A Lattice Boltzmann model for multi-component vapor-liquid two phase flow

In traditional multi-phase multi-component Lattice Boltzmann (LB) models, the phase properties especially the vapor-liquid equilibrium calculations failed to model the actual flow realistically. A new multi-component vapor-liquid two phase LB model that involves a four-parameter (critical temperature, critical pressure, acentric factor and volume shift factor) equation of state (EOS) is proposed. The new model employs a four-parameter EOS to calculate the force on each lattice and then to determine the force between different fluid phases accurately. An accurate difference method is proposed to integrate the interaction force into the evolution functions of each component. Moreover, the Lorentz-Bray-Clark viscosity model is implemented to calculate the viscosity of lattice fluid according to the component density. The new model is validated and applied to forecast the phase behavior of methane, ethane, and propane mixture at multiple temperatures and pressures. The simulation results show a good agreement with experimental data and theoretical predictions.