Begell House Inc.
Heat Transfer Research
HTR
1064-2285
31
5
2000
LOW-REYNOLDS k-ε MODEL OF TURBULENCE
312-318
10.1615/HeatTransRes.v31.i5.10
V. I.
Mikhin
State Scientific Center of Russian Federation, A. I. Leipunskii Institute of Physics and Power Engineering, Obninsk, Russia
A low-Reynolds k-ε model of turbulence with model functions not containing a spatial coordinate similar to y+ as an argument (this coordinate is usually used to correctly model turbulence near walls) is suggested. The model which is tried out on the developed flow of an incompressible fluid in a plane channel describes the laminar-to-turbulent flow transition correctly. The obtained coefficients of resistance obey the known Dean and Zarbi-Reynolds laws. Mean-velocity distributions virtually coincide with those calculated by the three-layer Karman model.
HEAT TRANSFER IN A LAMINAR VISCOUS FLUID FLOW IN TUBES AND COAXIAL CHANNELS WITH LOCAL TWISTING OF FLOW
319-325
10.1615/HeatTransRes.v31.i5.20
T. O.
Shinkevich
Kazan Branch of Moscow Power Institute (Technical University), Russia
E. N.
Krepostina
Kazan Branch of Moscow Power Institute (Technical University), Russia
Yu. G.
Nazmeev
Kazan Branch of Moscow Power Institute (Technical University), Russia
Heat transfer in a laminar viscous fluid flow in tubes and coaxial channels with local twisting of the flow is studied. The problem was formulated in two versions - in the "vortex-stream function" form and in the Galerkin approximation. The method of finite differences and the Galerkin method are used in realization of the mathematical model.
HEAT TRANSFER IN THE RELAXATION ZONE BEHIND LOCAL CLOSED SEPARATIONS
326-332
10.1615/HeatTransRes.v31.i5.30
Eleonora Ya.
Epik
Institute of Engineering Thermophysics of National Academy of Sciences of Ukraine (IET NASU), 2a Zhelyabov Str., 03057, Kyiv, Ukraine
L. E.
Yushina
Institute of Technical Thermophysics of the National Academy of Sciences of Ukraine, Kiev, Ukraine
Tatyana T.
Suprun
Institute of Technical Thermophysics, National Academy of Sciences of Ukraine, Kiev, Ukraine
The results of an experimental study of temperature and velocity characteristics in the relaxation zone behind separations of various types are presented for the case of low turbulence of an outer flow. A general approach to employment of dimensionless viscosity on the outer edge of a dynamic boundary layer as a parameter which determins intensity and type of separation (laminar, transient, turbulent) is worked-out and widely used at the Institute of Technical Thermophysics of the National Academy of Sciences of Ukraine. A method for calculating the heat transfer in the relaxation zone behind turbulent separation is suggested. The data obtained confirm nonadequacy of prediction of the internal structure and different velocities of recovery of thermal and hydrodynamic boundary layers in the relaxation zone.
THE k-ε MODEL FOR CALCULATION OF HEAT TRANSFER AND FRICTION IN PRESEPARATION FLOWS
333-340
10.1615/HeatTransRes.v31.i5.40
E. V.
Shishov
N. E. Bauman Moscow State Technical University, Russia
Alexander
Leontiev
Joint Institute for High Temperatures
A. V.
Gerasimov
Kazan State Technological University, Kazan, Russia
The "k-ε" model of turbulent viscosity for low-Reynolds numbers is suggested. Physically substantiated corrections, which allowed us to make agreement between the experiment and the distribution of a turbulence scale in the region of diffuse flows, are introduced into the dissipation equation of the model. These corrections improved the capability of the "k-ε" model for prediction of heat transfer and friction in the region of diffuse flows, pre-separation flows being included.
CONVECTIVE HEAT TRANSFER IN FERROCOLLOIDS
341-349
10.1615/HeatTransRes.v31.i5.50
G. F.
Putin
Perm State University, Russia
T. V.
Pilyugina
Perm State University, Russia
A. A.
Bozhko
Perm State University, Russia
D. V.
Shupenik
Perm State University, Russia
The results of an experimental study of heat transfer in plane layers of ferrocolloids in the presence and absence of an outer uniform magnetic field are presented. The stability of mechanic equilibrium of a magnetic fluid for the cases when the strength vector is directed perpendicular or parallel to the layer is considered. The dependence of the dimensionless heat flux on governing parameters and the chart of convective instability are presented.
FREE-CONVECTION TURBULENT HEAT TRANSFER ON AN INCLINED SURFACE AT LARGE RAYLEIGH NUMBERS
350-358
10.1615/HeatTransRes.v31.i5.60
Leonid I.
Zaichik
Nuclear Safety Institute (IBRAE)of the Russian Academy of Sciences; Department of Heat Transfer, Institute for High Temperatures,
Russian Academy of Sciences, 127412 Moscow, Russia
Vladimir M.
Alipchenkov
Nuclear Safety Institute of the Russian Academy of Sciences
Free-convection turbulent heat transfer on inclined surfaces at large Rayleigh numbers is analyzed. A relation obtained for the Nusselt number is compared to a wealth of experimental data on heat and mass transfer on vertical, horizontal and inclined surfaces within a wide range of variation of the Prandtl number. The model applies to heat through a wall and in semicylindrical and semispherical vessels with internal heat liberation. A model of an effective turbulent heat conduction is suggested.
NATURAL CONVECTION AND HEAT AND MASS TRANSFER BY THE METHOD OF FINITE ELEMENTS
359-366
10.1615/HeatTransRes.v31.i5.70
M. B.
Ivanov
A. P. Aleksandrov Scientific-Research Technological Institute, Sosnovyi Bor, Leningrad Region, Russia
A computational program for calculation of natural convection and heat and mass transfer in two-dimensional geometry by the method of finite elements is developed and tested. An effective counter-current approximation is used in the program which allows the calculation high Rayleigh number.
FORMATION OF HEAT AND EROSION RESISTANT COATINGS ON THE SURFACES OF CONSTRUCTION MATERIALS
367-374
10.1615/HeatTransRes.v31.i5.80
P. V.
Nikitin
Moscow State Aviation Institute (Technical University), Moscow, Russia
Yu. P.
Frolov
Moscow State Aviation Institute (Technical University), Russia
S. M.
Prorokov
Moscow State Aviation Institute (Technical University), Russia
A. G.
Smolin
Moscow State Aviation Institute (Technical University), Moscow, Russia
Basic principles of laws governing the mechanism of the formation of surface coatings obtained by a low-temperature gasdynamic method (LTGDM) developed at the Moscow State Aviation Institute [1] are formulated. A physical essence of the method is presented in brief. The processes of the formation of coatings are analyzed. The relationships for calculating distribution of kinetic energy of a particle at the instant of impact on deformation of a particle and substrate and their heating are obtained. The depth of deformation determined by kinetic energy of the particle is estimated.