Simulating Turbulent Buoyant Flow by a Simple LES-Based Thermal Lattice Boltzmann Model

Abstract

To simulate turbulent buoyant flow in geophysical science, where usually the vorticity-streamfunction equations instead of the primitive-variables Navier-Stokes equations serve as the governing equations, a novel and simple thermal lattice Boltzmann model is proposed based on large eddy simulation (LES). Thanks to its intrinsic features, the present model is efficient and simple for thermal turbulence simulation. Two-dimensional numerical simulations of natural convection in a square cavity were performed at high Rayleigh number varying from 10 4 to 10 10 with Prandtl number at 0.7. The advantages of the present model are validated by numerical experiments.