Prediction of the acoustic behavior of a parallel assembly of hollow cylinders

Verdière, Kévin; Panneton, Raymond; Elkoun, Saïd

doi:10.1016/j.apacoust.2015.09.016

Cited by 3 publications

(2 citation statements)

References 14 publications

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“…Lagarrigue et al [21] have shown that sound diffusers based on natural material such as bamboo rods can behave as sonic crystals and display metamaterial features. Verdière et al [39] have shown that a parallel transfer matrix approach can be used to describe the acoustic properties of a parallel assembly of hollow cylinders such as straws.…”

Section: Introductionmentioning

confidence: 99%

Sound absorption properties of a sunflower composite made from crushed stem particles and from chitosan bio-binder

et al. 2016

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International audienceA recent study investigated the mechanical, thermal and acoustical properties of a bio-based composite made from crushed particles of sunflower stalks binded together by chitosan, a bio-based binder. The acoustical performance in absorption was found to be poor as the material was highly compacted and with low porosity. The present study focuses on the acoustical properties of a higher porosity composite, with lower density while the mechanical rigidity remains fairly high. A higher absorption coefficient is obtained. The experimental results on the absorption coefficient are compared to the prediction of a model involving 5 physical parameters (porosity, tortuosity, airflow resistivity, thermal and viscous characteristic lengths). The characterization methods to determine these parameters are described. The comparison between experimental and theoretical results shows that this material exhibits peculiar microstructural features. It is found that the sound absorption properties can involve dead-end pores or clusters and multiple porosity scales in the material

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Section: Introductionmentioning

confidence: 99%

Sound absorption properties of a sunflower composite made from crushed stem particles and from chitosan bio-binder

et al. 2016

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“…They have been used as building materials for centuries due to their large availability throughout the world. Previous empirical 9 , phenomenological 10 , and theoretical 11 studies showed that viscous and thermal diffusion through the arrangement of stems play a dominant role in acoustic performances. Attention was mainly paid to the effects of the length, concentration, and relative orientations of the straws on sound absorption.…”

Section: Introductionmentioning

confidence: 99%

3D-printed sound absorbing metafluid inspired by cereal straws

Huang

Schwan

Romero‐García

et al. 2019

Sci Rep

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Used as building biomaterials for centuries, cereal straws are known for their remarkable acoustic performances in sound absorption. Yet, their use as fibrous media disregards their internal structure made of nodes partitioning stems. Here, we show that such nodes can impart negative acoustic bulk modulus to straw balls when straws are cut on either side of a node. Such metafluid inspired by cereal straws combines visco-thermal diffusion with strong wave dispersion arising from quarter-wavelength resonances within straws. Large spectral bandgaps and slow sound regimes are theoretically predicted and experimental data from impedance tube measurements on an idealised 3D-printed sample layer are in good agreement with the theoretical model. Perfect absorption is achieved at wavelengths 13 times larger than the thickness of the metafluid layer, and slow sound entails an increased density of states causing a cascade of high absorption peaks. Such features could lead cereal straws to serve as cheap acoustic bio-metamaterials.

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