In this study, an extended residual-based variational multiscale method is proposed for two-phase flow. The extended residual-based variational multiscale method combines a residual-based form of the variational multiscale method and the extended finite element method (XFEM). By extending the solution spaces, it is possible to reproduce discontinuities of the solution fields inside elements intersected by the interface. In particular, we propose a quasi-static enrichment to reproduce time-dependent discontinuities. To capture the interface between the phases on a fixed grid, a level-set approach is used. A residual-based variational multiscale method is employed for computing both flow and interface motion. The presented method is tested for various two-phase flow examples exhibiting small and large density and viscosity ratios, with the focus on a kink enrichment of both velocity and pressure: a two-phase Couette flow, a Rayleigh-Taylor instability, a sloshing tank and a three-dimensional rising bubble. To the best of our knowledge, these are the first simulation results for representative time-dependent three-dimensional two-phase flow problems using an extended finite element method. Stable and accurate results are obtained for all test examples.     «

In this study, an extended residual-based variational multiscale method is proposed for two-phase flow. The extended residual-based variational multiscale method combines a residual-based form of the variational multiscale method and the extended finite element method (XFEM). By extending the solution spaces, it is possible to reproduce discontinuities of the solution fields inside elements intersected by the interface. In particular, we propose a quasi-static enrichment to reproduce time-depend...     »