Visualization of Stratified Flow Induced by a Rotating Circular Cylinder

Stratified flow induced by an impulsively started rotating circular cylinder was observed by means of dye injection. Effects of Reynolds number and Froude number on the behavior of the vortical flow were examined. The evolutions of dyed vortex formation lead to subsequent layered formation of dyed flow pattern. During the vortex formation and the rearrangement of the vortices, flow patterns exhibit the behavior of oscillating motion. Both the Reynolds number and Froude number affected the radial length scale of the layered formation, while the wavelength was almost independent of Reynolds number.