双叉式叶尖结构对风力发电机叶片固有频率影响的试验研究

Experimental Study on Influence of Double-fork Blade Tip Structure on Natural Frequency of Wind Turbine Blade

在风洞实验室进行模态试验与风洞动频试验,研究双叉式叶尖结构对风力发电机叶片固有频率的影响。在研究中发现,双叉式叶尖结构叶片的固有频率在低阶时有减小的趋势,在高阶时有增大的趋势。振型图显示,双叉式叶尖结构可将未改型叶片的一部分扭转振型变为挥舞振型,并且明显改良了未改型叶片前缘出现的扭转振型。动频数据显示,双叉式叶尖结构可以调整风轮动频曲线的走势,使风轮进入共振区的时间缩短。通过研究确认,双叉式叶尖结构能够有效改良风力发电机叶片的固有频率等参数,为后续风力发电机叶片的减振研究奠定了基础。

The modality test and wind tunnel dynamic frequency test were conducted in a wind tunnel laboratory to study the influence of the double-fork blade tip structure on the natural frequency of the wind turbine blade.It is found in the investigation that the natural frequency of the blade with double-fork tip structure tends to decrease at low orders and increase at higher orders.The vibration mode diagram shows that the double-fork blade tip structure can change a part of the torsional vibration mode of the unmodified blade into a waving vibration mode,and significantly improves the torsional vibration mode appeared at the leading edge of the unmodified blade.The dynamic frequency data shows that the double-fork blade tip structure can adjust the trend of the dynamic frequency curve of the wind wheel,so that the time for the wind wheel to enter the resonance zone is shortened.It is confirmed through study that the double-fork blade tip structure can effectively improve the natural frequency and other parameters of the wind turbine blade,which lays the foundation for subsequent study on vibration damping of the wind turbine blade.