EFFECT OF HALL CURRENT AND ROTATION ON THERMAL STABILITY OF FERROMAGNETIC FLUIDS SATURATING IN A POROUS MEDIUM

This paper deals with the theoretical investigation of the effect of the Hall current and rotation on ferromagnetic fluids saturating in a porous medium under the varying gravity field. To find the exact solution for a ferromagnetic fluid layer contained between two free boundaries, we have used a linear stability analysis and normal mode analysis methods. A dispersion relation governing the effect of Hall current, rotation and magnetic field is derived. From the study, we have found that the Hall current has stabilizing effect on the system under the condition TA1 > P ε2 2 M and λ > 0. For λ < 0, Hall current has destabilizing effect on the system. Further, rotation is found to have stabilizing effect on the system for the case λ > 0 and destabilizing effect for λ < 0. The effect of magnetic field on the system is to stabilize the system under the condition TA1 < 4 Mε P2 2 and λ > 0 and to destabilize the system for λ < 0. The principle of exchange of stabilities is not satisfied for the present problem while in the absence of rotation and Hall current, it is found to be satisfied under certain condition.