open access

https://hdl.handle.net/2115/79358

Quantitative visualization of vortex ring structure during wall impingement subject to background rotation

英語

3D vortex structure

2019-10

Springer

Journal of visualization

22(5)

867-876

A single vortex ring subject to background rotation in the process of wall impingement has been experimentally investigated by particle tracking velocimetry (PTV). Two parameter conditions of Reynolds and Rossby numbers were chosen in addition to stationary environment as much strong and competitive Coriolis force emerges in comparison with inertia induced by vortex rings. From horizontal PTV windows set on the rotating experimental frame above the bottom wall, comprehensive influences of Coriolis force on the wall-impinging reaction are visualized as space-time three-dimensional vorticity distributions. Against natural growth of azimuthal waves due to Widnall instability, wall-impinging suppresses the waves and rather re-organizes original primary vortex because of cyclonic swirl coherently induced during impingement. This resists to turbulent collapse of vortex ring during the impingement and self-boosts own life time. We try to explain the mechanism of such an anti-decaying process in the final part, untangling the phenomenon with best read from the space-time correlations among three vorticity components.

学術雑誌論文

Accepted Manuscript

This is a post-peer-review, pre-copyedit version of an article published in Journal of visualization. The final authenticated version is available online at: http://dx.doi.org/10.1007/s12650-019-00575-4.

1343-8875