Begell House Inc.
Heat Transfer Research
HTR
1064-2285
35
7&8
2004
Some Aspects of Using the Heat of Solar Radiation in Communal Heat Supply
15
Alfred I.
Nakorchevskii
Institute of Engineering Thermophysics of the Academy of Sciences of Ukraine Kiev, Ukraine
B. I.
Basok
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine, Kiev, Ukraine
T. G.
Belyaeva
Institute of Engineering Thermophysics, National Academy of Sciences of Ukraine, Kiev, Ukraine
The search for nontraditional energy sources is considered, in particular, the use of the solar radiation heat on the Earth's surface. The data presented confirm the prospects of the "cluster" accumulation of solar energy.
Characteristic Features of Hydrodynamics and Heat Transfer in Transverse Flow Past Cylinders with Dimples in Single-Row Bundles
14
G. V.
Kovalenko
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine, Kiev
Artem
Khalatov
Institute of Engineering Thermophysics, National Academy of Sciences of Ukraine 2A Zhelyabov St., Kiev-57, 03057, Ukraine
The results of experimental investigation of heat transfer and characteristic features of the hydrodynamics in transverse air flow past single-row bundles of cylinders, the surface of which is made up of the systems of symmetric and asymmetric cylindrical dimples are presented. In the investigated range of Reynolds numbers from 3300 to 63,000, the maximum degree of heat transfer intensification in comparison with a smooth cylinder attains 1.78, whereas the hydraulic resistance of the bundle is increased by a value less than 14%. Some kinds of the investigated systems of dimples favor a decrease in the zone of reverse flows downstream of a cylinder by a factor of 2−4. The frequencies of sonic vibrations generated during flow past the dimples located near the front point of the cylinder are close to the frequencies appearing in flow past the same dimples located on a plane surface. The possibility of purposeful selection of the diameter of dimples for maximum reduction in the length of the zone of reverse flows behind cylinder is shown.
Mathematical Simulation of the Processes in a Pulsating Impact Disperser
11
G. K.
Ivanitskii
Institute of Technical Thermophysics, National Academy of Sciences of the Ukraine, Kiev, Ukraine
A. A.
Korchinskii
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine, Kiev, Ukraine
M. V.
Matyushkin
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine, Kiev, Ukraine
A general mathematical model of the hydrodynamic and aerodynamic processes proceeding in the liquid and gas circuits of a pulsating impact disperser is considered. A computer program intended for improving the construction of this type of industrial apparatuses and predicting optimal technological regimes has been developed.
Effects of Combined Processes in Food Technologies
10
O. G.
Burdo
Odessa State Academy of Foodstuff Technologies, Odessa, Ukraine
Based on thermodynamic analysis, the possible effects manifesting themselves during combined occurrence of processes in food technologies are explained. The mechanisms of the processes are explained with allowance for the specific properties of a food product. Using general approaches, electrokinetic effects in extraction and cryoelectric processes, the possibilities of barothermal activation of raw material, and the effects of self-cleaning of a heat-transfer surface are considered. Scientific foundations and the results of industrial tests are given that confirm the correctness of the hypotheses adopted.
Thermal Conductivity of Composite Materials Having a Chaotic Structure
9
V. V.
Novikov
"Kiev Polytechnic Institute" National Technical University of Ukraine, Kiev, Ukraine
A. N.
Piven'
"Kiev Polytechnic Institute" National Technical University of Ukraine, Kiev, Ukraine
L. N.
Udovenko
"Kiev Polytechnic Institute" National Technical University of Ukraine, Kiev, Ukraine
Based on the fractal model of a chaotic structure of an inhomogeneous material, the thermal conductivity of a composite material is determined. Comparison of calculated and experimental data is carried out.
Turbulent Mixed Convection Heat Transfer in Channels
15
Povilas
Poskas
Lithuanian Energy Institute, Branduolines inzinerijos problemas laboratorija, Breslaujos str. 3, LT-44403 Kaunas, Lithuania
Jurgis
Vilemas
Lithuanian Energy Institute, 3 Breslaujos str., LT-44403 Kaunas-35, Lithuania
Turbulent mixed-convection heat transfer in different channels and for different orientation of them is reviewed. A most thorough analysis is presented on mixed convection in vertical channels for aiding flows and inclined flat channels. It is demonstrated that there is some progress in defining characteristic buoyancy parameters for different flow conditions and in determining critical buoyancy parameters. Mixed convection in inclined flat channels is analyzed.
Investigation of Condensation Implosion Event
18
R.
Pabarcius
Lithuanian Energy Institute, Kaunas, Lithuania
Marijus
Seporaitis
Lithuanian Energy Institute, 3 Breslaujos g., Kaunas, LITHUANIA, LT-44403
Kazys
Almenas
Lietuvos energetikos institutas, Branduoliniø árenginiø saugos laboratorija, Breslaujos g. 3, LT-44403 Kaunas, Lithuania
This paper summarizes the results of the experiments conducted in a cylindrical horizontal test section called the "pulser" (L/D = 2), where condensation implosion events can be initiated in a controlled and reproducible manner It is shown that such event can be generated solely by modulating the degree of turbulence in the stratified liquid region. The turbulence level is influenced by the rate of subcooled water supply into the pulser volume filled by saturated vapor. The rising and expanding surface leads to an increased condensation rate, vapor flow and condensation-induced shear initiate surface waves and when these exceed a critical growth rate a complete interface disruption leading to a rapid condensation implosion event occurs. The presented experimental results show that the vapor-water interface perturbation required for the initiation of such condensation implosions can be generated internally and depends solely on the rate at which liquid is supplied to the pulser. Four distinct condensation modes have been identified. The influence of residual amounts of non-condensables during development of the condensation implosion event is analyzed. It is shown that the influence of non-condensables is of an equivalent importance as the liquid side turbulence that is modulated by the rate of liquid supply. Based on the experimental results the sequence of physical phenomena that lead to a condensation implosion event is described and the heat-transfer coefficient in different condensation modes is estimated and compared.
Experimental Study of Heat Transfer from a Rod Bundle of Wire-Wrapped Tubes in Axial Air Flow
14
Benediktas B.
Cesna
Lithuanian Energy Institute, Kaunas, Lithuania
Results of the experimental study of heat transfer from a 85-rod bundle in the axial air flow are presented. The rods were spaced by two- and four-start unidirectional or opposing wire wrapping. The relative pitch of bundle packing is P/d = 1.23 and the relative pitch of wire wrapping is T/d = 14, 28, and 69.8. The experiments were conducted in an air flow.
Analysis of Heat Transfer in the Zones of Ceramics-Metal Contact in the Temperature Range of 77-1000 K
12
R.
Bolsaitis
Lithuanian Energy Institute, Kaunas, Lithuania
J.
Balcevic
Lithuanian Energy Institute, Kaunas, Lithuania
V.
Matulionene
Lithuanian Energy Institute, Kaunas, Lithuania
Jurate
Cesniene
Lithuanian Energy Institute, Kaunas, Lithuania
Thermal conductivity of the ceramics-metal contacts and gaps between them has been measured. The results of the measurements are analyzed. A formula for calculation of the coefficient of thermal conductivity in the case of small gaps between the surfaces, which allows for the effect of a quasi-stationary electromagnetic field, is suggested.
Experimental Determination of the Heat-Transfer Coefficient of Tube Bundles in a Transverse Foam Flow
7
Jonas
Gylys
Department of Thermal and Nuclear Energy, Kaunas University of Technology, K.Donelaièio str. 20, LT-44239 Kaunas, Lithuania
Stasys
Sinkunas
Department of Thermal and Nuclear Energy, Kaunas University of Technology, Donelaicio 20, LT-44239 Kaunas, Lithuania
Mindaugas
Jakubcionis
Kaunas University of Technology, Donelaicio str.20, LT-3000 Kaunas, Lithuania
Results of the experiments on heat transfer of a vertical bundle of horizontal tubes in a transverse foam flow are presented. The bundle consists of three rows with three tubes in each. The dependence of heat transfer of the tube on its position in the bundle is determined. The effect of liquid drainage from foam on the rate of heat transfer is studied. A simple equation is obtained for engineering calculations of mean heat transfer of the staggered tube bundle.
Heat Transfer During Boiling of Liquids under the Conditions of Dynamic Overloads
6
A. A.
Voloshko
Astrakhan Scientific-Research and Design Institute of Gas, Astrakhan, Russia
The paper presents the results of investigations of the influence exerted by dynamic overloads on the conditions of vapor phase formation. Characteristic distributions of the liquid temperature and saturation temperature over the height of the liquid layer on the heating surface at different dynamic overloads are shown. It is shown that with increase in overloads at a constant temperature of the heating surface different forms of heat transfer are observed: from developed nucleate boiling to free convection of liquid.
Effects of Viscous Dissipation on Forced Convection in a Porous Saturated Duct with a Uniform Wall Temperature
11
Kamel
Hooman
Mechanical Engineering Department, Persian Gulf University, Bushehr 75168, Iran
Mofid
Gorji-Bandpy
University of Mazandaran
In this paper, the effects of viscous dissipation on thermal entrance heat transfer in a parallel plate channel filled with a saturated porous medium are investigated analytically on the basis of a Darcy model. The case of an isothermal boundary is treated. The local and the bulk temperature distribution along with the Nusselt number in the thermal entrance region were found. The fully developed Nusselt number — independent of the Brinkman number — is found to be 6. It was observed that neglecting the effects of viscous dissipation would lead to the well-known case of internal flows, with the Nusselt number equal to 4.93.
BOOK REVIEWHeat Conduction, Second Edition, by Latif M. Jiji
2
Edwin P.
Russo
Mechanical Engineering Dept, University of New Orleans; Consultant at Lockheed Martin, NASA External Tank-Space Shuttle
Author Index, Vol.35
4
Table of Contents, Vol. 35
0