A lattice Boltzmann scheme for incompressible multiphase flow and its application in simulation of Rayleigh-Taylor instability

In this pager, we propose a new lattice Boltzmann scheme for simulation of multiphase flow in the nearly incompressible limit. The new scheme simulate s fluid flows based on distribution functions. The interfacial dynamics, su ch as phase segregation and surface tension, are modeled by incorporating m olecular interactions. The lattice Boltzmann equations are derived from the continuous Boltzmann equation with appropriate approximations suitable for incompressible flow. The numerical stability is improved by reducing the e ffect of numerical errors in calculation of molecular interactions. An inde x function is used to track interfaces between different phases. Simulation s of the two-dimensional Rayleigh-Taylor instability yield satisfactory res ults. The interface thickness is maintained at 3-4 grid spacings throughout simulations without artificial reconstruction steps. (C) 1999 Academic Pre ss.