A fugacity-based Lattice Boltzmann method for multicomponent multiphase systems

Abstract

The free energy model can extend the Lattice Boltzmann method to multiphase systems. However, there is a lack of models capable of simulating multicomponent multiphase fluids with partial miscibility. In addition, existing models cannot be generalized to honor thermodynamic information provided by any multicomponent equation of state of choice. In this paper, we introduce a free energy Lattice Boltzmann model where the forcing term is determined by the fugacity of the species, the thermodynamic property that connects species partial pressure to chemical potential calculations. By doing so, we are able to carry out multicomponent multiphase simulations of partially miscible fluids and generalize the methodology for use with any multicomponent equation of state of interest. We test this fugacity-based Lattice Boltzmann method for the cases of vapor-liquid equilibrium for two and three-component mixtures in various temperature and pressure conditions. We demonstrate that the model is able to reliably reproduce phase densities and compositions as predicted by multicomponent thermodynamics and can reproduce different characteristic pressure-composition and temperature-composition envelopes with a high degree of accuracy. We also demonstrate that the model can offer accurate predictions under dynamic conditions.

References in corpus (9)

• Lattice Boltzmann Simulation of Non-Ideal Fluids
• Lattice Boltzmann modeling of multiphase flows at large density ratio with an improved pseudopotential model
• A Lattice Boltzmann Model of Ternary Fluid Mixtures
• Ternary Free Energy Lattice Boltzmann Model with Tunable Surface Tensions and Contact Angles
• Ternary free-energy entropic lattice Boltzmann model with high density ratio
• Chemical-potential Multiphase Lattice Boltzmann Method with Superlarge Density Ratios
• Well-balanced lattice Boltzmann equation for two-phase flows
• Lattice Boltzmann simulation of mixtures with multicomponent van der Waals equation of state
• Shaping the equation of state to improve numerical accuracy and stability of the pseudopotential lattice Boltzmann method