Broadband Acoustic Modal Identification by Array Nonsynchronous Measurements with One Reference

Ran Wang, Mingjie Yu, Yue Bai, Yu Liang, Guangming Dong

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

This paper proposes a broadband acoustic modal identification method based on nonsynchronous measurements from a microphone array, which overcomes the acoustic modal aliasing problem caused by a limited number of microphones. In the proposed method, the number of measurement points is augmented by sequentially rotating a circular microphone array that is circumferentially mounted in the wall of the compressor duct. This technique employs only one reference microphone to enhance the robustness of the cross-spectral matrix completion for nonsynchronous measurements. The fast iterative shrinkage threshold algorithm is adopted to iteratively complete the cross-spectral matrix of all measurement points for acoustic modal identification. The in-duct acoustic modal coefficients of the broadband noise are then determined using the least-squares method with the sound pressure vector recovered from the completed cross-spectral matrix. The accuracy of the cross-spectral matrix and the identified acoustic modals is verified through numerical simulations. The proposed method is validated by experimental results from an axial flow compressor. The results show that it can effectively suppress the modal aliasing problem and identify the azimuthal modes of compressor broadband noise.

Original languageEnglish
Pages (from-to)4018-4031
Number of pages14
JournalAIAA Journal
Volume61
Issue number9
DOIs
StatePublished - Sep 2023
Externally publishedYes

Fingerprint

Dive into the research topics of 'Broadband Acoustic Modal Identification by Array Nonsynchronous Measurements with One Reference'. Together they form a unique fingerprint.

Cite this