Mixed convection in an insulated rectangular enclosure with two obstacles subject to various configurations using multi-relaxation-time lattice Boltzmann method

Abstract

Mix convection heat transfer is studied in a rectangular lid-driven cavity comprising two obstacles. One of the obstacles is isothermally heated and the other is isothermally cooled. The mass flow and transfer are simulated, taking regular, incompressible, Newtonian, and viscid fluid using Numerical techniques. The fluid follows the Boussinesq approximation. The effect of pertinent parameters like Richardson number (Ri = 0.01, 0.1, 1, 5, 10, 100), Grashof number (), and Prandtl number (Pr = 0.71, 1, 7) is studied. Two aspect ratios of the lid-driven cavity are taken to study the fluid behavior. The effect of centric and eccentric locations of the heated blockages and the effect of different sizes of the obstruction on the fluid flow and thermal transportation are reported. and models of MRT-LBM are implemented for the simulation of flow and heat transfer regimes respectively. Also, Local and Average Nusselt numbers along the walls of a heated obstacle for different dimensionless parameters are calculated. The contour plots for the flow's horizontal and vertical velocity profiles are also discussed. The validation of our result is also checked by the grid independence test. The convergence of against different grid sizes shows that our code is valid.