Aeroelastic Stability of Idling Wind Turbines

The Science of Making Torque from Wind

Wang, Kai^1 ; Riziotis, Vasilis A.^1 ; Voutsinas, Spyros G.^2

China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, 1037 Luoyu Rd, Wuhan, China^1

School of Mechanical Engineering, National Technical University of Athens, Athens

GR15780, Greece^2

关键词: Aeroelastic analysis;    Aeroelastic stability;    Eigenvalue analysis;    Eigenvalue stability;    High angles of attack;    Induced vibrations;    Out-of-plane modes;    Wind turbine rotors;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/753/4/042008/pdf
DOI  :  10.1088/1742-6596/753/4/042008

来源: IOP

【 摘 要 】

Wind turbine rotors in idling operation mode can experience high angles of attack, within the post stall region that are capable of triggering stall-induced vibrations. In the present paper rotor stability in slow idling operation is assessed on the basis of non-linear time domain and linear eigenvalue analysis. Analysis is performed for a 10 MW conceptual wind turbine designed by DTU. First the flow conditions that are likely to favour stall induced instabilities are identified through non-linear time domain aeroelastic analysis. Next, for the above specified conditions, eigenvalue stability simulations are performed aiming at identifying the low damped modes of the turbine. Finally the results of the eigenvalue analysis are evaluated through computations of the work of the aerodynamic forces by imposing harmonic vibrations following the shape and frequency of the various modes. Eigenvalue analysis indicates that the asymmetric and symmetric out-of-plane modes have the lowest damping. The results of the eigenvalue analysis agree well with those of the time domain analysis.