Fractional step two-phase flow lattice Boltzmann model implementation

Abstract

A hybrid method that combines an advanced lattice Boltzmann model with traditionalfinite difference techniques is developed. An operator splitting technique is applied toseparate the numerical scheme into two subproblems. Each subproblem is solved withdifferent techniques, namely lattice Boltzmann and finite differences. This method isapplied for the first time to a two-phase flow simulation case. Major simplifications areobtained in the lattice Boltzmann implementation. Simulations are presented to show theseimprovements and to validate the technique with kinematic viscosity down to10−4 in lattice Boltzmann units. This technique does not add instabilities, and in contrastimproves the stability behavior compared to reducing the relaxation time.