MAGNETO AND ROTATORY THERMOSOLUTAL CONVECTION IN COUPLE-STRESS FLUID IN POROUS MEDIUM

摘要

The thermosolutal convection in a couple-stress fluid in a porous medium in the presence of uniform rotation and uniform vertical magnetic field (separately) is studied. Using linearized stability theory and normal mode analysis, the dispersion relation is obtained in each case. In the case of magneto thermosolutal convection, the stable solute gradient, magnetic field and couple-stress are found to have stabilizing effects, whereas medium permeability has a destabilizing effect on the system for stationary convection. For rotatory thermosolutal convection, the stable solute gradient and rotation are found to have stabilizing effects, whereas medium permeability and couple-stress have both stabilizing and destabilizing effects for stationary convection. Further, the solute gradient, magnetic field, and rotation 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.