A Finite Element Formulation of the Eigenvalue Problem in Lined Ducts with Flow

Author

R. Jeremy Astley
Walter Eversman, Missouri University of Science and TechnologyFollow

Abstract

A finite element method is used to formulate the eigenvalue problem for a lined duct with flow. Either two dimensional or axially symmetric ducts with sheared flows can be studied, although the examples cited are two dimensional. The primitive variables of velocity and pressure are used with quadratic shape functions in each element. Results indicate that a useful level of accuracy can be achieved with a modest number of elements. Spurious eigenvalues, easily identified by obviously inconsistent eigenvectors, occur in certain instances. If the number of elements is not too small, these spurious modes are among the higher order eigenvalues of otherwise questionable accuracy. The possibility of using higher order elements which have slope continuity is proposed for future investigations to eliminate the spurious results. © 1979.

Recommended Citation

R. J. Astley and W. Eversman, "A Finite Element Formulation of the Eigenvalue Problem in Lined Ducts with Flow," Journal of Sound and Vibration, Elsevier, Jan 1979.

The definitive version is available at https://doi.org/10.1016/0022-460X(79)90528-5

Department(s)

Mechanical and Aerospace Engineering

International Standard Serial Number (ISSN)

0022-460X

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1979 Elsevier, All rights reserved.

Publication Date

01 Jan 1979