STABILITY OF FREE-CONVECTION IN A ROTATING POROUS LAYER DISTANT FROM THE AXIS OF ROTATION

The stability and onset of convection in a rotating fluid saturated po rous layer subject to a centrifugal body force and placed at an offset distance from the center of rotation is investigated analytically. Th e marginal stability criterion is established in terms of a critical c entrifugal Rayleigh number and a critical wave number for different va lues of the parameter representing the dimensionless offset distance f rom the center of rotation. At the limit of an infinite distance from the center of rotation the results are identical to the convection res ulting from heating a porous layer from below subject to the gravitati onal body force. At the other limit, when the parameter controlling th e offset distance approaches zero, the results converge to previously found solutions for the convection in a porous layer adjacent to the a xis of rotation. The results provide the stability map for all positiv e values of the parameter controlling the offset distance from the cen ter of rotation, hence bridging the gap between the two extreme limit cases.