Camille Perrot (Univ. Gustave Eiffel)

Polydisperse sound absorbers: Characterization, reconstruction, and transport properties

Camille Perrot -  Univ Gustave Eiffel, Univ Paris Est Creteil, CNRS, UMR 8208, MSME, F-77454 Marne-la-Vallée, France

Porous materials (fibrous, foams, granular) are widely used as thermal and acoustic insulation components (construction and transportation industries). The main societal, industrial, and scientific challenges concern weight reduction (reduction of material and energy consumption) at iso-performance using recycled and/or recyclable materials (decarbonization, circular economy) or even bio-/geo-sourced materials, which suggests a better understanding of local transport mechanisms. However, recycled and bio-sourced materials are characterized by a large variability. More specifically, polydispersity refers to a situation where the structural pattern is associated with a wide distribution of characteristic sizes, which complexifies the identification of the representative elementary volume. The hypothesis is that it is possible, using imaging, geometric reconstruction, and numerical homogenization techniques, to identify the salient features having a significant impact at the higher scale—where the physical properties of interest are measured (i.e., porosity, permeability, sound absorption coefficient). This talk illustrates, through the study of two main families of polydisperse porous media, namely (i) recycled fibrous materials [1, 2] and (ii) foams obtained as a result of a perturbation of the nucleation process induced by graphite particles [3, 4, 5], the methodological developments implemented within the framework of a dialogue between numerical modeling and experimentation. In all instances, polydispersity appears to be a necessary ingredient for a detailed understanding of the dissipation mechanisms, but also as a new lever of optimization, that should therefore be controlled by an appropriate manufacturing process.

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[1] Q. V. Tran, C. Perrot, R. Panneton, M. T. Hoang, L. Dejaeger, V. Marcel, M. Jouve, “Effect of poly-dispersity on the transport and sound absorbing properties of three-dimensional random fibrous struc-tures,” International Journal of Solids and Structures 296, 112840 (2024). DOI: 10.1016/j.ijsolstr.2024.112840.

[2] Q. V. Tran, C. Perrot, R. Panneton, M. T. Hoang, L. Dejaeger, V. Marcel, M. Jouve, “Utilizing poly-dispersity in three-dimensional random fibrous based sound absorbing materials,” Materials & Design 247, 113375-11 (2024). DOI: 10.1016/j.matdes.2024.113375.

[3] C. T. Nguyen, V. Langlois, J. Guilleminot, F. Detrez, A. Duval, M. Bornert, P. Aimedieu, C. Perrot “Polydisperse solid foams: Multiscale modeling and simulations of elasto-acoustic properties includ-ing thin membrane effects,” International Journal of Solids and Structures 249, 111684-14 (2022). DOI: 10.1016/j.ijsolstr.2022.111684.

[4] C. T. Nguyen, V. Langlois, J. Guilleminot, A. Duval, C. Perrot, “Effect of pore size polydispersity on the acoustic properties of high-porosity solid foams,” Physics of Fluids 36(4), 047101 (2024). DOI: 10.1063/5.0191517.

[5] C. T. Nguyen, D. Li, Z. Xiong, M. He, L. Gautron, A. Duval, C. Perrot, “Structure-property relation-ships of polydisperse open-cell foams: Application to melamine foams,” Acta Acustica 8, 54-9 (2024). DOI: 10.1051/aacus/2024046.