Abstract

The effects of exponentially varying viscosity and linearly varying thermal conductivity on unsteady MHD natural convective flow past a semi infinite vertical plate in a thermally stratified medium is studied. The variables of both viscosity and thermal conductivity are considered only a function of temperature. The governing boundary layer equations of continuity, momentum and energy have been transformed into dimensionless coupled and nonlinear equations and after that solved by implicit finite-difference method of Crank-Nicolson type. The effects of the varying viscosity, thermal conductivity and stratification parameter at various times are discussed with velocity and temperature profiles and additionally the skin-friction and the rate of heat transfer.

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