Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Swirling Fluids
In this video, researchers investigate swirling fluids by studying the shapes of the free surface between air and the liquid. As parameters like the diameter of the glass, initial (unperturbed) height of the liquid, and angular velocity of the rotation change, the surface of the liquid displays different modal behaviors, seen in the photos on…
Surf’s Up
Diffusion of ink in water + Lego minifigs = an awesome example of fluid mechanics as art. (Photo credit: Alberto Seveso; via io9; thanks to Jennifer for the link!)
Reader Question: Creeping Flow
[original media no longer available] David asks: I’m taking an undergraduate fluid dynamics course, and I’m having trouble understanding what a Creeping Flow exactly is. The only thing I understand about that is that the Re should be 0 or close to 0 for the flow… Could you post an example of a creeping flow…
Reynolds Stress
[original media no longer available] From reader jessecaps who hung it on the office door. I expect this joke will make sense to very few but as someone who once dabbled in turbulence, I could not resist.
Particle Patterning
Here a container filled with a suspension of neutrally buoyant polystyrene beads and fluid is rotated. As the container rotates, a thin layer of fluid and bunches of particles get drawn up onto the wall by capillary forces capable of holding the particles in place even if the container stops rotating. The density and patterning of…
Science off the Sphere: Thin Films
Stuck here on Earth, it’s hard to know sometimes how greatly gravity affects the behavior of fluids. Fortunately, astronaut Don Pettit enjoys spending his free time on the International Space Station playing with physics. In his latest video, he shows some awesome examples of what is possible with a thin film of water–not a soap film…
Soap Film Breakup
This high-speed video shows a soap film formed across two rings and its deformation and breakup as the two rings are pulled apart. As the rings get further apart, surface tension deforms the soap film until the distance is too great to continue sustaining that shape. The film breaks into two–a sheet of soap film…
Colliding Jets
Two jets colliding can form a chain-like fluid structure. With increasing flow rate, the rim of the chains becomes wavy and unstable, forming a fishbone structure where droplets extend outward from the fluid sheet via tiny ligaments. Eventually, the droplets break off in a pattern as beautiful as it is consistent. (Photo credits: A. Hasha…
Examples of Flutter
Aeroelasticity is the study of the interaction of structural and aerodynamic forces on an object, and its most famous example is flutter, which occurs when the aerodynamic forces on an object couple with its natural structural frequencies in such a way that a violent self-excited oscillation builds. What does that mean? Take a look at the…
Vortices on an Airliner
Wingtip vortices form on airplanes due to the finite length of their wings. In general, lift on the wings results from low-pressure, high-velocity air moving over the top of the wing and high-pressure, low-velocity air moving below the wing. Near the wingtips, the high-pressure air is able to slip around the edge to the top…