Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Microfluidic Legos
Microfluidic devices are valuable tools in a lab, but they are difficult and time-consuming to manufacture. Researchers looking to simplify the building of such fluidic circuits have turned to toys. The uniformity and modularity of LEGO bricks makes them a promising platform for modifiable microfluidics. Using a micromilling machine, researchers cut narrow channels into bricks,…
Scallops and Erosion
Although we often think of solids as immovable in the face of flow, the motion of air and water sculpts many parts of our world. One common pattern, seen both on surfaces that melt and those that dissolve into a flow, is called scalloping. Mathematical analysis shows that flat surfaces exposed to a flow that…
“Breathe”
In black and white, the towering power of a thunderstorm looks almost apocalyptic. Photographer Mike Olbinski’s latest storm timelapse, “Breathe,” features roiling turbulence, distant downpours, and eerie mammatus clouds. Supercell thunderstorms churn and rotate over empty horizons. Billowing cumulus clouds condense from bright skies. Flashes of lightning reveal the outlines of massive thunderheads. It’s a beautiful…
In the Eye of a Hurricane
Although eyes are common at the center of large-scale cyclones, scientists are only now beginning to understand how they form. Since real-world cyclogenesis is complicated by many competing effects, researchers look at simplified model systems first. A typical one uses a shallow, rotating cylindrical domain in which heat rises from below. The rotation provides a…
Jumping Larvae
Gall midge larvae, despite their lack of legs, are prodigious jumpers. These worm-like creatures use hydrostatic pressure to jump more than 30 body lengths. To do so, the larva curls itself into a loop, latching its mouth to its tail. It then shifts the fluids inside its body, flattening itself as the pressure builds. When…
Withstanding Windstorms
Saguaro cacti can grow 15 meters tall, and despite their shallow root systems can withstand storm winds up to 38 meters per second without being blown over. Grooves in the cacti’s surface may contribute to its resilience, by adding structural support and/or through reducing aerodynamic loads. The latter theory mirrors the concept of dimples on…
Water Walking, Exploding Droplets, and Colliding Vortices
Every year I look forward to the APS DFD conference in November. It brings thousands of researchers together to share the latest in fluid dynamics. So much goes on in those three days that it’s impossible to capture, but last year I teamed up with Tom Crawford and the Journal of Fluid Mechanics to attempt just…
An Armored Bed
A river’s flow constantly changes its underlying bed. The rocks and particulates beneath a flowing river can typically be divided into two zones: an upper layer called the bed-load zone where the flow moves particles with it and a lower layer where particles are mostly trapped but may creep over long periods. In gravelly river-beds…
Juno’s Citizen Science
The Juno mission’s JunoCam has been producing stunning photos each time the spacecraft swoops past Jupiter. The instrument has a planning team, but its primary use is for citizen scientists, who have been suggesting images to take each orbit and have been processing those images. Most of the photos we see are like the one…
The Foggy Grand Canyon
On occasion in the late fall and early winter, the Grand Canyon can fill with clouds of fog. This occurs when a layer of warm air traps cold, moist air inside the canyon, creating what’s known as a temperature inversion. The trapped air’s moisture condenses into fog, creating the appearance of a cloud sea lapping…