Aplicabilidade de modelos teóricos de previsão de absorção sonora para o estudo de desempenho acústico de absorvedores fibrosos e granulares

Applicability of Theoretical Models for Predicting Sound Absorption in the Study of Acoustic Performance of Fibrous and Granular Absorbers

LOUREDO, J. M. Programa de pós-graduação em arquitetura e urbanismo, Universidade de Brasília, Brasília, DF, Brasil.

LUNA, C. Programa de pós-graduação em arquitetura e urbanismo, Universidade de Brasília, Brasília, DF, Brasil.

Resumo

A pesquisa em desenvolvimento de materiais renováveis e com maior eficiência energética é atual e pertinente em relação a absorvedores. Os painéis aglomerados de matéria-prima lignocelulósica se alinham com essa perspectiva e podem ser classificados como fibrosos ou granulares, a depender da estrutura final das partículas produzidas. Ambas as configurações apresentam características distintas em sua microestrutura oriundas da forma das partículas assim como da porosidade, viscosidade e densidade do material. Essas características influenciam na absorção sonora dos materiais, fator que é de forma comumente avaliado mediante aferição empírica em testes específicos de incidência sonora direta ou difusa. Modelos teóricos de previsão de absorção sonora são uma forma de aprimorar o estudo de materiais absorvedores e visam aliar os dados de características físicas e microestruturais dos materiais porosos e sua influência no desempenho acústico. O foco principal deste estudo é fornecer uma revisão, a fim de apoiar pesquisas que se ocupem em investigar o potencial acústico de painéis aglomerados de material lignocelulósico a partir do reconhecimento das suas características físicas e microestruturais e da concepção de modelos teóricos de previsão de desempenho.

Palavras-chaves:

absorvedores acústicos

matéria-prima lignocelulósica.

Abstract

Research and development of renewable and energy-efficient materials is current and relevant in relation to acoustical absorbers. The agglomerated panels of lignocellulosic material are aligned with this perspective and can be classified as fibrous or granular, depending on the final structure of the particles produced. Both configurations have different characteristics in their microstructure from the shape of the particles as well as the porosity, viscosity and density of the material. These characteristics influence the sound absorption of the materials, a factor that is commonly assessed through empirical measurement in specific tests of direct or diffuse sound incidence. Theoretical models of sound absorption prediction are a way to improve the study of absorbent materials and aim to combine the data of physical and microstructural characteristics of porous materials and their influence on acoustic performance. The main focus of this study is to provide a review with the objective of supporting research that is concerned with investigating the acoustic potential of agglomerated panels of lignocellulosic material from the recognition of their physical and microstructural characteristics and the design of theoretical models of performance prediction.

Keywords:

technical paper

FIA

Sobrac

acoustics

vibration.

Referências

[1] Asdrubali F, Schiavoni S, Horoshenkov KV. A review of sustainable materials for acoustic applications. Build Acoust 2012;19(4):283–312.

[2] Tang X, Yan X. Acoustic energy absorption properties of fibrous materials: A review. Composites: Part A 101 (2017) 360–380.

[3a] Egab L, Wang X, Fard M. Acoustical characterisation of porous sound absorbing materials: a review. Int. J. Vehicle Noise and Vibration, Vol. 10, Nos. 1/2, 2014.

[3b] Cao, L.; Qiuxia, F.; Yang, S.; Bin, D.; Jianyong, Y. Porous materials for sound absorption. Compos. Commun. 2018, 10, 25–35.

[4] Cox, Trevor J.. | D’Antonio, Peter. Acoustic absorbers and diffusers. Third edition. Boca Raton : Taylor & Francis, 2017. LCCN 2016027694 | ISBN 9781498740999.

[5] Biot, M. (1956a) ‘Theory of propagation of elastic waves in a fluid saturated porous solid. I. Lowfrequency range’, Journal of the Acoustical Society of America, Vol. 28, No. 2, pp.168–178.

[6] Biot, M. (1956b) ‘Theory of propagation of elastic waves in a fluid saturated porous solid. II. Higher frequency range’, Journal of the Acoustical Society of America, Vol. 28, No. 2, pp.179–191.

[7] DELANY, M. E.; BAZLEY, E. N. Acoustical properties of fibrous absorbent materials. National Physical Laboratory, Teddington, Middlesex (Gt. Britain). August, 1969. AppliedAcoustics(3) (1970).

[8] Johnson D L, Koplik J e Dashen R. Theory of dynamic permeability and tortuosity in fluidsaturated porous media. Journal of Fluid Mechanics / Volume 176 / March 1987, pp 379 402. DOI: 10.1017/S0022112087000727, Published online: 21 April 2006.

[9] Champoux Y, Allard J. Dynamic tortuosity and bulk modulus in airsaturated porous media. Journal of Applied Physics 70, 1975 (1991); doi: 10.1063/1.349482.

[10] Zhou B, Zhang J, Li X, Liu B. An Investigation on the Sound Absorption Performance of Granular Molecular Sieves under Room Temperature and Pressure. Materials 2020, 13, 1936; doi:10.3390/ma13081936.

[11] ISO 10534-2 (Acoustics – Determination of sound absorption coefficient and impedance in impedance tubes-Part 2: Transfer-function method).

[12] Abdi D D, Monazzam M, Taban E, Putra A, Golbabaei F, Khadem M. Sound absorption performance of natural fiber composite from chrome shave and coffee silver skin. Applied Acoustics 182 (2021) 108264. https://doi.org/10.1016/j.apacoust.2021.108264.

[13] Santoni A, Bonfiglio B, Fausti P, Marescotti C, Mazzanti V, Mollica F, Pompoli F. Improving the sound absorption performance of sustainable thermal insulation materials: Natural hemp fibres. Applied Acoustics 150 (2019) 279–289.

[14] Glé P, Gourdon E, Arnaud L. Acoustical properties of materials made of vegetable particles with several scales of porosity. Applied Acoustics 72 (2011) 249–259.

[15] Chabriac P.A, Gourdon E, Glé P, Fabbri A, Lenormand H. Agricultural by-products for building insulation: Acoustical characterization and modeling to predict micro-structural parameters. Construction and Building Materials 112 (2016) 158–167.

[16] Botterman B, Doudart de la Grée G.C.H, Hornikx M.C.J, Yu Q.L, Brouwers H.J.H. Modelling and optimization of the sound absorption of wood-wool cement boards. Applied Acoustics 129 (2018) 144–154.

[17] Bhingare N. H, Prakash S. An experimental and theoretical investigation of coconut coir material for sound absorption characteristics. Materials Today: Proceedings 43 (2021) 1545–1551.

[18] Mamtaz H, Fouladi M. H, Nuawi M. Z, Namasivayam, S.N, Ghassem M, Al-Atabi M. Acoustic absorption of fibro-granular composite with cylindrical grains. Applied Acoustics 126 (2017) 58–67.

[19] Boubel A, Garoum M, Bousshine S, Bybi A. Investigation of loose wood chips and sawdust as alternative sustainable sound absorber materials. Applied Acoustics 172 (2021) 107639.

Publicado em:
01/09/2022