Contribution
On the Fitting of Equivalent Fluid Model Parameters for Time-Domain Poroacoustic Applications
* Presenting author
Abstract:
The propagation of sound in porous media is described by equivalent fluid models (EFM) with the frequency-dependent effective material parameters, such as effective density and bulk modulus, that account for the sound absorption in the material. In general, this frequency dependence leads to convolution integrals in the governing equations when converting them from frequency to time domain. The usual approach to the computation of convolution integrals is the auxiliary differential equations method, which requires partial fraction expansions of the frequency-dependent quantities. The focus of this research lies on obtaining partial fraction expansions of the effective material parameters provided by the commonly used EFMs, such as Johnson-Champoux-Allard and Delany-Bazley-Miki. The procedure is based on the adaptive Antoulas-Anderson (AAA) algorithm for rational approximation of the material parameters taking into account their properties according to the chosen EFM.