The studies on floating offshore wind turbines have been increasing over recent decades due to the growing investments of industries in marine renewable energy. Compared with horizontal-axis wind turbines, research on vertical-axis wind turbines is relatively few, though the latter may have advantages over the former in some aspects, for example, potentially lower cost of energy. In this paper, the characteristics of the motion responses of a barge-type floating system with four moonpools and a vertical-axis wind turbine are experimentally and numerically investigated. The focus is on the gyroscopic effects of turbine rotations on the motion responses of the floating system under different wave conditions. Physical model tests are conducted in a wave tank, where a 2-MW-class turbine is modelled in the 1:100 scale. It is found that the first-order sway and roll motion amplitudes near the resonant frequencies are reduced by the turbine rotations, whereas the first-order heave motion of the floating system is hardly influenced. The second-order motion responses and mooring tether tensions may be significantly amplified with the increasing rotating speed of turbine. The maximum ratio of the second-order response amplitude of roll motion to the first-order roll amplitude is up to 17% in the experiments of this study. A radiation and diffraction code based on linear potential flow theory is used to predict the motion responses and mooring forces. The comparisons with experimental data suggest that the viscous damping of water resonance in moonpools and the gyroscopic effects of turbine rotations should be taken into account in predictions.

由于工业对海洋可再生能源的投资不断增长，近几十年来对浮动式海上风力涡轮机的研究一直在增加。与水平轴风力涡轮机相比，对垂直轴风力涡轮机的研究相对较少，尽管后者在某些方面可能比前者更具优势，例如潜在地降低了能源成本。本文对具有四个月池和垂直轴风力发电机的驳船式漂浮系统的运动响应特性进行了实验和数值研究。重点是在不同的波浪条件下，涡轮旋转对浮动系统的运动响应的陀螺效应。物理模型测试是在波浪罐中进行的，其中一个2兆瓦级的涡轮机以1：100的比例建模。已经发现，在共振频率附近的一阶摇摆和侧倾运动幅度通过涡轮旋转而减小，而浮动系统的一阶升沉运动几乎不受影响。随着涡轮机转速的增加，二阶运动响应和系泊绳索的张力可能会显着放大。在这项研究的实验中，横摇运动的二阶响应幅度与一阶横摇幅度的最大比率高达17％。基于线性势流理论的辐射和衍射代码用于预测运动响应和系泊力。与实验数据的比较表明，在预测中应考虑月池中水共振的粘性阻尼和涡轮旋转的陀螺效应。