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Investigation of turbulent flow past a flagged short finite circular cylinder

Kiani, F ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1080/14685248.2015.1125491
  3. Publisher: Taylor and Francis Ltd
  4. Abstract:
  5. This study was conducted to investigate the flow structures of turbulent flow passing over a short finite cylinder in which a rigid flag is attached to the rear of the cylinder, in wake region. The length-to-diameter ratio of the cylinder was chosen to be L/D = 2, whereas the rigid flag had a width-to-diameter ratio of W/D = 1.5. Wall-adapted large-eddy simulation (LES-WALE) was used to resolve unsteady turbulent flow structures. The far field Reynolds number based on cylinder diameter was chosen to be 20,000. The results were compared with the regular case wherein no flag was attached to the cylinder. Results revealed that the flow pattern behind the cylinder with flag was totally different in comparison with the regular case one. However, top free end of the cylinder was not influenced by the flag in contrast with the wake region. At far downstream from the cylinder, most of the flow structures in both cases appeared the same. The horseshoe vortices in both cases appeared to be an unsteady phenomenon, with slightly different patterns. Moreover, in the case of flag attachment, the pressure coefficient was smaller than that of with no flag. Finally, it was shown that the main and secondary Strouhal numbers locations were different in both cases
  6. Keywords:
  7. Drag force coefficient ; Finite circular cylinder ; LES-WALE ; Rigid flag attachment ; Short free-end cylinder ; Strouhal number ; Cylinder ; Drag coefficient ; Flow structure ; Large eddy simulation ; Reynolds number ; Turbulent flow ; Wake
  8. Source: Journal of Turbulence ; Volume 17, Issue 4 , 2016 , Pages 400-419 ; 14685248 (ISSN)
  9. URL: http://www.tandfonline.com/doi/abs/10.1080/14685248.2015.1125491?journalCode=tjot20