Abstract Summary
The prediction of vortex-induced vibrations is an essential topic for slender and lightweight structures like chimneys. In recent years, the available prediction models have been questioned in the context of their application for towers of wind turbines. One reason is that the significant tower height has simply not been covered in former model calibrations (based on measurements on chimneys). Another aspect is the different dynamic and aerodynamic behavior of wind turbines due to the structural features and the influence of the rotor on the aerodynamic damping. Measurements in the BLWT have been performed using a force-vibration test set-up to determine the pressure correlation over height, which is a piece of essential information for the modeling and prediction of VIV. Measurements have been performed for different ratios of slenderness, different reduced velocities, and different excitation amplitudes. Based on the quite broad set of parameters, it is possible to update a present widely distributed prediction model, which is the "correlation length method." The paper will implement such a recommendation, especially for very tall and slender supporting structures of WTG. The specific behavior of wind turbines is discussed using a specific turbine model for the same set-up of forced-induced wind tunnel test. In doing so, the aerodynamic influence due to the presence of the rotor can be studied for different positions. Additionally, aeroelastic tests with the same wind turbine have been performed, focussing on the aerodynamic damping and the influence of different blade positions. The findings have been compared to analytical models, and suitable recommendations are made.
