Comparison between analog and digital microphone phased arrays for aeroacoustic measurements

Roberto Merino-Martínez, Martinus P.J. Sanders, Luciano C. Caldas, Francesco Avallone, Daniele Ragni, Leandro D. de Santana, Mirjam Snellen, Dick G. Simons

    Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

    3 Citations (Scopus)

    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).

    Original languageEnglish
    Title of host publication2018 AIAA/CEAS Aeroacoustics Conference
    PublisherAmerican Institute of Aeronautics and Astronautics Inc. (AIAA)
    ISBN (Print)978-1-62410-560-9
    DOIs
    Publication statusPublished - 1 Jan 2018
    Event24th AIAA/CEAS Aeroacoustics Conference 2018 - Atlanta, United States
    Duration: 25 Jun 201829 Jun 2018
    Conference number: 24

    Conference

    Conference24th AIAA/CEAS Aeroacoustics Conference 2018
    Abbreviated titleAeroacoustics 2018
    CountryUnited States
    CityAtlanta
    Period25/06/1829/06/18

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  • Cite this

    Merino-Martínez, R., Sanders, M. P. J., Caldas, L. C., Avallone, F., Ragni, D., de Santana, L. D., ... Simons, D. G. (2018). Comparison between analog and digital microphone phased arrays for aeroacoustic measurements. In 2018 AIAA/CEAS Aeroacoustics Conference [AIAA 2018-2809] American Institute of Aeronautics and Astronautics Inc. (AIAA). https://doi.org/10.2514/6.2018-2809