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Effect of the acoustic boundary layer on the wave propagation in ductsAn analysis is presented for the wave propagation in two-dimensional and circular lined ducts taking into account the effects of viscosity in both the mean and the acoustic problems. The method of composite expansions is used to express each acoustic flow quantity as the sum of an inviscid part and a boundary layer part insignificant outside a thin layer next to the wall. The problem is reduced to solving a second-order ordinary differential equation for the pressure perturbation as in the inviscid acoustic case but with a modified specific wall admittance. An analytic expression is presented for the variation of the modified admittance with the wall and flow parameters, such as the acoustic boundary layer thickness, the mean velocity and temperature gradients at the wall, the frequency of oscillation, and the wavelength.
Document ID
19740038821
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Nayfeh, A. H.
(Virginia Polytechnic Institute and State University Blacksburg, Va., United States)
Date Acquired
August 7, 2013
Publication Date
December 1, 1973
Publication Information
Publication: Acoustical Society of America
Subject Category
Fluid Mechanics
Accession Number
74A21571
Funding Number(s)
CONTRACT_GRANT: NGR-47-004-109
Distribution Limits
Public
Copyright
Other

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