Effects of Thermal Radiation on MHD Axisymmetric Stagnation Point Flow and Heat Transfer of a Micropolar Fluid over a Shrinking Sheet

In this paper, a comprehensive study of hydromagnetic (MHD) axisymmetric stagnation point flow and heat transfer characteristics of an electrically conducting viscous incompressible micropolar fluid towards a shrinking sheet with radiation effects is investigated under the action of a transverse magnetic field. The governing partial differential equations (PDEs) are reduced to non linear ordinary differential equations (ODEs) in dimensionless form using suitable similarity transformations. The transformed ODEs are solved numerically by an algorithm based on finite difference approximations. Flow and heat transfer characteristics in terms of the velocity, microrotation and temperature fields for various values of the governing parameters are analyzed. Our studies show that the influences of various governing parameters have contending effect on the flow and thermal characteristics of the problem under consideration. Increase in the micropolar structure parameter and the shrinking rate of the sheet promotes flow reversal and the boundary layer thickness and reduces heat transfer rate from the sheet to the fluid, whereas the strength of magnetic field acts vice versa. The heat transfer rate increases by increasing the values of the radiation parameter.