An exact solution to the problem of an unsteady free and forced convective MHD flow of an incompressible viscous electrically conducting fluid through a porous medium bounded by an infinite vertical hot plate impulsively held fixed in a uniform stream is presented. A uniform magnetic field is assumed to be applied transversely to the direction of the flow, taking into account the induced magnetic field. The governing equations are solved by Laplace Transform technique. The expressions for the velocity field, induced magnetic field and skin friction at the plate are obtained and demonstrated graphically for the various values of the parameters involved in the problem. The expressions for the co-efficient of rate heat transfer and current density are also derived in non dimensional form. The effects of the Hartmann number, the Prandtl number, the magnetic Prandtl number, the porosity parameter and the other parameters involved on the velocity field, induced magnetic field and skin friction at the plate are discussed. It is observed that the velocity field, skin friction, induced magnetic field and current density are significantly affected by the applied magnetic field.
Transient free and forced convection, Porosity, Electrically conducting, Skin friction, Induced magnetic field, 2000 Mathematics Subject classification-76(D)
