Aeroacoustic noise prediction for wind turbines using Large Eddy Simulation

• Validated aero-acoustic analysis of an aerofoil using LES.
• Far-field acoustic spectra computed using a rotational reference frame.
• Results show good agreement with measured data.

Noise disturbance is one of the major factors considered in the development of wind farms near urban areas, and therefore an accurate estimate of the noise levels generated by wind turbines is required before production and installation. Horizontal-axis wind turbines are the most popular type of turbines and the aeroacoustic noise generated by their rotating blades is known to be the most significant noise source. The region of the turbine blade that produces the strongest acoustic sources has been identified in published acoustic camera measurements. In the present work, a Large Eddy Simulation (LES) of this region is carried out using an annular computational domain, which leads to a significant reduction of computational expense compared to full blade simulations. The Ffowcs-Williams and Hawkings (FW–H) acoustic analogy is then used to predict the far field sound. Numerical results for a simulation of the CART-2 wind turbine show good agreement with the available experimental data.