Modeling of micro-perforated panels effect in a complex Vibro-Acoustic Environment using Patch Transfer Function approach

The micro-perforated panel with a backing cavity is a well known device for providing efficient noise absorption. This device has been thoroughly studied in the experimental conditions of an acoustic tube (Kundt tube) to quantify its absorption coefficient. In such situation, the system has one single dimension and the micro-perforated panel is excited by a normal incident plane wave. In a more practical and industrial setting, the efficiency of Micro-Perforated Structure (MPS) may be influenced by the vibro-acoustic behavior of the surrounding systems as well as different finds of excitation. In this paper, a Patch Transfer Functions (PTF) approach is proposed to model the MPS behaviour in such Complex Vibro-Acoustic Environment (CVAE). PTF is a substructuring approach which allows assembling different vibro-acoustic subsystems coupled through surfaces. The proposed PTF formulation of the MPS is capable of taking the microperforations and the flexibility of the panel into account and allows easy prediction of the efficiency of a MPS in a practical vibro-acoustic environment. In order to validate the present approach, PTF results are compared with experimental measurements on a test case from published literature.