the.com/propeller blade
A twisted wing that screws itself through air or water for a living.
means One of the angled, twisted arms of a propeller, which pushes against air or water to drive a boat, plane, or drone forward.
from 'Propeller' comes from Latin propellere — 'pro' (forward) plus 'pellere' (to drive or push) — the same root that gives us 'repel' and 'compel.' It entered English in the 1700s–1800s for anything that drives something forward, then attached itself specifically to the spinning screw-like devices developed for ships and later aircraft. 'Blade' is older and homegrown, from Old English 'blæd,' originally meaning a leaf or a flattened part of a plant before it came to describe the flat edge of a sword, an oar, or — once engineers needed a word for it — the twisted fin of a propeller.
- shape secret
- each cross-section is a tiny airfoil, like a wing
- twist purpose
- blade twists so tip and root push equally
- failure mode
- cavitation can chew metal blades into lace
- count tradeoff
- more blades mean smoother thrust but less efficiency