Ohmic Heating and Viscous Dissipation Effects over a Vertical Plate in the Presence of Porous Medium

An analysis is performed to investigate the ohmic heating and viscous dissipation effects on an unsteady natural convective flow over an impulsively started vertical plate in the presence of porous medium with radiation and chemical reaction. Numerical solutions for the governing boundary layer equations are presented by finite difference scheme of the Crank Nicolson type. The influence of various parameters on the velocity, the temperature, the concentration, the skin friction, the Nusselt number and the Sherwood number are discussed. It is observed that velocity and temperature increases with increasing values of permeability and increasing values of Eckert number, whereas it decreases with increasing values of magnetic parameter. An increase in ohmic heating and viscous heating increases the velocity boundary layer. An increase in ohmic heating decreases the temperature. An increase in magnetic field reduces the temperature profile. The velocity profile is highly influenced by the increasing values of permeability. It is observed that permeability has strong effect on velocity. An enhancement in ohmic heating increases the shear stress, decreases the rate of heat transfer and induces the rate of mass transfer.