On a Couple-Stress Fluid Heated from Below in a Porous Medium in the Presence of a Magnetic Field and Rotation

Abstract

A layer of couple-stress fluid heated from below in a porous medium is considered in the presence of a uniform vertical magnetic field and uniform vertical rotation. For the case of stationary convection, the rotation postpones the onset of convection. The magnetic field and couple-stress may hasten the onset of convection in the presence of rotation while In the absence of rotation, they always postpone the onset of convection. The medium permeability hastens the onset of convection in the absence of rotation while in presence of rotation, it may postpone the onset of convection. Graphs have been plotted by giving numerical values to the parameters, to depict the stability characteristics. The rotation and magnetic field are found to introduce oscillatory modes In the system which were nonexistent in their absence. A sufficient condition for the nonexistence of ovestabllity is also obtained.