A five-equation model for the numerical simulation of interfaces in two-phase flows

Abstract In the Eulerian approach for simulating interfaces in two-phase flows, the main difficulties arise from the fixed character of the mesh which does not follow the interface. Therefore, near the interface there are computational cells containing both fluids which require a suitable modelling of the mixture. Furthermore, most numerical algorithms, such as the volume of fluid or the level set method, involve the transport of a function indicating the localization of each phase. Due to unavoidable numerical diffusion, they have the tendency to thicken this mixture layer around the interface. It is thus necessary to model correctly the two-phase mixture. In the context of compressible gas dynamics we propose such a model, valid for any type of state laws, which satisfies an important property of pressure stability through the interface.