Open-loop control of fully nonlinear self-excited oscillations

M. P. Hallberg, P. J. Strykowski

Research output: Contribution to journalConference articlepeer-review

16 Scopus citations

Abstract

Experiments conducted using a low-density axisymmetric jet reveal that the self-excited nature can be altered by modulating the external pressure field using an acoustic driver. A region exists in the forcing frequency-amplitude space where the self-sustaining frequency is entirely absent and solely replaced by the forcing frequency and harmonics thereof. Inside this region, the centerline streamwise velocity disturbance level can be significantly increased or decreased. Visual evidence suggests these alterations coincide with dramatic changes in jet spreading and demonstrates that forcing can provide an effective means of controlling mixing in self-excited jets. Results support theoretical predictions made by Pier [B. Pier, Proc. R. Soc. London, Ser. A 459, 1105 (2003)].

Original languageEnglish (US)
Article number041703
JournalPhysics of Fluids
Volume20
Issue number4
DOIs
StatePublished - Apr 2008
EventSymposium of the International Union of Theoretical and Applied Mechanics on Recent Advances in Multiphase Flows: Numerical and Experimental, IUTAM - Istanbul, Turkey
Duration: Jun 11 2007Jun 14 2007

Bibliographical note

Funding Information:
The authors would like to acknowledge support from the National Science Foundation under Grant No. CTS-0317429 as well as University of Minnesota support provided through a doctoral dissertation fellowship.

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