✦ LIBER ✦

Acoustic properties of fibrous materials

✍ Scribed by N. Voronina

Publisher: Elsevier Science
Year: 1994
Tongue: English
Weight: 404 KB
Volume: 42
Category: Article
ISSN: 0003-682X
DOI: 10.1016/0003-682x(94)90005-1

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✦ Synopsis

ABSTRA CT

The acoustic behaviour of fibrous materials which depends upon physical structural parameters has been investigated experimentally. Numerous values of characteristic impedance and propagation constant have been determined for materials having different fibre diameter and density. For quantitative estimation of acoustic energy losses in media a term equal to the real part of the characteristic impedance has been introduced as a 'structural characteristic'. From comparative analyses of experimental results and taking into account the viscous boundary layer thickness present in Rayleigh's theory an empirical expression of structural characteristic has been derived as a function of porosity and fibre diameter. Empirical relationships between acoustic parameters and structural characteristic have been obtained also. This model can be used to predict values of the sound absorption coefficient.

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