Backwash Causes Lift?

Phil wrote in news:1191952801.357185.176540
@r29g2000hsg.googlegroups.com:


Le Chaud Lapin wrote:
If you
don't like the concept that the top of the wing is being sucked upward
by that lower pressure

It is not a matter of whether I like it or not. It is something that
simply does not happen. There is no sucking force.

then think of it this way. Imagine a cross-
section of the wing. The top surface of the wing forms a line. The
air just above this line has lower pressure. The air below this line
(inside the wing) has normal pressure.

So the air below the line is
pressing upward against it with more force than the air above is
pressing down.


I think you mis-understood me here. When I say the air below the line
is pressing upward, I am not referring to the air pressing upward on
the bottom of the wing. I am referring to the air _inside_ the wing
pressing upward on the underside of the top surface of the wing. The
air above the wing top surface has lower than normal pressure. The
air inside the wing has normal pressure. So it presses upward on the
top surface of the wing. This is lift generated by the top surface of
the wing.


What if your wing doesn't have any air in it?

Bertie

On Oct 9, 1:03 pm, Bertie the Bunyip wrote:
Phil wrote in news:1191952801.357185.176540
@r29g2000hsg.googlegroups.com:







Le Chaud Lapin wrote:
If you
don't like the concept that the top of the wing is being sucked upward
by that lower pressure

It is not a matter of whether I like it or not. It is something that
simply does not happen. There is no sucking force.

then think of it this way. Imagine a cross-
section of the wing. The top surface of the wing forms a line. The
air just above this line has lower pressure. The air below this line
(inside the wing) has normal pressure.

So the air below the line is
pressing upward against it with more force than the air above is
pressing down.

I think you mis-understood me here. When I say the air below the line
is pressing upward, I am not referring to the air pressing upward on
the bottom of the wing. I am referring to the air _inside_ the wing
pressing upward on the underside of the top surface of the wing. The
air above the wing top surface has lower than normal pressure. The
air inside the wing has normal pressure. So it presses upward on the
top surface of the wing. This is lift generated by the top surface of
the wing.

What if your wing doesn't have any air in it?

Bertie- Hide quoted text -

- Show quoted text -

It will still fly, of course. If you talk about the upper wing
surface as a solid, with the air inside the wing under it, or if you
talk about the whole wing as a solid with air under it, the principle
is the same. You have lower pressure above the wing, and it
contributes lift.

Phil wrote in
ups.com:

On Oct 9, 1:03 pm, Bertie the Bunyip wrote:
Phil wrote in news:1191952801.357185.176540
@r29g2000hsg.googlegroups.com:







Le Chaud Lapin wrote:
If you
don't like the concept that the top of the wing is being sucked
upward by that lower pressure

It is not a matter of whether I like it or not. It is something
that simply does not happen. There is no sucking force.

then think of it this way. Imagine a cross-
section of the wing. The top surface of the wing forms a line.
The air just above this line has lower pressure. The air below
this line (inside the wing) has normal pressure.

So the air below the line is
pressing upward against it with more force than the air above is
pressing down.

I think you mis-understood me here. When I say the air below the
line is pressing upward, I am not referring to the air pressing
upward on the bottom of the wing. I am referring to the air
_inside_ the wing pressing upward on the underside of the top
surface of the wing. The air above the wing top surface has lower
than normal pressure. The air inside the wing has normal pressure.
So it presses upward on the top surface of the wing. This is lift
generated by the top surface of the wing.

What if your wing doesn't have any air in it?

Bertie- Hide quoted text -

- Show quoted text -

It will still fly, of course. If you talk about the upper wing
surface as a solid, with the air inside the wing under it, or if you
talk about the whole wing as a solid with air under it, the principle
is the same. You have lower pressure above the wing, and it
contributes lift.


Well, you needn't think of the interior of a wing unless it's very very
leaky!

Bertie