Modeling and Measurement Study for Offshore Wind Turbine Blade Amplitude Modulation Noise

Offshore wind turbine (WT) noise can affect marine organisms and seabirds, while the aerodynamic noise of WT blades serves as an indicator of turbine operating status. Investigating WT noise characteristics under varying wind conditions is thus crucial for monitoring operational states, such as wake interference. This paper presents an intelligent acoustic sensor system for WT health detection based on the IEEE 1451.9 standard. The system enables data transmission, processing, and display of real turbine blade sound, comparing results with blade self-noise calculated by the BPM model and also validating the model's accuracy. Furthermore, with the help of the aero-elastic coupling software FSAT. Farm developed by the National Renewable Energy Laboratory (NREL), the study also examines the effects of wind speed (8 m/s , 10 m/s, and 12 m/s) and turbulence (6%, 10%) on turbine aerodynamic noise. The results demonstrate a strong correlation between the simulation and measured data. Higher wind speeds increase aerodynamic noise emissions and amplify the amplitude modulation (AM) characteristics of the noise. At a wind speed of 8 m/s, increased turbulence intensity enhances the AM characteristics, whereas, at 10 m/s and 12 m/s, it diminishes these characteristics.