This study aims to provide a comprehensive exploration of the nonlinear vortex-induced vibration (VIV) characteristics of the wind turbines in parked conditions. Considering the influences of the aero-damping and structure of the wind turbine, a vibration mitigation strategy for VIV is proposed to avoid the potential harm caused by VIV in practical projects. The finite element method (FEM) is used to analyze the mode of the wind turbine, and the aerodynamic performance of the wind turbine is analyzed by employing the blade element theory. Using the van der Pol equation for modeling fluid-structure coupling, a nonlinear equation for simulating the VIV of the tower, accounting for the aero-damping of the wind turbine, is established through the application of Hamilton's principle and the assumed mode method, and is solved by the method of multiple scales. The results show that the VIV in fore-aft bending mode direction of the wind turbine tower should be considered. The VIV of the wind turbine can be mitigated by changing azimuth angles and pitch angles. Furthermore, the effectiveness of the proposed vibration mitigation strategy is validated by the on-site vibration experiment.

中文翻译：

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非线性涡激振动及其对停放条件下风力涡轮机的缓解


本研究旨在全面探索风电机组在停放条件下的非线性涡旋激振 （VIV） 特性。考虑到风力涡轮机的气动阻尼和结构的影响，为避免了风力涡轮增振在实际项目中可能造成的危害，提出了一种 VIV 减振策略。采用有限元法 （FEM） 分析风力涡轮机的模式，采用叶片元理论分析风力涡轮机的气动性能。利用范德波尔方程对流固耦合进行建模，通过应用汉密尔顿原理和假设模态法，建立了模拟塔架 VIV 的非线性方程，该方程考虑了风力涡轮机的空气阻尼，并采用多尺度方法求解。结果表明，应考虑风力发电机塔筒前后弯曲模式方向的 VIV。可以通过改变方位角和俯仰角来减轻风力涡轮机的 VIV。此外，现场振动实验验证了所提出的减振策略的有效性。