Unsteady Mhd Heat And Mass Transfer Over An Infinite Porous Flat Plate With Convective Surface Boundary Conditions

ABSTRACT

Unsteady MHD heat and mass transfer over an infinite flat plate with convective surface

boundary condition problems have received little attention yet they are of great importance

in many scientific and engineering fields particularly in the manufacture and maintenance

of ship propulsion unit and thermal energy storage processes in nuclear plants. Every

research work that would give results aimed at improving the efficiency of the modern

marine vessels is of significance to the fields of naval architecture and marine engineering.

Past studies by various researchers in the field of MHD fluid flows seems to have

ignored the effects of ion-slip and Hall currents on velocity, temperature and concentration

profiles of fluid flow. In this research, unsteady MHD heat and mass transfer over

an infinite flat porous plate with convective surface boundary conditions is studied and

more specifically to investigate the contribution of the combined effects of ion-slip and

Hall currents on the velocity, temperature and concentration of an incompressible, viscous

and electrically conducting fluid subject to cooling and heating of the plate by free convectional

currents and constant heat flux. The objective of this study was to formulate and

solve, using explicit finite difference scheme, the coupled partial differential equations of

momentum, energy and concentration of species describing the flow. The flow equations

were non-dimensionalized, transformed then programmed into a mathematica code and

results generated in graphs. The effects of physical parameters on velocity, temperature

and concentration fields are analyzed from graphs. Our analysis of the graphical results

obtained shows that velocity and thermal boundary layer thickness increase with increase

in ion-slip and Hall parameters for the cooling of the plate by free convection in the presence

of constant heat flux. The thermal boundary layer thickness increases with cooling

of the plate by free convection and presence of constant heat flux. The concentration of

the fluid increases with increase in time or decrease in mass diffusion parameter or withdrawal

of suction velocity. The results of this research can serve as prototype for practical

propulsion type of problems, for example, generation of propulsion force in moving ship.