Streamwise evolution of an inclined cylinder wake

H. F. Wang, Siti Fatin Mohd Razali, T. M. Zhou, Y. Zhou, L. Cheng

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The streamwise evolution of an inclined circular cylinder wake was investigated by measuring all three velocity and vorticity components using an eight-hotwire vorticity probe in a wind tunnel at a Reynolds number Re d of 7,200 based on free stream velocity (U ) and cylinder diameter (d). The measurements were conducted at four different inclination angles (α), namely 0°, 15°, 30°, and 45° and at three downstream locations, i.e., x/d = 10, 20, and 40 from the cylinder. At x/d = 10, the effects of α on the three coherent vorticity components are negligibly small for α ≤ 15°. When α increases further to 45°, the maximum of coherent spanwise vorticity reduces by about 50%, while that of the streamwise vorticity increases by about 70%. Similar results are found at x/d = 20, indicating the impaired spanwise vortices and the enhancement of the three-dimensionality of the wake with increasing α. The streamwise decay rate of the coherent spanwise vorticity is smaller for a larger α. This is because the streamwise spacing between the spanwise vortices is bigger for a larger α, resulting in a weak interaction between the vortices and hence slower decaying rate in the streamwise direction. For all tested α, the coherent contribution to v2̄ is remarkable at x/d = 10 and 20 and significantly larger than that to u2̄ and w 2̄. This contribution to all three Reynolds normal stresses becomes negligibly small at x/d = 40. The coherent contribution to u 2̄ and v2̄ decays slower as moving downstream for a larger α, consistent with the slow decay of the coherent spanwise vorticity for a larger α.

Original languageEnglish
Pages (from-to)553-570
Number of pages18
JournalExperiments in Fluids
Volume51
Issue number2
DOIs
Publication statusPublished - Aug 2011
Externally publishedYes

Fingerprint

Vorticity
wakes
vorticity
Vortex flow
vortices
free flow
wind tunnels
decay
circular cylinders
Circular cylinders
decay rates
Wind tunnels
inclination
Reynolds number
spacing
augmentation
probes

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Fluid Flow and Transfer Processes
  • Computational Mechanics
  • Mechanics of Materials

Cite this

Streamwise evolution of an inclined cylinder wake. / Wang, H. F.; Mohd Razali, Siti Fatin; Zhou, T. M.; Zhou, Y.; Cheng, L.

In: Experiments in Fluids, Vol. 51, No. 2, 08.2011, p. 553-570.

Research output: Contribution to journalArticle

Wang, H. F. ; Mohd Razali, Siti Fatin ; Zhou, T. M. ; Zhou, Y. ; Cheng, L. / Streamwise evolution of an inclined cylinder wake. In: Experiments in Fluids. 2011 ; Vol. 51, No. 2. pp. 553-570.
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