Assessment of the accuracy of microphone array methods for aeroacoustic measurements

Assessment of the accuracy of microphone array methods for aeroacoustic measurements

Merino Martinez, R. (TU Delft Aircraft Noise and Climate Effects)
Luesutthiviboon, S. (TU Delft Aircraft Noise and Climate Effects)
Zamponi, R. (von Karman Institute for Fluid Dynamics)
Rubio Carpio, A. (TU Delft Aircraft Noise and Climate Effects)
Ragni, D. (TU Delft Wind Energy)
Sijtsma, P. (TU Delft Aircraft Noise and Climate Effects; PSA3: Pieter Sijtsma Advanced AeroAcoustics)
Snellen, M. (TU Delft Aircraft Noise and Climate Effects)
Schram, Christophe (von Karman Institute for Fluid Dynamics)

2020-03-31

In this paper, the performance of four acoustic imaging methods: conventional frequency domain beamforming (CFDBF), functional beamforming (FUNBF), enhanced high resolution CLEAN–SC (EHR–CLEAN–SC) and generalized inverse beamforming (GIBF), is investigated in terms of accuracy and variability. Three experimental test cases are considered: 1) a single speaker emitting synthetic broadband noise, 2) two speakers emitting incoherent synthetic broadband noise, and 3) trailing–edge noise generated by a tripped NACA 0018 airfoil. All the measurements were performed in the anechoic wind tunnel of Delft University of Technology. Overall, GIBF and EHR–CLEAN–SC offer the most accurate results when point sources (speakers) are present. They even achieve super–resolution by separating sound sources beyond the Rayleigh resolution limit. Repeating the measurements indicates a standard deviation in the results of less than 1 dB. When analyzing distributed sound sources, such as trailing–edge noise, CFDBF and FUNBF provide the best performance. This indicates that the acoustic imaging method needs to be selected based on the expected sound source configuration.

Acoustic imaging
Aeroacoustics
Microphone arrays

http://resolver.tudelft.nl/uuid:d485bd2c-a004-40c9-8d41-3b067eb3867c

https://doi.org/10.1016/j.jsv.2020.115176

0022-460X

Journal of Sound and Vibration, 470

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2020 R. Merino Martinez, S. Luesutthiviboon, R. Zamponi, A. Rubio Carpio, D. Ragni, P. Sijtsma, M. Snellen, Christophe Schram