Numerical Study of MHD Boundary Layer Stagnation Point Flow and Heat Transfer of a Micropolar Fluid over a Permeable Horizontal Surface with Injection/Suction Effects

The paper deals with the investigations of boundary layer stagnation point flow and heat transfer characteristics of an electrically conducting micropolar fluid impinging normally on a permeable horizontal surface in the presence of a uniform magnetic field. The fluid is considered to be non-Newtonian, whose flow is governed by the equations of a micropolar fluid. The governing continuity, momentum, angular momentum and heat equations together with the associated boundary conditions are reduced to a system of coupled non-linear differential equations. The reduced self-similar equations are then solved numerically by an algorithm based on finite difference discretization. The results are further refined by Richardson’s extrapolation. An attempt is made to predict the behaviors of the injection/suction parameter, the magnetic parameter, the micropolar parameters and the Prandtl number on the flow and temperature fields in tabular and graphical forms. The investigations show that the thermal boundary layer thickness increases with an increase in the injection while it decreases in case of increasing the suction. The velocity and thermal boundary layers become thinner as the values of the magnetic parameter are increased for both the suction and injection cases. The micropolar fluids reduce shear stress and heat transfer rate as compared to Newtonian fluids. The study may be beneficial in flow and thermal control of polymeric processing.