Source: wikibot/vortex-ring
= Vortex ring
{wiki=Vortex_ring}
A vortex ring is a structure in fluid dynamics characterized by a toroidal (doughnut-shaped) rotation of fluid around an axis. It typically forms when a volume of fluid is displaced quickly into a surrounding fluid, resulting in a stable, self-contained whirlpool-like motion. Vortex rings can be observed in various scenarios, such as: 1. **Smoke Rings**: When a puff of smoke is expelled in a specific way (e.g.