Active management of naturally separated flow over a solid surface. Part 1. The forced reattachment process

Research output: Contribution to journalArticle

128 Citations (Scopus)

Abstract

The forced reattachment of flow to an inclined flat surface, simulating a simple flap, was investigated experimentally. The transition from a separated to an attached state of the flow was initiated by an abrupt change in the frequency and the amplitude of periodic perturbations emanating from a slot at the flap shoulder. The excitation parameters determined the total duration of the reattachment process. Minimum reattachment time occurred at an optimal excitation frequency of Fopt+ ≈ 1.5, which was independent of amplitude and flap inclination. The control over the process was achieved by enhancing large spanwise vortices in the flow. Spatial amplification of consecutive vortices induces mean transport of fluid away from the flap surface which causes the main stream to reattach. The time scales of the excitation are at least an order of magnitude smaller than the typical reattachment times.

Original languageEnglish (US)
Pages (from-to)105-129
Number of pages25
JournalJournal of Fluid Mechanics
Issue number510
DOIs
StatePublished - Jul 10 2004

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separated flow
solid surfaces
attachment
Vortex flow
Amplification
vortices
excitation
Fluids
shoulders
slots
inclination
flat surfaces
perturbation
causes
fluids

ASJC Scopus subject areas

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

Cite this

Active management of naturally separated flow over a solid surface. Part 1. The forced reattachment process. / Darabi, A.; Wygnanski, Israel J.

In: Journal of Fluid Mechanics, No. 510, 10.07.2004, p. 105-129.

Research output: Contribution to journalArticle

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