Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
New Signs of Turbulence in Blood Flow
Our bodies are filled with a network of blood vessels responsible for keeping our cells oxygenated and carrying away waste products. In many ways, our blood vessels are tiny pipes, but there’s a crucial difference in the flow they carry: it’s pulsatile. Because the flow is driven by our hearts, rather than a continuous pump,…
Seeping Sculptures
Drips, blobs, and squishes – that’s how artist Dan Lam describes her recent series of sculptures. The pieces are a mix of polyurethane foam, resin, and acrylic, decorated in bold gradients of neon color. I love the fluidity of each piece, as well as the decorative piping of spikes on many of them. (As a…
Aerodynamic Flight Testing
Flight testing models has a long history in aerodynamics. Above you see a Curtiss JN-4 biplane in flight with a model wing suspended below the fuselage. This test was conducted circa 1921 by NASA’s predecessor, NACA. At the time, of course, computational simulations were non-existent, and, although wind tunnels existed, presumably they could not recreate…
Particle-filled Splashes
Adding particles to a liquid can significantly alter its splash dynamics, as shown in this new study. In the first image, a purely-liquid droplet spreads on impact into a thin liquid sheet that destabilizes from the rim inward, ripping itself into a spray of droplets. At first glance, the particle-filled droplet in the second image…
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…