Simulation of double diffusive natural convection and entropy generation of power-law fluids in an inclined porous cavity with Soret and Dufour effects (Part II: Entropy generation)

Abstract

In this paper, entropy generation of associated with double diffusive natural convection of non-Newtonian power-law fluids in an inclined porous cavity has been analyzed by Finite Difference Lattice Boltzmann Method (FDLBM). The entropy generations due to fluid friction, heat and mass transfer have been simulated and analyzed for the certain pertinent parameters of thermal Rayleigh number (RaT=104 and 105), Darcy number (Da=10−4, 10−3, and 10−2), power-law index (n=0.6–1.4), Lewis number (Le=2.5 and 5), inclined angles (θ=0°, 40°, 80°, and 120°), Dufour parameter (Df=0, 1, and 5), Soret parameter (Sr=0, 1, and 5) and the buoyancy ratio (N=−1 and 1). Results indicate that the augmentation of the thermal Rayleigh number enhances different entropy generations and declines the average Bejan number. The increase in the Darcy number provokes various irreversibilities to enhance and the average Bejan number decreases significantly. The augmentation of the inclined angle from θ=0° to 40° enhances various total entropy generations and plummets the average Bejan number. The increase in the inclined angle from θ=40° to 80° results in the drop of different total entropy generations and rises the average Bejan number. The rise of Soret and Dufour parameters enhances the entropy generations due to heat transfer and fluid friction. The change of power-law index alters various entropy generations, but the alteration does not follow a specific manner in different studied parameters.