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> Well. I can't add to the Bernoulli discussion because it's over 30 days
> old or has been closed by the moderator. (Remove it from the list,
> then). And someone tell us how to explain how circulation induces lift
> to a budding pilot. Bernoulli is easier to understand and demonstrate.
> Oh, yeah, FWIW, a supercritical wing produces lift because it's at an
> angle of attack, just like a symmetrical or plane surface airfoil is to
> develop lift. And if in ground effect, lift is still developed but
> because circulation is limited by the presence of the earth's surface
> below the wing, less drag is experienced, hence 'float' is experienced.
A point to consider. Only the flow in the boundary layer is
constrained to follow the exact profile of the airfoil, and that only
when there is no seperation. Smoke tunnel photographs show that flow
at reasonable distances from the airfoil surface for a symmetrical
airfoil do not look unlike those for a non-symmetrical airfoil.
Unfortunately, there IS no simple explanation of the effect of airfoil
camber without getting into advanced fluid mechanics and differential
equations. I liked the explanation of a former sci.aero moderator,
Mary Shafer- action of the "lift daemons". It is the only thing
understandable without getting really into the nitty-gritty of fluid
dynamics.
This is true for any situation where viscous flow dominates. At low
enough air density where the mean free path becomes a sizeable portion
of the airfoil chord, things change, momentum flow can give a good
approximation of lift. But no airplanes except the shuttle fly in this
regime.
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