A BEM-level set domain decomposition strategy for nonlinear and fragmented interfacial flows

A domain-decomposition algorithm has been developed to handle two-phase flows with large deformation, breaking and fragmentation of the interface. The strategy couples a boundary element method with a Navier-Stokes solver combined with a level-set technique for the tracking of the interface. The former is used in the fluid region where the interface can be modelled as a smooth surface. In the rest of the domain the field solver is applied. This results in an efficient and accurate method. In this paper, the features of the used strategy are described and the challenges connected with the coupling are deeply discussed. The numerical investigation highlighted the importance of a proper rational study when CFD methods are considered. In the present case, a crucial aspect is represented by the domain-composition step, that is when the information from one solver to the other have to be properly reconstructed and made consistent with the receiver sub-domain