Numerical simulation of Rayleigh-Benard convection in non-Newtonian phase-change-material slurries

被引:40
作者
Inaba, H [1 ]
Dai, C [1 ]
Horibe, A [1 ]
机构
[1] Okayama Univ, Grad Sch Nat Sci & Technol, Div Energy Convers Sci, Okayama 7008530, Japan
关键词
natural convection; phase change material slurry; numerical; non-Newtonian fluid; functionally thermal fluid;
D O I
10.1016/S1290-0729(02)00048-0
中图分类号
O414.1 [热力学];
学科分类号
摘要
A two-dimensional numerical study has been conducted to obtain fluid flow and heat transfer characteristics for Rayleigh-Benard natural convection of non-Newtonian phase-change-material (PCM) slurries in a rectangular enclosure with isothermal horizontal plates and adiabatic lateral walls. Generally, with the melting of PCM, the slurry's density draws down sharply but continuously and the slurry's specific heat capacity shows a peak value. Some PCM slurries such as microemulsions can exhibit pseudoplastic non-Newtonian fluid behavior. This paper deals with the differences in natural convection and flow patterns between Newtonian and non-Newtonian fluids with or without PCM theoretically. Due to the participation of PCM in natural convection, the dependency of Rayleigh number Ra alone cannot reflect its intensity that a modified Stefan number has to be taken into account. A correlation is generalized in the form of Nu = C . Ra-l . Ste(-m) which has a mean deviation of 10.4% in agreement with the calculated data. The numerical simulation has been performed with the following parameters: a shear thinning pseudoplastic fluid for pseudoplastic index 0.8 less than or equal to n less than or equal to 1.0, 6 x 10(3) less than or equal to Ra less than or equal to 2 x 10(6), Prandtl number Pr = 70-288, and the aspect ratio of the rectangular enclosure from 10 : 1 to 20 : 1. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.
引用
收藏
页码:471 / 480
页数:10
相关论文
共 25 条
[1]  
Akino N., 1994, S 31 HEAT TRANSF JAP, P589
[2]   CONVECTION IN A VARIABLE-VISCOSITY FLUID - NEWTONIAN VERSUS POWER-LAW RHEOLOGY [J].
CHRISTENSEN, U .
EARTH AND PLANETARY SCIENCE LETTERS, 1983, 64 (01) :153-162
[3]  
DALE JD, 1972, J HEAT TRANSF, V94, P64, DOI 10.1115/1.3449874
[4]  
DAOUD M, 1999, SOFT MATTER PHYSICS
[5]  
DATTA P, 1996, S 33 HEAT TRANSF JAP, P225
[6]  
Datta P., 1992, GEN PAPERS HEAT TRAN, P133
[7]   NATURAL-CONVECTION IN A SQUARE CAVITY - A COMPARISON EXERCISE [J].
DAVIS, GD ;
JONES, IP .
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, 1983, 3 (03) :227-248
[8]   Heat transport in stagnant lid convection with temperature- and pressure-dependent Newtonian or non-Newtonian rheology [J].
Dumoulin, C ;
Doin, MP ;
Fleitout, L .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 1999, 104 (B6) :12759-12777
[9]  
Getling A.V., 1998, ADV SERIES NONLINEAR, V11
[10]   LAMINAR FORCED-CONVECTION HEAT-TRANSFER IN MICROCAPSULATED PHASE-CHANGE MATERIAL SUSPENSIONS [J].
GOEL, M ;
ROY, SK ;
SENGUPTA, S .
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 1994, 37 (04) :593-604