The ship to ship operation system of FSRU and LNG is taken as the research object in this paper. Based on the three-dimensional frequency-domain potential flow theory, numerical analysis of the resonance characteristics of wave surface elevation in the gap between FSRU and LNG. The effect of potential flow was modified by adding artificial damping, and the influence of wave period (wave frequency), incident direction and other parameters on the wave surface elevation was discussed. Furthermore, the problem of the resonance of the intermediate water body was further explored and analyzed based on the different distances between the two ships and different draughts.
Floating LNG storage and regasification unit (FSRU), which integrates LNG receiving, storage, transfer, regasification and export and other functions, it can used as LNG receiving terminal while it is moored at the dock and can also be used for the transportation of LNG. As the emergence of FSRU, it has become an important option for the receiving of LNG, and adopted by more and more countries and regions. According to statistics, up to now, there are 30 projects in operation and another 8 projects area being under construction.
In the loading and unloading operation period, ship to ship operation mode between FSRU and LNG is usually used, as shown in Figure 1. While this mode is used, the hydrodynamic interference and coupled motion between them are more complex. Especially when the two ships are very close to each other, the disturbance between the two ships is aggravated, which brings great safety risks to the loading and unloading operation. Therefore, it is necessary to consider the interaction of the hydrodynamic forces between the two ships, and know well about the hydrodynamic characteristics of the two ships in different conditions and the wave surface rise between the two ships.