@fuckyeahfluiddynamics / fuckyeahfluiddynamics.tumblr.com
To 3D print with fiber-infused liquids, we need to understand how these drops form, break-up, and splash. That's the subject of this research poster, which shows drops of a fiber suspension forming and pinching off along the top of the image. (Image credit: S. Rajesh and A. Sauret; via GoSM) Read the full article
Anyone who's dealt with hot glue guns is familiar with the long, thin tails of glue they leave behind. 3D printers suffer from a similar problem with the nozzle pulls away from viscoelastic materials like plastics and polymers. (Image credit: 3D-print - T. Claes, illustration - H. Hill/Physics Today, animation - S. Chan et al.; research credit: S. Chan et al.; via Physics Today) Read the full article
Capillary action combines the cohesive forces within a liquid and the adhesive forces between a liquid and solid to enable a liquid to fill narrow spaces, even against the force of gravity. To control capillary action, researchers are 3D-printing what they call "unit cells," tiny structures that water and other liquids can climb. (Image and research credit: N. Dudukovic et al.; via Nature; submitted by Kam-Yung Soh) Read the full article
For 3D printers to reach their potential, they need to handle more than one material and be able to swap quickly and seamlessly between them. (Image and video credit: Nature, with M. Skylar-Scott et al.; research credit: M. Skylar-Scott et al.; via Nature; submitted by Kam-Yung Soh)
Inkjet printing and other methods for directing and depositing tiny droplets rely on the force of gravity to overcome the internal forces that hold a liquid together. But that requires using a liquid with finely tuned surface tension and viscosity properties. If your fluid is too viscous, gravity simply cannot provide consistent, small droplets. So researchers are turning instead to sound waves.
Using an acoustic resonator, scientists are able to generate forces up to 100 times stronger than gravity, allowing them to precisely and repeatably form and deposit micro- and nano-sized droplets of a variety of liquids. In the images above, they’re printing tiny drops of honey, some of which they’ve placed on an Oreo cookie for scale. The researchers hope the technique will be especially useful in pharmaceutical manufacturing, where it could precisely dispense even highly viscous and non-Newtonian fluids. (Image and research credit: D. Foresti et al.; via Smithsonian Mag; submitted by Kam-Yung Soh)
If you’ve drizzled viscous liquids like honey or syrup, you’ve no doubt witnessed their ability to coil. Combine that coiling with a moving platform and you form a system known as the fluid dynamical sewing machine, which creates different consistent patterns of loops and curves depending on the speed at which the liquid falls and the velocity of the moving platform. The predictability of these patterns makes them especially useful for 3D printing. Previously a group at MIT developed a glass printer that could use the instability, and here a group from Montreal demonstrates how they can build solid coils at various scales. Their video also explores what the structural properties of such coils are after they solidify. (Image, video, and research credit: R. Passieux et al.)
Inside Science has a new documentary all about fluid dynamics! It features interviews with five researchers about current work ranging from the physics of surfing to the spreading of diseases. Penguins, sharks, archer fish, 3D printing, and influenza all make an appearance (seriously, fluid dynamics has everything, guys). If you’d like to learn more about some of these topics, I’ve touched on several of them before, including icing, penguin physics, shark skin, archer fish, and disease transmission via droplets. (Video credit: Inside Science/AIP)
Time for another look at some of the best fluids content out there. It’s the fluids round-up - with a special focus this week on oceans!
- Ryan Pernofski spent two years filming the ocean in slow motion with his iPhone to make the short film “Slowmocean” seen above. It’s a gorgeous ode to the beauty of breaking waves.
- Oceans with higher salinity than Earth’s could drive global circulation that would make exoplanets more hospitable to life.
- Speaking of alien oceans that could harbor signs of life, there’s discussion afoot of how future missions to icy moons like Europa or Enceladus could collect samples from plumes ejected from beneath the ice.
- Wind and waves make harsh, erosive environments. This photo essay from SFGate shows how greatly the sands of Pacifica shift over time. (submitted by Richard)
Bonuses:
- New research explores how Martian mountains may have been carved out by the wind.
- Ever listened to an orchestra made from ice? You should! Learn about Tim Linhart, who builds and maintains ice instruments. (submitted by ashketchumm)
- MIT has demonstrated a new 3D-printing technique that allows for printing liquid and solid parts simultaneously, allowing would-be creators to rapid-prototype hydraulically-driven robotics.
Even more bonus bonus!
- ICYMI, the new FYFD video made Gizmodo!
If you’re a fan of FYFD, please consider becoming a patron. As a bonus, you’ll get access to this weekend’s planetary science webcast!
(Video credit: R. Pernofski; via Flow Visualization; Pluto image credit: NASA/APL)
A group at MIT have created a new 3D printer that builds with molten glass. This allows them to manufacture items that would difficult, if not impossible, to create with traditional glassblowing or other modern techniques. One of the coolest aspects of this technique is that it can use viscous fluid instabilities like the fluid dynamical sewing machine to create different effects with the glass. You can see this around 1:56 in the video. Varying the height of the head and the speed at which it moves will cause the molten glass to fall and form into different but consistent coiling patterns. All in all, it’s a very cool application for using some nonlinear dynamics! (Video credit: MIT; via James H. and Gizmodo)
Most flows vary in three spatial dimensions and time. In experimental fluid dynamics, the challenge is measuring as much of this information as possible. For those who use computational fluid dynamics to study flows, their simulations provide massive amounts of data and the challenge comes in visualizing and processing that data in a useful way. Unless you can find and analyze the important aspects of the simulation results, they’re just a bunch of numbers. As computers have advanced, the size and complexity of simulation results has increased, too, making the task even more difficult. Using technologies like virtual reality projections (above) or 3D printing (below) allow researchers to interact with flow information in completely new but intuitive ways, hopefully leading to new insights into the data.
(Video credit: M. Stock; photo credit: K. Taira et al.)
** The 3D-printed vortices are an image I took of a poster at the APS DFD Gallery of Fluid Motion in 2013, but I’m missing the researchers’ names. If you know whose poster these were from, please let me know (fyfluids [at] gmail [dot] com) so that I can update the credits accordingly. Thanks to Shervin for helping me find the right lab to credit!
