Double-diffusive convection in a porous enclosure with cooperating temperature and concentration gradients and heat generation or absorption effects

The problem of unsteady, laminar double-diffusive convective flow of a binary gas mixture in a rectangular enclosure filled with a uniform porous medium is considered. A temperature-dependent heat source or sink is assumed to exist within the enclosure boundaries. Transverse cooperating gradients of heat and mass are applied on the two opposing vertical walls of the enclosure while the other two horizontal walls are adiabatic and impermeable to mass transfer. A numerical solution based on the finite-difference methodology is obtained. Representative results illustrating the effects of the inverse Darcy number, the heat generation or absorption coefficient, and the buoyancy ratio on the contour maps of the streamline, temperature, and concentration as well as the profiles of velocity, temperature, and concentration at the midsection of the enclosure are reported. In addition, results for the average Nusselt and Sherwood numbers are presented in tabulated form and discussed for various parametric conditions.