HYDRODYNAMIC AND HYDROMAGNETIC TRIPLY DIFFUSIVE CONVECTION IN A VISCOELASTIC FLUID THROUGH POROUS MEDIUM

The triply diffusive convection in an Oldroydian viscoelastic fluid is mathematically investigated in the absence and presence of magnetic field through porous medium. Using linearized stability theory and normal mode analysis, the dispersion relation is obtained in each case. In the hydrodynamic case, the stable solute gradients are found to have stabilizing effects, whereas medium permeability has a destabilizing effect on the system for stationary convection. For the hydromagnetic case, the magnetic field and stable solute gradients are found to have stabilizing effects, whereas medium permeability has a destabilizing effect for stationary convection. Graphs have been plotted by giving numerical values of the parameters to depict the stability characteristics. Further, solute gradients and magnetic field are found to introduce oscillatory modes, which were non-existent in their absence. The sufficient conditions for the non-existence of overstability are also obtained in each case.