Effects of force discretization on mass conservation in lattice Boltzmann equation for two-phase flows

Abstract

Discretization of interaction force is an important issue in the lattice Boltzmann equation (LBE) method for two-phase systems. A variety of discretization schemes for the interaction force have been developed from different viewpoints. Although these schemes are totally identical mathematically, they may have quite different behaviors in actual applications. In this paper we investigate the mass conservation properties of four discretization forcing schemes that have been adopted in a variety of two-phase LBE models. It is found that LBE with the mixed scheme does not conserve the total mass, and the violation is related to grid resolution, fluid velocity, and density variation.