A time domain equivalent fluid model for the acoustic wave equation (en)

* Presenting author
Day / Time: 07.03.2023, 14:00-14:20
Room: Saal X 5-6
Typ: Regulärer Vortrag
Abstract: Acoustically absorbing materials such as acoustic foam can be described by the equivalent fluid model. The homogenized fluid's acoustic behavior is thereby described by complex-valued, frequency-dependent material parameters (equivalent density and compression modulus). In this case, convolution integrals of the material parameters and the acoustic pressure arise when the acoustic wave equation is transformed from frequency to time domain. We circumvent the numerically demanding calculation of these integrals by introducing auxiliary differential equations (ADEs), which are coupled to the wave equation according to the ADE method. The set of coupled differential equations is solved using the finite element method (FEM). The methodology requires the equivalent fluid parameters to be modeled by a rational function representing the frequency-dependent material behavior (frequency response function - FRF). Thereby, the order of the FRF defines the number of additionally introduced ADEs and auxiliary variables. The derivation of the formulation is presented, and validation examples are shown.


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