Experimental analysis on flow around a circular and an elliptic hoop-typed ring by using a PIV technique

In the present study, we measured velocity vector fields around hoop rings at each divided sections by using a particle image velocimetry method. The ring model used in this study was made of brass with two different aspect ratios and the experiment is carried out in a circulating water channel. As a result, we can observe two counter-rotating vortical flow structures around each hoop regime that is attributed to the interaction between direct pass through flow of hoop center and the shear flow separated from sharp-edged end of ring hoop.