SPH multiphase simulation of bubbly flows

The widely-used single-fluid SPH scheme allows for the successful modelling of various high dynamic flows although the role of additional non miscible phases cannot be neglected in many cases. These phases must actually be taken into consideration in order to obtain results more in line with the experiments for flows such as, sloshing, flooding of a confined volume, bubbly flows, or to capture a pressure peak smoothing by air entrapment in various situations. Two stable two-phase SPH models addressing the issue of accurately evaluating the quantities which are discontinuous across the interface were derived and validated in [1] and [2]. They are used here to study bubbly flows of increasing complexity. The viscosity and surface tension role are especially investigated. The study cases chosen are, a Rayleigh-Taylor instability, a single rising bubble reaching its terminal velocity and two merging bubbles. The results are compared to solutions given by mesh-based Level Set solvers.