Print Email Facebook Twitter Comparison between analog and digital microphone phased arrays for aeroacoustic measurements Title Comparison between analog and digital microphone phased arrays for aeroacoustic measurements Author Merino Martinez, R. (TU Delft Aircraft Noise and Climate Effects) Sanders, Martinus P.J. (University of Twente) Caldas, Luciano C. (University of Twente) Avallone, F. (TU Delft Wind Energy) Ragni, D. (TU Delft Wind Energy) de Santana, Leandro D. (University of Twente) Snellen, M. (TU Delft Aircraft Noise and Climate Effects) Simons, D.G. (TU Delft Aircraft Noise and Climate Effects) Date 2018-01-01 Abstract 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). To reference this document use: http://resolver.tudelft.nl/uuid:77c3210c-bf2d-4aca-a9f6-3fb4f20eaa1a DOI https://doi.org/10.2514/6.2018-2809 Publisher American Institute of Aeronautics and Astronautics Inc. (AIAA) Embargo date 2019-01-01 ISBN 9781624105609 Source 2018 AIAA/CEAS Aeroacoustics Conference Event AIAA/CEAS Aeroacoustics Conference, 2018, 2018-06-25 → 2018-06-29, Atlanta, United States Bibliographical note 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. Part of collection Institutional Repository Document type conference paper Rights © 2018 R. Merino Martinez, Martinus P.J. Sanders, Luciano C. Caldas, F. Avallone, D. Ragni, Leandro D. de Santana, M. Snellen, D.G. Simons Files PDF 6.2018_2809.pdf 1.49 MB Close viewer /islandora/object/uuid:77c3210c-bf2d-4aca-a9f6-3fb4f20eaa1a/datastream/OBJ/view