A pressure-evolution-based multi-relaxation-time high-density-ratio two-phase lattice-Boltzmann model

Two of the major challenges in extending the application of multiphase lattice-Boltzmann (LB) models to realistic fluid flow simulations are their numerical instability at high liquid-to-gas density ratios, and at low viscosities. In this paper, a model, recently presented in the literature, for simulating high-density ratios is extended to lower viscosities by employing multiple-relaxation-times for particle collision. In applying the multiple-relaxation-time (MRT) model, the collision term is treated explicitly and the three-step solution procedure suggested by the prior author is employed. The model is evaluated by verifying the Laplace–Young relation for a static infinitely long liquid cylinder, comparing frequency of oscillations of an initially elliptic cross-section liquid cylinder with analytic values and comparing the behavior of a two-dimensional (2D) planar drop impinging on a wet wall with prior results. The results show satisfactory agreement with available data, and a significant gain in numerical stability.