风波耦合作用下风载荷对两种漂浮式风力机平台动态响应影响

Effects of Wind Load on Dynamic Response of Two Floating Wind Turbine Platform under Wind Wave Coupling

为分析风载荷对漂浮式平台的重要影响,建立了基于单桩式及张力腿平台的漂浮式风力机整机模型,基于叶素-动量理论与辐射/绕射理论,运用水动力软件AQWA并结合有限元方法验证了风载荷及风波耦合的重要性,研究了波浪单独及风波耦合作用下漂浮式平台的时频域动态响应。结果表明:风载荷使平台产生了较大纵荡与垂荡漂移,其产生的倾覆力矩改变了纵摇平衡位置,风载荷使纵荡响应偏离平衡位置较垂荡与纵摇响应明显;对于纵荡响应,风载荷使两平台低频固有频率处的响应峰值增加;对于垂荡响应,风载荷使单桩式平台固有频率处的响应峰值减小,使张力腿平台纵荡-垂荡耦合响应及波浪频率处的响应峰值大幅增加;对于纵摇响应,风载荷使单桩式平台及张力腿平台低频固有频率处的响应峰值大幅增加;风载荷是引起单桩式平台纵荡-垂荡耦合运动的关键因素;波浪载荷是引起张力腿平台纵荡响应幅值较大的关键因素。

In order to analyze the significant influence of wind load on floating wind turbines,floating wind turbine models based on spar and tension leg platform are established.Based on the bladed element momentum theory and radiation/diffraction theory,the importance of wind load and wind wave coupling is verified by using the hydrodynamic software AQWA and the finite element method.The dynamic response in time-frequency domain of floating wind turbines under the action of wave alone and wind wave coupling are studied.The results show that wind load causes the platform to drift in pitch and heave,and the overturning moment generated by the platform changes the pitch balance position.Wind load makes the surge response deviate from the equilibrium position more evidently than that of heave and pitch.For the surge response,the wind load increases the response peak at the natural frequency of the two platforms.For the heave response,the wind load reduces the response peak at the natural frequency of the spar platform.The wind load greatly increases the response peak of the tension leg platform at the surge and heave coupling response and wave frequency.For pitch response,wind load greatly increases the response peak at the low frequency natural frequency of spar platform and tension leg platform.Wind load is the key factor that causes the coupled motion of spar platform,and leads to the large amplitude of surge response of tension leg platform.