Effect of Suspended Particles and Magnetic Field on Thermal Convection in Ferromagnetic Fluid with Varying Gravitational Field in Porous Medium.

The aim of this paper is to study the effect of magnetic field and suspended particles on thermal convection in ferromagnetic fluid with varying gravity field saturating in a porous medium. A linear stability analysis and normal mode analysis methods are used to find the exact solution for a ferromagnetic fluid layer contained between two free boundaries. A dispersion relation governing the effect of magnetic field, suspended particles and medium permeability is derived theoretically. From the analysis, we have found that in case of stationary convection, the magnetic field has stabilizing effect on the system for λ>0 and has a destabilizing effect for λ<0. For stationary convection, it is also found that suspended particles and medium permeability have destabilizing effect on the system under the condition λ>0 whereas for λ<0, the nature of their effect reverses i.e. both parameters stabilizes the system for λ<0. Further, the case of oscillatory mode is also considered. It is found that the principle of exchange of stabilities is valid for the problem under certain condition. The effect of all studied parameters on ferromagnetic fluid is also verified numerically.