Influence of double-fork blade tip structure on wind turbine vibration
DAI Yuanjun1,2,3*,HE Kai2,LI Baohua1,ZHAI Mingcheng2
1. Mechanical college, Shanghai DianJi University, Shanghai 201306, China; 2. College of Mechanical and Electrical Engineering, Xinjiang Agricultural University, Urumqi, Xinjiang 830091, China; 3. College of Energy Engineering, Xinjiang Institute of Enginee-ring, Urumqi, Xinjiang 830091, China
Abstract：In order to reduce the vibration of the wind turbine wheel, a modified design scheme of double-fork blade tip structure for small wind turbine is proposed. Through the wind wheel modal test and wind wheel vibration characteristic test, the modal parameters, vibration frequency and vibration acceleration amplitude of the wind wheel before and after the modification design were measured to study the influence of the double-fork blade tip structure with different angles on the vibration characteristics of the wind turbine wheel. By comparing the test results of the unmodified wind wheel with double-fork blade tip structure wind wheel, it is found that the double-fork blade tip structure increases the second-order to fourth-order natural frequency and damping ratio of the wind wheel. The double-fork tip structure can adjust the trend of the wind wheel vibration frequency curve, make the wind wheel pass through the resonance zone faster, and make the speed corresponding to the resonance point far from the rated speed. When the rotation speed is 360 r/min, the vibration acceleration amplitude of the wind wheel increases suddenly. The double-fork blade tip structure will not eliminate the sudden increase, but it can reduce the amplitude of the vibration acceleration during the sudden increase. The double-fork blade tip structure reduces the vibration acceleration amplitude of the wind wheel under the condition that the rotation speed of the wind wheel is continuously increased. Therefore, the double-fork blade tip structure can effectively reduce the vibration of the wind wheel of small wind turbine, and the improvement effect has a greater correlation with the angle of the blade tip. The relevant research conclusions provide a new idea for the vibration reduction research of the wind wheel.
