Combined effect of magnetic field and viscous dissipation on a power-law fluid over plate with variable surface heat flux embedded in a porous medium

An analysis is presented to investigate the influences of viscous dissipation on buoyancy-induced flow over (a horizontal or a vertical flat plate) embedded in a non-Newtonian fluid saturated porous medium under the action of a transverse magnetic field. The Ostwald-de Waele power-law model is used to characterize the non-Newtonian fluid behavior. Similarity solutions for the transformed governing equations are obtained with prescribed variable surface heat flux, fat: each position of the plate. Numerical results for the details of the velocity and temperature profiles are shown on graphs, for the two cases horizontal and vertical plate, for different values of the magnetic field parameter, power-law index n and the exponent lambda as well as the Eckert number. Values of the excess surface temperature which are entered in tables or plotted in figures have been presented for different values of the different parameters, for the two cases, horizontal and vertical plate., (C) 2003 Elsevier Science B.V. All rights reserved.