Influence of the microstructure of 2D-random heterogeneous media on the propagation of acoustic coherent waves

Adrien Rohfritsch (1) , Jean-Marc Conoir (2) , Tony Valier-Brasier (3) , Régis Marchiano (4)

1 DALEMBERT - Institut Jean Le Rond d'Alembert
2 IJLRDA-MPIA - Modélisation, Propagation et Imagerie Acoustique
3 LAUM - Laboratoire d'Acoustique de l'Université du Mans
4 LMDH - Laboratoire des Milieux Désordonnés et Hétérogènes

Multiple scattering of waves arises in all fields of physics either in periodic or random media. For random media the organization of the microstructure (uniform or non-uniform statistical distribution of scatterers) has effects on the propagation of coherent waves. Using a recent exact resolution method and different homogenization theories, the effects of the microstructure on the effective wavenumber are investigated over a large frequency range (ka between 0.1 and 13.4) and high concentrations. For uniform random media, increasing the configurational constraint makes the media more transparent for low frequencies and less for high frequencies. As a side but important result, we show that two of the homogenization models considered here appear to be very efficient at high frequency up to a concentration of 60%, in the case of uniform media. For non-uniform media, for which clustered and periodic aggregates appear, the main effect is to reduce the magnitude of resonances and to make network effects appear. In this case, homogenization theories are not relevant to make a detailed analysis.

Domaines: Physique [physics]; Sciences de l'ingénieur [physics]; Acoustique [physics.class-ph]

Adrien Rohfritsch, Jean-Marc Conoir, Tony Valier-Brasier, Régis Marchiano. Influence of the microstructure of 2D-random heterogeneous media on the propagation of acoustic coherent waves. Physical Review E , In press. ⟨hal-02459496v1⟩