Modeling microperforated panels and permeable membranes for a room acoustic solver with plane-wave enriched FEM

Abstract

Plane-wave-enriched finite element method (FEM), an efficient wave-based prediction method, uses shape functions incorporating a set of plane waves propagating in various directions to enhance the sound field approximation capability. The method can be an efficient wave-based acoustic solver for room acoustic simulations because it can simulate wave phenomena in rooms accurately with markedly fewer finite elements in spatial discretization than those used for standard FEM. However, several aspects remain to be addressed before its use for practical room acoustic simulations. Accurate sound absorber modelings able to address their frequency and incident angle dependence of absorption characteristics present extremely important issues. This paper presents a proposal of a method of implementing an extended-reaction model of microperforated panel (MPP) and permeable membrane (PM) sound absorbers into a room acoustic solver with plane-wave-enriched FEM. First, we demonstrate the validity of the proposed method in comparison with theoretical values in which impedance tube problems including three sound absorbers composed of MPP and PM are used. Then, the effectiveness over standard FEM is demonstrated via 2D real-scale office problems with the three MPP-PM sound absorbers.