Investigation of parameters affecting the acoustic absorption coefficient of industrial liners

Abstract

© Springer International Publishing AG 2018. Reducing the noise generated in the industrial environment becomes the main objective of industrial designers in many applications (building, transport industry, etc.). The passive control represents one of the used methods to achieve this objective. It is based on the use of acoustic absorbent materials like porous materials, Helmholtz resonators, or perforated plates, etc. In order to obtain high-quality acoustic absorbers, the acoustic performance of each element is used and sometimes coupled to increase the total acoustic absorption of the liner. In this study, three industrial acoustic liners are studied: porous material, porous material with perforated plate, and perforated plate with air cavity. The liner characteristic impedance is defined using the material and the plate impedances. The porous material impedance is formulated by two models: the Delany–Bazley and the Lafarge–Allard ones. A comparative study is elaborated in order to show the impact of plate and material parameters variation on the acoustic absorption coefficient.