As turbofan bypass ratio continues to increase, civilian aircraft noise is increasingly dominated by fan noise. Fan noise propagating from its rotor and stator origins to the community passes through the inlet or aft flow duct, where its confined situation makes it susceptible to characterization by wall-mounted microphone arrays. Recently, the NASA-Glenn Research Center adapted its W-8 Single Stage Axial Compressor Facility to this type of measurement. OptiNav, Inc. took the opportunity to improve and simplify the duct mode processing in its Beamform Interactive computer program. A new approach to in-duct beamforming with a 2D wall-mounted array of microphones was developed. The purpose of this paper is to document the beamforming approach and provide some sample results from the W-8 facility.


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    Title :

    Two-Dimensional Modal Beamforming in Wavenumber Space for Duct Acoustics


    Contributors:

    Conference:

    AIAA Aviation Forum ; 2018 ; Atlanta, GA, United States


    Publication date :

    2018-06-25


    Type of media :

    Conference paper


    Type of material :

    No indication


    Language :

    English




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