The Impossibility of Flying Heavy Aircraft Without Training

Jose wrote:
I don't think leaving out density changes leaves out very
much that's relevant to lift, but I have to admit to not
being sure exactly what question this discussion is trying
to answer, so I'll hold off any comment.

The question was whether Bernoulli (did I get it right?) supersedes
Newton.

Maybe I mised something becuase I did not see that particular question
posed.


I maintain that, while Bernoulli's equations are very useful,
they obscure something Newtonian about the source of the force. If you
have lower pressure above and higher pressure below, you get lift. But
you can't get to that condition without throwing air down.

No, you can throw it horizontally.

...
Globally, because of the earth's surface, there is no net downflow
during steady state flight. (I believe that's the point you want me to
concede - I do concede that point).

Dunno about him, but that has been my point.
....

So if I understand this, you are saying that if air were
incompressible, there would be no lift?

No. If air were truely incompressible, there would be no downflow at
all; the entire earth would be pushed away just as it does when I jump.


If the Earth is pushed away, wouldn't that stretch out
the air molecules between the plane and the Earth decreasing
the pressure below the wing?

--

FF

No, you can throw it horizontally.

.... where it throws the air in the way down to get it out of the way.
Why down? Because the wing is going up, and below is where the (new)
room is.

If the Earth is pushed away, wouldn't that stretch out
the air molecules between the plane and the Earth decreasing
the pressure below the wing?

Not if the air is truly incompressible. There would be more air
molecules between the wing and the earth because the wing is up there
and not down here.

Jose
--
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