Three-Dimensional Simulation of Heat and Mass Transfer by the Hybrid Lattice Boltzmann Method

hybrid model has been developed to analyze the process of joint mass and heat transfer in a three-dimensional formulation. The flow velocity was calculated using the mesoscopic lattice Boltzmann equations, and the temperature and concentration fields were obtained by finite-difference solution of the macroscopic energy and diffusion equations. Numerical studies were performed by varying the Rayleigh and Lewis numbers and of the ratio of lift forces (BR) due to temperature and concentration gradients. It is established that at BR ≤ 0 and BR ≥ 2 stratified concentration and thermal fields are formed in the cubic cavity. Three flow regimes are distinguished depending on BR: quasitwo-dimensional, three-dimensional nonstationary and two-dimensional. Correlation formulas are proposed for calculating the average Nusselt and Sherwood numbers.