Double-diffusive convection in an annular vertical porous layer

This paper reports an analytical and numerical study of double-diffusive na tural convection through a fluid-saturated, vertical and homogeneous porous annulus subjected to uniform fluxes of heat and mass from the side. The in fluence of each leading parameter and especially curvature, a major paramet er of this geometry, has been numerically investigated. Solutions are prese nted for 1 less than or equal to A less than or equal to 10, 1 less than or equal to Ra-T less than or equal to 200, 1 less than or equal to Le less t han or equal to 20, 0.1 less than or equal to N less than or equal to 10 an d 0 less than or equal to gamma less than or equal to 10 where A, Ra-T, Le, N and gamma denote the aspect ratio, thermal Rayleigh number, Lewis number , buoyancy ratio and curvature parameter, respectively. For the steady stat e, an analytical solution valid for stratified flow in slender enclosures i s presented. A good agreement is observed between the analytical prediction s and the numerical simulation for sufficiently high aspect ratios. (C) 199 9 Elsevier Science Ltd. All rights reserved.