Comparisons of numerical methods applied to violent sloshing flows

Abstract

The present study aims the application of numerical methods for violent sloshing flows and the comparison of their results. To tins ends, two different approaches are implemented to the cases that experimental data are available. The methods to be considered are a finite volume method based on the hybrid VOF scheme and a finite difference method based on the SOLA-SURF algorithm The hybrid VOF scheme is developed by combining a volume capturing VOF method with the Level-Set reinitialization procedure. Tins scheme improves numerical smearing effects accompanying by the conventional VOF method especially for the regions on violent flows or poor grid resolution. The conception of the application of the SOLA-SURF scheme is based on the assumption that the sloshing- mduced impact loads are dictated by global fluid motion. According to experimental observation, despite the occurrence of overturning, splashes, bubbles, and other complicated physical phenomena, the magnitude of sloshuig-mduced impact pressure seems to be dictated by the global motion of fluid volume. When this is the case, the simulation of the global flows is a key in the prediction of impact occurrence. In the viewpoint of computational efficiency, such concept has a strong advantage by ignoring some complicated physical issues, as long as it does not pervert the global flow. The present two different numerical methods are applied to the rectangular tank model with three different liquid filling level conditions (30%, 50%, and 70%) near natural frequencies. Hie hydrodynamic impact pressures on the side wall and top comer of the tank and violent free-surface flows are compared with the experiment.