Double-diffusive convection in an inclined porous enclosure with opposing temperature and concentration gradients

The problem of unsteady, laminar double-diffusive convective flow of a bina ry gas mixture in an inclined rectangular enclosure filled with a uniform p orous medium is considered. Transverse gradients of heat and mass are appli ed on two opposing walls of the enclosure while the other two walls are adi abatic and impermeable to mass transfer. A numerical solution based on the finite-difference methodology is obtained. in the absence of the porous med ium, an oscillatory flow behavior within the enclosure is predicted for a b uoyancy ratio of unity. In the presence of the porous medium, however, a de cay in the oscillatory behavior is observed. Representative results illustr ating the effects of the inverse Darcy number and the enclosure tilting or inclination angle on the contours of streamline, temperature, concentration and density as well as the profiles of velocity, temperature and concentra tion at mid section of the enclosure are reported. In addition, results for the average Nusselt and Sherwood numbers are presented and discussed for v arious parametric conditions. In this study, the thermal and the compositio nal buoyancy forces are assumed to be opposite. (C) 2001 Editions scientifi ques et medicales Elsevier SAS.