Numerical simulation of MHD mixed convection in alumina-water nanofluid filled square porous cavity using KKL model: Effects of non-linear thermal radiation and inclined magnetic field

摘要

This study examines the influence of non-linear thermal radiation and inclined magnetic field on mixed convection in a square porous cavity. Here, the cavity is saturated with alumina-water nanofluid. Darcy-Brinkman-Forchheimer-extended model has been adopted to formulate governing differential equations. After transforming equations to dimensionless form, these are solved by utilizing weighted residual Galerkin finite element method. Latest Koo-Kleinstreuer-Lee (KKL) model is employed for the evaluation of effective thermal conductivity and dynamic viscosity of nanofluid. Effect of pertinent parameters in specific ranges such as Richardson number (0.01 <= Ri <= 100), radiation parameter (0 <= Rd <= 5), temperature ratio parameter (1.1 <= Nr <= 1.4), inclined magnetic field parameter (0 degrees <= gamma <= 90 degrees), Darcy number (10(-6) <= Da <= 10(-3)), porosity parameter (0.2 <= epsilon <= 0.8) and volume fraction of solid particles (0 <= phi <= 0.04) has been studied and presented in the form of streamlines, isotherms and plots. Moreover, kinetic energy and average temperature have also been taken into account for better understanding the flow philosophy. It is found that radiation parameter, temperature ratio parameter, Darcy number and porosity parameter augment heat transfer, kinetic energy and average temperature while inclined magnetic field parameter in selected aforementioned range declines heat transfer due to hot bottom wall. (C) 2017 Elsevier B.V. All rights reserved.