Chemical Reaction Effects on Unsteady Mhd Free Convective Flow past an Exponentially Accelerated Vertical Porous Plate

An analytical study is performed to investigate the effects of chemical reaction and radiation on unsteady MHD flow past an exponentially accelerated vertical plate with variable temperature and variable mass diffusion in the presence of applied transverse magnetic field. It is assumed that the effect of viscous dissipation is negligible in the energy equation and there is a first order chemical reaction between the diffusing species and the fluid. The flow is assumed to be in x' ‐ direction which is taken along the infinite vertical plate in the upward direction and y' ‐ axis is taken normal to the plate. At time t' > 0, the both temperature and species concentration levels near the plate are raised linearly with time t. A general exact solution of the governing partial differential equations is obtained by usual closed analytical method. The velocity, temperature and concentration fields are studied for different physical parameters like thermal Grashof number (Gr), mass Grashof number (Gm), Schmidt number (Sc), Prandtl number (Pr), radiation parameter (R), magnetic field parameter (M), accelerated parameter (a), heat absorption parameter, chemical reaction parameter (K) and time (t) graphically. 1. INTRODUCTION Free convection flows are of great interest in a number of industrial applications such as fiber and granular insulation, geothermal systems etc. Buoyancy is also of importance in an environment where differences between land and air temperatures can give rise to complicated flow patterns. Magneto hydro-dynamic has attracted the attention of a large number of scholars due to its diverse applications. In astrophysics and geophysics, it is applied to study the stellar and solar structures, interstellar matter, radio propagation through the ionosphere etc. In engineering it finds its applications in MHD pumps, MHD bearings etc. The phenomenon of mass transfer is also very common in theory of stellar structure and observable effects are detectable, at least on the solar surface. The study of effects of magnetic field on free convection flow is important in liquid metals, electrolytes and ionized gases. The thermal physics of hydro magnetic problems with mass transfer is of interest in power engineering and metallurgy. Diffusion rates can be altered tremendously by chemical reactions. The effect of a chemical reaction depend whether the reaction is homogeneous or heterogeneous. This depends on whether they occur at an interface or as a single phase volume reaction. In well-mixed systems, the reaction is heterogeneous, if it takes place at an interface …