The Virginia Tech Stability Wind Tunnel is a unique low-speed facility with a Kevlar-walled test section developed for aeroacoustic measurements. A 251-channel configurable microphone array has been custom-designed for this facility to exploit the large available sensing area. Due to its large aperture, particularly for a laboratory scale instrument, the array has useful resolution down to very low frequencies, particularly in the streamwise direction. The considerable range of receiving angles and high number of sensors allows for direct measurement of source directivity. An experiment has been conducted in order to demonstrate the improved capability of the facility and investigate methods for the accurate measurement of acoustic sources at these low frequencies. Noise produced by a 50.8 mm diameter cylinder mounted in the Stability Wind Tunnel at flow speeds from 20 m/s to 60 m/s was measured. The cylinder produced shedding tones from 74 Hz to 212.5 Hz and measurable broadband noise and harmonics well beyond this. Delay and sum beamforming, deconvolution methods, and an inverse method are used to analyze the sound from the cylinder. When used in combination, these methods work well to identify the location of the source and reveal its changing directivity.

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