Affiliations: Department of Mechanical Engineering, University of
Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan, S7N 5A9, Canada.
E-mail: david.sumner@usask.ca | Department of Civil and Environmental Engineering,
University of Windsor, Essex Hall, 401 Sunset Avenue, Windsor, Ontario, N9B
3P4, Canada
Abstract: Flow visualization was used to study the fluid-structure interaction
between a circular cylinder and a shallow turbulent open channel flow. The
Reynolds number ranged from R_{eD}=1500–4400 based on the cylinder
diameter, and from R_{eH}=7,800–27,600 based on the channel hydraulic
radius. The cylinder was mounted vertically on the channel bed and the flow
depth-to-cylinder-diameter ratio was varied from d/D=7.0–11.7. Tests
were carried out over smooth and rough beds, with the rough beds being either
permeable or impermeable. The study showed that the horseshoe vortex forming at
the cylinder-bed junction affects many of the flow structures, including the
mode of vortex shedding, the shear layer dynamics, the vortex formation length,
and the width of the near-wake region. The influence of the horseshoe vortex
can be recognized throughout the depth of flow; however, its influence
decreases with an increase in distance from the channel bed. It was also
possible to discern that the bed roughness resulted in a change to the above
interaction and the permeability of the bed resulted in additional changes.
Keywords: Cylinder, Open Channel Flow, Horseshoe Vortex, Vortex Shedding
