Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Draining Soap Film
The brilliant colors of a soap film are directly related to the film’s thickness. Black regions, like the one in the upper right of this image, are the thinnest regions and may be less than 100 nanometers thick. (That’s smaller than the shortest wavelength of visible light!) The colors of the peacock-feather-like blooms along the…
APS DFD 2015
Heads-up for those coming to Boston for APS DFD 2015. I’m giving a talk about FYFD and outreach Sunday evening at 5:16pm in Room 102. I’ll also be around the conference all weekend, so hopefully I’ll see you around. Also, I have FYFD stickers, but you have to come talk to me to get one! (Image…
Oil Film on Water
This award-winning short film features a thin layer of volatile oil on water. The oil evaporates quickest from shallow pools only microns deep, which appear bluish in the video. Surface instabilities along the edge of the pool create flow that draws oil in, generating the iridescent droplets seen floating among the evaporation pools. The droplets…
Jovian Belts and Zones
Jupiter’s colorful cloud bands alternate between dark belts and light zones. The bands mark convection cells in Jupiter’s atmosphere, and, like on Earth, powerful jet streams form due to this atmospheric heating and the planet’s rotation. The jet winds can even move in opposite directions, creating strong shear forces between neighboring cloud bands. The shear…
From Dripping to Beading
When water drips, it quickly breaks up into a string of smaller droplets due to a surface-tension-driven instability called the Plateau-Rayleigh instability. But adding just a tiny bit of polymer to the fluid changes the behavior entirely. Instead of breaking into droplets, a narrow filament dotted with tiny satellite droplets forms between the larger drops.…
Trampolining Droplet
Imagine a droplet sitting on a rigid surface spontaneously bouncing up and then continuing to bounce higher after each impact, as if it were on a trampoline. It sounds impossible, but it’s not. There are two key features to making such a trampolining droplet–one is a superhydrophobic surface covered in an array of tiny micropillars…
Science Hackathon
Just a heads-up that I’ll be at Brown University tomorrow giving a talk and then helping out with a science visualization hackathon. I’m super excited for the opportunity to have some hands-on flow visualization fun with folks! The lecture is public, but I think only Brown students can register for the workshop.
Ignition
Shown here are the first instants after a bubble full of methane gas is ignited via laser. Using the schlieren optical method and a high-speed camera, scientists recorded the deflagration at 10,000 frames per second. Because schlieren imaging is very sensitive to small changes in density, we see not only the expanding flame front as…
The Droplet Slide
One of the joys of science is the sense of discovery that can come even from looking at something seemingly simple. Take, for example, a water droplet sitting on a plate. If you slowly tilt the plate, the droplet’s shape will shift until a critical angle where it starts sliding down the plate. But what…
Viscous Fingers
Take a viscous fluid, like laundry detergent, and sandwich it between two plates of glass. Fluid dynamicists call this set-up a Hele-Shaw cell. If you then inject a less viscous fluid, like air, between the plates–or if you try to pry them apart–you’ll see a distinctive pattern of dendritic fingers form. This viscous fingering, also…