MHD MIXED CONVECTION FLOW OF WATER AT C PAST A VERTICAL POROUS PLATE UNDER CHEMICAL REACTION AND SUCTION

Abstract

Flow of water at its maximum density past a porous vertical plate is considered. Effects of a transversely applied magnetic field, first order chemical reaction and suction of the plate on the flow field are studied by a similarity transformation of the governing equations. For various values of the magnetic, chemical reaction and suction parameters numerical values proportionate to Skin friction, Nusselt number and Sherwood number are tabulated and graphical results for the velocity, temperature and concentration profiles are presented. Computed values and graphical results for flow of water at a normal temperature are compared with I. Introduction Flow of electrically conducting fluid past a vertical plate is a widely studied problem in fluid dynamics. The fact that magnetic field has profound influence on boundary layer flow of an electrically conducting fluid, has attracted the attention of researchers due to its various applications in plasma physics, nuclear science, engineering design and space dynamics. Such flows are termed as MHD flows in the broader sense and abundant literature reviews are available concerning MHD convective flow of fluid past a vertical plate. Convection heat transfer coefficients, natural or forced, are a strong function of the fluid velocity. In dealing with forced convection flow we generally ignore the effects of free convection. Similarly we assume the forced convection as negligible while dealing with free convection flow. The error involved in ignoring natural convection while studying forced convection is negligible at high velocities but may be considerable at low velocities. Situations may arise for which free and forced convection effects are comparable, in which case it is inappropriate to neglect either process. Therefore it is desirable to have a criterion to assess the relative magnitude of natural convection in the presence of forced convection flows. Such flows situations where both free and forced convection effects are of comparable order belong to the mixed convection regime. In several practical applications of heat transfer theory to the vertical plate problems there exists significant temperature difference between the surface of the hot plate and the free stream. This temperature difference cause density gradients in the fluid medium and in the presence of a gravitational body force, free convection effects become