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0 pointshbk19669y ago0 comments

No, the effect is negligible if it wasn't planes wouldn't be able to fly upside down. It's the pitch of the wing that generates most of the lift. That's why helicopters don't alter the rotor RPM they adjust the pitch of the blades to take a larger bite.

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foldr9y ago

The poster wasn't talking about the 'curved upper surface' myth. You can understand the lift to be a consequence of the pressure differential, and that is not inconsistent with planes flying upside down.

usrusr9y ago

And the pitch of the wing causes one side of the wing to be hit harder by air molecules than the other, just like GP said. Maybe you hit reply on the wrong post?

jabl9y ago

The 'air molecules impinging on the airfoil' theory of lift is not wrong, but does not account for a large fraction of the lift generated either. In a dense enough medium such as air at normal flight altitudes, you have to take into account how those air molecules interact with other air molecules and not only the airfoil. Sum up all those interactions, and you get fluid dynamics rather than a molecule hitting a surface in vacuum.

Retric9y ago

Fluid dynamics is a useful, but simplistic model. It's not actually true, but can accurately model truth.

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