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Wavenumber-frequency deconvolution of aeroacoustic microphone phased array data of arbitrary coherenceDeconvolution of aeroacoustic data acquired with microphone phased arrays is a computationally-challenging task for distributed sources with arbitrary coherence. A new technique for performing such deconvolution is proposed. This technique relies on analysis of the array data in the wavenumber-frequency domain, allowing for fast convolution and reduced storage requirements when compared to traditional coherent deconvolution. A positive semidefinite constraint for the iterative deconvolution procedure is implemented and shows improved behavior in terms of quantifiable convergence metrics when compared to a standalone covariance inequality constraint. A series of simulations validates the method's ability to resolve coherence and phase angle relationships between partially-coherent sources, as well as determines convergence criteria for deconvolution analysis. Simulations for point sources near the microphone phased array show potential for handling such data in the wavenumber-frequency domain. In particular, a physics-based integration boundary calculation is described, and can successfully isolate sources and track the appropriate integration bounds with and without the presence of flow. Magnitude and phase relationships between multiple sources are successfully extracted. Limitations of the deconvolution technique are determined from the simulations, particularly in the context of a simulated acoustic field in a closed test section wind tunnel with strong boundary layer contamination. A final application to a trailing edge noise experiment conducted in an open-jet wind tunnel matches best estimates of acoustic levels from traditional calculation methods and qualitatively assesses the coherence characteristics of the trailing edge noise source.
Document ID
20210010325
Acquisition Source
Langley Research Center
Document Type
Accepted Manuscript (Version with final changes)
Authors
Christopher J. Bahr
(Langley Research Center Hampton, Virginia, United States)
Louis N. Cattafesta
(Florida State University Tallahassee, Florida, United States)
Date Acquired
February 18, 2021
Publication Date
July 21, 2016
Publication Information
Publication: Journal of Sound and Vibration
Publisher: Elsevier
Volume: 382
Issue Publication Date: November 10, 2016
ISSN: 0022-460X
Subject Category
Acoustics
Report/Patent Number
TPSAS Form ID: 20416
Funding Number(s)
WBS: 699959.02.07.07.08
Distribution Limits
Public
Copyright
Portions of document may include copyright protected material.
Technical Review
NASA Technical Management
Keywords
phased array
beamforming
deconvolution
wavenumber-frequency
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