Task 1.2 Linear and nonlinear sound absorption mechanisms in flexible micro-perforated plates
This task will focus on high-amplitude pressure waves impinging on the plate, while the plate, rather than remaining motionless, is driven to perform flexural (i.e. out-of-plane) vibrations. Two likely sound absorption mechanisms will be studied in detail: (i) damping of acoustic waves by their interaction with hydrodynamic structures (jets, vortices) at the edges of the orifices, and (ii) loss of acoustic energy due to dry friction at the tips of the individual orifices. A combined experimental and numerical approach based on Temiz et al (2015) will be taken: the experimental part will use impedance tube measurements, and the numerical simulations will be performed with Comsol.