An efficient lattice Boltzmann multiphase model for 3D flows with large density ratios at high Reynolds numbers

Abstract

We report on the development, implementation and validation of a new Lattice Boltzmann method (LBM) for the numerical simulation of three-dimensional multiphase flows (here with only two components) with both high density ratio and high Reynolds number. This method is based in part on, but aims at achieving a higher computational efficiency than Inamuro et al.'s model (Inamuro et al., 2004). Here, we use a LBM to solve both a pressureless Navier-Stokes equation, in which the implementation of viscous terms is improved, and a pressure Poisson equation (using different distribution functions and a D3Q19 lattice scheme); additionally, we propose a new diffusive interface capturing method, based on the Cahn-Hilliard equation, which is also solved with a LBM. To achieve maximum efficiency, the entire model is implemented and solved on a heavily parallel GPGPU co-processor. The proposed algorithm is applied to several test cases, such as a splashing droplet, a rising bubble, and a braking ocean wave. In all cases, numerical results are found to agree very well with reference data, and/or to converge with the discretization.