Couple Stress Fluid Flow Through a Porous Media Past A Solid Sphere

Abstract

A steady, two-dimensional, incompressible couple stress fluid flow over a rigid sphere of radius ‘a’ surrounded by infinite porous region specifying a constant velocity away from the boundary is considered. An exact solution is found for the governing equations which leads to the expression for the stream function and shearing stress. The impact of couple stress parameter and porosity on the flow patterns is examined through streamlines. Also shear stress is computed for various values of couple- stress parameter and porous parameter. The obtained results reveal that as coupling stress parameter increases for fixing the porosity, streamlines are symmetric and meandered near the rigid sphere. But for fixed coupling stress parameter and increase in porous parameter cause the streamlines to move away from the solid sphere. Also, the dimensionless shear stress increases as couple-stress parameter intensifies for fixed porous parameter and vanishes at two stagnation points. The amplitude of the shearing stress raises with raise in porous parameter for fixed coupling stress parameter.