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Sound attenuation in two-dimensional ducts with anisotropic liners

โœ Scribed by A.H. Nayfeh; J. Sun

Publisher
Elsevier Science
Year
1975
Tongue
English
Weight
551 KB
Volume
41
Category
Article
ISSN
0022-460X

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โœฆ Synopsis

An analysis is presented of the transmission and attenuation of waves propagating in a two-dimensional duct carrying a uniform mean flow and treated by an acoustic liner consisting of an anisotropic porous material backed by a cellular honeycomb core. The results show that for a given porous material the attenuation is strongly dependent on the orientation of the material fibers. The influence of the fiber orientation is very sensitive to both the sound frequency and the fnaterial axial resistivity. The convective effects of the mean flow--a shift in the tuning frequency and a decrease in attenuation with increasing Mach number---demonstrated previously for point-reacting liners do not occur, in general, for anisotropic bulk-reacting liners.

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