Begell House Inc.
Heat Transfer Research
HTR
1064-2285
33
5&6
2002
TRIBUTE TO CHANG-LIN TIEN
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10.1615/HeatTransRes.v33.i5-6.10
William
Begell
Begell House, Inc., 50 Cross Highway, Redding, Connecticut 06896 USA
Professor C. L. Tien died in October 2002 after a year-long battle for his life in California. A personal and professional friend for many years, Chang-Lin will be sorely missed by the heat-transfer community.
Before he fell ill, Professor Tien delivered a Plenary Speech at the 2000 National Heat Transfer Conference in Pittsburgh. I consider this speech to be Chang-Lin’s testament to the international heat transfer community and it is printed below.
Here are the words of Chang-Lin Tien which I call the Global Strategy on Technical Research and Development in the New Millennium*:
I have been working in heat transfer for 45 years and moved among its various areas. After serving as the Chancellor of University of California at Berkeley, I returned to the faculty with a title of University Professor in Management of Technology. My office is located in the Mechanical Engineering Department and I still work on research, guiding students and seeking funding. With my experience in the recent years, I would like to address the Global Technical R&D Strategy in this new Millennium. This is an especially timely issue in this era of a New Economy. This New Economy is showing that it has the volatile nature of dynamic changes. If we do not pay sufficient attention to our strategy of R&D, there is the risk that we will get lost and fall behind the competition.
Experimental Study of Distribution of Local Coefficients of Mass Transfer on Walls of Complex-Shape Channels
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10.1615/HeatTransRes.v33.i5-6.20
Nikolay
Pecherkin
Kutateladze Institute of Thermophysics Siberian branch of the Russian academy of sciences
Vladimir Yu.
Chekhovich
Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Bulat I.
Nigmatulin
Experimental Scientific-Research Center—All-Russian Scientific-Research Institute of Atomic Power Plants, Moscow, Russia
The paper presents the results of the experimental study of distribution of local coefficients of mass transfer on the walls of a channel with a flow turn by 90° and in a channel with sudden expansion. The coefficients of mass transfer are measured by an electrodiffusion method. The flow in the channel with sudden expansion is photographed and recorded by a video camera. The zones with elevated coefficients of mass transfer on the inner surface of channels are found. The effect of gas content on the position of the zones with maximum coefficients of mass transfer and on the value of the coefficients of mass transfer is studied. Empirical relations for dimensionless maximum coefficients of mass transfer are obtained.
Calculation of Heat and Mass Transfer Processes in Binary Two-Phase Systems Used in Absorption Thermotransformers
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10.1615/HeatTransRes.v33.i5-6.30
N. I.
Grigor'eva
S. S. Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk
V. E.
Nakoryakov
S. S. Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Pr. Ac. Lavrentev, 1, Novosibirsk, 630090, Russia
Processes of interrelated heat and mass transfer in a film of the solution running off the surface and absorbing steam which is in contact with the film are studied. The models allowing for heat liberation in absorption that leads to a change in equilibrium values of temperature and concentration on the phase interface are suggested for description of interrelated processes of transfer in these systems. On the basis of the solutions obtained a technique is developed for calculation of combined heat and mass transfer in absorption in the case of film running-off along the bundle of horizontal tubes.
Experimental Study of Thermal Effects in Sterilization of Disperse Systems
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10.1615/HeatTransRes.v33.i5-6.40
A. A.
Dolinsky
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine, Kiev
Yu. A.
Shurchkova
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine, Kiev, Ukraine
Borys I.
Basok
Head of the Department of Thermophysical Basics of Energy-Saving Technologies, Institute of Engineering Thermophysics National Academy of Sciences of Ukraine ul.
Bulakhovs'koho, 2a, Kyiv, 03164, Ukraine
T. S.
Ryzhkova
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine, Kiev, Ukraine
Results of experimental studies of thermal effects in realization of discrete-pulse transformation of energy in two-component disperse system are presented. The experimental setup is described and results of the estimation of the effects of sterilization and pasteurization of liquid systems of the type of water-fat emulsions are presented. The obtained experimental results confirm high efficiency of the principle of discrete-pulse transformation of energy for the processes of vapor sterilization and pasteurization.
Heat Transfer in Laminar-Turbulent Bypass Transition
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10.1615/HeatTransRes.v33.i5-6.50
V. A.
Grigorenko
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine, Kiev, Ukraine
Eleonora Ya.
Epik
Institute of Engineering Thermophysics of National Academy of Sciences of Ukraine (IET NASU), 2a Zhelyabov Str., 03057, Kyiv, Ukraine
The results of the study of heat transfer in bypass laminar-to-turbulent transition (BLTT), arising in the presence of local separation on the leading edge of a flat plate with non-gradient streamlining at an elevated degree of turbulence Tue = 3.6−2.6% are presented. It is confirmed that an upper BLTT characterized by monotonic changes in the coefficients of heat transfer takes place under these conditions. BLTT of this type is diagnosed and its boundaries are determined on the basis of an analysis of distributions of coefficients of friction and heat transfer, velocity profiles, fluctuations and a formparameter. A scheme for calculation of heat transfer in the presence of BLTT that is based on use of eddy viscosity on the outer edge of a dynamic boundary layer as a main criterion which determines intensity of heat transfer.
Calculation of Critical Heat Flux in Natural and Forced Convection Boiling
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10.1615/HeatTransRes.v33.i5-6.60
V. V.
Budrik
Kriogenmash Stock Company, Balashikha, Moscow Region, Russia
A new model of the nucleate boiling crisis with a general approach is presented for different conditions of natural and forced convection. The mechanism of crisis is adequately described and the influence of all main factors on critical heat flux q and its intensification up to maximum allowed values are established within a wide range of regime and geometric parameters. The model is supported by satisfactory generalization of data obtained and reported for the critical heat flux q in pool boiling of cryogenic and non-cryogenic fluids in the free space and in smooth and rough channels as well as under the conditions of flow onto the rods and interaction of two-phase jets and vortex flows with the wall. The equations obtained for calculation are rather simple and have no more than one empirical constant that is physically substantiated and verified in generalization of data.
The Structure of a Liquid Microlayer under a Bubble Growing on a Heating Surface and the Determination of Its Departure Radius
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10.1615/HeatTransRes.v33.i5-6.70
Oleg A.
Sinkevich
Science Technological Center of Associated Institute for High Temperature, Russian Academy of Science and Moscow Power Engineering Institute (Technical University), Russia
D. N.
Gerasimov
Moscow Energy Institute (Technical University), Russia
Within the framework of the quasistationary approximation the expression is obtained which determines the shape of the surface of a liquid interlayer under the vapor bubble. The criterion of bubble departure from the heating surface is suggested and the expression is obtained for determining its departure radius.
Experimental Investigation of Heat Transfer Enhancement by Forced Vibrations
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10.1615/HeatTransRes.v33.i5-6.80
L. M.
Kul'gina
Stavropol State University, Stavropol, Russia
Results of an experimental investigation of the effect of vibration on the parameters of boiling and heat transfer are presented. Vibration was exerted in two different ways: by vibrating the heater surface and by creating variable pressure of the column over the surface of the liquid. The effect of the amplitude and frequency of vibrations of the heater on the coefficient of heat transfer and critical heat load was determined. Experiments showed that low-frequency vibrations of liquid stabilized the process of bubble formation, led to an increase in their mean detachment frequency and in the coefficient of heat transfer.
Two-Dimensional Laminar Free Convection in the Cavity Having a Shape of a Square with Rounded-off Corners
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10.1615/HeatTransRes.v33.i5-6.90
G. V.
Makhnova
St. Petersburg State Technical University, Russia
Evgueni M.
Smirnov
Department of Aerodynamics,
St. Petersburg State Polytechnic University,
29, Polytechnitcheskaya Str.,
St. Petersburg, 195251, Russia
Vladimir V.
Ris
Peter the Great St.Petersburg Polytechnic University, Polytechnicheskaya 29, St.Petersburg, 195251, Russia
Two-dimensional steady laminar free convection in cavities produced by rounding-off of initially square corners is studied numerically at the Rayleigh numbers of from 104 to 5·109 at the Prandtl number 0.03, 0.1, 0.71, 2, 5, and 10. It is found for the cavities with isothermal vertical and adiabatic horizontal walls that rounding-off of the corners (the length of isothermal portions being preserved) leads to an increase in the Nusselt number up to 20%. The strongest effect of rounding-off of the corners is in lowering the limit of stability of steady convection.
Modeling of Heat and Mass Transfer in Polydisperse Turbulent Jets with Coagulation, Break-up, and Evaporation of Droplets
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10.1615/HeatTransRes.v33.i5-6.100
V. A.
Naumov
Kaliningrad State Technical University, Kaliningrad, Russia
Stationary nonisothermal two-phase turbulent jets (TTJ) with coagulation, break-up, and evaporation of droplets are considered. The TTJ model is developed using the transfer equation of turbulence energy. The boundary layer theory limits are exact and it is possible to neglect rotation of droplets. The equations are solved numerically. Results of the calculations agree well with experimental data. The calculations with account for interactions between droplets lead to slowing down of the reduction of a mean diameter of roplets. As a result, interphase heat transfer decreases.
Investigation of the Dynamics of an Explosive Boiling of Toluene
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10.1615/HeatTransRes.v33.i5-6.110
B. P.
Avksentyuk
Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
V. V.
Ovchinnikov
Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
We carried out experimental investigations of the dynamics of heterogeneous pool boiling of toluene. A platinum wire of diameter 100 mm and length 68 mm served as a working section. Nonstationary heating of the working section was used to attain high levels of the metastability of liquid. The working section was also used as a resistance thermometer to determine the temperature of the heat transfer surface. High-speed filming of the processes investigated was made. The experiments were carried out at a pressure in the working volume from 1.6 kPa to 76 kPa and subcoolings from 4 K to 83 K. Comparison was made between the experimental data for the velocity of the evaporation front with calculations made by the model suggested by the present authors earlier. The discrepancy did not exceed 15%.
Pulse Superheating of the Solutions of Ethyl Alcohol with Water at Negative Pressures
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10.1615/HeatTransRes.v33.i5-6.120
V. E.
Vinogradov
Institute of Thermophysics, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
Pavel A.
Pavlov
Institute of Thermophysics, Ural Branch of the Russian Academy of Sciences, Amundsen Street
107a, Ekaterinburg, 620016, Russia
We carried out an experimental study of the boiling-up of ethyl alcohol, water, and their solutions on pulse superheating on a thin platinum wire within the range of temperatures from 100 to 310°C and negative pressures of up to –10 MPa. We obtained the dependences of the temperature of limiting superheating of liquid on a wire on a value of negative pressure. In the case of a pure alcohol (with the concentration 96 vol.%), the limit of attainable superheating of liquid (Tsuperh(P)) continually passes from the region of positive pressures to the region of negative ones. The addition of water to ethanol causes a discontinuity of Tsuperh(P) in transition to negative pressures toward a decrease in the temperature of limiting superheating of liquid.
Modeling of Impurity Deposition and Transfer Processes in Vapor-Generating Pipes
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10.1615/HeatTransRes.v33.i5-6.130
Yu. V.
Muranov
State Scientific Center of the Russian Federation—Physics and Power Engineering Institute, Obninsk, Russia
V. M.
Kashcheev
State Scientific Center of the Russian Federation—Physics and Power Engineering Institute, Obninsk, Russia
Yu. S.
Yur'ev
State Scientific Center of the Russian Federation—Physics and Power Engineering Institute, Obninsk, Russia
Mathematical models of one- and two-dimensional heat and mass transfer processes in deposition and transfer of soluble impurities in heated pipes upon the dispersed annular and dispersed flow regimes are considered. The models include problems on determination of concentration fields of the impurity in a vapor flow, film, flow of droplets, and spraying flow with precipitating droplets. In order to provide an adequate description of processes of impurity deposition a thermomechanical model is used. Results of the numerical solution of transfer equations for 1D and 3D models are analyzed.
Bubble Boiling of Emulsions with a Low-Boiling Dispersed Phase
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10.1615/HeatTransRes.v33.i5-6.140
N. V.
Bulanov
Institute of Thermophysics, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
V. G.
Baidakov
Institute of Thermophysics, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
B. M.
Gasanov
Institute of Thermophysics, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
We suggest a model of the process of heat transfer from a solid surface to emulsions. On the basis of this model we obtained formulas for describing the heat flux density and bubble boiling crisis of emulsions. The formulas are checked on the array of experimental data on heat transfer from wires to water−oil and Freon-113−water emulsions.
Instability and Heat Transfer in Film Condensation of Vapor Moving on a Vertical Surface
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10.1615/HeatTransRes.v33.i5-6.150
V. V.
Tsvetkov
Nizhnii Novgorod Technical University, Nizhnii Novgorod, Russia
I. A.
Shemagin
Nizhnii Novgorod Technical University, Nizhnii Novgorod, Russia
A. A.
Mikhalevich
Nizhnii Novgorod Technical University, Nizhnii Novgorod, Russia
The results of the investigation of stability of condensation of vapor moving on a vertical surface are presented. A mathematical model similar to two-boundary-layer approximation provides the best approximation within a wide range of variation of parameters. The results obtained make it possible to determine the upper applicability limit of the existing methods of calculation.
Effect of Air Injection on Free-Convective Heat Transfer
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10.1615/HeatTransRes.v33.i5-6.160
V.
Kaznacheeva
Kaluga State Pedagogical University, Kaluga, Russia
S. E.
Gusev
Kaluga State Pedagogical University, Kaluga, Russia
The paper presents experimental data on hydrodynamics and heat transfer for the case of an air-liquid flow past a horizontal cylinder. The flow is produced by the injection of air through the system of nozzles positioned under the cylinder.
Study of the Effect of Heat and Mass Transfer on Propagation of Pulse Disturbances in Vapor-Liquid Bubble Media
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10.1615/HeatTransRes.v33.i5-6.170
A.
Mamytov
Tyumen’ Affiliate of the Institute of Theoretical and Applied Mechanics, Siberian Branch of the Russian Academy of Sciences, Tyumen’, Russia
A. A.
Gubaidullin
Tyumen’ Affiliate of the Institute of Theoretical and Applied Mechanics, Siberian Branch of the Russian Academy of Sciences, Tyumen’, Russia
Specific features of evolution and damping of pulse disturbances in vapor-liquid mixtures of a bubble structure at high initial static pressures are studied. It is shown that with an increase in an initial pressure leading to a decrease in heat of vapor generation, a rarefaction zone which may have an oscillatory structure is formed behind the peak of compression. A similar picture is observed with a decrease in heat of vapor generation of the medium or with an increase in the intensity of phase transitions, which takes place, e.g., in transition from water to liquid helium.
Heat Transfer in a Gas-Liquid Contact Evaporator
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10.1615/HeatTransRes.v33.i5-6.180
E. I.
Krupnov
Engineering-Construction Academy, Ivanovo, Russia
A. L.
Efimov
Moscow Power Institute (Technical University), Russia
We conducted experinentsl study of heat exchange between a gas jet and evaporating liquid, with different position of a nozzle cross section for gas outflow relative with respect to a liquid level in the physical model of the apparatus containing a submerged burner. It is found that two flow modes — jet and bubbling — are possible when the outlet cross section of the nozzle lies above the liquid level. The conditions of transition from jet to bubbling flow mode are determined. Empirical relations for calculation of temperature of the vaporgas mixture at the apparatus outlet are obtained for each mode. The results of the study are used in the development of energy-saving technological schemes of processing wastes of potato-starch production and evaporative decontamination of mineralized sewage.
An Optical Method of Measuring of True Vapor Velocity and Relative Motion of Phases
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10.1615/HeatTransRes.v33.i5-6.190
I. A.
Popov
Ivanovo State Energy University, Russia
V. A.
Lovyagin
Sevastopol Institute of Nuclear Energy and Industry, Ukraine
D. M.
Saida
Sevastopol Institute of Nuclear Energy and Industry, Ukraine
K. B.
Matusaev
Sevastopol Institute of Nuclear Energy and Industry, Ukraine
A method of measuring an actual velocity of motion of vapor in a two-phase flow on the basis of the system of technical vision is considered. To determine the velocity, the process of motion of vaporwater mixture is recorded by a videocamera and then a certain sequence of frames is recorded in the computer memory where spatial shifts of statistically stable features of optical images are distinguished and analyzed.
Gas-Bubble Dynamics with Unstable Operation of a Transpiration Cooling System
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10.1615/HeatTransRes.v33.i5-6.200
B. V.
Kichatov
N. E. Bauman Moscow State Technical University, Moscow
V. M.
Polyaev
N. E. Bauman Moscow State Technical University, Moscow, Russia
S. V.
Runovskii
N. E. Bauman Moscow State Technical University, Moscow, Russia
We studied gas-bubble dynamics when stable oscillations arise in the system of liquid evaporative transpiration cooling due to nonrigidity of the supply system. A model of origination of stable oscillations in the system is constructed on the basis of the Rayleigh-Lamb equation, the amplitude of a bubble radius is determined.
Analysis of Processes with Variation of the Volume of a Binary Two-Phase Expeller
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10.1615/HeatTransRes.v33.i5-6.210
A. M.
Pylaev
N. E. Bauman Moscow State Technical University, Russia
M. D.
Diev
N. E. Bauman Moscow State Technical University, Russia
A technique, formulas, and specific results of calculation of an equilibrium composition and properties of a binary two-phase system are presented. Computational data are compared to available experimental results. The possibility to use computational relations under moderately nonisothermal conditions even with possible localization of a two-phase region is shown. The formulation of a complex nonstationary problem of heat conduction for the regions with a moving boundary is considered due to a substantial effect of the character of temperature distribution on the properties of the system; an analytical solution of the problem is presented in a specially selected form with an accuracy up to initially indeterminate coefficients for the determination of which a reducible linear algebraic system is obtained.