FDLBM simulation of entropy generation due to natural convection in an enclosure filled with non-Newtonian nanofluid

Abstract

In this paper, heat transfer and entropy generation due to laminar natural convection in a square cavity filled with non-Newtonian nanofluid have been analyzed by Finite Difference Lattice Boltzmann Method (FDLBM). The cavity is filled with water and nanoparticles of copper (Cu) while the mixture shows shear-thinning behavior. This study has been conducted for the certain pertinent parameters of Rayleigh number (Ra=104–105), power-law index (n=0.6–1), and the volume fraction has been studied from φ=0 to 0.06. Results indicate that the augmentation of the power-law index causes heat transfer to drop while increase in volume fraction of nanoparticles augments it. Entropy generation due to fluid friction and heat transfer rises as the Rayleigh number enhances. Augmentation of volume fraction enhances entropy generations due to heat transfer and fluid friction in different power-law indexes. The total entropy generation declines slightly as power-law index increases.