The Nonlinear Eigenfrequency Problem of Room Acoustics with Porous Edge Absorbers

Activity: Talk or presentationTalk at conference or symposiumScience to science

Description

Using porous absorbers is common practice in the acoustic treatment of rooms. Often, the absorber material is placed in the edge of the room which is commonly known as an edge absorber. In addition to its high-frequency absorption abilities, this type of absorber is especially effective at low frequencies, for which distinct modal frequencies are present in the room. However, standard room acoustic simulation methods such as ray tracing or mirror sources cannot predict the edge absorber's influence on the acoustic field for low frequencies because the frequency limits of geometrical room acoustics are not met. Hence, a finite element model is employed to simulate the edge absorber's influence on a room's eigenfrequencies, wherein the edge absorber material is modeled using an equivalent fluid model. This results in a nonlinear eigenvalue problem due to the frequency dependence of the equivalent fluid parameters. The paper presents an iterative solution approach to the nonlinear eigenvalue problem based on the fixed-point method, and its application to acoustic predictions of edge absorbers. It is shown that using edge absorbers influences the eigenfrequencies of a room.
Period11 Sept 202323 Sept 2023
Event titleForum Acusticum 2023: 10th Convention of the European Acoustics Assoiation
Event typeConference
LocationTurin, ItalyShow on map
Degree of RecognitionInternational