Simulations of strongly phase-separated liquid-gas systems

TL;DR

This paper demonstrates that by adjusting parameters, lattice Boltzmann simulations can effectively model strongly phase-separated liquid-gas systems with high density ratios, surpassing previous limitations.

Contribution

It introduces a method to achieve high density ratios in lattice Boltzmann simulations by reducing the speed of sound and interfacial pressure contributions, with explicit parameter limits.

Findings

Achieved density ratios of 1000 or more in simulations.

Derived explicit parameter bounds for accurate results.

Identified stability limits specific to lattice Boltzmann methods.

Abstract

Lattice Boltzmann simulations of liquid-gas systems are believed to be restricted to modest density ratios of less than 10. In this article we show that reducing the speed of sound and, just as importantly, the interfacial contributions to the pressure allows lattice Boltzmann simulations to achieve high density ratios of 1000 or more. We also present explicit expressions for the limits of the parameter region in which the method gives accurate results. There are two separate limiting phenomena. The first is the stability of the bulk liquid phase. This consideration is specific to lattice Boltzmann methods. The second is a general argument for the interface discretization that applies to any diffuse interface method.