski Central Aerohydrodynamics Institute (Russian Federation)
2013-06-15T23:59:59.000Z
Based on numerical solution of the Boltzmann equation by direct statistic simulation, the Couette flow with heat transfer is studied in a broad range of ratios of plate temperatures and Mach numbers of a moving plate. Flow regime classification by the form of the dependences of the energy flux and friction stress on the Knudsen number Kn is proposed. These dependences can be simultaneously monotonic and nonmonotonic and have maxima. Situations are possible in which the dependence of the energy flux transferred to a plate on Kn has a minimum, while the dependence of the friction stress is monotonic or even has a maximum. Also, regimes exist in which the dependence of the energy flux on Kn has a maximum, while the dependence of the friction stress is monotonic, and vice versa.
Low-melting point inorganic nitrate salt heat transfer fluid
Bradshaw, Robert W. (Livermore, CA); Brosseau, Douglas A. (Albuquerque, NM)
2009-09-15T23:59:59.000Z
A low-melting point, heat transfer fluid made of a mixture of four inorganic nitrate salts: 9-18 wt % NaNO.sub.3, 40-52 wt % KNO.sub.3, 13-21 wt % LiNO.sub.3, and 20-27 wt % Ca(NO.sub.3).sub.2. These compositions can have liquidus temperatures less than 100 C; thermal stability limits greater than 500 C; and viscosity in the range of 5-6 cP at 300 C; and 2-3 cP at 400 C.
Grid-independent Issue in Numerical Heat Transfer
Yao Wei; Wang Jian; Liao Guangxuan
2006-09-26T23:59:59.000Z
Grid independent is associated with the accuracy or even rationality of numerical results. This paper takes two-dimensional steady heat transfer for example to reveal the effect of grid resolution on numerical results. The law of grid dependence is obtained and a simple mathematical formula is presented. The production acquired here can be used as the guidance in choosing grid density in numerical simulation and get exact grid independent value without using infinite fine grid. Through analyzing grid independent, we can find the minimum number of grid cells that is needed to get grid-independent results. Such strategy can save computational resource while ensure a rational computational result.
Effect of translucence of engineering ceramics on heat transfer in diesel engines
Wahiduzzaman, S.; Morel, T. (Integral Technologies, Inc., Westmont, IL (United States))
1992-04-01T23:59:59.000Z
This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition. Thus, to insure the optimum thermal barrier operation for either clean or heavily sooted surfaces, a ceramic material with high scattering coefficient provides the best choice.
Effect of translucence of engineering ceramics on heat transfer in diesel engines. Final report
Wahiduzzaman, S.; Morel, T. [Integral Technologies, Inc., Westmont, IL (United States)
1992-04-01T23:59:59.000Z
This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition. Thus, to insure the optimum thermal barrier operation for either clean or heavily sooted surfaces, a ceramic material with high scattering coefficient provides the best choice.
Carlson, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States); Kruizenga, A. [Sandia National Laboratory (United States); Anderson, M.; Corradini, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States)
2012-07-01T23:59:59.000Z
Closed-loop Brayton cycles using supercritical carbon dioxide (SCO{sub 2}) show potential for use in high-temperature power generation applications including High Temperature Gas Reactors (HTGR) and Sodium-Cooled Fast Reactors (SFR). Compared to Rankine cycles SCO{sub 2} Brayton cycles offer similar or improved efficiency and the potential for decreased capital costs due to a reduction in equipment size and complexity. Compact printed-circuit heat exchangers (PCHE) are being considered as part of several SCO{sub 2} Brayton designs to further reduce equipment size with increased energy density. Several designs plan to use a gas cooler operating near the pseudo-critical point of carbon dioxide to benefit from large variations in thermophysical properties, but further work is needed to validate correlations for heat transfer and pressure-drop characteristics of SCO{sub 2} flows in candidate PCHE channel designs for a variety of operating conditions. This paper presents work on experimental measurements of the heat transfer and pressure drop behavior of miniature channels using carbon dioxide at supercritical pressure. Results from several plate geometries tested in horizontal cooling-mode flow are presented, including a straight semi-circular channel, zigzag channel with a bend angle of 80 degrees, and a channel with a staggered array of extruded airfoil pillars modeled after a NACA 0020 airfoil with an 8.1 mm chord length facing into the flow. Heat transfer coefficients and bulk temperatures are calculated from measured local wall temperatures and local heat fluxes. The experimental results are compared to several methods for estimating the friction factor and Nusselt number of cooling-mode flows at supercritical pressures in millimeter-scale channels. (authors)
Bauman, Fred; Jin, Hui
2007-01-01T23:59:59.000Z
simulation, five heat transfer model options are possible.fluid dependent. The heat transfer model selected for theapplications. The heat transfer model is used to predict the
Heat transfer and material flow during laser assisted multi-layer additive manufacturing
Manvatkar, V.; De, A.; DebRoy, T. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)
2014-09-28T23:59:59.000Z
A three-dimensional, transient, heat transfer, and fluid flow model is developed for the laser assisted multilayer additive manufacturing process with coaxially fed austenitic stainless steel powder. Heat transfer between the laser beam and the powder particles is considered both during their flight between the nozzle and the growth surface and after they deposit on the surface. The geometry of the build layer obtained from independent experiments is compared with that obtained from the model. The spatial variation of melt geometry, cooling rate, and peak temperatures is examined in various layers. The computed cooling rates and solidification parameters are used to estimate the cell spacings and hardness in various layers of the structure. Good agreement is achieved between the computed geometry, cell spacings, and hardness with the corresponding independent experimental results.
Accepted Manuscript A wall heat transfer correlation for the baffled-rotary kilns with secondary air
Boyer, Edmond
Accepted Manuscript A wall heat transfer correlation for the baffled-rotary kilns with secondary Date: 22 January 2014 Please cite this article as: L.G. Lauredan, H. Florian, D. Jean, A wall heat;1 A wall heat transfer correlation for the baffled- rotary kilns with secondary air flow and recycled
Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland
Graaf, Martin de
Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland M. de Graaf #12;Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland Martin de is used to calculate surface heat fluxes over glaciers. As determination of surface fluxes still
HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME
Boyer, Edmond
1 HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME P. H and the sheet metal: This is ventilation by natural convection. The remaining conductive heat from the sheet or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers
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
TRANSIENT HEAT TRANSFER ANALYSIS FOR SRS RADIOACTIVE TANK OPERATION
Lee, S.
2013-06-27T23:59:59.000Z
The primary objective of the present work is to perform a heat balance study for type-I waste tank to assess the impact of using submersible mixer pumps during waste removal. The temperature results calculated by the model will be used to evaluate the temperatures of the slurry waste under various tank operating conditions. A parametric approach was taken to develop a transient model for the heat balance study for type-I waste tanks such as Tank 11, during waste removal by SMP. The tank domain used in the present model consists of two SMP?s for sludge mixing, one STP for the waste removal, cooling coil system with 36 coils, and purge gas system. The sludge waste contained in Tank 11 also has a decay heat load of about 43 W/m{sup 3} mainly due to the emission of radioactive gamma rays. All governing equations were established by an overall energy balance for the tank domain, and they were numerically solved. A transient heat balance model used single waste temperature model, which represents one temperature for the entire waste liquid domain contained in the tank at each transient time.
Prakash, C.; Zerkle, R. [General Electric Co., Cincinnati, OH (United States)
1995-04-01T23:59:59.000Z
The present study deals with the numerical prediction of turbulent flow and heat transfer in a 2:1 aspect ratio rectangular duct with ribs don the two shorter sides. The ribs are of square cross section, staggered and aligned normal (90 deg) to the main flow direction. The ratio of rib height to duct hydraulic diameter equals 0.063, and the ratio of rib spacing to rib height equals 10. The duct may be stationary or rotating. The axis of rotation is normal to the axis of the duct and parallel to the ribbed walls (i.e., the ribbed walls form the leading and the trailing faces). The problem is three dimensional and fully elliptic; hence, for computational economy, the present analysis deals only with a periodically fully developed situation where the calculation domain is limited to the region between two adjacent ribs. Turbulence is modeled with the {kappa}-{epsilon} model in conjunction with wall functions. However, since the rib height is small, use of wall functions necessitates that the Reynolds number be kept high. (Attempts to use a two-layer model that permits integration to the wall did not yield satisfactory results and such modeling issues are discussed at length.) Computations are made here for Reynolds number in the range 30,000--100,000 and for Rotation number = 0 (stationary), 0.06, and 0.12. For the stationary case, the predicted heat transfer agrees well with the experimental correlations. Due to the Coriolis-induced secondary flow, rotation is found to enhance heat transfer from the trailing and the side walls, while decreasing heat transfer from the leading face. Relative to the corresponding stationary case, the effect of rotation is found to be less for a ribbed channel as compared to a smooth channel.
J. Yang; F. B. Cheung; J. L. Rempe; K. Y. Suh; S. B. Kim
2005-07-01T23:59:59.000Z
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.
A Semi-Empirical Model for Porous Media Heat Exchanger Design Richard A. Wirtz1
Wirtz, Richard A.
A Semi-Empirical Model for Porous Media Heat Exchanger Design Richard A. Wirtz1 Mechanical-dimensional temperature Introduction Compact heat exchangers invariably incorporate heat transfer augmentation technology matrix at the fluid-solid interface of a compact heat exchanger will also enhance performance
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
Study of heat transfer in attics with a small scale simulator
Katipamula, Srinivas
1985-01-01T23:59:59.000Z
University Chairman of Advisory Committee: W. D. Turner An experimental study concerned with different modes of heat. transfer in fibrous and cellulose insulating material is presented. A series of experiments was conducted using an attic simulator... to deter- mine the effects of ventilation on attic heat transfer. and the effect of infrared radiation on the thcrn&al conductivity of th& insulation sys- tem and on attic heat transfer. All the tests were perl'ormed at, steady state conditions...
A method of correlating heat transfer data for surface boiling of liquids
Rohsenow, Warren M.
1951-01-01T23:59:59.000Z
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 ...
Visual Simulation of Heat Shimmering and Mirage
Mueller, Klaus
and the surrounding air. We introduce a heat transfer model between the heat source objects and the ambient flow the heat sources to the ambient flow. Although heat transfer modeling has been used before in computer
Development of a small-channel nucleate-boiling heat transfer correlation
Kasza, K.E.; Wambsganss, M.W.
1994-06-01T23:59:59.000Z
Development of an improved semimechanistic-based set of correlation parameters for nucleation-dominant flow-boiling heat transfer in small channels is described. Formulation of these parameters is on the basis of a recently published open-literature model for vapor bubble growth at a heated surface. This work is part of a program directed at obtaining an understanding of the physical mechanisms that influence boiling in compact heat exchangers through the use of high-speed video and microscope optics to characterize bubble nucleation, growth, and interaction with the confining walls of small heat transfer passages. The correlation parameters presented here represent the first step in the development of an improved boiling correlation for geometrically confined small-channel flows. In such flows, the nucleating bubbles can become nominally the same size as the channel cross section, thereby invalidating existing correlations that are based on large-channel data. Initial efforts to correlate small-channel-boiling data obtained at Argonne National Laboratory from nontransparent electrically heated metal tube tests appear promising.
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 ...
International Conference on Computational Heat and Mass Transfer Paper Number 135
Khandekar, Sameer
of heat transfer enhancement in sodium heat exchangers used in the fast breeder nuclear reactor [6 and liquid metals (Sodium, Potassium and Mercury) are utilized in the simulation. The critical sizes
Extensions and enhancements to the iLab heat transfer project site
Saylor, David P. (David Patrick)
2005-01-01T23:59:59.000Z
The iLab Heat Transfer Project website started four years ago to enable web access to experiments related to movement of heat through transport processes. This thesis details improvements made to the site which extend and ...
Pare, Louis Alphonse
1984-01-01T23:59:59.000Z
insulated, adiabatic surface. A heat transfer analysis intended to yield a conservative estimate of the non-adiabatic condition was performed. A Finite element heat transfer computer code was developed and used to compute the steady state temperature... identified regions on the surface of the model susceptible to surface heating and the magnitude of the respective surface temperatures. The addition of insulation within the cavity to limit surface heating was also investigated. The geometry...
HEAT AND MASS TRANSFER IN A FAULT-CONTROLLED GEOTHERMAL RESERVOIR CHARGED AT CONSTANT PRESSURE
Goyal, K.P.
2013-01-01T23:59:59.000Z
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
Radiative Heat Transfer in Enhanced Hydrogen Outgassing of Glass
Kitamura, Rei; Pilon, Laurent
2009-01-01T23:59:59.000Z
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
2009-01-01T23:59:59.000Z
slabs. Moreover, the total heat input during furnace heatingperformed for the same heat input. The optical propertiesheating for the same total heat input. Similarly, Figure 7
HEAT TRANSFER IN POROUS MEDIA WITH FLUID PHASE CHANGES
Su, Ho-Jeen.
2010-01-01T23:59:59.000Z
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
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
Heat transfer through horizontal films of liquids evaporating under high vacuum
Stiles, Graham Bill
1961-01-01T23:59:59.000Z
). . . . . . . 17 6. 7 ~ 9. 10 ~ 12 ' 13 ' 14 ' Effect of Liquid Depth on the Heat Transfer Coefficient (Natural Convection') . . . . . . . . 27 Effect of Liquid Depth on the Heat Transfer Coefficient (Nucleate Boiling, 875 BTU/Hr. Ft... of boiling was first discussed by Nukiyama (22). Three main types exist. They are natural convection, nucleate boiling and fi. lm boiling (6, 17, 20). Natural convection occurs when the liquid heated at the heating surface is hotter than that above...
Medina, M. A.
1992-01-01T23:59:59.000Z
studies under a diversity of climates, insulation levels and attic airflow patterns. Model predictions and results were presented on the basis of savings produced by the use of radiant barriers. Hourly, daily, and seasonal predictions by the model were...
Heat Exchangers for Solar Water Heating Systems
Broader source: Energy.gov [DOE]
Heat exchangers transfer solar energy absorbed in solar collectors to the liquid or air used to heat water. Learn how to choose the best model for your household.
Fu, Wen-Lung
2005-08-29T23:59:59.000Z
.............................................................................15 Figure 2.2 Geometry of the AR=1:2 Test Section with Angled Ribs ............................18 Figure 2.3 Cross Sectional View of the Test Sections ...................................................19 Figure 2.4 Heat Transfer Model (AR=1...=25.4 mm Rib 21 Figure 2.4 shows the heat transfer model of the AR=1:1 test section. Each pass is divided into six segments. As described earlier, the AR=1:4 and AR=1:2 test sections should have six copper plates in each segment, but the AR=1...
Heat transfer and pressure drop for air flow through enhanced passages
Obot, N.T.; Esen, E.B.
1992-06-01T23:59:59.000Z
An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.
Heat transfer and pressure drop for air flow through enhanced passages. Final report
Obot, N.T.; Esen, E.B.
1992-06-01T23:59:59.000Z
An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.
Effect of Mixed Working Fluid Composition on Binary Cycle Condenser Heat Transfer Coefficients
Dan Wendt; Greg Mines
2011-10-01T23:59:59.000Z
Effect of Mixed Working Fluid Composition on Binary Cycle Condenser Heat Transfer Coefficients Dan Wendt, Greg Mines Idaho National Laboratory The use of mixed working fluids in binary power plants can provide significant increases in plant performance, provided the heat exchangers are designed to take advantage of these fluids non-isothermal phase changes. In the 1980's testing was conducted at DOE's Heat Cycle Research Facility (HCRF) where mixtures of different compositions were vaporized at supercritical pressures and then condensed. This testing had focused on using the data collected to verify that Heat Transfer Research Incorporated (HTRI) codes were suitable for the design of heat exchangers that could be used with mixtures. The HCRF data includes mixture compositions varying from 0% to 40% isopentane and condenser tube orientations of 15{sup o}, 60{sup o}, and 90{sup o} from horizontal. Testing was performed over a range of working fluid and cooling fluid conditions. Though the condenser used in this testing was water cooled, the working fluid condensation occurred on the tube-side of the heat exchanger. This tube-side condensation is analogous to that in an air-cooled condenser. Tube-side condensing heat transfer coefficient information gleaned from the HCRF testing is used in this study to assess the suitability of air-cooled condenser designs for use with mixtures. Results of an air-cooled binary plant process model performed with Aspen Plus indicate that that the optimal mixture composition (producing the maximum net power for the scenario considered) is within the range of compositions for which data exist. The HCRF data is used to assess the impact of composition, tube orientation, and process parameters on the condensing heat transfer coefficients. The sensitivity of the condensing coefficients to these factors is evaluated and the suitability of air-cooled condenser designs with mixtures is assessed. This paper summarizes the evaluation of the HCRF data and discusses the next steps in the project evaluation of air-cooled condenser designs that can take advantage of the performance gains possible with these fluids.
Testing and modeling of underfloor air supply plenums
Jin, H.; Bauman, Fred; Webster, T.
2006-01-01T23:59:59.000Z
simulation, five heat transfer model options are possible:fluid dependent. The heat transfer model selected for the
Mukhopadhyay, Sumit; Sonnenthal, Eric L.; Spycher, Nicolas
2008-01-01T23:59:59.000Z
1941) in this paper. Rock Properties Except for the fracturethe hydrological properties of the rock. A model based onthe hydraulic properties of the rock (such as porosity,
Mukhopadhyay, S.; Sonnenthal, E.L.; Spycher, N.
2008-01-01T23:59:59.000Z
Fractured Rock of Yucca Mountain, Nevada: Heterogeneity andfractured rocks of Yucca Mountain have been extensivelyHydrothermal Flow at Yucca Mountain, Part I: Modeling and
Zhang, M.; Ibekwe, S.; Li, G.; Pang, S.S.; and Lian, K.
2006-07-01T23:59:59.000Z
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.
An experimental investigation of turbine blade heat transfer and turbine blade trailing edge cooling
Choi, Jungho
2005-02-17T23:59:59.000Z
and internal model of a gas turbine blade. It was also used to determine the film effectiveness on the trailing edge. For the internal model, Reynolds numbers based on the hydraulic diameter of iv the exit slot and exit velocity were 5,000, 10,000, 20...-1 AN EXPERIMENTAL INVESTIGATION OF TURBINE BLADE HEAT TRANSFER AND TURBINE BLADE TRAILING EDGE COOLING A Dissertation by JUNGHO CHOI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...
Ammerman, C.N.; You, S.M.; Hong, Y.S. [Univ. of Texas, Arlington, TX (United States). Dept. of Mechanical and Aerospace Engineering
1995-12-31T23:59:59.000Z
A recently developed photographic method is used to quantify vapor volumetric flow rate above a boiling wire. The volumetric flow rate is combined with additional analyses to determine the overall contributions to the total heat flux from four nucleate boiling heat transfer mechanisms (latent heat, natural convection, Marangoni flow, and micro-convection). This technique is used to quantify the boiling heat transfer mechanisms versus heat flux for a 510-{micro}m wire immersed in saturated water and in water with a small amount of liquid soap added. These data are compared with similar data taken for a 75-{micro}m wire boiling in saturated FC-72. For all cases, latent heat is the dominant heat transfer mechanism in the fully developed nucleate boiling regime. In addition, the latent heat component is significantly increased by the addition of small amounts of soap (surfactant).
JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER Vol. 19, No. 1, JanuaryMarch 2005
Al-Qahtani, Mohammad
&M University, College Station, Texas 77843 Computations were performed to study three-dimensional turbulent developed turbulent nonrotating tube flow Dh, D = hydraulic diameter, m h = heat transfer coefficient, W/m2 Program, Department of Civil Engineer- ing. Senior Member AIAA. Professor, Turbine Heat Transfer
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
Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow
Kostic, Milivoje M.
Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE M of nanofluids in tube flow has been developed, instrumented and computerized. It has been calibrated using) nanofluids show peculiar results with substantial friction drag reduction and heat transfer enhancement
Thole, Karen A.
Elsevier Inc. All rights reserved. Keywords: Duct flow; Ribbed channels; LES 1. Introduction In an effortExperimental validation of large eddy simulations of flow and heat transfer in a stationary ribbed Abstract Accurate prediction of ribbed duct flow and heat transfer is of importance to the gas turbine
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
Dehumidification heat transfer on copper surfaces Abhay Varghese Thomas, Nikhil Koratkar, Yoav Peles
Peles, Yoav
and Background When a cooled surface is placed in an air-steam mixture, liquid water droplets or film form Heat transfer Condensation Humid air a b s t r a c t Heat transfer during dehumidification on the surface if its temperature is sufficiently low. In this dehumidification process, the ambient airsteam
Bibliography of US patents on augmentation of convective heat and mass transfer-II
Webb, R.L.; Bergles, A.E.; Junkhan, G.H.
1983-12-01T23:59:59.000Z
Patents are an important source of information on the potential commercialization of augmented heat transfer technology. This report presents a bibliography of US patents pertinent to that technology. The total number of patents cited is 454. They are presented in three separate lists: by patent number, alphabetically by first inventor, and by augmentation technique (with secondary arrangement according to mode of heat transfer).
Proceedings of HT2007 2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference
Ghajar, Afshin J.
to a more complicated data set, forced and mixed convection developing laminar flow in a horizontal tube LAMINAR HEAT TRANSFER IN A HORIZONTAL TUBE USING ARTIFICIAL NEURAL NETWORK L. M. Tam (1) Department variables on our forced convective turbulent heat transfer data in a horizontal tube (Ghajar and Tam, 1994
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
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
Local heat transfer and film effectiveness of a film cooled gas turbine blade tip
Adewusi, Adedapo Oluyomi
1999-01-01T23:59:59.000Z
of internal and external cooling holes. Several studies have been conducted to help in understanding the heat transfer of gas turbines. This study presents the heat transfer and film effectiveness distribution on the cavity surface of a gas turbine blade tip...
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
Khounsary Named Associate Editor of ASME Journal of Heat Transfer
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
transfer. Contributions may consist of results from fundamental research that apply to thermal energy or mass transfer in all fields of mechanical engineering and related...
Standardization of Thermo-Fluid Modeling in Modelica.Fluid
Franke, Rudiger
2010-01-01T23:59:59.000Z
a replaceable heat transfer model with the flag use_heat transfer. A concrete heat transfer model extending fromcycle. Also note that the heat transfer model of the tank is
Neirotti, Juan Pablo
of heat transfer fundamentals. * Heat exchanger types and performances. * Extended surfaces and applications to heat exchanger design. * Radiant heat transfer; cosine law and configuration factors the performance of practical heat exchangers and turbomachines *use standard thermofluid data sources (tables
Micro and nanostructured surfaces for enhanced phase change heat transfer
Chu, Kuang-Han, Ph. D. Massachusetts Institute of Technology
2013-01-01T23:59:59.000Z
Two-phase microchannel heat sinks are of significant interest for thermal management applications, where the latent heat of vaporization offers an efficient method to dissipate large heat fluxes in a compact device. However, ...
Application of the TEMPEST computer code to canister-filling heat transfer problems
Farnsworth, R.K.; Faletti, D.W.; Budden, M.J.
1988-03-01T23:59:59.000Z
Pacific Northwest Laboratory (PNL) researchers used the TEMPEST computer code to simulate thermal cooldown behavior of nuclear waste glass after it was poured into steel canisters for long-term storage. The objective of this work was to determine the accuracy and applicability of the TEMPEST code when used to compute canister thermal histories. First, experimental data were obtained to provide the basis for comparing TEMPEST-generated predictions. Five canisters were instrumented with appropriately located radial and axial thermocouples. The canister were filled using the pilot-scale ceramic melter (PSCM) at PNL. Each canister was filled in either a continous or a batch filling mode. One of the canisters was also filled within a turntable simulant (a group of cylindrical shells with heat transfer resistances similar to those in an actual melter turntable). This was necessary to provide a basis for assessing the ability of the TEMPEST code to also model the transient cooling of canisters in a melter turntable. The continous-fill model, Version M, was found to predict temperatures with more accuracy. The turntable simulant experiment demonstrated that TEMPEST can adequately model the asymmetric temperature field caused by the turntable geometry. Further, TEMPEST can acceptably predict the canister cooling history within a turntable, despite code limitations in computing simultaneous radiation and convection heat transfer between shells, along with uncertainty in stainless-steel surface emissivities. Based on the successful performance of TEMPEST Version M, development was initiated to incorporate 1) full viscous glass convection, 2) a dynamically adaptive grid that automatically follows the glass/air interface throughout the transient, and 3) a full enclosure radiation model to allow radiation heat transfer to non-nearest neighbor cells. 5 refs., 47 figs., 17 tabs.
Hierarchical Modeling for Population-Based Heat Exchanger Design
Geb, David
2013-01-01T23:59:59.000Z
transfer in tube banks in crossflow. [60] Zukauskas, A. ,law based optimisation of crossflow plate-fin heat exchanger
Thole, Karen A.
delta winglets Michael J. Lawson *, Karen A. Thole Mechanical and Nuclear Engineering Department the formation of streamwise vortices and increase heat transfer between a working fluid and the surface on which importance for fuel econ- omy. Advantages to decreasing heat exchanger size include weight savings, as well
Downflow heat transfer in a heated ribbed vertical annulus with a cosine power profile
Anderson, J.L.; Condie, K.G.; Larson, T.K.
1991-10-01T23:59:59.000Z
Experiments designed to investigate downflow heat transfer in a heated, ribbed annulus test section simulating one of the annular coolant channels of a Savannah River Plant production reactor Mark 22 fuel assembly have been conducted at the Idaho National Engineering Laboratory. The inner surface of the annulus was constructed of aluminum and was electrically heated to provide an axial cosine power profile and a flat azimuthal power shape. Data presented in this report are from the ECS-2c series, which was a follow on series to the ECS-2b series, conducted specifically to provide additional data on the effect of different powers at the same test conditions, for use in evaluation of possible power effects on the aluminum temperature measurements. Electrical powers at 90%, 100%, and 110% of the power required to result in the maximum aluminum temperature at fluid saturation temperature were used at each set of test conditions previously used in the ECS-2b series. The ECS-2b series was conducted in the same test rig as the previous ECS-2b series. Data and experimental description for the ECS-2b series is provided in a previous report. 18 refs., 25 figs., 3 tabs.
Theoretical Design of Thermosyphon for Process Heat Transfer from NGNP to Hydrogen Plant
Piyush Sabharwall; Mike Patterson; Fred Gunnerson
2008-09-01T23:59:59.000Z
The Next Generation Nuclear Plant (NGNP) will most likely produce electricity and process heat, with both being considered for hydrogen production. To capture nuclear process heat, and transport it to a distant industrial facility requires a high temperature system of heat exchangers, pumps and/or compressors. The heat transfer system is particularly challenging not only due to the elevated temperatures (up to ~ 1300K) and industrial scale power transport (=50 MW), but also due to a potentially large separation distance between the nuclear and industrial plants (100+m) dictated by safety and licensing mandates. The work reported here is the preliminary analysis of two-phase thermosyphon heat transfer performance with alkali metals. A thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. In contrast to single-phased forced convective heat transfer via ‘pumping a fluid’, a thermosyphon (also called a wickless heat pipe) transfers heat through the vaporization / condensing process. The condensate is further returned to the hot source by gravity, i.e. without any requirement of pumps or compressors. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. Two-phase heat transfer by a thermosyphon has the advantage of high enthalpy transport that includes the sensible heat of the liquid, the latent heat of vaporization, and vapor superheat. In contrast, single-phase forced convection transports only the sensible heat of the fluid. Additionally, vapor-phase velocities within a thermosyphon are much greater than single-phase liquid velocities within a forced convective loop. Thermosyphon performance can be limited by the sonic limit (choking) or vapor flow and/or by condensate entrainment. Proper thermosyphon requires analysis of both.
Endley, Saurabh
1996-01-01T23:59:59.000Z
This experimental research investigates the heat transfer characteristics of air flows in serpentine cooling channels in stationary stator blades of gas turbines. The internal cooling channels are modeled as a smooth two-pass channel of trapezoidal...
Dual-circuit embossed-sheet heat-transfer panel
Morgan, G.D.
1982-08-23T23:59:59.000Z
A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed for form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet.
Vibration damping and heat transfer using material phase changes
Kloucek, Petr (Houston, TX); Reynolds, Daniel R. (Oakland, CA)
2009-03-24T23:59:59.000Z
A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.
Radiative heat transfer in anisotropic many-body systems: Tuning and enhancement
Nikbakht, Moladad, E-mail: mnik@znu.ac.ir [Department of Physics, Faculty of Sciences, University of Zanjan, Zanjan 45371-38791 (Iran, Islamic Republic of)
2014-09-07T23:59:59.000Z
A general formalism for calculating the radiative heat transfer in many body systems with anisotropic component is presented. Our scheme extends the theory of radiative heat transfer in isotropic many body systems to anisotropic cases. In addition, the radiative heating of the particles by the thermal bath is taken into account in our formula. It is shown that the radiative heat exchange (HE) between anisotropic particles and their radiative cooling/heating (RCH) could be enhanced several order of magnitude than that of isotropic particles. Furthermore, we demonstrate that both the HE and RCH can be tuned dramatically by particles relative orientation in many body systems.
WHICH MODEL OF TECHNOLOGY TRANSFER FOR NANOTECHNOLOGY?
Paris-Sud XI, Université de
1 WHICH MODEL OF TECHNOLOGY TRANSFER FOR NANOTECHNOLOGY? A Comparison with Biotech.genet@grenoble-em.com Website: www.nanoeconomics.eu Abstract. Nanotechnologies are often presented as breakthrough innovations. This article investigates the model of knowledge transfer in the nanotechnologies in depth, by comparing
Hodges, James L. (3 Hilltop Ave., Vernon, CT 06066); Cerkanowicz, Anthony E. (8 Fieldstone Dr., Livingston, NJ 07039)
1983-01-01T23:59:59.000Z
In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.
Hodges, James L. (3 Hilltop Ave., Vernon, CT 06066); Cerkanowicz, Anthony E. (8 Fieldstone Dr., Livingston, NJ 07039)
1982-01-01T23:59:59.000Z
In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.
Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor
Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)
1996-11-05T23:59:59.000Z
Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.
Jiang, Huan Wanda
1994-01-01T23:59:59.000Z
Experiments were performed to study the effect of film hole location on local heat transfer coefficient and film effectiveness distributions of a turbine blade model with air (D.R. = 1.0) and C02 (D.R. = 1.52) film injection. Tests were performed...
Liu, Yao-Hsien
2009-05-15T23:59:59.000Z
at the highest rotation number of 0.58. Heat transfer coefficients are also experimentally measured in a wedge-shaped cooling channel (Dh =2.22cm, Ac=7.62cm2) to model an internal cooling passage near the trailing edge of a gas turbine blade where the coolant...
Optimization of Phase Change Heat Transfer in Biporous Media
Reilly, Sean
2013-01-01T23:59:59.000Z
demand for efficient evaporators for heat pipes and spreaders will increase in kind. Sintered copper
Simulation of FCC riser flow with multiphase heat transfer and cracking reactions.
Chang, S. L.; Zhou, C. Q.; Energy Systems
2003-08-01T23:59:59.000Z
A validated Computational Fluid Dynamics (CFD) code ICRKFLO was developed for simulations of three-dimensional three-phase reacting flows in Fluid Catalytic Cracking (FCC) riser reactors. It calculates the product yields based on local flow properties by solving the fundamental conservation principles of mass, momentum, and energy for the flow properties associated with the gas, liquid, and solid phases. Unique phenomenological models and numerical techniques were developed specifically for the FCC flow simulation. The models include a spray vaporization model, a particle-solid interaction model, and an interfacial heat transfer model. The numerical techniques include a time-integral approach to overcome numerical stiffness problems in chemical kinetics rate calculations and a hybrid hydrodynamic-kinetic treatment to facilitate detailed kinetics calculations of cracking reactions. ICRKFLO has been validated with extensive test data from two pilot and one commercial FCC units. It is proven to be useful for advanced development of FCC riser reactors.
Uddin, Mohammed Jalal
2000-01-01T23:59:59.000Z
transfer patterns from the leading and trailing surfaces. The heat transfers from the first pass trailing and the second pass leading walls are enhanced by rotation. However, the first leading and second pass trailing surfaces show a decrease in heat...
Achanta, Vamsee Satish
2004-09-30T23:59:59.000Z
In this work, we study the enhanced endwall heat transfer for flow past non conducting pin fin arrays. The aim is to resolve the controversy over the heat transfer that is taking place from the endwall and the pin ...