Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Crown Splash Sealing
A sphere falling into water generates a spectacular crown splash at the surface. The object’s impact ejects a thin sheet of fluid that rises vertically. The air pulled down into the cavity by the sphere’s passage makes the air pressure inside the sheet lower than the ambient air pressure on the exterior of the sheet.…
Auroras From Space
NASA has released a jaw-dropping new compilation of Earth’s auroras viewed from the International Space Station. It’s available in up to 4K resolution, and I heartily recommend watching it fullscreen at the highest resolution you can comfortably manage. (To paraphrase: this is ultra high definition – it’s better resolution than real life!) I don’t think…
Pinning a Drop
The shape of a droplet sitting on a surface depends, in part, on its surface tension properties but also on the nanoscale roughness of the surface. Small variations in the height and shape of the surface will change the area a drop contacts as well as the contact angle the edge of the drop makes…
Shock Waves in Flight
This week NASA released two new images of the shock waves surrounding T-38C jets in free flight. They’re the result of NASA’s new adaptations of the schlieren photography technique, which has let scientists visualize shock waves (in the lab, at least) for more than a century. To celebrate, I thought it would be fun to…
Fluids Round-up
Time for another look at some of the best fluids content out there. It’s the fluids round-up – with a special focus this week on oceans! – Ryan Pernofski spent two years filming the ocean in slow motion with his iPhone to make the short film “Slowmocean” seen above. It’s a gorgeous ode to the beauty…
The Brazil Nut Effect
The Brazil nut effect is a common name for the phenomenon where large particles tend to rise to the top of a mixture when it’s shaken. It’s also the subject of the latest FYFD video, which you can see above. I’ve seen other mentions of the topic previously, but when I started researching the literature,…
Upcoming Webcast
This weekend I’ll be holding my second live webcast for FYFD patrons. This month we’ll be focusing on the subject of planetary science, one of the coolest applications out there for fluid dynamics. My guests will be Keri Bean, a NASA JPL mission operations engineer and atmospheric scientist, and Professor Geoffrey Collins, a geologist at…
Plasma Flow Control
Engineers frequently face the challenge of maintaining control of air flow around an object across a wide range of conditions. After all, wind turbines and airplanes don’t always get to choose the perfect weather. To widen their operating ranges, designers can use active flow control to keep air flowing around an airfoil instead of separating…
Bonbon Coatings
If you’ve ever bitten into a chocolate-covered bonbon, you may have noticed that the candy’s chocolate coating is remarkably uniform. Inspired by this observation, a group of engineers have investigated how viscous fluids poured over a curved surface flow and solidify; their findings were published this week. Rather than heated chocolate, the group used polymer-filled…