Airplane Pilot's As Physicists

Uncle Al wrote in
:

Le Chaud Lapin wrote:

Hi All,

There is a long discussion ongoing in rec.aviation.piloting about
what causes lift on a plane. You can read from the link below.
Please note that about 80% of the post are mostly ad hominem attacks
and should be ignored. There are some small bits of real discussion.


http://groups.google.com/group/rec.a...wse_frm/thread
/b85a49e900a0c791/bb11fa289cd7864a#bb11fa289cd7864a

I am an electrical engineer with experience in analag design and
software, with math and physics background that you would expect of
an electrical engineer.

There are many points made in the discussion, but I would like to
focus on one in particular for the sake of progress.

There are people in the pilot's group, who think that lift on a wing
is analyzed as such:

1. There is air on outside of top of wing that is pushing down, but
reduced because of aerodynamics.
2. The *inside* of the wing contains air pushing up against the
underside of top of wing .
3. Let us ignore that the same air inside the wing pushes down on the
overside of bottom part of wing.
3. The difference in pressure against the underside of the top wing
on the inside of wing and top of wing on outside, is what gives plane
lift.

Note that they ignore the pressure inside the wing that pushes
downward on the wing.

I am trying to convince them that, if there is air on the inside of
the wing, it pushes against all sides of the inside of the wing,
including both top underside and bottom overside, and thereby
nullifying any effect it would have on the wing. Lift is caused by a
difference in pressure between the underside of the bottom of the
wing, and the overside of the top of the wing.

I count 8-9 people in the group who are utterly convinced that I am
inept at physics, mathematics, etc.

Note that some of these people have been flying aircraft for years,
even decades, while I am still a student pilot.

Comments from anyone who knows physics welcome.

1) Acrobatic airplane wings are essentially symmetric in
cross-section. They fly equally well rightside-up or inverted. Angle
of attack is important.

2) Bernoulli's law is strictly a 2-D analysis.

3) Dr. Penelope Smith rigorously derived vortex shedding is a major
lift component in 3-D. Don't be Cessna behind a jumbo.


Wow, you are a cut and paste genius Anthony.


Bertie