FORCED MIXING LAYER BETWEEN PARALLEL STREAMS.

Research output: Contribution to journalArticle

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Abstract

The effect of periodic two-dimensional excitation on the development of a turbulent mixing region was studied experimentally. Controlled oscillations of variable amplitude and frequency were applied at the initiation of mixing between two parallel air streams. The frequency of forcing was at least an order of magnitude lower than the initial instability frequency of the flow in order to test its effect far downstream. The effect of the velocity difference between the streams was also investigated in this experiment. It was determined that the spreading rate of the mixing layer is sensitive to periodic surging even if the latter is so small that it does not contribute to the initial energy of the fluctuations. Oscillations at very small amplitudes tend to increase the spreading rate of the flow by enhancing the amalgamation of neighboring eddies, but at higher amplitudes the flow resonates with the imposed oscillation. Amalgamation of large coherent eddies is resumed beyond the resonance region, but the flow is not universally similar. Refs.

Original languageEnglish (US)
Pages (from-to)91-130
Number of pages40
JournalJournal of Fluid Mechanics
Volume123
StatePublished - Oct 1982
Externally publishedYes

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oscillations
vortices
turbulent mixing
Air
air
Experiments
excitation
energy

ASJC Scopus subject areas

  • Computational Mechanics
  • Mechanics of Materials
  • Physics and Astronomy(all)
  • Condensed Matter Physics

Cite this

FORCED MIXING LAYER BETWEEN PARALLEL STREAMS. / Oster, D.; Wygnanski, Israel J.

In: Journal of Fluid Mechanics, Vol. 123, 10.1982, p. 91-130.

Research output: Contribution to journalArticle

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