Acoustic Source Localization on Wind Turbines

Kurzfassung

In the framework of the DFWind project, the department of Engine Acoustics of the DLR Institute of Propulsion Tech�nology (DLR-AT-TRA) has developed a mobile microphone array system for acoustic source localization measurements on wind turbines. The department has extensive experience with the localization of sound sources on aircraft in flight, but these methods have so far not been adapted to the rotating blades of wind turbines. The system consists of a rugged data acquisition unit with 128 channels and a platform where the microphones can be mounted. Microphone mounting brackets allow a quick deployment and removal of the microphones on fixed positions on the platform, combined with foam wind screens to reduce wind noise. Measurements have been performed at the DLR research wind farm WiValdi in Krummendeich (https://forschungspark-windenergie.de) at a position between the two wind turbines. Short data seg�ments with a duration of one minute have been recorded under different conditions, with either one or both of the wind turbines running. The data have been analyzed using beamforming methods from the Acoular package of TU-Berlin and the DLR implementation of CLEANT with source grid refinement, using stationary and rotating source grids.