抄録
Vortex rings have been historically the most fundamental target for studying fluid mechanics and its relation to turbulence [1][2]. We have measured influence of background rotation on the spatial transition of vortex rings, which arises during impacting on a solid wall. The combination of the background rotation and presence of the wall provides unique three dimensional reaction of vortex ring due to rapid spiral distortion of fluid that is induced by the interaction between stretching of vortex cores and Coriolis force [3][4]. The phenomenon associates with a variety of fluid behaviours from geo-physics to wall turbulence. Our PIV measurement, which is mounted on the rotating frame, has shown two characteristic flow structures. One is cyclonic structure for angular momentum conservation during the impact, which erases azimuthal waves away. Another is generation of a spiral column in the wake region, which emits fluid like a high-speed jet in opposite direction to the wall.
