Wall treatments for aeroacoustic measurements in closed wind tunnel test sections

Aeroacoustic tests in closed wind tunnels are affected by reflections in the tunnel circuit and background noise. Reflections can be mitigated by lining the tunnel circuit. The present study investigates if lining exclusively the most accessible segment of a closed wind tunnel circuit, in particular the test section, is an approach which...

Assessment of the accuracy of microphone array methods for aeroacoustic measurements

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)...

Deterministic Model of AcousticWave Propagation in a Cavity

A mathematical model is proposed that evaluates acoustic propagation of turbulent boundary layer waves on top of a cavity enclosing a microphone. The goal is to optimize these cavity geometries to improve the signal-to-noise ratio of acoustic measurements. This model predicts the attenuation of the turbulent boundary layer fluctuations...