Soret and Dufour Effects on Steady MHD Natural Convection Flow Past a Semi-Infinite Moving Vertical Plate in a Porous Medium with Viscous Dissipation in the Presence of a Chemical Reaction

Abstract

Transportation of heat through porous media has been a subject of many studies due to the increasing need for a better understanding of the associated transport processes. There are numerous practical applications which can be modeled or can be approximated as transport through porousmedia such as grain storage, packed sphere beds, high performance insulation for buildings, migration of moisture through the air contained in fibrous insulations, heat exchange between soil and atmosphere sensible heat storage beds and beds of fossil fuels and geothermal energy systems, among other areas. Double diffusive is driven by buoyancy due to temperature and concentration gradients. Magnetohydrodynamic flows have many applications in solar physics, cosmic fluid dynamics, geophysics and in the motion of earth’s core as well as in chemical engineering and electronics. Huges and Young (1996) gave an excellent summary of applications. Soret and Dufour effects become significant when species are introduced at a surface in fluid domain, with different (lower) density than the surrounding fluid. When heat and mass transfer occur simultaneously in a moving fluid, the relations between the fluxes and the driving potentials are more intricate in nature. It is now known that an energy flux can be generated not only by temperature gradients but by composition gradients as well. This type of energy flux is called the Dufour or diffusion-thermo effect. We also have mass fluxes being created by temperature gradients and this is called the Soret or thermal-diffusion. The effect of chemical reaction depends on whether the reaction is heterogenous or homogenous. Motivated by previousworks Abreu (et al. 2006) Alam & Rahman (2006), Don & Solomonoff (1995) Shateyi (2008) and many possible industrial and engineering applications, we aim in this chapter to analyze steady two-dimensional hydromagnetic flow of a viscous incompressible, electrically conducting and viscous dissipating fluid past a semi-infinite 16