Visualization of standing vortices behind a cylinder in glycerin–water solutions

摘要

The standing vortices behind a circular cylinder have been visualized by means of direct shadows produced in glycerin–water solutions, and the length of the vortices has been measured. It has been thereby confirmed that the method is applicable to visualize the closed regions of standing vortices correctly. The shadow pattern over the whole flow field, however, seems to correspond to none of the patterns of common hydrodynamic lines.