The conception and mechanism of ship frequency scattering due to maneuvering motions in regular waves

By adopting ship motion equation of rolling with single-freedom degree, together with coupled heave-pitch motion equation, the irregular oscillatory motion of maneuverability response in regular waves was numerically simulated in this paper. Based on the presupposition of harmonic wave encounter frequency, the concept of frequency scattering of wave encounter frequency was presented. The constant value, as well as intensity and frequency, of wave frequency of encounter were defined, and the dispersion relation of wave encounter frequency was deduced also. Furthermore, two kinds of mechanism for the frequency scattering resulted from the change of speed and wave angle respectively, were obtained.