Investigation of entropy generation in MHD and slip flow over a rotating porous disk with variable properties

In the present study the effects of magnetic interaction number, slip factor and relative temperature difference on velocity and temperature profiles as well as entropy generation in magnetohydrodynamic (MHD) flow of a fluid with variable properties over a rotating disk are investigated using numerical methods. The nonlinear governing equations of flow and thermal fields are reduced to ordinary differential equations by the Von Karman approach and are then solved numerically under the related boundary conditions. The results are compared with previous studies. The profiles for radial, tangential and axial velocities and temperature profiles, average entropy generation rate and average Bejan number are sketched for different values of magnetic interaction number, slip factor, relative temperature difference, suction/injection parameter and the effects of these parameters are discussed. (C) 2013 Elsevier Ltd. All rights reserved.