The numerical simulation and sensitivity analysis of a non-Newtonian fluid flow inside a square chamber exposed to a magnetic field using the FDLBM approach

Abstract

This paper simulated the free convective heat transfer (CHT) and generation of entropy (GOE) of a non-Newtonian fluid (NNF) in a square chamber using the FDLBM approach. The NNF is modeled by the power-law method. A magnetic field (MF) is able to take different angles which has affected the chamber. A hot square barrier exists in the middle of the chamber. The side edges of the chamber have sinusoidal temperature profiles, and the top and bottom sides are insulated. The effective studied parameters include the Hartmann number (Ha), angle of MF, exponential function index, and the aspect ratio (AR) of the hot barrier. The results of simulation disclosed that shear-thinning NNF has the highest CHT and shear-thickening NNF has the lowest GOE. Increasing the AR of the hot barrier led to an increase in the Nusselt number (Nu) and GOE and a decrease in the Bejan number (Be). Increasing the angle of the MF at small ARs with Newtonian fluid increases the Nu. Increasing the Ha from 0 to 40 in shear-thinning NNF, shear-thickening NNF, and Newtonian fluid reduced CHT by 43%, 15%, and 43%, respectively. Increasing the Ha also reduces the GOE by 27% for Newtonian fluid and 763% and 4% shear-thinning NNF and shear-thickening NNF, respectively. Eventually, a relation is proposed for the mean Nu, GOE, and Be.