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Research on Vibration Suppression of a Wind Mill

风车减振研究

基本信息

批准号：
16560208
负责人：
ISHIDA Yukio
金额：
$ 2.69万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

As the development of wind mil generation, vibrations and sounds became a serious problem. However, most of the research on wind mills are those related to the generation of the electric power, such as, the shape of blade, number of blades, etc. Recently, the size of the blade becomes large. Some wind mills has a long blade of almost 50 meters. Therefore, very unique vibration problems which are not observed in the ordinary rotating machinery occur. For example, the wind forces at the top position and the bottom position of the blade are different and this difference makes a periodic excitation force. When a blade passes near the pole, a pressure impulse works. Such excitation forces may cause various kinds of vibrations of the blades. We clarified the followings.(1) Due to the periodic excitation force, a harmonic resonance occurs. (2) Since the restoring forces at the top position and the bottom position are different, this system becomes a periodically-excited system. (3) The coexistence of the parametric excitation due to the gravity and the periodic excitation due to wind force causes various kinds of superharmonic resonances. (4) As the stiffness of the blade decreases, the effect of parametric excitation increases. (5) Unstable zone appears when the stiffness of the blades becomes smaller than a certain value due to the periodic excitation.From this research, it became clear that wind turbines has a potential to cause vibrations even if they are made without manufacturing errors.

随着风力发电的发展，振动和声音成为一个严重的问题。然而，大多数关于风力发电机的研究都是与发电有关的，如叶片的形状、叶片的数量等。最近，叶片的尺寸变大了。有些风车的叶片长约50米。因此，出现了在普通旋转机械中观察不到的非常独特的振动问题。例如，叶片顶部位置和底部位置的风力是不同的，这种差异产生周期性激振力。当叶片经过极附近时，就会产生压力脉冲。这种激励力会引起叶片的各种振动。我们澄清了以下几点。(1)由于周期性激振力的作用，产生谐振。(2)由于顶部位置和底部位置的恢复力不同，该系统成为周期性激励系统。(3)由重力引起的参数激励和由风力引起的周期激励共存，导致了各种超谐波共振。(4)随着叶片刚度的减小，参数激励的作用增强。(5)在周期性激励作用下，当叶片刚度小于某一值时，就会出现不稳定区。从这项研究中可以清楚地看出，即使没有制造错误，风力涡轮机也有可能引起振动。