# Magnetohydrodynamic Free Convection Flow of a Heat Generating Fluid Past a Semi-Infinite Vertical Porous Plate with Variable Suction

Magnetohydrodynamic free convection flow of a heat generating fluid past a semi-infinite vertical porous plate with variable suction Mutua, N.M 1*, Musyoki, I, N.M1, Kinyanjui, M.N2, Kwanza, J.K2 Taita Taveta University College Jomo Kenyatta University of Agriculture and Technology *Corresponding author E-mail: nicholasmuthama@ttuc.ac.ke 2 1

Abstract In this paper, a magnetohydrodynamic convection flow of an electrically conducting heat generating fluid past a semiinfinite vertical porous plate with variable suction is considered. The fluid flow is unsteady and a variable magnetic field is transversely applied to the plate. Evaluation of velocity gradients, temperature gradients and concentration gradients across the plate is done. Observations and discussions of the effects of various parameters on flow variables are done. The non-dimensional parameters observed and discussed are Hall parameter, M; Magnetic number, M 2; Eckert number, Ec; Rotational parameter, Er; Suction parameter, S and Injection parameter, w. The velocity profiles, temperature profiles and concentration profiles are presented graphically for both convectional heating and free convectional cooling of the plate. The skin friction and rate of heat transfer values are obtained and presented in tables. For free convectional heating and cooling of the plate, the Grashof number is taken as constants -5 and 5 respectively. Prandtl number is 0.71 which corresponds to air. The variation of the parameters mentioned above is noted to increase or decrease or had no effect on the skin friction, mass transfer, rate of heat transfer, the velocity profiles, concentration profiles and temperature profiles. Keywords: Finite difference method, Free convection, MHD, Semi infinite plate, Variable suction order.

1

Introduction

The study of MHD rotating fluids has had considerable progress in the last few decades. MHD free convection flow past a semi-infinite vertical porous plate with variable suction is a study which has many applications such as in MHD pumps, MHD power generator, purification of crude oil in petroleum industries, polymer technology and aerodynamic heating and accelerators. The study of MHD free convection flow of a heating generating fluid past a semi-infinite vertical porous plate with variable suction finds very many applications in cooling of electronic devices (e.g. mobiles, computers etc.) and solar panels. Some other applications in this study are design of; flow meters, MHD generators, heat exchangers, space vehicle, propulsion and breaking, electromagnetic pumps and MHD electrical power generation. Fluid flow involving rotation is observed in earth’s atmosphere and in oceans. Meteorologist can use this study to understand dynamics of meteorology and air pollution. It is in the light of this that this study will be useful to welfare of mankind. MHD flow past an infinite porous plate with variables suction was studied by [1]. An investigatation of MHD free convection and Mass transfer flow through a porous medium with heat source was undertaken [2]. A study of Heat and Mass transfer of viscous heat generating fluid with Hall currents has been accomplished [7]. [11] investigated the hydromagnetic convective flow of a heat generating fluid past a vertical plate with Hall current and heat flux through a porous medium. MHD free convection heat and mass transfer of a heat generating fluid past an impulsively started infinite vertical porous plate with Hall current and radiation absorption was investigated [5]. Studies on MHD Stokes free convection flow past an infinite vertical porous plate subjected to constant heat flux with ion-slip current and radiation absorption was done [6]. Hydromagnetic flow past parallel porous plate was studied by [10] and [3] explained the effect of magnetic field on a...

References: [1] [2] Chartuvedi, N. (1996): MHD flow past an infinite porous plate with Variable Suction. Energy Convers management, 37(5):623-7. Dorch, F . et al. (2007): Schorlapedia 2(4): 2295.

Please join StudyMode to read the full document