a. mohamad

The significance of inconstant gravity force and uniform throughflow on the start of convective movement in an anisotropic porous matrix is investigated numerically utilizing large-term Galerkin procedure. The porous layer is acted to uniform upright throughflow and inconstant downward gravitational force which changes with the height from the layer. In this study, two types of gravity field digression were examined: (a) linear and (b) parabolic. It is found that the throughflow parameter Pe, the thermal anisotropy parameter η and gravity deviation parameter λ postpone the beginning of convective activity, whereas the mechanical anisotropy parameter ξ rapids the onset of convective activity. The dimension of the convection cells enhances on enhancing the thermal anisotropy parameter η, the mechanical anisotropy parameter ξ and gravity deviation parameter λ while, the throughflow parameter Pe decreases the extent of the convective cells. It is also noted that the structure with linear variation of gravity force is more stable.