Wenjing Lyu, M. Eng., Prof. Dr.-Ing. Bettar Ould el Moctar Study on Ship Motions Coupled with Liquid Sloshing

Due to high demand for energy, the worldwide petroleum gas and natural gas production have grown rapidly. Very Large Crude Carrier (VLCC), Liquefied Petroleum Gas (LPG) carrier and Liquefied Natural Gas (LNG) carrier are often subjected to severe sloshing loads during transportation or loading/offloading operations. The concern for their safe transport plays an important role in the carrier ship design. How to reduce sloshing loads and how to ensure the safety and stability of the ship motions in waves are urgent problems. Considering the introduction of the Energy Efficiency Design Index (EEDI) for new ships and the related decreasing installed power on ships, the necessity arose to the reliable prediction of the interaction between sloshing loads and ship motions at sea.

The project is to deal with the modeling and study of sloshing of liquid in tank coupled with the motions of the ship across the sea. In particular, 1) a more reliable prediction of sloshing will be conducted based on Finite Volume Method (FVM) and a free surface capturing method. 2) suitable numerical models to address the complicated coupled liquid-tank-ship interaction problem will be developed and used to study the effects of sloshing coupled with ship motions, i.e. ship seakeeping and ship manoeuvring. Furthermore, the newly developed numerical methods will be validated by model tests.

 

Figure 1  the comparison between simulation and model test of sloshing