Transfer matrix modeling and numerical verification of locally reacting acoustic mosaics
Résumé
This paper deals with the modeling of the acoustic behavior (absorption and transmission) of an acoustic mosaic having heterogeneous surface properties. On the surface, the material can be viewed as a collection of independent cells reacting locally. Each cell is filled with an absorbent material different from its neighbors. Such a mosaic may be seen as a generalization of the typical case of a honeycomb liner filled with absorbent materials. The originality of the study lies in the modeling of such heterogeneous material by an Admittance Sum Method (ASM) and a Transfer Matrix Method (TMM). The transfer matrix modeling of the heterogeneous material uses the summation of parallel arrays to form the transfer matrix of the mosaic. Using a finite element model of a measuring impedance tube, the proposed developments are checked on an acoustic mosaic built from three periodic cells filled with a mixture of flax fibers with different levels of compaction. Two configurations (one for sound absorption, one for sound transmission) are studied under normal incidence plane wave excitation. It is shown that the developed ASM and TMM give good correlation with finite element simulations when the mosaic is backed by a hard wall. When the mosaic is backed by a layer of air or anechoic end, only the transfer matrix method gives good results.
Domaines
Sciences de l'ingénieur [physics]Origine | Fichiers produits par l'(les) auteur(s) |
---|