THERMAL DISPERSION AND INERTIA EFFECTS ON VORTEX INSTABILITY OF A HORIZONTAL MIXED CONVECTION FLOW IN A SATURATED POROUS-MEDIUM

A numerical analysis is made to analyze the thermal dispersion and inertia effects on the vortex mode of instability of a horizontal mixed convection boundary layer flow with a uniform free stream velocity in a saturated porous medium adjacent to a uniform heat flux surface. The stability analysis is based on the linear stability theory and the resulting eigenvalue problem is solved by the local similarity method. The critical Rayleigh number and the associated wave number at the onset of vortex instability are obtained for various values of thermal dispersion and inertia parameters. It is found that the thermal dispersion effect stabilizes the flow to the vortex mode of disturbance, while the inertia effect destabilizes it.