Fractional step two-phase flow lattice Boltzmann model implementation

A hybrid method that combines an advanced lattice Boltzmann model with traditional finite difference techniques is developed. An operator splitting technique is applied to separate the numerical scheme into two subproblems. Each subproblem is solved with different techniques, namely lattice Boltzmann and finite differences. This method is applied for the first time to a two-phase flow simulation case. Major simplifications are obtained in the lattice Boltzmann implementation. Simulations are presented to show these improvements and to validate the technique with kinematic viscosity down to 10−4 in lattice Boltzmann units. This technique does not add instabilities, and in contrast improves the stability behavior compared to reducing the relaxation time