Study of new beam microphone array operation based on aerodynamic noise sources localization

To develop the effective noise suppression means, it is necessary to have information on the distribution of acoustic sources in space. For these purposes, noise measurement is carried out by microphone arrays. Typically, commercial versions of such microphone arrays do not provide the rearrangement of the microphones in the arrays. The paper considers the design of a new beam microphone array, which is capable to quickly rearrange the microphone configurations in the radial and angular coordinates. The operability of the microphone array was studied based on localization of aerodynamic noise sources. The measurements were carried out in PNRPU anechoic chamber with a jet rig. It was used a wing model with a flap and a conical nozzle. The experiments were conducted for the following cases: a free turbulent jet; the turbulent jet between the wing model and the microphone array, which are parallel to each other (reflected sources); the wing model between the turbulent jet and the microphone array (shielded sources). The results of the noise source localization were compared with those obtained with Bruel & Kjaer beam microphone array. In all cases, the location and size of the sources obtained from the measurements by both microphone arrays coincide. The difference in the levels of the noise sources at different frequencies does not exceed 1 dB. Thus, one can conclude that the developed beam microphone array enables reliable and high quality localization of the aerodynamic noise sources and can be used in further research activities to develop the new measurement schemes and algorithms for the noise source localization.