REDUCTION OF MOTIONS OF AN OFFSHORE STRUCTURE IN WAVES

研究了波浪中海洋结构物运动的衰减问题。作用在结构上的波浪力被作为结构一部分的扑翼板的反作用力抵消。扑动板由直流电动机主动驱动，直流电动机由作用在扑动板上的激振力信号控制。利用水波的辐射和绕射理论计算扑翼板的最佳振动，确定了控制系统的最佳传递函数，并进行了水池模型试验。试验结果表明，锚链系泊的驳船式海洋结构物的横摇运动可减少65%。

A reduction of the motions of an offshore structure in waves is studied. Wave forces acting on the structure are canceled by the reaction of the flapping plates, consisting of a part of the structure. The flapping plates are actively driven by a D.C. motor which is controlled by the signals of the exciting force acting on the flapping plates. Optimum oscillation of the flapping plates could be calculated by the radiation and diffraction theory of water waves, and the optimum transfer function of the control system is also determined from the calculation.To verify the above theory, model tests were conducted in the water tank. 65 % of rolling motions of a barge type offshore structure moored by chains could be reduced in the experiments.