Linear investigation of sound-flow interaction along a corrugated plate
Massimo Emiliano d'Elia, Thomas Humbert, Yves Aurégan
Abstract
The experimental investigation of the aeroacoustic behaviour of a corrugated plate with small cavities in presence of a grazing flow is discussed. In particular, the linear regime of the aeroacoustic interaction has been investigated. The obtained Strouhal number corresponds to those used in the recent literature for nonlinear investigations. Even if acoustic feedback was eliminated in the experimental setup, loss and gain frequency bands can still be identified. Then, the acoustic and Laser Doppler Velocimetry (LDV) measurements were used to analyse the acoustic power at four different frequencies: the four components that compose the acoustic power have been characterised and their relative importance identified. Finally, the difference behind gain and loss mechanisms are spotted and explained.