Triple-Diffusive Convection in Walters’ (Model B´) Fluid in Porous Medium in Hydromagnetics

The triple-diffusive convection in Walters’ (Model B´) fluid in porous medium is considered in the presence of uniform vertical magnetic field. For the case of stationary convection, the stable solute gradients and magnetic field have stabilizing effect on the system, whereas the medium permeability has a destabilizing (or stabilizing) effect on the system under certain conditions. A linear stability analysis theory and normal mode analysis method have been carried out to study the onset convection. The kinematic viscoelasticity has no effect on the stationary convection. The solute gradients, magnetic field, porosity and kinematic viscoelasticity introduce oscillatory modes in the system, which were non-existent in their absence. The sufficient conditions for the nonexistence of overstability are also obtained.