A calm, sunny day erupted into a thunderstorm off the coast of Scotland for photographer Brian Matthews. Turbulent clouds streak the sky, and a downpour on the left releases a stream of precipitation. Storms like these were once uncommon in the United Kingdom, but with increasingly hot weather due to climate change, more water vapor and more energy in the atmosphere create conditions for storms like these. (Image credit: B. Matthews; via Wildlife POTY)
Tag: turbulence
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)
“Serenity”
Peering from directly above, landscapes take on a whole different aspect. That idea is the heart of Vadim Sherbakov’s “Serenity,” filmed by drone. From seething waters and meandering rivers to eroded landscapes and twisting ice, there’s lots of fluid dynamics on display here. (Video and image credit: V. Sherbakov)
Fediverse Reactions
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Visualizing Wingtip Vortices
At the ends of an airplane‘s wings, the pressure difference between air on top of the wing and air below it creates a swirling vortex that extends behind the aircraft. In this video, researchers recreate this wingtip vortex in a wind tunnel, visualized with laser-illuminated smoke. The team shows the progression from no vortex to a strong, coherent vortex as the flow in the tunnel speeds up. Along the way, there are interesting asides, like the speed where the honeycomb used to smooth the upstream flow is suddenly visibly imprinted on the smoke! (Video and image credit: M. Couliou et al.)
“Nimbus”
Ephemeral clouds drift through unusual places in artist Berndnaut Smilde‘s works. He creates his clouds from smoke and water, launching them for a matter of seconds before they dissipate. During that time, he and his collaborators take photographs of the clouds, creating a memento of a time already past. Catch more of Smilde’s short-lived weather on his website and Instagram. (Image credit: B. Smilde and collaborators; via Colossal)
Simeis 147
Sometimes known as the Spaghetti Nebula, Simeis 147 is the remnant of a supernova that occurred 40,000 years ago. The glowing filaments of this composite image show hydrogen and oxygen in red and blue, respectively. These are the outlines of the shock waves that blew off the outer layers of the one-time star within. What remains of that star’s core is now a pulsar, a fast-spinning neutron star with a solar wind that continues to push on the dust and gas we see here. (Image credit: S. Vetter; via APOD)
“Sfumato”
Handmade kinetic sculptures by artists Marion Pinaffo and Raphaël Pluvinage spin and paint the sky in colorful smoke in “Sfumato”. Named for an artistic technique in which shading gradually changes tone and hue, the installation was built, the artists note, “without motors, electronics, computer generated images, or artificial intelligence”. Just pure hands-on engineering and physics. Watch the short video of the installation in action for the full effect. You can find more of their work on their website, Vimeo, and Instagram. (Image and video credit: M. Pinaffo and R. Pluvinage; via Colossal)
“Origin”
Billowing turbulence, mushroom-like Rayleigh-Taylor instabilities, and spreading flows abound in Vadim Sherbakov’s “Origin.” The short film takes a macro looks at fluids — inks, alcohols, soaps, and other household liquids. It was filmed entirely on a DJI Pocket 2, a rather small, stabilized pocket camera. It’s a testament to what you can achieve with some experimentation and relatively inexpensive equipment. (Video and image credit: V. Sherbakov)
Convection in Action
We’re surrounded daily by convection — a buoyancy-driven flow — but most of the time it’s invisible to us. In this video, Steve Mould shows off what convection really looks like with some of his excellent tabletop demos. The first half of the video gives profile views of turbulent convection, with chaotic and unsteady patterns. When he switches to oil instead of water, the higher viscosity (and lower Reynolds number) offer a more structured, laminar look. And finally, he shows a little non-temperature-dependent convection with a mixture of Tia Maria and cream, which convects due to evaporation changing the density. (Image and video credit: S. Mould; submitted by Eric W.)
Rough Surfaces
In fluid dynamics, we’re often concerned with flow moving past a solid surface — air past an airplane wing, water past fish scales, oil between moving parts — and those surfaces are rarely perfectly smooth. Rough surfaces affect the flow near them, sometimes in unexpected ways. Here, researchers show a rough surface’s effect on the eddies of the atmospheric boundary layer. Put differently, this poster shows how buildings, trees, and other features influence the lowest layer of the atmosphere. From the tiny gaps between buildings to the eddies towering many times higher, the turbulence reflects roughness’s effects. (Image credit: J. Kostelecky and C. Ansorge)
