Impact of Gravity Variation on the Onset of Double-Diffusive Convection in a Horizontal Porous Layer with a Boundary Slab of Finite Conductivity

Abstract

The purpose of this study was to investigate the combined impact of boundary slab and gravity variance on the onset of binary convective motion in a porous layer. The lower boundary of the porous bed is subjected to a steady-state heat flux. Furthermore, the conductivity of the plate is usually different from the conductivity of the porous sheet. We considered three cases of gravity field variations: (a) linear, (b) parabolic, and (a) cubic. The analytical solutions are achieved by perturbation technique for small values of the gravity parameter, conductivity, and depth of the plate. It is obtained that the gravity parameter, depth ratio, and conductivity ratio of the plate are to hold up the beginning of convective motion. It is also found that the system is more consistent for the linear variation and more inconsistent for the cubic variation.KeywordsVariable gravityBinary fluidsThermal conductivityStability