Free convection flow of electrically conducting couple stress fluid in a vertical channel

Abstract

The effects of buoyancy forces on the free convective couple stress fluid in the presence of applied magnetic field along a vertical channel is studied using the theory of couple stress fluids formulated by Stokes. The governing momentum and energy equations are solved analytically by perturbation method and numerically by Runge-Kutta-Gill method. New approach is established to analyze the flow for strong, weak and comparable magnetic field with couple stress parameter. For all strengths of magnetic field, effect of couple stress parameter is to suppress the flow. Physical parameters such as mass flow rate, skin friction and rate of heat transfer are also studied and displayed graphically. For small values of buoyancy parameter N (<1) analytical solutions agree with numerical results.