Numerical Simulation for Sloshing Behavior of Moss-type LNG Tank Based on an Improved SPH Model

In our previous research, a series of numerical simulations based on smoothed particle hydrodynamic (SPH) theory was performed, and these showed a good correlation with the model test results. However, the accuracy of the numerical prediction was highly dependent on the particle size used in the SPH model, which usually results in a computation-time-consuming problem for three-dimensional simulations. In this research, the SPH model was improved to obtain similar prediction accuracy with larger particles. A smoothed-boundary model (SBM) was proposed to better describe a boundary with complex geometry. An unphysical gap was clearly observed. Quantitative discussion of the relationship between the size of this unphysical gap and the particle size was presented based on a two-dimensional benchmark test. Dummy boundary conditions were applied to solve the unphysical gap problem caused by the original dynamic boundary conditions. The accuracy for prediction of the sloshing load was significantly enhanced by using dummy boundary conditions. Finally, the influence of the SBM on the local pressure and local particle distribution near the solid boundary was addressed.