On the near-field of a square jet with vortex-generating tabs

X.K. Wang, L.P. Chua, Ching Man Yu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

17 Citations (Scopus)

Abstract

A square jet with four vortex-generating tabs has been investigated by flow visualizations using Laser Induced Fluorescence technique and by velocity measurements using a Laser Doppler Anemometer. The tabs, which are triangular in shape, are tilted into the jet at either ? = 45° or 135° with respect to the main flow direction. The flow visualization results illustrate that with the addition of fourtabs, the cross-section of the jet core is bifurcated into a four-"finger" structure. For ? = 135° in particular, there is an additional "mushroom" structure between two neighboring fingers. Secondary velocities show that a pair of streamwise vortices is generated by each tab. These streamwise vortices tend to spread the jet fluids "outward" along the diagonal direction, resulting in a four-finger structure of the jet core. In the case of ? = 135°, the additional third pair of streamwise vortices previously proposed by other researchers is confirmed in the present study, which is responsible for the unique mushroom structure. The tab effects on the jet spreading and on the axis-switching phenomenon are also discussed. © 2003 Published by The Japan Society of Fluid Mechanics and Elsevier Science B.V. All rights reserved.
Original languageEnglish
Pages (from-to)99-117
Number of pages19
JournalFluid Dynamics Research
Volume32
Issue number3
DOIs
Publication statusPublished - 1 Jan 2003
Externally publishedYes

Keywords

  • Laser Doppler Anemometer
  • Laser Induced Fluorescence
  • Square jet
  • Vortex-generating tab

ASJC Scopus subject areas

  • Mechanical Engineering
  • Physics and Astronomy(all)
  • Fluid Flow and Transfer Processes

Cite this