simonhadjaje
- Reposted by simonhadjajeRipple bugs use a special fan-like structure on their middle legs to speed and steer through turbulent waters. In a new Science study, researchers report a water-walking robot inspired by this feature. Learn more in our latest issue: scim.ag/3V8FjDU
- Reposted by simonhadjajeNew paper in PLOS Biology: as we raise the difficulty of our 3D printed puzzles, bees keep landing on combs with ever stranger hexagonal order! 🐝 Led by the brilliant Golnar Gharooni Fard, in collaboration with CK Prasanna & FL Jiménez journals.plos.org/plosbiology/...
- 🚰 Fluid inertia limits microporous flow efficiency, out in EPJ Plus this week, with Kaare Jensen @jensen-research.bsky.social rdcu.be/eBV2C 👇
- Even if you reduce viscous drag with optimal geometry or special coatings, you still need to accelerate the fluid through the pore. That acceleration -- fluid inertia -- sets an upper bound on flow efficiency through micropores
- Inertial correction to viscous drag along a pore length (Hagen-Poiseuille) are well studied; but this effect at the pore entrance (Sampson resistance) has received little attention, for example in work on end corrections for long pipes a century ago (Johansen Proc. R. Soc. A 1930)
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View full threadWant to know if inertia matters in your system? 🤓Compute the transition pressure pt and compare ΔP/pt: • If <1 → inertia negligible • If >1 → big efficiency loss Ex: 💧through a pore of square aspect ratio h/a=1 of radius… 1️⃣ 10 nm pore @30 bar → safe; 2️⃣ 10 µm pore @30 kPa → ~70% lost!
