Accurate Prediction of Violent Slosh Loads via a Weakly Compressible VoF Formulation

The standard CFD scheme used today for the purpose of slosh loads predictions is based on an incompressible type volume of fluid (VoF) scheme. This however results in over-predicted pressure spikes and slow simulations due matrix conditioning in the case of violent slosh. In a recent review article Ibrahim (2020) further postulates the importance of accounting for gas compression in quantifying pressures due wave impact. We have therefore furthered the development of a novel weakly compressible Elemental® formulation for the accurate modelling of violent slosh loads. New developments include the introduction of a momentum conservative HiRAC VOF scheme as well as accounting for surface tension effects via higher order accurate height functions Ilangakoon et al. (2020). The developed modelling capability was proven via application to simulating two violent slosh experiments viz. lateral and verticle slosh in the presence of gravity. Particularly high accuracy was demonstrated, where the L2 error norm in the latter case was less than 2%. It was further shown that accounting for gas compressibility in a weak sense reduces predicted pressure peaks by up to 50% while the solver was 7 times faster to run. This is seen as a key development for more effective slosh impact design