A Three-Dimension Double-Population Thermal Lattice BGK Model for Simulation of Natural Convection Heat Transfer in a Cube

Abstract

In this paper, a double-population thermal lattice Boltzmann was applied to solve three dimensional, incompressible thermal fluid flow problem. The simplest lattice BGK D3Q6 model was proposed to determine the temperature field while D3Q15 or D3Q19 for the density and velocity Felds. The simulation of natural convection in a cubic cavity with Prandtl number 0.71 and Rayleigh number ranging from $10^3$ to $10^5$ were carried out and compared with the published results in literature. It was observed that the combination of D3Q6 and D3Q19 gave better numerical stability and accuracy compared to D3Q6 with D3Q15 for the simulation at high Rayliegh number. Keywords: Double population; lattice Boltzmann; distribution function; natural convection.