A Double Diffusive Unsteady MHD Convective Flow Past a Flat Porous Plate Moving through a Binary Mixture with Suction or Injection

The problem of unsteady magnetohydrodynamic convective flow with radiation and chemical reaction past a flat porous plate moving through a binary mixture in an optically thin environment is considered. The governing boundary layer equations are converted to nonlinear ordinary differential equations by similarity transformation and then solved numerically by MATLAB “bvp4c” routine. The velocity, temperature, and concentration profiles are presented graphically for various values of the material parameters. Also a numerical data for the local skin friction coefficient, the local Nusselt number, and local Sherwood number is presented in tabular forms. 1. Introduction Combined heat and mass transfer problems with chemical reaction are of importance in many processes and have, therefore, received a considerable amount of attention in research. In processes such as drying, evaporation at the surface of a water body, energy transfer in a wet cooling tower, and the flow in a desert cooler, heat and the mass transfer occur simultaneously. Study towards boundary layer flow of a binary mixture of fluids is very important in view of its application in various branches of engineering and technology. A familiar example is an emulsion which is the dispersion of one fluid within another fluid. Typical emulsions are oil dispersed within water or water within oil. Another example where the mixture of fluids plays an important role is in multigrade oils. Some polymeric type fluids are added to the base oil so as to enhance the lubrication properties of mineral oil [1]. Moreover through chemical reaction, all industrial chemical processes are designed to transform cheaper raw materials to high value products. Naturally these transformations occur in reactors. Fluid dynamics plays a pivotal role in establishing relationship between the reactor hardware and reactor performance. Unsteady free convection boundary layer flows with heat and mass transfer encounter an important criterion of species chemical reaction with finite Arrhenius activation energy defined by Makinde [2]. This phenomenon is useful in the areas such as geothermal or oil reservoir engineering where more numbers of experimental works happen. It is very important for theoretical works to predict the effects of the activation energy in these flows. But very few theoretical works are available in the literature as the chemical reaction process involved in the systems are quite complex. This may be simplified by restricting the reaction to binary type chemical reaction. The thermomechanical balance equations for