Open-source software for modelling of free surface flows

Problems of free-surface flow of viscous incompressible fluid are very useful in different practical cases. There are many specifies and limitations in these problems which are critically important for correct solving. The main goal is the review of existing numerical methods which can apply for modeling of free-surface flows and open-source programs where these methods are realized. Three methods for solving problems of free-surface flow were considered: Volume of Fluid, Smoothed Particle Hydrodynamics, Particle Finite Element Method v.2. They are realized in five open-source packages: OpenFOAM, Gerris, pySPH, DualSPHysics, Kratos. These packages were compared by modeling of two chosen cases: breaking of a dam and droplet impact to the liquid layer. Results of computations were compared with experimental results. There are good coincidence between them. The best results were obtained in OpenFOAM and Gerris. All main tools for modeling of free-surface flow are realized in these packages — the possibility of computations in 2D, 3D and axisymmetric model setup and also correct modeling of surface tension. Gerris can significantly accelerate computations in "big cases" due to dynamically adaptive remeshing. Further, DualSPHysics is the package for modeling of problems of coastal infrastructure where the most number of cases is 3D and the surface tension effect is negligible. The package pySPH was designed for clear demonstration of SPH working. The pySPH source code is on the Python language and not optimized. Kratos is the new package, which is in development now, therefore some tools are not developed in this moment.