Novel Hybrid Finite-Difference Thermal Lattice Boltzmann Models for Convective Flows

چکیده مقاله

ABSTRACT In this article, two Hybrid Thermal Lattice Boltzmann (HTLB) methods are proposed to simulate thermally driven flows. In these methods, the velocity field is solved by a Fractional Volumetric Multi Relaxation Time Lattice Boltzmann (FV-MRT-LB) scheme and an En-tropic Lattice Boltzmann (ELB) method, while the advection-diffusion equation for temperature is solved separately by a finite difference technique. In order to demonstrate the ability of the FV-MRT-LB and ELB methods for simulation of isothermal flows, a two-dimensional cavity-driven flow has been simulated at different Reynolds numbers. Then two classical cases of buoyancy-induced flows, i.e., a differentially heated cavity flow and a Rayleigh-Be′nard convective flow, have been studied numerically at different Rayleigh numbers with a Prandtl number of 0.71. The numerical results show that both HT-FV-MRT-LB and HT-ELB methods can produce accurate results.