Morphology influence on the acoustic properties of permeo-elastic media

• Published in: Wave motion 2022-11, Vol.115, p.103080, Article 103080
• Main Authors: Boutin, Claude, Venegas, Rodolfo
• Format: Article
• Language: English
• Subjects: Acoustic properties; Engineering Sciences; Homogenisation; Morphology; Permeo-elastic media; Wave propagation
• ISSN: 0165-2125; 1878-433X
• DOI: 10.1016/j.wavemoti.2022.103080

This paper deals with the acoustics of permeo-elastic media. These media comprise a rigid porous skeleton with attached elastic films that interact with the fluid that saturates the pores. The pore-scale fluid/film interaction introduces elastic energy that interacts with viscous dissipation and inertial effects. The corresponding non-conventional flow regimes are studied by the two-scale asymptotic homogenisation method by successively considering permeo-elastic media with (i) fully connected pores, (ii) strictly unconnected pores (i.e. pores closed by films), (iii) partially connected pores, and (iv) mixed morphologies. This analysis allows to precisely describe how the morphology both influences, quantitatively and qualitatively, the interaction of the elastic and kinetic energies of the films with the viscous and kinetic energies of the fluid, and modifies the effective properties. It is shown that, in specific frequency ranges, the film–fluid system behaves as an equivalent visco-elastic fluid and that local film–fluid resonances can be observed. Numerical examples illustrate the main features in the different cases. The presented synthetic approach enables the design of materials that exhibit unconventional conductivity, unconventional compressibility, or both, in different or the same frequency range, by means of tuning their morphological and/or mechanical parameters. •Analysis of the acoustic properties of permeo-elastic media that comprise a rigid porous skeleton with attached elastic films.•Demonstration of the influence of morphology by considering permeo-elastic media with (i) fully connected pores, (ii) strictly unconnected pores, (iii) partially connected pores, and (iv) mixed morphologies.•Explicit description of how morphology influences, quantitatively and qualitatively, the interaction of the elastic and kinetic energies of the films with the viscous and kinetic energies of the fluid, and modifies the effective properties.•Identification of specific frequency ranges, where the film–fluid system behaves as an equivalent viscoelastic fluid and where local film–fluid resonances occur.•Theoretical results illustrated by numerical examples.