Natural convection in rotating flows

The effect of rotation is shown to have a significant impact on the natural convection in pure fluids as well as in porous media. In isothermal systems, this effect is limited to the effect of the Coriolis acceleration on the flow. It is shown that Taylor-Proudman columns and geostrophic flows exist in both pure fluids as well as porous media subject to rotation. Results of linear stability analysis for natural convection in a rotating fluid layer heated from below are presented, identifying the unique features corresponding to this problem as compared to the same problem without rotation. In nonisothermal porous systems, the effect of rotation is expected in natural convection. Then the rotation may affect the flow through two distinct mechanisms, namely thermal buoyancy caused by centrifugal forces and the Coriolis force (or a combination of both). Since natural convection may be driven also by the gravity force, and the orientation of the buoyancy force with respect to the imposed thermal gradient has a distinctive impact on the resulting convection, a significant number of combinations of different cases arise in the investigation of the rotation effects in nonisothermal porous systems. Results pertaining to some of these cases are presented.