The method of wave phase compressed and the research of calculation of oscillatory motion responses for ships

The phenomenon of wave phase compressed is very important to oscillatory motion responses for ships. The mathematical expressions of wave phase increments of the wave forces in different frequencies of ship longitudinal velocity vibrating was obtained. The response curves of ship single-degree of freedom and coupling oscillatory motions (pitch and heave) were numerical simulated. The results of numerical simulation shows that ship oscillatory motions are affected by the phenomenon of wave phase compressed. The irregular and constant amplitude oscillatory motions appear while low and high frequencies of ship longitudinal velocity vibrating, respectively. The conclusion is very important on theoretic research and underlying practical apply about wave phase compressed.