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Old September 17th 05, 05:34 PM
Peter Duniho
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Thanks Roger...good post. I do have to nitpick one little thing:

"Roger Long" wrote in message
...
[...] Because of the symmetries required by conservation of energy, the
pressure differential will be equal to the weight of the aircraft.


Two problems:

1) Pressure is measured as a force over area. Pounds per square inch, for
example. Lift is measured as a force. The two cannot be "equal"...they
aren't the same kind of measurement.

2) Perhaps you meant to say that the pressure differential will be equal to
the weight of the aircraft divided by the area of the wing. However, that's
only true during unaccelerated flight. The airplane regularly is flown so
as to create more or less lift than the weight of the airplane; it's an
essential component of maneuvering.

None of this, however, takes away from your nice way of presenting in a
simplified way, why it is that the air speeds up over the top of a wing.

Pete