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Methods for the calculation of axial wave numbers in lined ducts with mean flowA survey is made of the methods available for the calculation of axial wave numbers in lined ducts. Rectangular and circular ducts with both uniform and non-uniform flow are considered as are ducts with peripherally varying liners. A historical perspective is provided by a discussion of the classical methods for computing attenuation when no mean flow is present. When flow is present these techniques become either impractical or impossible. A number of direct eigenvalue determination schemes which have been used when flow is present are discussed. Methods described are extensions of the classical no-flow technique, perturbation methods based on the no-flow technique, direct integration methods for solution of the eigenvalue equation, an integration-iteration method based on the governing differential equation for acoustic transmission, Galerkin methods, finite difference methods, and finite element methods.
Document ID
19820030509
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Eversman, W.
(Missouri-Rolla, University Rolla, MO, United States)
Date Acquired
August 10, 2013
Publication Date
May 1, 1981
Subject Category
Acoustics
Meeting Information
Meeting: Meeting
Location: Ottawa
Country: Canada
Start Date: May 18, 1981
End Date: May 22, 1981
Sponsors: Acoustical Society of America
Accession Number
82A14044
Funding Number(s)
CONTRACT_GRANT: NSG-3231
Distribution Limits
Public
Copyright
Other

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