Soret Effect on Double-Diffusive Convection in a Square Porous Cavity Heated and Salted from Below

This article presents a numerical study of the Soret effect on double diffusion in a two-dimensional square cavity filled with a saturated Darcy porous medium. The horizontal walls of the cavity are subject to different but uniform temperatures and concentrations such that the medium is heated and salted from below. The left and right vertical walls are adiabatic and impermeable. Combined effects of the buoyancy ratio N (−1.5 < N < 4.4) and the Soret parameter M (−60.5 < M < 155) on the fluid flow and heat and mass transfer characteristics corresponding to monocellular, bicellular, and tricellular modes are studied for R T = 200 and Le = 10. It is found that the thresholds of N marking the transitions towards the oscillatory regime strongly depend on the Soret parameter M. The thermodiffusion phenomenon considerably affects the heat transfer; the Nusselt number increases with M in the case of the tricellular flow, but it goes through a maximum in the case of monocellular and bicellular flows.