Hole Interaction Effects under High and Medium Sound Intensities for Micro-Perforated Panels Design

International audienceMost models for predicting the acoustic response of perforated panels are based on the assumption that there are no interactions between the holes. This paper investigates the Hole Interaction Effect (HIE) and distribution effect on the sound absorption coefficient of perforated panels when submitted to medium and high sound pressure levels. It is experimentally demonstrated that though the HIE is mostly an added mass effect, the nonlinear resistance parameters depend on the separation distance between the apertures. Analysis of the data reveals the fact that even with HIE, the nonlinear reactance dependency with velocity is very low compared to the resistance-velocity-dependency. Two sets of four perforated panels with hole diameters less than 2 mm with different separation distances between the holes are built and tested. Experimental results performed with an impedance tube are compared with a classical adapted model of HIE. The theoretical way of taking into account the HIE is by Fok's function. The results can be used for designing optimal perforated panels for ducts, silencers or for the automotive industry