What Bernoulli Missed About Flight

GrokSoup writes: "How come planes can fly upside-down? The Bernoulli principle as applied to flight -- air moves faster over the top of the wing creates low pressure, sucking the plane upward -- always bugged me because it didn't explain inverted flight. Turns out I'm not the only one. The current New Scientist has an entertaining interview with Fermilab physicist David Anderson who explains why the Bernoulli explanation is only partial: lift from wing-shape is the least significant component of lift. Much more important is the wing's angle of attack."

Comments

This is an old debate/flamewar

[K-Man]

People have debated this on the net for years, and not without reason. The bernoulli effect got put into textbooks years ago, and everyone was convinced that a wing cross-section was some magical shape that produced lift without drag, or with little drag, and that simpler shapes, like a fan blade, simply didn't have the right stuff to hold up an honest-to-goodness airplane.

The truth is much simpler. Aircraft stay up by accelerating air downwards. The viscosity of air allows it to be pushed down by a flat object held at a positive angle of attack. Any such object will have a net difference in pressure between its top and bottom, referred to as lift (and drag). Making the wing teardrop-shaped makes the flow more laminar and reduces drag, but that's really just streamlining.