Acoustic Propagation at High Frequencies in Ducts
Abstract
In order to achieve satisfactory results with finite element formulations for pressure in a propagating acoustic field with relatively high non-dimensional frequencies, the problem of ever-diminishing mesh size must be resolved. The convected potential formulation describing an acoustic field introduces problems not addressed in the simple Helmholtz equation. Post-processing to calculate pressure is necessary and this leads to additional dimensionality problems beyond those encountered in modeling acoustic potential due to an inaccuracy appearing in the calculation of the potential derivatives. This oscillating erroneous behavior is rooted in the element shape functions and modifications have been made, using elements of higher order, to contain this discrepancy enough to where post-processing does not add significantly to the dimensionality problem. In so doing, satisfactory pressure models for non-dimensional frequencies up to 100 in a variable area circular duct with a wide range of subsonic Mach numbers and angular modes can be calculated in a reasonable sized domain. © 2000 by Walter Eversman.
Recommended Citation
E. Listemd and W. Eversman, "Acoustic Propagation at High Frequencies in Ducts," 6th Aeroacoustics Conference and Exhibit, American Institute of Aeronautics and Astronautics, Dec 2000.
Department(s)
Mechanical and Aerospace Engineering
Document Type
Article - Conference proceedings
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 American Institute of Aeronautics and Astronautics, All rights reserved.
Publication Date
01 Dec 2000
