TY - GEN
T1 - Comparison between analog and digital microphone phased arrays for aeroacoustic measurements
AU - Merino-Martínez, Roberto
AU - Sanders, Martinus P.J.
AU - Caldas, Luciano C.
AU - Avallone, Francesco
AU - Ragni, Daniele
AU - de Santana, Leandro D.
AU - Snellen, Mirjam
AU - Simons, Dick G.
N1 - Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Microphone arrays are useful measurement devices for estimating the location and strength of sound sources. Numerous comparative studies have been conducted regarding the performance of acoustic imaging methods in the past, but literature lacks of a systematic investigation on the role of the hardware on the measurements. This research focuses on the performance differences between two 63-microphone arrays: one with digital MEMS (Micro Electro Mechanical Systems) microphones and the other with analog condenser microphones. Both systems are used on an aeroacoustic experiment performed in an anechoic open-jet wind tunnel featuring two airfoils (NACA 0012 and NACA 0018) equipped with trailing-edge serrations. Whereas both arrays provided similar frequency spectra when analyzing trailing-edge noise emissions (which are in agreement with previous research), the analog array seems to offer source maps of higher quality with a higher dynamic range (lower sidelobe level). Moreover, the results of the digital array featuring trailing-edge serrations show a noise increase at the higher frequencies (4 kHz) with respect to the straight-edge case, which is not expected from the findings of previous experimental research. The results of the analog array do not present such behavior. This manuscript is the result of a collaboration project between the University of Twente (UTwente) and Delft University of Technology (TU Delft).
AB - Microphone arrays are useful measurement devices for estimating the location and strength of sound sources. Numerous comparative studies have been conducted regarding the performance of acoustic imaging methods in the past, but literature lacks of a systematic investigation on the role of the hardware on the measurements. This research focuses on the performance differences between two 63-microphone arrays: one with digital MEMS (Micro Electro Mechanical Systems) microphones and the other with analog condenser microphones. Both systems are used on an aeroacoustic experiment performed in an anechoic open-jet wind tunnel featuring two airfoils (NACA 0012 and NACA 0018) equipped with trailing-edge serrations. Whereas both arrays provided similar frequency spectra when analyzing trailing-edge noise emissions (which are in agreement with previous research), the analog array seems to offer source maps of higher quality with a higher dynamic range (lower sidelobe level). Moreover, the results of the digital array featuring trailing-edge serrations show a noise increase at the higher frequencies (4 kHz) with respect to the straight-edge case, which is not expected from the findings of previous experimental research. The results of the analog array do not present such behavior. This manuscript is the result of a collaboration project between the University of Twente (UTwente) and Delft University of Technology (TU Delft).
UR - http://www.scopus.com/inward/record.url?scp=85051289360&partnerID=8YFLogxK
UR - http://resolver.tudelft.nl/uuid:77c3210c-bf2d-4aca-a9f6-3fb4f20eaa1a
U2 - 10.2514/6.2018-2809
DO - 10.2514/6.2018-2809
M3 - Conference contribution
AN - SCOPUS:85051289360
BT - 2018 AIAA/CEAS Aeroacoustics Conference
PB - American Institute of Aeronautics and Astronautics Inc. (AIAA)
T2 - AIAA/CEAS Aeroacoustics Conference, 2018
Y2 - 25 June 2018 through 29 June 2018
ER -