Begell House Inc.
Heat Transfer Research
HTR
1064-2285
31
1-2
2000
Heat Transfer from a Vertical Isothermal Surface in the Mode of Laminar-Turbulent Transition in a Free-Convection Boundary Layer
1-4
Vladimir S.
Berdnikov
Kutateladze Institute of Thermophysics SB RAS
V. I.
Semyonov
Institute of Thermophysics, Novosibirsk, Russia
The evolution of a free-convection boundary layer at a heated vertical wall was studied experimentally. Studies were carried out on two models with close linear and equal relative dimensions HIL = 11.5 and under conditions of independent development of boundary layers on working surfaces. One of the models had two excellent heat-conducting boundaries. One of the boundaries of the second model was transparent. The similarity of laminar-turbulent transition processes in these models was shown. The use of a transparent boundary allowed a comparison of the evolution of three-dimensional secondary flows during laminar-turbulent transitions.
Electroconvective Heat Transfer in Tubes
5-8
M. K.
Bologa
Institute of Applied Physics, Academy of Sciences of Moldova, Kishinev
I. A.
Kozhukhar'
Institute of Applied Physics, Academy of Sciences of Moldova, Kishinev, Moldova
I. V.
Kozhevnikov
Institute of Applied Physics, Academy of Sciences of Moldova, Kishinev, Moldova
Heat transfer characteristics of an electroconvective heat exchanger equipped with electrohydrodynamic means for heat carrier pumping and turbulization and ensuring high-efficiency at small pumping rates were investigated experimentally. The field of application of the results obtained are discussed.
Structure of Turbulent Gas Flow under Conditions of Hydrodynamic Nonstationarity
9-12
V. B.
Bukharin
Moscow State Aviation Institute, Moscow, Russia
Guenrikh A.
Dreitser
Department of Aviation-Space Thermal Techniques,
Moscow Aviation Institute, Volokolamskoe shosse, 4, Moscow, 125993, Russia
V. M.
Kraev
Moscow State Aviation Institute (Technical University), Moscow, Russia
A. S.
Neverov
Moscow State Aviation Institute, Moscow, Russia
A method of measurement is found and some experiments are made concerning the determination of the longitudinal and radial components of the air speed in a tube with a time history of the gas flow rate. A constant temperature thermoanemometer with an X-shaped movable probe was used. Different profiles of the longitudinal and radial velocity components, their fluctuations and for correlations are presented for accelerating and decelerating flows. It is shown that in unsteady processes these parameters differ substantially from their quasisteady values. The validity of the hydrodynamic unsteady parameter as an integral parameter for the generalization of experimental data is substantiated.
Calculation of Convective Heat and Mass Transfer in Flows Past Small Bodies
13-16
V. N.
Buz
Odessa State Refrigeration Academy, Odessa, Ukraine
Computational relations for forced and natural convection heat and mass transfer within the range of small Peclet or Reynolds numbers are obtained. Results of calculations are compared with the available literature data for heat transfer from cylinders and spheres.
Heat Transfer in the Laminar - Turbulent Transition Region at Elevated Flow Turbulence
17-20
E. P.
Dyban
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine Kiev, Ukraine
Tatyana T.
Suprun
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
Experimental data are presented for the case of the onset of dynamic and thermal laminar-turbulent transition (LTT) on the surface of a flat plate under the elevated turbulence level of an external flow. It is shown that the ratio of the end-to-start LTT determined by means of characteristic thicknesses is the same as at Tue ≈ 0.3% (Ree/Re ≈ 2.7). However, the length of LTT increases substantially with external turbulence (Rexe/Rexs ≈ 1.7 at Tue ≈ 0.25% and Rexs/Rexs ≈ 2.8 at Tue ≈ 4.75%).
Susceptibility of a Thermal Turbulent Boundary Layer to a Various Effects
21-25
E. P.
Dyban
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
On the basis of experimental data an analysis of the combined effect of various disturbances (high free-stream turbulence, longitudinal pressure gradients, local closed separation on a leading edge of a streamlined surface) on the development of a turbulent boundary layer is carried out. It is shown that thermal characteristics are more conservative than hydrodynamic ones. A universal method of local heat transfer calculation under the superposition of the above effects is proposed. The method is based on the reaction of the characteristic thickness of a boundary layer to these effects.
Hydrodynamics and Heat Transfer of Electrically Conducting Fluid in a Flat Channel in Presence of a Transverse Magnetic Field
26-30
E. V.
Sviridov
Joint Institute for High Temperatures of the RAS, 125412 Izhorskaya st. 13 Bd.2, Moscow, Russia
L. G.
Genin
Moscow Power Institute (Technical University), 14 Krasnoarmeiskaya str., Moscow, 111250, Russia
T. E.
Krasnoshchekova
Moscow Power Engineering Institute, Moscow, Russia
Experimental data are summarized and an interpolation relation for the coefficient of friction of an electrically conducting flow of a fluid in a flat channel affected by a transverse magnetic field is obtained. A relation describing the diffusivity of momentum in the presence of the transverse magnetic field is proposed. The relation is used in calculations of the coefficients of friction and heat transfer based on the results of numerical solution of the equations of momentum and energy.
Heat Transfer and Resistance in Channels with Spherical Grooves on the Walls
31-35
Yu. F.
Gortyshov
A. N. Tupolev Kazan State Technical University, Kazan, Russia
V. V.
Olimpiev
Kazan State Power Engineering Institute, Kazan, Russia
R. D.
Amirkhanov
Kazan State Technical University, Kazan, Russia
The results of theoretical and experimental investigations of heat transfer intensification by the use of spherical cavities formed on heat transfer surfaces are presented. A calculation model for determination of the heat transfer and hydraulic resistance for a turbulent flow in channels with spherical cavities in the walls is proposed.
Parameters of Thermoerosion Destruction of Different Materials in Heterogeneous Flows
36-42
D. S.
Mikhatulin
Institute of High Temperatures of the Russian Academy of Science, Moscow, Russia, 127412
Yury V.
Polezhaev
Department of Heat Transfer, Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 127412, Russia
I. V.
Repin
Moscow Aviation Institute, Russia
The paper presents the results of an experimental-numerical analysis of the interaction between a high-velocity heterogeneous flow and bodies protected by various composite materials (carbon-carbon, glass-fibre-reinforced plastic, etc.).A physical model is proposed which allows us to arrive at a main idea concerning the effect of the external gas flow conditions on the behavior of composite materials.
Heat Exchange Intensification in the Case of Film Condensation on the Outer Surface of Horizontally Knurled Tubes
43-46
V. I.
Tsoi
Tashkent
V. V.
Galagan
Tashkent
I. I.
Zakirov
Tashkent
K. F.
Karimov
Tashkent
The results of an experimental investigation of the heat exchange in film condensation of the refrigerants R-22, R-142, and R-717 (ammonia) on horizontal knurled and smooth tubes are presented. The application of knurled tubes of this structure as a heat transfer surface made it possible to increase the coefficient of heat transfer.
Heat Transfer from the Surface of an Inner Annulus with Spherically Shaped Indentations in a Flow with Variable Fluid Properties
47-51
A. V.
Turkin
Moscow, Russia
A. G.
Sorokin
All-Union Heat Engineering Institute after F. E. Dzerzhinsky, Moscow, USSR
O. N.
Bragina
All-Union Heat Engineering Institute after F. E. Dzerzhinsky, Moscow, USSR
N. N.
Yakovleva
Moscow, Russia
I. B.
Aleshina
Moscow, Russia
Heat transfer and friction for a turbulent air flow in an annulus with indented inner wall are studied. The inner wall is uniformly heated and the outer wall is insulated. It is shown that for wall-to-bulk temperature ratios greater than 1.15 the Nusselt number is independent of the above parameter. Heat transfer and friction factors are 60 and 35% higher than those in a smooth channel, respectively.
Intensification of Heat Transfer at the Critical Point of a Hemisphere in a Supersonic Heterogeneous Flow
52-54
I. V.
Repin
Moscow Aviation Institute, Russia
Yury V.
Polezhaev
Department of Heat Transfer, Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 127412, Russia
D. S.
Mikhatulin
Institute of High Temperatures of the Russian Academy of Science, Moscow, Russia, 127412
A physical model of heat transfer by bodies in a high-temperature heterogeneous flow is constructed by generalizing a large volume of empirical data. The studies embrace the range of Mach numbers 2.6−4.2 and the range of Reynolds numbers (calculated on the basis of the radius of the model) 0.2·106−5·106. The dimensions and concentrations of the disperse impurity are varied from 20 to 250 μ;m and from 0.1 to 1%, respectively.
Efficiency of Heat-Exchanging Equipment
55-58
G. V.
Konyukhov
"M. V. Keldysh Research Center" Federal Unitary Enterprise, Moscow, Russia
A. I.
Petrov
Moscow, Russia
The paper deals with the evaluation of the efficiency of surfaces of heat-transfer equipment under conditions of convective heat transfer, using the criterion of thermal-hydraulic efficiency. Experimental data are presented on the heat transfer and hydraulic efficiency of heat-transfer equipment, having specially shaped fins, over the range of the Reynolds number 102 < Re < 105.
Enhancement of Heat Transfer in Channels with Artificial Agitation of Flow
59-63
Boris V.
Dzyubenko
Moscow Aviation Institute (State Technical University), 4 Volokolamskoe Highway, Moscow, 125993, Russia
Guenrikh A.
Dreitser
Department of Aviation-Space Thermal Techniques,
Moscow Aviation Institute, Volokolamskoe shosse, 4, Moscow, 125993, Russia
R. I.
Yakimenko
Moscow State Aviation Institute (Technical University), Moscow, Russia
The results are presented of an experimental investigation of heat transfer by the method of “tube in a tube” − type heat exchanger for differently shaped tubes with artificial turbulization of the flow. Dimensionless equations of heat exchange are obtained for water flow in tubes and in annular channels. These equations were used for estimating the effectiveness of heat transfer surfaces. The investigation of the structure of a turbulent swirled flow made it possible to explain the mechanisms of the enhancement of heat exchange in channels with flow swirling.
Heat Removal Augmentation in Steam Generating Channels with Swirled and Transit Flows
64-67
E. A.
Boltenko
Elektrogorsk Scientific Research Center of Safety of Nuclear Power Stations, Elektrogorsk, Russia
The paper presents the results of investigations of the effect of flow swirling and of the combined effect of swirling and transit flow on the heat removal rate and critical heat flux (CHF) in steam generating channels of annular type. It is established that a significant reduction in CHF and in the rate of heat removal occurs on convex heat transfer surfaces. Using swirled and transit flows allows one to considerably enhance the heat removal rate and CHF on convex heat transfer surfaces. Pressure losses and heat removal rate are shown to be dependent on the swirled-to-transit flow ratio. With an optimal relation between these flows it is possible to develop and construct highly efficient steam generating devices in which pressure losses differ only slightly from those in smooth channels.
Intensification of Heat Transfer in a Triangular Channel with Turbulizing Inserts
68-72
L. A.
Arsen'ev
Nizhnii Novgorod, Russia
N. P.
Sokolov
Saint Petersburg State Politechnical University 29, Politechnicheskaya str., Saint Petersburg, 195251, Russia
V. G.
Polishchuk
Saint Petersburg State Politechnical University 29, Politechnicheskaya str., Saint Petersburg, 195251, Russia
Results of an experimental investigation of the possibility to intensify heat transfer in a channel of a triangular cross section by installing 2 types of longitudinal turbulizing inserts are given. It is shown that the use of a turbulizing insert with alternating edges of cuts that are bent back in opposite directions and at an angle of 45° to the channel axis leads to an approximately 35% increase in the average coefficients as compared to the heat-transfer level in the channel without the insert.
NATIONAL FORUM ON HEAT TRANSFER
73-75
Alexander V.
Klimenko
Moscow Power Engineering Institute (Technical University), Russia
RADIATION AND COMBINED HEAT TRANSFER: A REVIEW
76-90
Sergey T.
Surzhikov
Institute of Problems of Mechanics, Russian Academy of Sciences, Moscow, Russia
The reports that were presented at the Section on the Radiative and Combined Heat Transfer at the Second Russian National Conference on Heat Transfer (RNKT-2) are analyzed. The papers are classified as follows: combined heat transfer (CHT) upon material failure; CHT in furnaces and engines; CHT in energy devices; theoretical methods of radiative and combined heat transfer; CHT in technological processes; optical properties, emissivity and absorptivity; heat exchange by radiation and convection; CHT under extreme conditions; experimental benches and techniques; heat transfer in intricate structural units. Comparison with the world level of investigations in each field is given.
HEAT AND MASS TRANSFER WITH CHEMICAL REACTIONS: A REVIEW
91-102
V. P.
Motulevich
Moscow Power Institute (Technical University), Russia
At the Second Russian National Conference on Heat Transfer (RNCHT-2), papers related to the effect of homogeneous and heterogeneous chemical reactions on heat and mass transfer were presented. The specific features of processes that occur during both laminar and turbulent motion of fluids were studied both theoretically and experimentally. A large number of communications were devoted to a wide circle of applied problems of the traditional and new engineering: from the specific features of fuel combustion in power energy boilers to the processes that play an important role in space technology and in the exploitation of nuclear reactors.
TWO-PHASE FLOWS: A REVIEW
103-122
O. N.
Kaban'kov
A. P.
Sevast'yanov
Moscow Power Institute (Technical University), Russia
The papers presented to the Section Two-Phase Flows of the Second National Russian Conference on Heat Transfer (RNKT-2) held at the Power Engineering Institute, Moscow in October 1998 have been reviewed. The papers presented to this Section cover a large scope of the problems including nonstationary hydraulic thermal processes during pulsed heat transfer in a wall, the interaction between a heated surface and a cold liquid, two-phase flows at thermal nonequilibrium, critical flows of adiabatic two-phase media in nozzles and channels; nonisothermal mixing of gas-droplet jets with a gas flow, heat and mass transfer in two-phase binary systems and channels of complicated shapes, and the experimental methods for studying two-phase flow patterns. Some presentations were devoted to the analysis of processes occurring in two-phase media in various technical devices. As usual, the references to the published books and articles in the text are given in square brackets, whereas the ordinal numbers of the papers reviewed are given in vertical lines.
FORCED CONVECTION OF SINGLE-PHASE LIQUID: A REVIEW
123-145
L. G.
Genin
Moscow Power Institute (Technical University), 14 Krasnoarmeiskaya str., Moscow, 111250, Russia
Anatoly F.
Polyakov
Department of Heat Transfer, Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 127412, Russia
The papers presented to the Section Forced Convection of Single-Phase Liquid of the Second Russian National Heat-Transfer Conference (RNKT-2) held at the Moscow Power Engineering Institute in October, 1998 have been reviewed. These papers are published in the Second Volume of the Proceedings of the Conference and are devoted to the experimental and theoretical studies of heat transfer in channels, external flows, and thermal protection of the surfaces of various apparatus.