Visualization of vortices in the wake of a diamond-shaped cylinder

Abstract

The turbulence flow around a square or diamond-shaped cylinder has received far less attention than the flow around a circular cylinder. An experimental study was performed to visualize the wake flow behind a diamond-shaped cylinder. Two kinds of aspect ratios d/w=10.0 and d/w=1.0 are selected in the experiment, where d is a depth of the duct and w is a width of the cylinder. The wake flows are visualized at a top view, a side view and front views using the fluorescein dye illuminated by a laser light sheet. It is shown that the three dimensional longitudinal vortices appear in the wake flow behind the diamond-shaped cylinder.