CFD simulation of wave-induced motions of an LNG ship considering tank sloshing effects

This study uses a CFD approach to perform numerical simulations of the hydrodynamic interactions between LNG ship motions induced by waves and the sloshing behavior of cargo tanks. First, a CFD simulation is performed by solving the RANS equations to analyze the sloshing behavior of liquid in a three-dimensional rectangular tank subjected to forced simple harmonic motion. The accuracy of the RANS solver in addressing the sloshing problem is validated through comparisons with experimental data and other numerical methods. Next, the study considers the coupling effects of both the internal sloshing flow field and the external wave field on the motion of a simplified LNG vessel. The motion response of the LNG carrier in regular waves was simulated, and the sloshing impact pressure on the bulkheads under various conditions was analyzed. The simulation results of the LNG ship’s hydrodynamic behavior were compared with experimental and numerical data from previous studies. The effect of liquid tank sloshing on ship motion and tank wall pressure was examined under both head and beam wave conditions. Additionally, different forward speeds under head wave conditions were considered. It is crucial to account for the coupled effects of tank sloshing and ship dynamics when designing and evaluating liquid cargo ships.