As part of the demolition of a decommissioned coal-fired power plant in Nottinghamshire, workers simultaneously demolished eight cooling towers. The video is here. As the towers collapse, smoke and dust gets blown both out of the base and up each tower. The flow details are fascinating. The plumes have rings in them, perhaps related to how the blast’s waves reflect in the tower or how the structure itself fails. Vortex rings curl up as the rising plumes mix with the surrounding air. If you’re anything like me, you’ll have to replay it several times! (Image credit: BBC; submitted by jshoer)
Tag: plumes
Slipping Along Enceladus
Home to a sub-surface ocean, Saturn‘s moon Enceladus is a fascinating candidate for life in our solar system. As it orbits Saturn, plumes periodically shoot out long surface features known as tiger stripes that sit near the icy moon’s southern pole. A recent study, based on numerical simulation, suggests a geophysical mechanism that could account for the plumes.
The team suggests that, like the San Andreas Fault, the tiger stripes are a fault subject to strike-slip motion. In this type of fault, the ice on either side meets along a vertical face and the two sides will slide past one another in opposite directions. As Enceladus orbits, its proximity to Saturn causes tidal compression across the fault that modulates how much slip motion occurs. In their model, the authors found that strike-slip motion would intermittently open gaps in the fault that would allow water from the subsurface ocean to create plumes at intervals consistent with those observed. (Image credit: top – NASA/JPL-Caltech/Space Science Institute, illustration – A. Berne et al.; research credit: A. Berne et al.; via Gizmodo)
Illustration of the strike-slip mechanism over the course of Enceladus’s tides. The two sides of the “tiger stripe” fault move in opposite directions. How much they move depends on the amount of tidal compression caused by Enceladus’s orbit around Saturn. At times, motion along the fault pulls apart narrow sections of the ice, allowing a plume to spray out. 
A Comet’s Tail
A comet‘s tail changes from day-to-day depending on how much material the comet is losing and how strong the solar wind it’s facing is. This image sequence shows Comet 12P/Pons-Brooks over nine days in 2024 from March 6th (top) through March 14th (bottom). The variations in the comet’s appearance are striking; some days show nearly no tail while others have long plumes with swirls of turbulence. It’s a reminder that, even if they appear unchanging in the moment you see one, a comet is in constant flux. (Image credit: Shengyu Li & Shaining; via APOD)
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. But, as the image above shows, there’s more that goes on beneath the surface. A vortex ring forms and spreads under the film, driven by the shear layer under the edge of the plumes. Here, the vortex ring is visible in the swirling particles near the water surface. (Image and research credit: A. Pant and B. Puthenveettil)
“-37F Winter in Yellowstone”
Yellowstone National Park is always fascinating and surreal, but especially so in winter when volcanically-heated geysers and springs meet frigid, snowy weather. This short film from Drew Simms shows the park and its wildlife in the depths of winter. The bison rely on thick, shaggy fur coats to trap heat and keep dry. Steam and mist mingle around springs and giant plumes rise from geysers. What a strange and beautiful landscape! (Video and image credit: D. Simms)
“Alive”
In “Alive,” filmmaker Christopher Dormoy explores acrylic paints and the variety of ways in which the medium can be used. From a fluids perspective, there’s dripping, viscous flow, turbulent eddies, billowing plumes, and “accidental painting” due to density-driven instabilities. It’s a fun tour of fluid phenomena in art. What examples do you spot? (Video and image credit: C. Dormoy)
Icelandic Glow
Solar wind particles slam into the atmosphere near Earth’s poles, creating billowing curtains of glowing plasma known as auroras. Beneath the earth, molten rock seethes and flows, squeezed up fissures to release explosive gases and spurts of lava to the surface world. These natural phenomena are captured in the left and center of this image, respectively. To the right, three plumes of water vapor rise from a geothermal power plant. Three very different phenomena — all fluid dynamical in nature and all captured in a single image of Iceland. It’s no wonder the island is covered in tourists. (Image credit: W. Gorecka; via APOD)
The Best of FYFD 2023
A fresh year means a look back at what was popular last year on FYFD. Usually, I give a numeric list of the top 10 posts, but this year the analytics weren’t as clear. So, instead, I’m combining from a few different sources and presenting an unordered list of some of the site’s most popular content. Here you go:
- Eroding the Sphinx
- Getting Water Out of Your Ear
- Can Water Solve a Maze?
- Dandelion Seeds
- Black Holes in a Bathtub
- Mixing With E. coli
- Beneath the Cavity
- Leidenfrost Explosions
- Toilet Plumes
- Exascale Simulations
- Ghosts of Rivers Past
- Blood Flow in a Fin
- Snake Tracks
- Lagoon Nebula
- “Chaosmosis”
I’m really pleased with the mix of topics this year; many of these topics are straight from research papers, and others are artists’ works. At least one is both. From swimming bacteria to star-birthing nebulas, fluid dynamics are everywhere!
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(Image credits: sphinx – S. Boury et al., ear model – S. Kim et al., maze – S. Mould, dandelion – S. Chaudhry, water tank – P. Ammon, e. coli – R. Ran et al., drop impact – R. Sharma et al., Leidenfrost – L. Gledhill, toilet – J. Crimaldi et al., engine sim – N. Wimer et al., rivers – D. Coe, fin – F. Weston, snake – P. Schmid, nebula – J. Drudis and C. Sasse, flames – C. Almarcha et al.)
Flipping Ice
In nature ice is ever-changing — growing, shrinking, and shifting. This poster illustrates that with a cylinder of ice floating in room temperature water. As the ice melts, it flips over into a new orientation, stays that way for a time, and then shifts again, as seen in the series of blue images. This flipping results from the melting flows around the ice, illustrated in the colorful central photo. This color schlieren image shows dense plumes of cold meltwater sinking beneath the ice. As that cold water drips down the sides of the ice, it leaves behind a wavy, patterned surface. Eventually, melting from the bottom of the ice leaves the remaining ice top-heavy, which triggers a flip into a more stable orientation. (Image and research credit: B. Johnson et al.)
“The Reef”
Artist Alberto Seveso returns to his colorful ink plumes (1, 2, 3, 4, 5), but this time with a twist. Here, Seveso took ink injected in water and digitally altered it, adding texture and shaping the ink to mimic the shapes of coral reefs. The results are stunning, though I confess a few of them remind me of mushrooms or organs more than reefs. (Image credit: A. Seveso; via Colossal)
