Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Updating Undergraduate Heat Transfer
For many engineering students, their first exposure to fluid dynamics comes in a heat transfer class. The typical focus in these classes is not on the underlying physics but on learning to use empirical formulas and correlations that are used in engineering heat exchangers, computer fans, and other applications. As part of this, students are…
“Focus, Vol. 2”
This short film from photographer Roman De Giuli focuses on ethereal and abstract fluids. What you’re watching is primarily paint, with a little in the way of flow additives. There’s lovely marbling and some impressively sharp edges, but mostly you can just sit back and enjoy the flow! (Image and video credit: R. De Giuli)
The Naruto Whirlpools
Enormous whirlpools are not simply the work of overactive imaginations. There are several spots in the world, including Japan’s Naruto Strait, that regularly see these spectacular vortices. Naruto’s whirlpools are formed through the interaction of tidal currents with the local topography. Spring tides funneled through the vee-shaped strait can reach speeds of 20 kph as…
Fractal Flame Propagation
Hydrogen is a promising alternative to carbon-based fuels, but it comes with its own special challenges. Hydrogen gas is extremely flammable, including under circumstances that would normally quench flames, as shown in this recent study. What you see above are water condensation patterns left behind after the passage of hydrogen flames through a narrow gap…
Bubble Dynamics Govern Faster Pouring
We’re all familiar with the problem of pouring a liquid from a narrow-necked bottle. To a certain extent, tilting the bottle further will reduce the time it takes to empty, but if you tilt too far, your smooth pour becomes violent glugging as bubbles forming at the bottle’s mouth block liquid from exiting. Researchers find…
Aerosol Transport
NASA Goddard has produced another gorgeous visualization of how various aerosols move around our world. This visualization is constructed from data collected between August 2019 and January 2020, which means that it captures numerous typhoons as well as the extreme bushfires that occurred in Australia. Different colors represent different aerosol sources: carbon (red), sulfate (green),…
Building Ferrofluid Sculptures
Eric Mesplé is an artist, but he’s also a blacksmith, welder, programmer, engineer, and innovator. Many of his sculptures feature ferrofluids, magnetic liquid whose movement is driven by electromagnets Mesplé designs and builds himself. In this video from Wired, we get a behind-the-scenes look at some of his work, and to me, one of the…
Studying Active Polymers Using Worms
I’ve covered some odd studies in my time, but this might be the strangest: to understand how active polymers affect viscosity, researchers loaded drunk worms into a rheometer. Active polymers are long-chain molecules that, like worms, can move on their own using stored energy or by extracting energy from their surroundings. Their dynamics are tough…
Colorful Tides
This false-color satellite image — the recent winner of NASA Earth Observatory’s Tournament Earth 2020 — shows sands and seaweed off the coast of the Bahamas. Ocean currents and tides eroded these elaborate fluted designs in much the same way that winds sculpt desert dunes. The overlap in form is no accident; as seen in…
Growing Metal Fingers
Eutectic gallium-indium alloy is a room-temperature liquid metal with an extremely high surface tension. Normally, that high surface tension would keep it from spreading easily. But once the metal oxidizes, the surface tension drops. When that oxidation is combined with an electric field, the metal spreads into fingers. The higher the voltage, the more complex…