Mode localization in linear and periodically time-varying mistuned wind rotor
Mode localization in linear and periodically time-varying mistuned wind rotor
复制标题
线性和周期性时变失调风轮的模态定位
DOI：
10.1002/we.2618
复制
发表时间：
2021
期刊：
影响因子：
4.1
通讯作者：
Kraemer Peter
中科院分区：
文献类型：
--
作者：
Guo Xin;Li Dongsheng;Guo Peng;Kraemer Peter
转子叶片是涡轮机中最重要、最昂贵的部件，其动态特性对维护计划和安全运行具有重要意义。在这项研究中，失谐对转子叶片的振动模式的影响进行了研究，重点是线性时变风力涡轮机转子的模式局部化。研究的意义在于发现模态局部化会加剧叶片的损伤，降低叶片的疲劳寿命。旋转叶片近似为悬臂伯努利-欧拉梁，并考虑了每个叶片的挥舞和摆振模态。采用拉格朗日方法建立了风力涡轮机转子的线性时变动力学方程。针对某涡轮机转子因叶片刚度的微小波动而发生失谐的问题，采用Floquet分析方法对失谐后的涡轮机转子进行模态分解，深入分析了模态局部化的机理。数值模拟结果表明，单个叶片的轻微失谐足以触发模态局部化。分析了叶片失谐量和转子转速对模态局部化严重程度的影响。最后，考虑了不同的量化措施来表征失谐涡轮机转子的模态局部化程度。
Rotor blades are the most important and most expensive part of a wind turbine; their dynamic behavior is of great significance for maintenance planning and safe operation. In this study, the effect of mistuning on the vibration modes of rotor blades was investigated, with a focus on the mode localization of linear time‐varying wind turbine rotors. And the significance of the work lies in finding that the mode localization may aggravate the blade damage and potentially reduced fatigue life of the blade. The rotating blades were approximated as cantilever Bernoulli–Euler beams, and the flapwise and edgewise modes of each blade were considered. The Lagrangian method was employed to derive the linear time‐varying dynamic equations of the wind turbine rotor. A wind turbine rotor was mistuned because of slight fluctuations in the blade stiffness; subsequently, Floquet analysis was employed for modal decomposition of a mistuned wind turbine rotor, and the mechanism of mode localization was examined in depth. Numerical simulation results indicated that slight mistuning of a single blade is sufficient for triggering mode localization. The effects of the magnitude of the blade mistuning and rotor speed on the severity of mode localization were analyzed. Finally, different quantitative measures were considered for characterizing the degree of mode localization in mistuned wind turbine rotors.