Effect of thermal stratification on MHD free convection with heat and mass transfer over an unsteady stretching surface with heat source, Hall current and chemical reaction

Abstract
The present investigation is concerned with the effect of thermal stratification on magnetohydrodynamic free convection boundary layer flow with heat and mass transfer of an electrically conducting fluid over an unsteady stretching sheet in the presence of strong magnetic field. The electron–atom collision frequency is assumed to be relatively high, so that the Hall effect is assumed to be exist, while induced magnetic field is neglected. The transformed nonlinear boundary layer equations are solved numerically by applying Keller-box method. Effect of Prandtl number, magnetic parameter, Hall parameter, heat source parameter, radiation parameter, Schmidt number, chemical reaction parameter, Grashof number, modified Grashof number, as well as the local skin friction coefficient, heat and mass transfer rates are depicted graphically and in tabulated form. It has been found that these parameters affect considerably the considered flow characteristics.