Combined effects of Joule heating and chemical reaction on unsteady magnetohydrodynamic mixed convection of a viscous dissipating fluid over a vertical plate in porous media with thermal radiation

This paper deals with the interaction of convection and thermal radiation on an unsteady hydromagnetic heat and mass transfer for a viscous fluid past a semi-infinite vertical moving plate embedded in a porous media in the presence of heat absorption and firstorder chemical reaction of the species. The fluid is considered to be a gray, absorbing– emitting but non-scattering medium, and the Cogley–Vincent–Gilles formulation is adopted to simulate the radiation component of heat transfer (Cogley et al. (1968) [25]). The plate moves with a constant velocity in the direction of fluid flow while the free stream velocity is assumed to increase exponentially. A uniform transverse magnetic field is applied to the porous surface which absorbs the fluid with suction velocity varying with time. Analytical perturbation solutions are obtained for the velocity, temperature and concentration fields as well as for the skin friction coefficient, Nusselt number and Sherwood number. Results are presented graphically and in tabulated forms to study the effects of various physical parameters. The computed results are in good agreement with the earlier published results. © 2011 Elsevier Ltd. All rights reserved.