为找到不同几何参数V型叶尖结构对风力机结构动力学特性的影响,利用PULSE18.0结构振动分析系统和ME scopeVES 5.1模态测试软件结合瞬态激振法,选取振动频率范围0~400 Hz和特定激励点,获得叶轮的固有频率;在低速风洞中,通过三向振动加速度传感器测定额定风速12 m/s时不同转速所对应的振动加速度,并分析改型前后叶轮前三阶振动频率.结果表明:3种叶片均在叶轮转速375~625 rad/min发生明显振动现象,叶轮在500 rad/min一二阶低频时,V-1型叶尖叶片偏离值为5.6%和4.4%,发生共振的可能性较低,V-2型叶尖叶片偏离值为3.4%和2.1%,发生共振的可能性较高,在三阶时改型前后的偏离值超过20%发生共振的可能性都比较低.该结果对风力机叶片叶尖改型的设计和避免共振提供一定的数据参考.%In order to find the effects of V type blade tip structures with different geometric parameters on the structural dynamic characteristics of wind turbines, PULSE 18.0 structural vibration analysis system and ME scopeVES 5.1 modal test software, in combined with the transient excitation method, the vibration frequency range 0-400 Hz and the specific excitation point were used to obtain the natural frequency of the impeller. In a low-speed wind tunnel, the vibration acceleration corresponding to different speeds was measured with a three-way vibration acceleration sensor when the rated wind speed was 12m/s and the vibration frequency of the impeller of the first three orders before and after the modification was analyzed. The results show that the three blades have significant vibrations when the speed is 375-625 rad/min, when the impeller operates at 500 rad/min of first and second orders, the occurrence possibility of resonance is low when the deviation of the V-1 type blade is 5.6% and 4.4%, and the occurrence possibility of resonance is high when the deviation of the V-2 type blade is 3.4%and 2.1%. At the third order, the occurrence possibility of resonance is low before or after modification when the deviation exceeds 20%. The results provide certain data reference for the design of the blade tip of the wind turbine and avoidance of resonance.
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