A feedback model of the edge tone, using the adjoint Orr–Sommerfeld equation

The description of the feedback mechanism is one of the crucial points in the understanding of self-sustained flow oscillations, such as the edge tone or the cavity tone. In this paper a new model for the edge tone, using linear adjoint modes is proposed for low speeds, when acoustic effects are neg...

Full description

Saved in:
Bibliographic Details
Published inJournal of fluid mechanics Vol. 915
Main Authors Nagy, Péter Tamás, Szabó, András, Paál, György
Format Journal Article
LanguageEnglish
Published Cambridge, UK Cambridge University Press 09.03.2021
Subjects
Acoustics
Computational fluid dynamics
Feedback
JFM Papers
Orr-Sommerfeld equations
Oscillations
Reynolds number
Velocity
Vortices
aeroacoustics
vortex interactions
absolute/convective instability
Online AccessGet full text

Cover

More Information
Summary:The description of the feedback mechanism is one of the crucial points in the understanding of self-sustained flow oscillations, such as the edge tone or the cavity tone. In this paper a new model for the edge tone, using linear adjoint modes is proposed for low speeds, when acoustic effects are negligible. The two crucial points of the model are (i) a new relationship between the jet oscillation and the generated vortex at the edge tip and (ii) a new model for the effect of the generated vortex on the oscillation. The frequency corresponding to the optimum open-loop gain of the feedback mechanism was compared with experimental data and good agreement was found.
ISSN:0022-1120
1469-7645
DOI:10.1017/jfm.2021.47