Unsteady MHD Free Convection Past an Impulsively Started Isothermal Vertical Plate with Radiation and Viscous Dissipation

The fluctuating flow produced by magneto - hydrodynamic free convection past an impulsively started isothermal vertical plate is studied taking into account the effects of radiation and viscous dissipation. By using the similarity transformation, the governing equations are transformed into dimensionless form and then the system of nonlinear partial differential equations is solved by a perturbation technique. The considered uniform magnetic field acts perpendicular to the plate, which absorbs the fluid with a given suction velocity. A comparison is made in velocity and temperature profiles for two particular cases of real and imaginary time dependent functions. The effects of various parameters like Prandtl number, Grashof number, magnetic parameter, radiation parameter, Eckert number and Schmidt number on the velocity and temperature profiles are studied quantitatively and are shown graphically. In case of real function, the frequency of excitation $\omega $ does not have much effect over temperature and velocity profiles, respectively, whereas in case of imaginary function, it has a significant effect along the wall and transverse to the wall.