Hall Effects on Unsteady Rotating MHD Flow Through Porous Channel with Variable Pressure Gradient

Abstract

Hall effects on an unsteady MHD flow of a viscous incompressible electrically conducting fluid in a horizontal porous channel with variable pressure gradient in a rotating system have been studied. We have considered three different cases (i) impulsive change of pressure gradient (ii) cosine oscillations of pressure gradient and (iii) sine oscillations of pressure gradient. The governing equations are solved analytically using the Laplace transform technique. It is found that interplay of Coriolis force and hydromagnetic force in the presence of pressure gradient and Hall currents plays an important role in characterizing the flow behavior. Effects of the parameters of these forces on the velocity distributions and shear stresses have been depicted graphically and discussed. It is found that the primary velocity increases with an increase in Hall parameter for the impulsive change, cosine and sine oscillations of the pressure gradient. The secondary velocity increases for the impulsive change and cosine oscillations of the pressure gradient while it decreases for sine oscillations of the pressure gradient with an increase in Hall parameter. Further, the shear stress due to the primary flow at the lower wall reduces for both the impulsive change and cosine oscillations of the pressure gradient whereas it increases for sine oscillations of the pressure gradient with an increase in Hall parameter.