Effects of wavy channel entrance design on streamwise counter-rotating vortices: A visualization study

A. C. Budiman*, H. Mitsudharmadi, Y. Bouremel, S. H. Winoto, H. T. Low

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Two different channel entrance designs, code named Valley First (VF) and Peak First (PF), were experimentally visualized by means of smoke-wire visualization technique to observe their effects towards the streamwise counter-rotating vortices generated. The spanwise wavelength of the vortices was pre-set by modifying the leading edge. The investigation was carried out on the laminar boundary-layer flow in a rectangular channel with one-sided wavy surface that has amplitude a and wavelength λ of 7.5 mm and 76 mm, respectively. The vortices in the channel with VF design preserve farther downstream than those on the PF design, which might be caused by the large favorable pressure gradient between the entrance flat plate and the first peak location. The counter-rotating vortices could still be observed at non-dimensionalized streamwise distance χ (= x/λ) = 2.47 for Reynolds number Re (= UH/ν) = 9900 in channel with VF design. For lower Re, the vortices could preserve further downstream. In contrast, in channel with PF design, the structures were only visible clearly up to approximately χ = 1.32 for Re = 4700 and χ = 0.39 for Re = 5200.

Original languageEnglish (US)
Pages (from-to)2161-2166
Number of pages6
JournalJournal of Applied Fluid Mechanics
Issue number5
StatePublished - 2016

Bibliographical note

KAUST Repository Item: Exported on 2023-07-22


  • Boundary-layer flow
  • Smoke-wire flow visualization
  • Wavy channel

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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