Validation of volume-of-fluid OpenFOAM® isoAdvector solvers using single bubble benchmarks

Free surfaces and fluid interfaces are encountered in a wide variety of gas-liquid configurations. Although many numerical approaches exist to solve such flows, there is still a need for improved simulation methods. Recently, a new efficient geometric VoF method for general meshes, called isoAdvector, was implemented in OpenFOAM®. More recently, the isoAdvector method was significantly improved by introducing a variant using a reconstructed distance function (RDF) in the interface reconstruction step. Elementary quantitative benchmarks are essential for validation and comparison of interfacial solvers. We present here three benchmarks results that were used for validation of the original and new variant of the isoAdvector method. Comparisons are made with reference data and OpenFOAM® VoF original solver, interFoam, employing the MULES limiter. The first case is the static bubble under zero gravity. The RDF reconstruction method demonstrates better prediction of the interface curvature, pressure jump between the phases and strong reduction of the spurious currents. The second and third validation cases are single rising bubbles in a quiescent liquid, with a spiraling path for the third case. Either on hexahedral or tetrahedral grids, the RDF reconstruction method demonstrates a better behavior.