Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Sandsculpting Bees
Building sandcastles is more than a pastime for the bumblebee-mimic digger bee. This species of bee collects water into an abdominal pouch, then uses it to wet sand to help her sculpt her nest. She’ll use the material she digs out to create a protective turret over the nest’s entrance, and once her eggs are…
Candy Clouds Mid-Storm
There’s nothing quite like a towering storm cloud to showcase nature’s power. This gorgeous photo by Laura Rowe shows pastel clouds over West Texas in the middle of a thunderstorm. Despite the dusk at ground level, the height of the cloud keeps it lit by direct sunlight, giving its turbulent convection that colorful glow. Rowe,…
Hydrodynamic Spin Lattices
Droplets bouncing on a fluid bath display some strikingly quantum-like behaviors thanks to the interactions between a drop and its guiding surface wave. Here, researchers use submerged wells beneath the drop to confine each droplet into a space where it bounces in a clockwise or anticlockwise trajectory. With an array of these wells, the droplets…
Breaking Up Is(n’t) Hard to Do
Engineers often need to break a liquid jet up into droplets. To do so quickly, they surround the jet with a ring of fast-moving air in a set-up known as a coaxial jet. Shear between the gas and liquid creates instabilities that quickly distort the jet’s initial cylinder into sheets and ligaments. Those formations then…
Keeping Cool in the Cretaceous
I love that fluid dynamics can bring new insights to other subjects, like this study on how heavily-armored ankylosaurs avoided heat stroke. Scans of ankylosaur skulls show a complicated, twisty nasal cavity that researchers likened to a child’s crazy straw. Using numerical simulations, they showed that the airflow through these passages acts like a heat…
Flying Out of the Water
Flying fish and diving birds often navigate the interface between water and air in their flight, but few studies have actually looked at the effects of this transition on lift. In this work, researchers measured forces on a small, fixed wing as it egresses from water into air at a constant velocity. The tests showed…
“Kármán Vortex Street”
Although engineers often consider fluid mechanics through the lens of mathematics, that’s far from the only way to understand fluid physics. Today’s video is an alternative interpretation of a classic flow — the flow around a cylinder — created in a collaboration between dancers and engineers. The result is what they call a “physics-constrained dance…
Moths in Flight
As student engineers, we often use fixed-wing aircraft to build our intuition for flight, but nature has so many other incredible examples to offer. Here we see high-speed video of seven different moth species taking off, and understanding fixed-wing flight won’t help you here at all! These moths have small, rough, and incredibly flexible wings…
Microjets and Needle-Free Injection
Some people don’t mind needles, and others absolutely detest them. But to replace needles with needle-free injections, we have to understand how high-speed microjets pass through skin. Given skin’s opacity, that’s tough, so researchers are instead using droplets as a model. If we can understand the dynamics of a microjet passing through different kinds of…
Whiffling Geese
This wild photograph shows a goose flying upside down with its head turned 180 degrees in a behavior known as whiffling. In this orientation, the bird’s typical lift characteristics are reversed, but as you can see in the video below, this doesn’t exactly make them fall out of the sky. I suspect the geese compensate…