Effect of Viscous Dissipation on Natural Convection in a Non-Darcy Po- rous Medium Saturated with Non-Newtonian Fluid of Variable Viscosity

This paper investigates the influence of the effect of viscous dissipation and radiation on natural convection heat transfer from vertical flat plate in a non-Darcy porous media saturated with non-Newtonian fluid of variable viscosity. The wall and the ambient medium are maintained at constant but different levels of temperature. The Ostwald–de Waele power law model is used to characterize the non-Newtonian fluid behavior. The viscosity of the fluid is assumed to follow Reynolds viscosity model. Rosseland approximation is used to describe the radiative heat flux in the energy equation. The governing equations in their non-similar form are solved numerically by local non-similarity method. The effects of variable viscosity, viscous dissipation, radiation and the power-law index parameters on the velocity and temperature profiles as well as on the heat transfer coefficient are analyzed.