Experimental study on the influence of centroid position of wind turbine section on flutter.

Aiming at the large aspect ratio characteristics of large wind turbines, it is easy to cause irreversible damage due to flutter during operation. A two-degree-of-freedom (plunge and pitch) flutter test bench was built using the time domain and frequency domain analysis methods of dynamic signals. The influence of different centroid positions on the flutter boundary was studied. The test shows that the closer the centroid position is to the leading edge of the wing segment, the better the aeroelastic stability of the wing segment is. Under the linear condition, the forward movement of the centroid position has a more significant influence on the flutter. In addition, the main reason for the wing flutter is related to the decrease of net damping and the coupling of the aeroelastic natural frequency of the pitching and plunging motions. The pitch motion is dominant in the two-degree-of-freedom motion. The farther the centre of mass is from the torsion axis, the greater the pitch and plunge motion displacement. The pitch motion has a more significant impact on the system than the plunge motion. Therefore, the study of flutter suppression should focus on pitch motion.