Numerical simulation on coupled ship motions with nonlinear sloshing

In this paper, sloshing coupled ship motions are solved numerically in a time domain approach, in which the external flow and sloshing are computed respectively with linear diffraction-radiation theory and the Arbitrary Lagrangian-Eulerian method. This numerical method simplifies and improves the coupled ship motion predictions. Large amplitude excitation is also investigated, and soft-spring and hard-spring phenomena, which are predicted by the perturbation theory, are observed. The sloshing induced pressure in the coupled ship motion model is compared and found to be consistent with that from a prescribed motion model. In this numerical method, the structure flexibility of the tank wall could be included without additional computational effort.