Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Sedimentary Swirls
Local currents swirl sediments and phytoplankton blooms in this satellite image of the Tarut Bay in Saudi Arabia. Such blooms typically occur where nutrients are being washed together, thereby creating a kind of natural flow visualization of currents and matter flow in the ocean. (Photo credit: NASA Earth Observatory)
Foam Array
Soap foams represent an interplay of gravitational, capillary, interfacial, and viscous forces, none of which is easily isolated in a laboratory experiment. This makes it difficult to sort out the various effects governing the foam since individual variables cannot be controlled independently. The image above is of a special foam, one in which the liquid phase…
Drop-Tower Droplets
A microgravity environment can cause some nonintuitive behaviors in fluids. Many of the effects that dominate fluid dynamics in space are masked by gravity’s effects here on Earth. As a result, it can be very difficult to predict how seemingly straightforward technologies like heat exchangers, refrigeration units, and fuel tanks will behave. The photos above…
Levitation By Sound
Levitation is an effect usually associated with electromagnetic forces, but it’s possible with sound as well. This acoustic levitation is achieved by using the pressure from sound waves to balance gravity’s effect. By manipulating the sound, it’s possible to bring separate objects together while continuing to levitate them. The behavior is demonstrated in the video…
Super-Highway Convection
In the ocean, many forces compete in driving convection, including the temperature and salinity of the water. In the laboratory, it’s possible to mimic these characteristics of oceanic circulation using two different fluids driven by temperature and concentration differences. Recently, researchers were exploring this problem–with the added twist of tilting the fluids ~1 degree–when they…
Fluids Round-up – 13 July 2013
Prepare yourselves for lots of links in today’s fluids round-up! Longtime FYFD favorite Mark Stock (see here, here, and here) and his collaborator James Susinno have unveiled a new interactive art piece, “Everything is Made of Atoms” that utilizes some impressive real-time fluids simulation. NVIDIA’s blog has some details on the computing. ScarbsF1 takes a detailed look at the F-duct used to stall an F1 car’s…
Fire-Breathing Physics
One of the most dangerous stunts for any fire-eater is breathing fire. Dr. Tim Cockerill explains some of the science behind the feat in this video. Volatility–the tendency of the liquid fuel to vaporize–is actually the enemy of a fire-eater. Use a fuel that is too volatile and it will catch fire too easily when…
Flow Around a Complex Airfoil
Flow around an airfoil with a leading-edge slat is visualized above. At this Reynolds number, alternating periodic vortices are shed in its wake. Understanding how multi-element airfoils and control surfaces affect local flow is important in controlling aircraft aerodynamics. When multiple instabilities interact–like those in the wing’s boundary layer interacting with the wake’s–it can generate…
Water Entry
In the image above we see two spheres of the same size, shape, and material being dropped into water. The left sphere has almost no splash, whereas the one on the right has a spectacular curtain-like splash. Why the big difference? It all comes down to the surface treatments. The glass sphere on the left…
“Adrift”
Sometimes the time scales of a flow can mask its similarities to other flows. Simon Christen’s “Adrift,” a video of timelapsed fog in the San Francisco Bay area, shows just how these low clouds undulate and flow over the land the way a stream of water flows over and around stones. From the flow of…