Numerical investigation of the combined impact of variable gravity field and throughflow on the onset of convective motion in a porous medium layer

The present article is to examine the joint influence of variable gravity filed and throughflow on the onset of convective motion in a porous medium layer using higher order Galerkin method. The porous layer subjected to a constant upward vertical throughflow and variable downward gravity field which differs with distance across the layer. We discussed the four cases of gravity field variation: (i) G(z) = -z, (ii) G(z) = -z(2), (iii) G(z) = -z(3) and (iv) G(z) = - (e(z) - 1). Results indicate that both the throughflow and gravity variation parameters are to postpone the onset of convective motion. The system is observed to be more stable for case (iv), while more unstable for case (iii).