Acoustics

 

 Acoustics is the science of sound waves, whatever the sound source. Therefore, it is not limited to sound emitted by vibrating structures, as in structural acoustics. Here, we are not only interested in the source mechanisms, but also in the propagation of sound waves in space. It is a recent extension of our activities at UME.

Regarding wind turbine noise, the project aims at predicting the noise perceived by neighboring residents at medium and large distances, and more specifically the amplitude modulations that can be a source of annoyance, especially at night. The 3 main objectives are:

  1. the prediction of aeroacoustic noise sources (trailing edge noise and turbulence inflow noise) using Amiet's theory

  2. the experimental study of stall noise from measurements on an oscillating airfoil in a wind tunnel

  3. wind turbine noise propagation at large distances (greater than 1km) taking into account realistic atmospheric conditions

Figure1: Model predictions of wind turbine noise at a 40 meter distance in terms of directivity (left) and amplitude modulation (right)

 

Figure 2: Experimental setup for dynamic stall measurements on a NACA 0024 airfoil (left) and lift coefficient measurements with respect to angle of attack for different oscillation frequencies (right)