Thermal lattice-BGK model based on large-eddy simulation of turbulent natural convection due to internal heat generation

Abstract

To simulate turbulent convection at high Rayleigh number ( Ra), we propose a new thermal lattice-BGK (LBGK) model based on large eddy simulation (LES). Two-dimensional numerical simulations of natural convection with internal heat generation in a square cavity were performed at Ra from 10 6 to 10 13 with Prandtl numbers ( Pr) at 0.25 and 0.60. Simulation results indicate that our model is fit to simulate high Ra flow for its better numerical stability. At Ra = 10 13, a global turbulent has occurred. With a further increase in Ra, the flow will arrive in a fully turbulence regime. The Nusselt–Rayleigh relationship is also discussed.