Flow details of a circular cylinder mounted on a flat plate


Ozturk N. A. , Akkoca A., ŞAHİN B.

JOURNAL OF HYDRAULIC RESEARCH, cilt.46, ss.344-355, 2008 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 46 Konu: 3
  • Basım Tarihi: 2008
  • Doi Numarası: 10.3826/jhr.2008.3126
  • Dergi Adı: JOURNAL OF HYDRAULIC RESEARCH
  • Sayfa Sayısı: ss.344-355

Özet

The main purpose of this study is to investigate the flow structure up- and downstream of a circular cylinder mounted on a flat surface in the boundary layer region using a Particle Image Velocimetry (PIV) technique for Reynolds numbers ranging from 750 to 9600. The interaction between the primary, incoming, and counter-clock-wise rotating vortices and the trail of the horseshoe vortices formed at the upstream base of the cylinder are quantitatively identified in terms of the instantaneous and time-averaged flow data. The entrainment is shown to be activated between the main and separated flow regions across the shear layer by interactions of opposite signed rotating vortices which are responsible for scour in the upstream region of the cylinder. The surface fluid bursts to create counter-clock-wise rotating vortices upstream of the cylinder to split the incoming clock-wise rotating vortex into an independent vortex. Since the counter-clock-wise rotating vortices are not fed continuously by the surface fluid, they gradually expand in size but lose the strength and later are swept away by the developing vortices.