파랑 중 반잠수식 시추선의 비선형 횡동요 운동

The importance to take into account second-order motion of semi-submersibles in waves is being emphasized because sometimes, the low frequency roll motions were enen greater than the wave frequency roll motions. The paper describes characteristics of second-order roll motion of semi-submersibles in regular and irregular waves with results obtained with model tests. From the model tests in regular head wave it was observed that a semi-submersible could take on a steady list angle in specific wave period Second-order motion characteristics of a semi-submersibles are investigated from the model tests at different drafts, wave and current speeds. Also, time domail analysis has been used to calculate the roll motion of the semi-submersible and the results gave a good agreement with those of the model test.