Numerical study of an unsteady free convective magnetohydrodynamic flow of a dissipative fluid along a vertical plate subject to a constant heat flux

A new method is presented to solve the transient free convection MHD flow of a dissipative fluid along a semi-infinite vertical plate with mass transfer, the surface of which is exposed to a constant heat flux. The non-linear system of partial differential equations is numerically solved by means of the network simulation method, based on the thermo-electric analogy. This method permits the direct visualisation and evolution of the local and/or integrated transport variables (temperatures, velocities, concentrations and fluxes) at any point or section of the medium. At the same time, the solution for both transient and steady-state problems is obtained, the only requirement being finite-difference schemes for the spatial variable, while its programming does not involve manipulation of the sophisticated mathematical software that is inherent in other numerical methods. The technique is always stable and convergent. Velocity, temperature and concentration profiles, local skin-friction, local Nusselt and local Sherwood numbers are plotted for air. The influence of the viscous dissipation, buoyancy ratio parameter, Schmidt number and magnetic parameter on heat and mass transfer and on the time needed to reach the steady-state are discussed. (c) 2006 Elsevier Ltd. All rights reserved.