- Profile
Turbulent Volcanic Plumes
Volcanic eruptions produce some of the largest flows on Earth. These towering ash clouds were imaged from orbit in May 2017 as an eruption began on Alaska’s Bogoslof Island. The clouds are a beautiful example of a turbulent flow. Turbulence is characterized by its many length scales. Some features in the plume are tens or…
Microfluidic Chips in Action
Earlier this year, The Lutetium Project explored how microfluidic circuits are made, and now they are back with the conclusion of their microfluidic adventures. This video explores how microfluidic chips are used and how microscale fluid dynamics relates to other topics in the field. Because these techniques allow researchers very fine control over droplets, there…
Resisting Coalescence
When a droplet falls on a pool, we expect it to coalesce. There are exceptions, like bouncing droplets, but in general a droplet only sticks around for a split second before being engulfed. And yet, from morning coffee (top image) to walks in the woods, we frequently see millimeter-sized droplets sticking around for far longer…
Liquid Sculptures
With patience and timing, one can create remarkable sculptures with fluids. To capture this shot, Moussi Ouissem used two droplets, perfectly timed. The first fell through the soap bubble (which stayed intact thanks to its powers of self-healing) and hit the pool of water. The impact caused a cavity, which then inverted into a Worthington…
Stopping a Bounce
One way to damp a bouncing ball is to partially fill it with a fluid (a) or granular material (b). For the fluid, the initial impact sloshes the liquid. That doesn’t change the trajectory of the initial bounce noticeably, but it interferes with the second impact, drastically damping the rest of the ball’s bounces until it comes…
Plate Tectonics
We don’t typically think of the ground beneath our feet as anything but solid, but over geologically long time scales, even mountains can flow. Buoyant convection inside the Earth’s mantle is thought to drive the plate tectonics that have shaped the Earth as we know it. The video above explains some of the major processes…
“Monsoon IV”
It’s a cliché to claim that the sky is bigger in the American West, but the wide, open views in that region do offer a very different perspective on weather. Photographer Mike Olbinski’s works give viewers a taste of that perspective of far-off thunderstorms, towering anvil clouds, and massive downpours in the distance. At the…
Revealing Stress
What goes on inside of a granular material like sand when an object moves through it? Individual grains will shift and may impact one another or simply slide past. Researchers use special photoelastic materials to see these forces in action. A photoelastic material responds to changes in stress by polarizing light, revealing areas of stress…
Blowing Bubbles in Space
Blowing bubbles in your fruit juice is a bad idea when you’re in space, as astronaut Jack Fischer demonstrates. On Earth, gravity dominates water’s behavior, except when things are very small. But in microgravity, a liquid’s other characteristics become more obvious. Adhesion between the straw and juice guides it up and onto Fischer’s face. Surface tension is…
APS DFD 2017
This year’s American Physical Society Division of Fluid Dynamics meeting starts this Sunday. I have a couple events scheduled: – Student Lunch, Monday, November 20, 12:55-13:45 (sold out) – FYFD: Getting started in science communication, Monday, November 20, 16:44-16:57, Four Seasons Ballroom Yes, the ballroom! If you’ve ever struggled to get into an FYFD talk,…