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SOUND PROPAGATION IN CIRCULAR DUCTS LINED WITH NOISE CONTROL FOAMS

โœ Scribed by Y.J. KANG; I.H. JUNG

Publisher
Elsevier Science
Year
2001
Tongue
English
Weight
329 KB
Volume
239
Category
Article
ISSN
0022-460X

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โœฆ Synopsis

Finite element predictions and corresponding measurements for sound attenuation and phase speed in a circular duct lined with poroelastic noise control foams are presented in this article. In the present study, four con"gurations having di!erent lining thickness are considered for three types of foam samples. An axisymmetric foam "nite element formulation based on Biot's theory is presented. The macroscopic physical properties of the foam lining samples were estimated using an optimization procedure based on measured physical and acoustical data. The results are also compared with Morse's local reaction solutions. The e!ects of lining thickness and foam properties on the sound attenuation are illustrated. Finally, by comparing measurements for thick and thin linings with predictions made using constrained and lubricated boundary conditions it is demonstrated that the manner in which lining materials are "tted into ducts can a!ect the sound attenuation.

๐Ÿ“œ SIMILAR VOLUMES

Analytical Solution Of Sound Propagation
Analytical Solution Of Sound Propagation In Lined Or Unlined Circular Ducts With Laminar Mean Flow
โœ G.R. Gogate; M.L. Munjal ๐Ÿ“‚ Article ๐Ÿ“… 1993 ๐Ÿ› Elsevier Science ๐ŸŒ English โš– 491 KB

Lined ducts often form a part of practical flow duct acoustic systems. The prediction of attenuation in such a duct has been a topic of research for many years. As far as the authors' knowiedge goes, the analysis of lined ducts with sheared mean flow has always been done numerically. In this paper,