Abstract
Unequally spaced transducer rings make it possible to extend the range of detectable azimuthal modes. The other side of the coin is that the response of the mode detection algorithm to a single mode is distributed over all detectable modes, similarly to the Point Spread Function of Conventional Beamforming with microphone arrays. With multiple modes the response patterns interfere, leading to a relatively high “noise floor” of spurious modes in the detected mode spectrum, in other words, to a low dynamic range. In this paper a deconvolution strategy is proposed for increasing this dynamic range. It starts with separating the measured sound into shaft tones and broadband noise. For broadband noise modes, a standard Non-Negative Least Squares solver appeared to be a perfect deconvolution tool. For shaft tones a Matching Pursuit approach is proposed, taking advantage of the sparsity of dominant modes. The deconvolution methods were applied to mode detection measurements in an AneCom fan rig. An increase in dynamic range of typically 10 to 15 dB was found.
Original language | English |
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Title of host publication | 23rd AIAA/CEAS Aeroacoustics Conference |
Subtitle of host publication | 5-9 June 2017, Denver, Colorado |
Publisher | American Institute of Aeronautics and Astronautics Inc. (AIAA) |
Number of pages | 14 |
ISBN (Electronic) | 9781624105043 |
DOIs | |
Publication status | Published - 2017 |
Event | 23rd AIAA/CEAS Aeroacoustics Conference - Denver, United States Duration: 5 Jun 2017 → 9 Jun 2017 Conference number: 23 https://doi.org/10.2514/MAA17 |
Conference
Conference | 23rd AIAA/CEAS Aeroacoustics Conference |
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Country/Territory | United States |
City | Denver |
Period | 5/06/17 → 9/06/17 |
Internet address |