Simulation on Nonlinear Ship Motions and Wave Loads with Large Amplitude Waves

A three-dimensional time-domain nonlinear strip theory was developed for predicting nonlinear hydrodynamic pressures and associated hydrodynamic wave loads in large amplitude regular waves. The emphasis was placed on the nonlinear hydrodynamic pressures on instantaneous body surface under incident waves and the consistence of ship motions and hydrodynamic forces that were achieved with a differential numerical scheme. The problem was solved with time-domain free-surface Green function and source distributions on instantaneous wetted hull surface in incident waves. The drawbacks of linear strip theory in predicting hydrodynamic pressures were pointed out with the comparisons of predicted and model test results. The nonlinear phenomena of hydrodynamic pressures with wave heights and the distributions of the positive and negative hydrodynamic pressures were illustrated. The primary calculation shows encouraging prospect for further development of the theory and its application.