In this paper, a simplified multiphase lattice Boltzmann method (SMLBM) is developed for modeling incompressible multiphase flows with large density ratios and complex interfaces. SMLBM is derived from reconstructing solutions to macroscopic equations recovered from the multiphase lattice Boltzmann model through Chapman-Enskog expansion analysis and resolved in a predictor-corrector step. The Cahn-Hilliard equation is utilized as the interface tracking algorithm, the solution of which is also reconstructed within the lattice Boltzmann framework. The resultant formulation of SMLBM reflects a direct update of macroscopic variables instead of distribution functions, which could remarkably save virtual memory and facilitate implementation of physical boundary conditions. Numerical tests also indicate that our scheme could effectively simulate challenging cases with large density ratios (up to 1000) and complex interfaces, and at high Reynolds numbers.

• Received 25 September 2018

DOI:https://doi.org/10.1103/PhysRevE.98.063314