Effects of a random porosity model on double diffusive natural convection in a porous medium enclosure

Abstract

A double diffusive natural convection in a rectangular enclosure filled with porous medium is investigated numerically. The distribution of porosity is based upon the random porosity model The Darcy-Brinkman-Forchheimer model is used and the factors of heat flux, mean porosity and standard deviation are taken into consideration. The SIMPLEC method with iterative processes is adopted to solve the governing equations. The effects of the random porosity model on the distributions of local Nusselt number are remarkable and the variations of the local Nusselt number become disordered. The contribution of latent heat transfer to the total heat transfer of the high Rayleigh number is larger than that of the low Rayleigh number and the variations of the latent heat transfer are not in order. (C) 2000 Elsevier Science Ltd.