LATTICE BHATNAGAR-GROSS-KROOK MODELS: A NEW NUMERICAL SCHEME FOR TWO-PHASE AND TURBULENT FLOWS SIMULATIONS

摘要

In this paper, we present an innovative method: the lattice BGK models, for numerical simulations of turbulent flows with two phases, complex geometries. A comparison with experimental data for flows over a backward-facing step is given. At low Mach numbers, good agreement for the recirculation length has been obtained for low Reynolds numbers R_e≤ 600. The secondary vortex on the opposite wall of the step begins to appear when the Reynolds number is approximately 250. In the simulations, unsteady solutions were obtained if the Reynolds number R_e is larger than 600, which was also observed experimentally. Flows with more complicated geometries such as a "T-plate" will also be shown. Two-phase flow in a channel will also be presented. The satisfactory results encourage the use of lattice BGK models for full three-dimensional simulations with higher Reynolds number flows with a subgrid modelling of turbulence in future studies. Another application is the thermal flows simulations with the lattice BGK models.