An improved PLIC-VOF method for tracking thin fluid structures in incompressible two-phase flows

A drawback common to PLIC schemes is the difficulty of reconstructing the interface when filaments of a thickness smaller than the cell size are present. In this work we present an improvement of the reconstruction method proposed by Lَpez et al. [A volume of fluid method based on multidimensional advection and spline interface reconstruction. J. Comput. Phys. 195 (2004) 718] for two-dimensional flows, which allows tracking fluid structures thinner than the cell size by allowing the interface to be represented in each cell by two non-contiguous linear segments. The method is based on using markers that are placed every time step at the mid-points of the reconstructed cell interface segments. The markers are used to improve the orientation and location of the interface segments, although the method essentially remains of a VOF type. Numerical tests show that a substantial improvement in accuracy is achieved over previous volume of fluid methods, and that the proposed method compares well even with a recent hybrid markers and volume of fluid method.