Abstract
Abstracts A two-dimensional numerical study has been conducted to obtain fluid flow and heat transfer characteristics of Rayleigh-Benard natural convection in non-Newtonian Phase-Change-Material (PCM) slurries inside a rectangular enclosure with isothermal horizontal hot and cold plates and adiabatic side walls. Generally, a PCM slurry has the properties that its density draws down sharply but continuously with the melting of PCM and its specific heat capacity shows a peak value during melting. 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 of which with or without PCM theoretically. Given in the paper are also some explanations and mechanisms about the results. The simulation is performed with the following parameters: a shear thinning pseudoplastic fluid for 0.8≤n≤1.0, Ra≤2×10^6, Pr=70〜210, and the aspect ratio from 1:5 to 1:20.
