ABSTRACT

This work deals with the numerical and analytical study of double diffusive natural convection in a two dimensional cavity filled with saturated porous medium. The vertical walls of the cavity are submitted to thermal and compositional gradients, and zero mass and heat fluxes are imposed at the horizontal walls. The Darcy-Brinkman equation and cooperating buoyancy forces are taken into account (N ≥ 0). The porous medium is assumed to be hydraulically anisotropic. The influence of the permeability anisotropy on flow, heat and mass transfer is studied. The evolution of the heat and mass transfer with hydraulic anisotropy shows existence of three regimes: diffusive, convective and channelling convectif. The effect of buoyancy ratio (N) on the different regimes is also studied. The scale analysis in the Darcy regime allows us to establish an analytical expression which is in good agreement with the numerical results.