#vortex rings

[fuckyeahfluiddynamics]

Vortex Rings at Dawn

Vortex rings blown from Mount Etna's vents drift through the dawn light in this beautiful image from Dario Giannobile.  (Image credit: D. Giannobile; via APOD) Read the full article

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VOLCANO IN CATANIA, ITALY BELCHES SMOKE RINGS INTO THE SKY

📹 Scenes from Catania, Sicily, south of the Italian peninsula where a volcano renewed activity in recent days, seen here belching smoke rings known as "Volcanic vortex" rings.

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Jellyfish produce two vortex rings when they swim

Credit: Brad Gemmell, associate professor of integrative biology, University of South Florida

[fuckyeahfluiddynamics]

Etna's Blowing Rings

Mount Etna has long been known for its smoke rings, but thanks to the opening of a new vent on the volcano's southeast crater, it's now making more rings than ever. Etna's smoke rings are, more precisely, vortex rings -- produced in the same way dolphins, swimmers, and whales make vortex rings: a sudden push of air through a roughly circular opening. (Video and image credit: The Straits Times; via Colossal) Read the full article

[fuckyeahfluiddynamics]

Supernova Rings

Some 20,000 years ago, a massive star blew off a ring of dust and gas that expanded into the surrounding interstellar medium. Later, in 1987, the star exploded as supernova 1987A. That explosion lit the surrounding area, revealing a clumpy ring astronomers have struggled to explain. But a new team believes they have a fluid dynamical answer: the Crow instability. (Image credits: NASA/ESA/CSA/M. Matsuura/R. Arendt/C. Fransson and NASA/ESA/A. Angelich + M. Wadas et al.; research credit: M. Wadas et al.; via APS Physics) Read the full article

[fuckyeahfluiddynamics]

Vortex Rings From a Square Outlet

When a vortex ring forms, it's often from fluid forced through a round outlet, whether that's someone's mouth, a pipe, or a dolphin's blowhole. But vortex rings can come from other shapes, too. (Image, video, and research credit: B. Steinfurth et al.) Read the full article

[fuckyeahfluiddynamics]

Vortex Below

When a drop of ethanol lands on a pool of water, surface tension forces draw it into a fast-spreading film. Evenly-spaced plumes form at the edges of the film, then the film stops spreading and instead retracts. All of this takes place in about 0.6 seconds.  (Image and research credit: A. Pant and B. Puthenveettil) Read the full article

[fuckyeahfluiddynamics]

Dolphins Playing With Bubble Rings

Blow a jet of air underwater and you can make a bubble ring. It takes some practice for humans, or you can use a device. In this video, a team introduced wild dolphins to a bubble-ring-making machine and observed how the dolphins reacted. (Image and video credit: BBC Earth)