摘要
利用PULSE16.1结构振动分析系统,针对直径1.4 m的小型水平轴风力机风轮分别在安装S型叶尖小翼与否的状态下进行静、动频测试,通过静频数据结合谱分析法识别风轮动频。研究发现,S型叶尖小翼导致风轮1、2阶振动静频下降,其对2阶振动静频的衰减幅值较1阶振动大,对同阶反对称振动静频的衰减作用较对称振动大,并具有显著调节风轮2阶反对称振动动频和对称振动动频间差值的效用。研究同时发现,S型叶尖小翼可有效改变风轮1、2阶振动动频曲线走势,从而有效调节风轮进入和脱离共振区的转速,这对于风轮最佳转速设计和避免共振设计具有较重要的意义。S型叶尖小翼对圆盘效应振动频率和轴向窜动效应振动频率影响很小,但在很大区域的转速范围内,圆盘效应振动动频曲线总是伴随风轮转速1倍频,并出现在1倍频振动带范围内,这一发现有可能为很多风力机叶片在远短于设计寿命期内频繁发生疲劳损伤事故提供新的解释。
The static and dynamic frequency measurements of wind wheels with a diameter of 1.4m for small type horizontal axis wind turbines were done by using PULSE16.1 structural vibration analysis system when S-shaped tip vanes were installed or not. Dynamic frequencies of a wind wheel were identified with the static frequency data and the spectral- analysis method. It was shown that the first and second order static frequencies decrease due to the tip vanes, the amplitude attenuation of the 2nd-order static frequency is bigger than that of 1 st-order static frequency and the amplitude attenuation of the asymmetric static frequencies is bigger than that of the same order symmetric static frequencies; the S- shaped tip vanes can significantly adjust the difference between the 2nd order symmetric dynamic frequency and the 2rid order symmetric dynamic frequency; the trend of the 1 st-order and 2rid-order dynamic frequencies curves can be changed effectively with the tip vanes, thus the tipvanes can effectively adjust the entering rotating-speed of a wind wheel and the leaving one from its resonance region, and it is very significant for design of the optimal rotating speed and avoiding resonance of a wind wheel; the S-shaped tip vanes had little effect on the vibration frequencies due to the disc effect and the axial movement effect, but the 1 octave of the wind wheel＇s rotating speed is always accompanied with the dynamic frequency curve due to the disc effect within a large range of the wind wheel＇s rotating speed, and this dynamic frequency curve appears within the 1 octave band, this discovery may provide some new explanations for that the fatigue damage accidents of blades occur frequently in a much shorter time perviod time than their design life.
出处
《振动与冲击》
EI
CSCD
北大核心
2013年第24期110-116,121,共8页
Journal of Vibration and Shock
基金
内蒙古自然科学重大基金资助项目(2012ZD08)
内蒙古自然科学基金资助项目(2013MS0726)
内蒙古工业大学科研基金资助项目(X201218)
关键词
风力机
风轮
S型叶尖小翼
振动频率
影响
wind turbine
wind wheel
S-shaped tip vane
vibration frequencies
effect
