Comparison of laminar model, RANS, LES and VLES for simulation of liquid sloshing

Liquid sloshing in storage tank is a fundamental problem of great engineering importance. Sloshing motion can be laminar or turbulent. However, the necessity for inclusion of turbulence in CFD simulation of sloshing flows has not yet been established. In this paper, three roll-induced sloshing cases are studied to assess the merits and shortcomings of the laminar model and three most-commonly used turbulence models (RANS k-epsilon, LES and Very LES). To overcome the deficiencies in the RANS and LES, the new Very LES (VLES) model, which combines the RANS k-epsilon and LES, is developed in this paper. The free surface profiles are reconstructed by a coupled Level-Set and Volume-of-Fluid (CLSVOF) method. To the authors' knowledge, the comprehensive and systematical assessment of the effect of turbulence on sloshing simulation has not been reported in the literature. The numerical results are evaluated using experimental measurements from Delorme and Souto-Iglesias. The present study indicates that the inclusion of an appropriate turbulence model has a profound influence on the simulations of violent and non-violent sloshing flows. The VLES and LES models can provide accurate predictions of free surface profiles and impact pressures, whereas the laminar flow assumption and the RANS model cannot adequately capture the energy dissipation in the sloshing simulation and lead to the inaccurate flow predictions. (C) 2016 Elsevier Ltd. All rights reserved.