Aerodynamic noise localization of a high-lift common research model in the wind tunnel with non-synchronous measurements

Abstract Aerodynamic noise localization in high-lift devices is a crucial method for analyzing noise generation mechanisms in wind tunnel environment. The performance of the aerodynamic noise localization via microphone array is mainly affected by background noise, shear layer interference, and the limited aperture size of microphone arrays. The algorithm for suppressing background noise and correcting shear layer effects has been already studied with some state-of-art methods. The size of aperture dominates the spatial resolution and measurement accuracy in the aerodynamic noise localization. However, the physical constraints of microphone array size and the cost requirements in engineering makes aperture expansion challenging. This study proposes a novel aerodynamic noise localization method in wind tunnels based on non-synchronous measurements (NSM) for solving limited size of aperture. By moving a microphone array across multiple positions and applying the fast iterative shrinkage-thresholding algorithm to complete the cross-spectral matrix of acoustic pressures, this method achieves high-frequency aerodynamic noise source localization with an expanded aperture using 143 microphones. This work represents the first aerodynamic noise test via NSM of the high-lift common research model conducted in the FL-10 acoustic wind tunnel. Experimental results demonstrate that the NSM method is effective for wind tunnel-based aerodynamic noise localization studies, enabling precise identification of aerodynamic noise.