Mocha Diffusion

These firework-like patterns spread when dyes are added atop a viscous but miscible lower fluid layer. Here, researchers use lower layers like corn syrup and xanthan gum; then they spread dye mixtures including ammonia and vinegar atop those layers.  (Image credit: T. Watson and J. Burton) Read the full article

Shaking on Impact

When objects impact water with enough speed, they create a smooth-walled, air-filled cavity around and behind them. Here, the impacting object is one with some give, like a spring.  (Image credit: J. Antolik et al.) Read the full article

The Hydrodynamics of Marbling

In marbling, an artist floats paints on a viscosified water bath, using various thin tools to manipulate the final image. Many cultures have developed a version of this art, but for many it will be most recognizable as a technique used to decorate book interiors.  (Video credit: Y. Sun et al.) Read the full article

Ciliary Pathlines

For tiny creatures, swimming through water requires techniques very different than ours. Many, like this sea urchin larva, use hair-like cilia that they beat to push fluid near their bodies. The flows generated this way are beautiful and complex. (Image credit: B. Shrestha et al.) Read the full article

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.  (Image credit: J. Kostelecky and C. Ansorge) Read the full article

Variations on a Theme by Edgerton

In the 1930s, Harold Edgerton used strobed lighting to capture moments too fast for the human eye, including his famous "Milk-Drop Coronet".  (Image credit: R. Zenit et al.) Read the full article

Beneath the Surface

Signs of a ship's passage can persist long after it's gone. The churn of its propellers and the oil leaked from its engines leave a mark on the water's surface that, in some cases, is visible even from orbit.  (Image credit: A. Calado and E. Balaras) Read the full article

Parting a Flame

A sheet of flame splits around a cylinder in this Gallery of Fluid Motion poster. Looking at the image sequences, you can see how the flames lift up as they flow around the cylinder, following the arms of a horseshoe vortex.  (Image credit: L. Shannon et al.) Read the full article

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.  (Video and image credit: M. Couliou et al.) Read the full article

Liquid Lace

3D printers are a neat apparatus for exploring flow instabilities. If too much material is extruded compared to the speed of the printer head, coiling takes place. But under-extrusion creates patterns, too.  (Video and image credit: L. Dreier et al.) Read the full article

Inside a Soap Bubble

Every child learns to blow soap bubbles, but it's rare that we have a chance to look inside them and see the flow there. In this poster, researchers seed a growing bubble with olive oil droplets, then illuminate them with a laser.  (Image credit: S. Rau et al.) Read the full article

Miniature Ice Stupas

Ice stupas are conical artificial glaciers built with snow cannons; they're used to store water for spring irrigation. Here, researchers explore a miniaturized lab-grown version made from atomized water droplets.  (Image credit: D. Papa et al.) Read the full article

"Coat or Collapse?"

Imagine a layer of particles sitting at the interface between oil and water. Known as a granular raft, these particles can interact in interesting ways with other objects.  (Image credit: C. Gabbard et al.) Read the full article

"Shaken, Not Stirred"

James Bond notoriously orders his martinis "shaken, not stirred," a request bartenders fulfill by shaking the cocktail over ice in a separate shaker. But what if you shake the martini glass itself? That's the question that inspired this lovely mixology. (Image and research credit: X. Song et al.; submitted by Zhao P.) Read the full article

Serpents and Ouroboros

Beads of condensation on a cooling, oil-slicked surface have a dance all their own in this video. Large droplets gobble up their fellows as they follow serpentine paths; each new droplet donates its interfacial energy to feed the larger drop's kinetic energy.  (Video and image credit: M. Lin et al.; research credit: M. Lin et al.) Read the full article

Tracking Break-Up

In fluid dynamics, researchers are often challenged with complicated, messy flows. With so much going on at once, it's hard to work out a way to keep track of it all. Here, researchers are looking at the break-up of two colliding liquid jets.  (Video and image credit: E. Pruitt et al.) Read the full article