Perceptual evaluation of wind turbine noise

The acoustic impact of wind turbines is currently hampering the societal acceptance and the deployment of green aeolian energy near dwellings. For this reason, an accurate physical and perceptual prediction of wind turbine noise is of crucial importance for the design and deployment of modern horizontal-axis wind turbines. In the present work, we discuss a novel methodology for the far-field propagation and auralization of wind turbine noise in complex rural environments. First, the sound sources are modelled analytically using a RANS-based Amiet’s theory, accounting for leading- and trailing-edge noise. Secondly, a geometrical ray-tracing solver is used to compute the multiple source-receiver paths and evaluate the directivity gain. Finally, the Harmonoise ray-based method is used to apply the noise attenuation due to atmospheric absorption, ground barriers, ground effects, and meteorological conditions. This methodology has been applied to the SWT 2.3-93 wind turbine, testing two different ground types for several different receivers. The preliminary results are consistent with previous studies, showing up to 3 dBA of modulation in amplitude for receivers close to the rotor plane. Furthermore, the noise levels in third octave band show that the modulation in amplitude is mainly affecting the medium- and high-frequency ranges.