Flapping wings while running may have helped the evolutionary ancestors of birds develop flight. Experiments with modern birds show that flapping wings while running helps even flight-capable birds ascend slopes Keep reading
Month: September 2024
Rocket Diamonds
The exhaust of a Pratt and Whitney J58 shines with Mach diamonds, a series of shock waves and expansion fans that form to equalize the exhaust and ambient pressures. This Keep reading
Propeller Cavitation
Cavitation occurs in moving liquids when the local pressure–in this case, at the tip of the propeller–drops below the vapor pressure. The fast-moving fluid transitions to a gas phase, creating Keep reading
Tank Shock Waves
High-speed video of a tank firing at 18000 fps shows shock waves made visible due to light distortion. When the air density changes (due to temperature or compression), it’s index Keep reading
Shear-Thinning at Home
Shear-thinning isn’t just confined to canned whipped cream. It’s also a feature of such non-Newtonian fluids as ketchup, shampoo, latex paint, and blood. The NASA research on shear-thinning the video Keep reading
Liquid Rope Coiling
Some liquids, when falling in a stream into a pool, tend to coil into a liquid rope. This video shows honey, but the effect can also be observed in syrups Keep reading
Drafting Flags
Wired Science has published a gallery of fluid dynamics photos and videos, several of which have been featured here previously. There’s some neat stuff there, well worth checking out. # Keep reading
Stall-Sensing Hairs
Bats use tiny hairs on their wings to sense the direction and speed of air flow. Researchers found that removing these hairs caused bats to fly faster and make wider Keep reading
Solutal Convection
Solutal convection, rather than relying on temperature gradients, can occur due to gradients in concentration or in surface tension. While less spectacular than this previously posted video, this video contains Keep reading
Beluga Whale Bubble Rings
Beluga whales and dolphins in captivity have taken to blowing bubble rings to entertain themselves. You can learn how to do the same in the pool. #