Simulations of the macroscopic and mesoscopic natural convection flows within rectangular cavities

Natural convection within closed cavities is of practical and theoretical interest in many nonlinear sciences and industrial applications. Using a simple lattice Boltzmann (LB) thermal model with the Boussinesq approximation, this study investigates 2D natural convection flows with nonlinear phenomena within enclosed rectangular cavities. The simulations are performed at a constant Prandtl number of Pr = 0.71 and the reference Rayleigh numbers of Ra * 6 2 � 10 4 at the macroscopic scale (Kn =1 0 � 4 ) and the mesoscopic scale