Rotational MHD Flows in two annular regions of a clear Viscous Fluid and Fully Saturated Porous Medium*

Abstract

The effects of constant applied magnetic field have been brought out and discussed in viscous fluid flows through a circular annular porous region bounded by an inner rigid permeable circular cylinder and an outer cylinder under different physical situations. The
porous medium is extended to infinite extent and bounded by the outer cylinder. Computational results have been discussed for two cases: whether the inner cylinder is rotating with a constant velocity or at rest and for similar conditions for bounded outer cylinder. A clear viscous fluid flows through the inner cylinder whereas the porous medium is fully saturated with same fluid. The most general result has been observed in all cases that applied magnetic field retards the flow. Wall shearing stress has been calculated on the outer cylinder which is rotating at constant angular velocity while the inner cylinder kept stationary. For a fix value of slip parameter σ at the interface, the wall shearing stress on the outer cylinder decreases with increasing value of the magnetic parameter Mo and for a fixed value of the parameter Mo, the wall shearing stress decreases with increasing value of slip parameter at the interface.