Simulation of the two phase flow of droplet impingement on liquid film by the lattice boltzmann method

A Lattice Boltzmann Method (LBM) with two-distribution functions is employed for simulating the two-phase flow induced by a liquid droplet impinging onto the film of the same liquid on solid surface. The model is suitable for solution of two-phase flow problem at high density and viscosity ratios of liquid to vapor and phase transition between liquid and its vapor. The roles of the vapor flow, the density ratio of liquid to vapor and the surface tension of the droplet in the splashing formation are discussed. It is concluded that the vapour flow induced by the droplet fall and splash in the whole impinging process may affect remarkably the splash behaviour. For the case of large density ratio of liquid to vapor a crown may engender after the droplet collides with the film. However, for the case of small density ratio of liquid to vapor a “bell” like splash may be observed.