Second law characteristics of heat transfer and fluid flow due to free convection of non-Newtonian fluids over a horizontal plate with prescribed surface temperature in a porous medium are analyzed. Velocity and temperature fields are obtained numerically using an implicit finite difference method under the similarity assumption and these results are used to compute the entropy generation rate $Ns$, irreversibility ratio $Φ$, and the Bejan number Be for both Newtonian and non-Newtonian fluids. The effects of viscous frictional parameter $G$, Rayleigh number Ra, temperature variation $λ$, axial distance $(x)$ on the dimensionless entropy generation rate $Ns$, and the Bejan number Be are investigated for Newtonian and non-Newtonian fluids and presented graphically.

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