Begell House Inc.
Heat Transfer Research
HTR
1064-2285
37
1
2006
A General Lumped Model for Unsteady Heat Conduction of an Asymmetric Cylinder and Unsteady Couette Flow
1-20
10.1615/HeatTransRes.v37.i1.10
Davood
Ganji (D.D. Ganji)
Babol University
Vahid
Ebrahimian
Faculty of Mechanical Engineering, University of Mazandaran P.O.Box 484, Shariati Avenue, Babol 47144, Iran
The goal of this paper is to show the application of lumped heat-conduction and fluid-mechanics models in engineering problems. Two-dimensional unsteady heat-conduction problem for an asymmetric cylinder is analyzed by this model and the results are compared with the ones of the numerical method. One-dimensional unsteady heat conduction for the slab, infinite cylinder, and sphere problems and also the Couette problem are analyzed using this model and the results of these analyses are compared with the ones of the exact solution. The results show that the step responses gained for these problems within the lumped model are in good agreement with the numerical and exact solutions.
Opposing Flow Turbulent Mixed-Convection Heat Transfer in a Vertical Flat Channel with One-Sided Heating
21-34
10.1615/HeatTransRes.v37.i1.20
Robertas
Poskas
Lithuanian Energy institute; Kaunas Univerity of Technology, Kaunas, Lithuania
Povilas
Poskas
Lithuanian Energy Institute, Branduolines inzinerijos problemas laboratorija, Breslaujos str. 3, LT-44403 Kaunas, Lithuania
Jokubas
Kolesnikovas
Lithuanian Energy Institute, Branduolinës inzinerijos problemø laboratorija, Breslaujos str. 3, LT-44403 Kaunas, Lithuania
The experimental investigation of heat transfer in a vertical flat channel with one-sided heating for turbulent mixed-convection opposing flow conditions have been performed in the region of Re = 4·103−4·104 and Grq = 1.7·108−1.4·1010. The data was analyzed using several buoyancy parameters and was compared with the results obtained by other authors in the vertical tubes.
Experimental Investigation of Opposing Turbulent Mixed-Convection Heat Transfer in an Inclined Flat Channel with One-Sided Heating. 1. Method and Investigations for an Inclination Angle φ = 60°
35-44
10.1615/HeatTransRes.v37.i1.30
Robertas
Poskas
Lithuanian Energy institute; Kaunas Univerity of Technology, Kaunas, Lithuania
Stasys
Sinkunas
Department of Thermal and Nuclear Energy, Kaunas University of Technology, Donelaicio 20, LT-44239 Kaunas, Lithuania
Povilas
Poskas
Lithuanian Energy Institute, Branduolines inzinerijos problemas laboratorija, Breslaujos str. 3, LT-44403 Kaunas, Lithuania
An experimental investigation of heat transfer in an inclined flat channel (φ = 60°) with one-sided heating (the upper wall is heated) and under the conditions of opposing turbulent mixed convection, where Re = 4·103−4·104 and Grq = 1.7·108−1.4·1010, was performed. The data was analyzed using several buoyancy parameters and was compared with the results obtained in the vertical channel.
Concerning Certain Characteristic Features of Heat and Mass Transfer on Permeable Surfaces
45-64
10.1615/HeatTransRes.v37.i1.40
E. P.
Volchkov
S. S. Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
It is shown that in the boundary layer on a porous surface at the given temperatures of the main stream and injected gas the heat flux on the wall qw depends nonmonotonically on the injection intensity. Its magnitude first increases with injection jw, then, having attained a maximum, decreases and tends to zero when jw → jcr. The problems of similarity of heat and mass transfer in boundary layers of variable composition are considered. The influence of the Lewis number Le on the similarity conditions is shown. Generally, not only the Lewis number but also an enthalpy drop influence the similarity relation. The usually adopted similarity form StTLen = StD is valid only in certain particular cases. Some results on the influence of flow accelerations and turbulence degree Tu on the characteristics of the boundary layer with combustion are given.
Characteristic Features of Heat Transfer in Flow of a Rarified Gas Past a Cylinder on Interference of an Oblique Shock with a Leading Shock Wave
65-76
10.1615/HeatTransRes.v37.i1.50
V. N.
Gusev
N. E. Zhukovskii Central Aerohydrodynamic Institute (TsAGI), Zhukovskii, Russia
Alexander Ivanovich
Erofeev
Central Aerohydrodynamic Institute (TsAGI), 1 Zhukovsky Street, Zhukovsky,
Moscow Region, 140180, Russian Federation
We investigate the characteristic features of a high-velocity gas flow past blunt bodies in the region of interaction of a plane leading shock wave with an oblique shock. We have investigated the characteristic features of formation of a high-pressure compressed gas jet on change in the Reynolds number. A change in pressure and heat transfer to the surface depending on the position of the shock relative to the cylinder center, on the Reynolds number, and on the surface temperature is analyzed. A comparison with the experimental data and results of numerical solution of the Euler and boundary-layer equations is given.
Experimental Investigation of a Diffusion Thermoeffect in a Boundary Layer During Helium Injection into Air
77-84
10.1615/HeatTransRes.v37.i1.60
E. P.
Volchkov
S. S. Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
V. P.
Lebedev
S. S. Kutateladze Institute of Thermophysics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
V. V.
Lukashov
S. S. Kutateladze Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
It has been established experimentally that in helium injection through a permeable wall into an air flow of the same temperature the heating of the wall up to about 8°C is observed. On the other hand, in the outer part of the boundary layer the flow is cooled. Such a structure of the thermal boundary layer is caused by redistribution of heat in the boundary layer due to the diffusion thermoeffect (Dufour effect). The magnitude of the thermal effect on the wall is preserved in transition from a laminar to a turbulent mode of flow.
Modeling of a Flow in a Channel with a Heated Barrier Having Rectangular Section on the Wall
85-91
10.1615/HeatTransRes.v37.i1.70
A. Ya.
Gorbachevskii
Lomonosov Moscow State University; and Institute for Mathematical Modeling, Russian Academy of Sciences, Moscow, Russia
Ya. K.
Lokhanskii
Lomonosov Moscow State University, Moscow, Russia
A. G.
Churbanov
NIKA Software; and Institute for Mathematical Modeling, Russian Academy of Sciences, Moscow, Russia
Zdenek
Chara
Institute of Hydrodynamics, Czech Academy of Sciences, Praga
B.
Horjeni
Institute of Hydrodynamics, Czech Academy of Sciences
The flow of a viscous incompressible fluid around a barrier (a heated cylinder with a rectangular cross section) is investigated in a 2D statement of the problem. The results of calculations are compared with license program packages "FLUENT" and "STAR-CD." The results of investigations can be used in analyzing the influence of heat and mass transfer on crystallization in designing technological apparatuses and in hydrodynamic constructions and heat exchangers.