Larger and taller wind turbines are characterized by larger tip masses and longer rotor-nacelle assembly (RNA) masts. Both result in a lower natural frequency, lowering the critical wind speed and increasing the likelihood of vortex resonance. While freestanding towers, such as stacks, have been extensively investigated for vortex-induced vibration (VIV), the completed wind turbine as a structure has not yet been fully investigated for VIV.
Slender structures subjected to vortex-induced vibrations experience an aeroelastic interaction in the lock-in range. The negative aerodynamic damping is the governing parameter for the onset of self-induced vibrations. However, available literature models still lack of a unified behaviour of the aerodynamic damping as a function of the oscillation. This is also reflected in codified methods to design slender structures in view of cross-wind actions.
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Last update: Aug 06, 2023