Wind turbine tower resonance

Wind turbine towers are large structures designed to withstand the unique loading conditions imposed on them by the turbine's nacelle and dynamic forces from the rotating blades. Observations and noise measurements of a particular wind turbine showed high noise levels at approximately 48 Hz, which could not be explained from the usual known potential noise sources. Correlated far field noise measurements and vibration measurements collected on the turbine tower, structural base and nearby ground have shown the source to be a resonance of the tower structure.