Abstract
The primary objective of this study was to obtain measurements of the noise generated by flow over an asymmetric trailing edge in an Anechoic Wind Tunnel (AWT) using a large aperture 40 microphone acoustic array. The sound field was complicated by the presence of unwanted or “parasitic” noise caused by the operation of the AWT. The ability of the array to separate the parasitic noise from the desired sound source was determined through a series of calculations using simulated source data. The bias errors that are caused by these extraneous sources were determined for three different array post processing algorithms: delay-sum (time-domain), weighted beamforming (frequency-domain), and a Deconvolution Approach to Mapping of Acoustic Sources (DAMAS). The results indicate that each method had advantages/disadvantages that were dependent on frequency. As such, different beamforming methods were utilized over different frequency ranges in order to produce the best possible spectral representation of the trailing edge source.
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