Aeroacoustic Wind Tunnel Studies with Suprema10K a MEMS Microphone Array with 12.000 sensors

Abstract

The signal-to-noise ratio of phased arrays can be improved by increasing the number of samples (the number of microphones or the number of averages). Increasing the array sized also allows the direct measurement of the source directivity, without moving the array. In this paper we present a module microphone array with data acquisition system, consisting of 1 m x 2m panels with 800 MEMS microphones, each. This modular architecture allows the time-synchronized measurement of an arbitrary number of panels and thus, aperture size and total number of sensors This architecture was used as a 7200 MEMS microphone array with a 6 m x 3 m aperture on an open wind tunnel airframe test at DNW-NWB. A second test used 12.000 MEMS microphones with a 6 m x 5 m aperture on an open wind tunnel test at DNW-LLF. Sources identification directivity measurements will be shown. Additional far-field microphones and a classical analog array are employed to validate the beamforming results and directivity analysis.