Secondary instability in variable-density round jets

Joseph W. Nichols, Jean Marc Chomaz, Peter J. Schmid

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

Abstract

Side jet formation in variable-density round jets is investigated by means of direct numerical simulation (DNS) and linear stability analysis. From DNS, it is observed that a light jet with density ratio S = ρ0/ ρj = 4 supports sustained side jets which eject fluid from the center of the jet in a star-shaped pattern. These side jets persist over an axial distance of approximately 5 jet diameters before the jet transitions to turbulence, and do not precess around the jet. It is conjectured that this behavior can be explained by a change in the local properties of the secondary instability from convective to absolute in nature. This hypothesis is tested by examining the spatio-temporal development of the wavepacket resulting from a small impulse, taken about a non-diffusing periodic base state corresponding to the saturated primary instability.
Original languageEnglish (US)
Title of host publicationAdvances in Turbulence XI - Proceedings of the 11th EUROMECH European Turbulence Conference
PublisherSpringer Verlagservice@springer.de
Pages32-34
Number of pages3
ISBN (Print)9783540726036
DOIs
StatePublished - Jan 1 2007
Externally publishedYes

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