Double-diffusive parallel flow induced in a horizontal Brinkman porous layer subjected to constant heat and mass fluxes: analytical and numerical studies
A. Amahmid et al., Double-diffusive parallel flow induced in a horizontal Brinkman porous layer subjected to constant heat and mass fluxes: analytical and numerical studies, HEAT MASS T, 35(5), 1999, pp. 409-421
Fluid flow and heat and mass transfer induced by double-diffusive natural c
onvection in a horizontal porous layer subjected to vertical gradients of t
emperature and concentration are studied analytically and numerically using
the Brinkman-extended Darcy model. Both cases of rigid and free horizontal
boundaries are examined in the present study. The parameters governing the
problem are the Rayleigh number R-T, the Lewis number Le, the buoyancy rat
io N, the Darcy number Da and the aspect ratio Ar. The analytical solution
is based on the parallel flow approximation. The critical Rayleigh number c
orresponding to the onset of the parallel flow in this system is determined
analytically as a function of Le, N and Da. For sufficiently small Da, bot
h free and rigid boundaries yield results which are identical to those pred
icted by the Darcy model. The present investigation shows that there exists
a region in the plane (N, Le) where the convective flow is not possible in
the layer regardless of the Rayleigh and Darcy numbers considered.