BDS wrote:
On May 21, 12:56 pm, Mxsmanic wrote:

Stealth Pilot writes:
aeroplanes fly because of lift generated by pressure differences on
the wing surfaces.
Airplanes fly because the wings divert the air through which they pass
downwards, creating a downwash and exerting a force in doing so that
engenders
an opposite force that is lift.

... these pressure differences are caused by the shape
of the aerofoil of the wing ...
The air is diverted because the wing has a positve angle of attack. It
can be
perfectly flat and it will still generate lift.

There is an interesting article in Flying magazine by Peter Garrison that
talks about lift theory.

I thought that one of the most interesting points he made was that the lift
force generated by an airfoil is greater at the optimum angle of attack than
would be the force imparted to it if you were to move it through the air
perpendicular to the air flow at the same speed.

I agree that a flat wing will produce lift at a positive AOA even without an
airfoil shape - it just won't be as efficient as it would otherwise be if it
were shaped like an airfoil, and talk about pitch divergent...

Oh yeah, the article also pretty much discounts Bernoulli as having anything
to do with why a wing produces lift.

BDS


Any article that "discounts Bernoulli" as having anything to do with
lift is incorrect. I just can't understand why there is so much trouble
in the pilot community understanding that Newton and Bernoulli do NOT
conflict in any way whatsoever, and that each explanation is correct in
itself. Newton AND Bernoulli are BOTH present simultaneously on th wing
at any moment lift is being created. EACH creates the other and EACH is
a complete explanation for how lift is created.

You can use either Newton or Bernoulli to explain lift, but the correct
way to explain it is to explain how both are correct.
In other words, anytime you have lift being created you have a Newton
explanation AND a Bernoulli explanation occurring at the SAME TIME!



--
Dudley Henriques