Analysis of the sound absorption characteristics of the curved microperforated panel with elastically restrained edges

This paper describes the analytical and experimental study on the sound absorption characteristics of the curved microperforated panel (CMPP) with elastically restrained edges backed by an air cavity. The arbitrary boundary conditions are realized by setting the restrained spring at the edges to zero or infinite. The acoustic impedance formula of the CMPP is derived based on the modal superposition method. The acoustic electrical analogy method is used to obtain the sound absorption coefficient of the CMPP, in which the effects of the structural parameters on the sound absorption coefficient such as aspect ratio, radius of curvature, perforation rates, micro holes diameters and panel thicknesses are also studied. To validate the accuracy of the present method, the impedance tube test system is designed to measure the sound absorption coefficient under different micro holes diameters and panel thicknesses. The results derived by the analytical method and the test one match well with each. This paper provides a new kind of sound absorption structures which could be used in the health environment. •The sound absorption of the curved microperforated panel under elastically restrained edges is analyzed for the first time.•The elastically restrained boundaries are simulated by setting the stiffness value of the boundary springs.•The effects of the parameters of the curved microperforated​ panel on the sound absorption are analyzed theoretically.