Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
“Kusho”
Artist Shinichi Maruyama uses photography to freeze the transient motion of fluids into water sculptures. Inertia, gravity, and surface tension are at war in each piece. Plateau-Rayleigh instabilities break long filaments of liquid into droplets that splash, collide, and reform. To see how he makes this art, check out his videos. (Photo credits: Shinichi Maruyama)
Grooving Bubbles
Here bubbles in a microchannel are subjected to an external ultrasonic acoustic field. Under the influence of this vibration, the bubbles self-organize into crystal-like structures with a fixed finite separation distance. Some bubbles cluster and contact. Some bubbles also pulsate in star-shaped vibration modes. When the external sound is turned off, the bubble crystal loses…
Microbubble Necklace
When a drop impacts a pool at very low velocity, a thin layer of air can be trapped between the drop and the pool. When this air film ruptures, a ring of microbubbles forms and expands. Multiple “bubble necklaces” can form if the film ruptures at several points. These rings travel outward until the film…
Leidenfrost Explosions
When a drop of water touches a very hot pan, it will skitter across the surface on a thin layer of water vapor due to the Leidenfrost effect. But what happens when another chemical is added to the droplet? Researchers find that adding a surfactant to the water droplets creates some spectacular results. As the…
APS Division of Fluid Dynamics 2012
Just a heads up that I’ll be at the annual American Physical Society Division of Fluid Dynamics meeting in San Diego starting this weekend. There are regular posts lined up, but additional supplemental posts may also go up in addition to plenty of Twitter updates.
Catastrophic Cracking from Cavitation
At your next party, you can break the bottom of a glass bottle with the palm of your hand and the power of fluid dynamics. As shown in the video above, striking the mouth of the bottle accelerates fluid at the bottom, lowering the local pressure below the vapor pressure and causing the formation of…
The Beauty of the Great Red Spot
Jupiter is home to one of the most famous storms in the solar system, the Great Red Spot, which Earth observations place at a minimum of 180 (Earth) years in duration. Some evidence suggests that it may have been observed by humans as early as 1665. The magnitude of such a storm is almost unimaginable.…
Jets from Hollows
Bubbles rising through a viscous fluid deform and interact. As they collapse into one another, the lower bubble induces a gravity-driven jet that projects upward into the higher bubble. The more elongated the bubble, the faster the jet. The same behavior is seen in the rebound of a cavity at the free surface of a…
Viscoelastic Jets
Unlike Newtonian fluids, such as air and water, viscoelastic fluids exhibit non-uniform reactions to deformation. In this video, researchers explore the effects of this behavior when a liquid jet falls into another fluid. When fluids move past one another at different speeds in this manner, there is a shearing force which often leads to the…
Dancing Droplet Clusters
When a fluid surface is vibrated, it’s possible to bounce a droplet indefinitely on the surface without the droplet coalescing into the pool. This is because each bounce of the droplet replenishes a thin layer of air that separates the droplet and the pool. If many droplets are added to the surface, as in the…