SLOSHING SIMULATIONS OF VARIOUS TYPES OF NG TANKS DUE TO SHIP MOTIONS

The major objective of this study is to investigate sloshing behavior in various types of Liquefied Natural Gas (LNG) tanks due to ship motions. A commercial Computational Fluid Dynamics (CFD) package, STAR-CCM+, was used to establish the simulation framework, which was first validated against model test results for wall pressures in a membrane-type prismatic tank. The CFD model was further applied to four types of non prismatic tanks. In addition to the resolved impact pressure peaks, numerical results demonstrated that the sloshing behavior is unique to each individual tank type. Numerical results also consistently showed, regardless of the tank type, that the largest wall pressure tends to occur near the original mean liquid surface, where structural analysis should be focused, especially for those tanks with internal members and baffles. The simulation framework developed herein could also be a solid basis for further analyses, including the design of new LNG tanks.