This photo, one of the winners of the Engineering and Physical Sciences Research Council’s (EPSRC) annual photography contest, shows a rotating viscoelastic jet. Rotating liquid jets are common to many manufacturing processes, and their sometimes-wild appearance comes from a balance of gravitational forces and centrifugal force against surface tension. But because this fluid contains a small amount of polymer additive, surface tension has the additional aid of some elasticity to help hold the jet together and keep the globules and ligaments you see from flying off. As centrifugal forces fling the fluid outward, it stretches the polymer chains within the fluid, and they pull back against that tension like a stretched rubber band. To see some of the other contest winners–including other fluids entries!–check out the Guardian’s run-down. (Image credit and submission: O. Matar et al., ICL press release)
Tag: fluids as art
Webcast Teaser Reel
Saturday I topped off a week of water-walking physics by holding a webcast with Professor Tadd Truscott and PhD student Randy Hurd of The Splash Lab. We had an absolutely blast talking about skipping balls, aesthetics and art, sailing, STEM outreach, and much more. The video above is a short teaser for the webcast – you can watch the full hour here. There are demos, a lab tour, and even a chance to learn about how I do FYFD. If you’d like to see or take part in future webcasts, you can do so by becoming an FYFD patron! (Video credit: FYFD)
Turbulent Convection
These golden lines reveal the complexity of turbulent convective flow. They come from a numerical simulation of turbulent Rayleigh-Benard convection, a situation in which fluid trapped between two plates is heated from below and cooled from above. This situation would typically create convection cells similar to those seen in clouds or when cooking. Inside these cells, warm fluid rises to the top, cools, and sinks down along the sides. With large enough temperature differences, instabilities will occur and cause the flow to become turbulent so that the clear structure of convection cells breaks down into something more chaotic. Such is the case in this simulation. This visualization shows skin friction on the bottom (heated) plate in a flow of turbulently convecting liquid mercury. The bright lines are areas with large velocity changes at the wall, an indication of high shear stress and vigorous convective flow. (Image credit: J. Scheel et al.; via Gizmodo)
Psychedelic Cymatics
Cymatics are the visualization of vibration and sound. Here photographer Linden Gledhill has taken a simple speaker vibrating a dish of water and turned it into some incredible art. When you vibrate liquids like water up and down, it disturbs the usually flat air-water interface and creates waves on the surface. These Faraday waves are a standing wave pattern that differs depending on which sound is being played. By combining the wave patterns with LED lighting and strobe effects, Gledhill creates some remarkable images that combine sound, light, and fluid dynamics all in one. If you watch the video (make sure to hit the HD button!), you’ll see the patterns in motion and hear the sounds used to generate them. In the last clip (around 0:19), he’s added glitter to the set-up, which highlights the circulation within the vibrating fluid. As you can see, there are strong recirculating regions in each lobe of the pattern, but other areas, like the center region are almost entirely stationary. You can see more photos from the project in his Flickr feed. Special thanks to Linden for letting me post the video of his work, too! (Video and image cred
its and submission: L. Gledhill)
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Freezing Soap Bubbles
I’m not a winter person, but there’s something almost magical about the way water freezes. From instant snow to snow rollers and weird ice formations to slushy waves, winter brings all kinds of bizarre and unexpected sights. The video above is an artistic look at one of my favorites – freezing soap bubbles. Normally, the thin film of a soap bubble is in wild motion, convecting due to gravity, surface tension differences, and the surrounding air. Such a thin layer of liquid loses its heat quickly, though, and, as ice crystals form, the bubble’s convection and rotation slow dramatically, often breaking the thin membrane. Happily photographer Paweł Załuska had the patience to capture the beautiful ones that didn’t break! (Video credit: P. Załuska; via Gizmodo)
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Fluids Round-up
Here’s to another fluids round-up, our look at some of the interesting fluids-related stories around the web:
– Above is a music video by Roman Hill that relies on mixing and merging different fluids and perturbing ferrofluids for its visuals as it re-imagines the genesis of life.
– GoPro takes viewers inside a Category 5 typhoon with 112 mph (180 kph; 50 m/s) winds.
– Astronaut Scott Kelly demonstrates playing ping pong with a ball of water in space. (via Gizmodo)
– See fluid dynamics on a global scale with Glittering Blue. (via The Atlantic)
– To make a taller siphon, you have to find a way to avoid cavitation.
– Speaking of siphons, Randall Munroe tackles the question of siphoning water from Europa over at What If? (submitted by jshoer)
– The Mythbusters make a giant tanker implode using air pressure.
– Sixty Symbols explores how tiny things swim.
– What happens when you bathe in 500 pounds of putty? Let’s just say that bathing in an extremely viscous non-Newtonian fluid is not recommended. (via Gizmodo)
(Video credit and submission: R. Hill et al.)
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Paint Flying
Paint getting flung from a spinning drill bit can create some incredible art. Here the Slow Mo Guys recreate the effect in high-speed video. What we’re seeing is tug of war between centrifugal force, which tries to fling the paint outward, and internal forces in the paint, which struggle to hold the the fluid together. Primarily, it’s surface tension keeping the fluid together, but, depending on what sort of non-Newtonian fluid the paint may be, there could be other internal forces helping keep the paint intact. In this case, centrifugal force is clearly winning out, though the paint stretches pretty far before it thins enough to break. It would be interesting to see how the balance plays out with the drill bit spinning at a lower RPM. (Image credit: Slow Mo Guys, source)
Fluids Round-Up
New year, new (or renewed) experiments. This is the fluids round-up, where I collect cool fluids-related links, articles, etc. that deserve a look. Without further ado:
- Above is a new music video from the Julia Set Collection, featuring all non-CGI, fluids-based visuals. I spy soap films, vibrating liquids, and lots of cool effects with reflection and refraction. We featured some of their previous work, too.
- The Atlantic has a great piece about jellyfish and how they might just change our understanding of efficient swimming.
- Check out the wild shape-shifting of these drops of oil during freezing and learn about the plastic crystal phase some matter experiences.
- Nature has an interesting article on active matter, an intersection of physics and biology exploring how matter self-organizes, whether at the level of cells or the flocking of birds. (submitted by 1307phaezr)
- Ever wonder what the human face looks like in 457 mph winds? Wonder no more.
- Gizmodo has a beautiful set of macro photos of snowflakes. Interested in how snowflakes form and why there are so many different shapes? We’ve got you covered.
- Wired takes a look at the surf forecaster who predicts the waves for the Mavericks big-wave competition.
- Robert Krulwich (and friends) took a closer look at our fish in microgravity. Here’s what they learned!
(Video credit and submission: Julia Set Collection/S. Bocci; image credit: IRPI LLC, source)
Falling Ink
Photographer Linden Gledhill created these nebula-like composites from photos of ink diffusing in water. The work was inspired by Mark Stock’s “Spherical Rayleigh-Taylor Instabilities” series featured here last week. Like Stock’s computational art, the twisted fingers and vortex rings above form due to the denser ink falling through less dense water. The interface between the two fluids distorts under the effects of gravity and the fluids’ relative motion. Such shapes are ephemeral at best; the falling ink will quickly become turbulent and diffuse throughout the water. (Photo credit and submission: L. Gledhill)
Numerical Rayleigh-Taylor
If you’ve ever dripped food coloring or ink into a glass of water, you’ve probably created a cascade of tiny vortex rings similar to the images above. This is the Rayleigh-Taylor instability, in which the heavier ink/food coloring falls under gravity into the less dense water. What’s shown above is a special case–one that no experiment can recreate. It’s a numerical simulation of a spherical Rayleigh-Taylor instability. Imagine a sphere of a dense fluid “falling” outward under the influence of a radial gravitational field. This is one of the interesting aspects of computational fluid dynamics–it can simulate situations that are impossible to create experimentally. That can be both a strength and a weakness, allowing researchers to probe otherwise unavailable physics or fooling the unwary into thinking they have captured something real. (Image credit: M. Stock)
