Entropy generation analysis during MHD mixed convection flow of non-Newtonian fluid saturated inside the square cavity

Abstract

The present computational study consists of the analysis of energy transport and entropy generation due to MHD mixed convective flow of non-Newtonian fluid filled inside the square cavity. The uniform, linear heat is provided to the fluid through the horizontal bottom and vertical side walls, while considering the top wall of the cavity as adiabatic. The governing flow equations are modeled for non-Newtonian bi-viscous fluid model by using the conservation laws. Galerkin-finite element method (FEM) is used to compute the solution of the governing problem and pressure is eliminated through penalty scheme. Furthermore, two-dimensional convective heat flow is identified by using the idea of Bejan heatlines. Numerical results are computed against wide range of pertinent flow control parameters such as bi-viscosity (β), Prandtl (Pr), Richardson (Ri), Reynolds (Re) and Grashof numbers (Gr). Results show that the fluid velocity, energy transfer rate and entropy generation are increased due to enhancement in bi-viscosity parameter (β). On the other side, the velocity and temperature are decreased by increasing Hartmann number (Ha), however the entropy generation increased. Hence, the minimum entropy generation is reported at β=0.002, Ha=100 and Ri=0.1, respectively.