visualisation of the lift distribution over a wing

Alan Baker wrote:
In article ,
"Morgans" wrote:

"Alan Baker" wrote
Anyone who thinks that the pressure of a fluid on a surface can act in
any direction but towards the surface is simply wrong.
I see. You are not lookng at the wing as a system, but taking an
observation at one point only, without reguard to what is happening around
it.

Point made.

Nope.

I'm making the point that the upper surface contributes absolutely *no*
lifting force.

None.

Zero.

In fact, it provides a downward force. Every time.



Sorry, Alan, old boy, I find must disagree.

In actuality, BOTH surfaces are below ambient pressure.
('splain why?)

But without that reduction of the pressure across the top curve of the wing,
the pressure below it can't do much at all, can it?

Alan Baker wrote:

Nope.

I'm making the point that the upper surface contributes absolutely *no*
lifting force.

None.

Zero.

In fact, it provides a downward force. Every time.



....and you are making the point that when you are breathing in, you are
not SUCKING air at all. It's atmospheric pressure on your chest that
inspires the air. Wow! Who would have guessed? :-)

Brian W

Alan Baker wrote:


Interesting comment: what would YOU call it when the fabric on the upper
wing surface wants to pull away from the ribs?

Air pressure from inside the wing pushing up on it more than the air
above is pushing down...



Let me take a wild guess he you did physics for an uundergraduate
degree. Is that right?

Brian W

In article ,
brian whatcott wrote:

Alan Baker wrote:


Interesting comment: what would YOU call it when the fabric on the upper
wing surface wants to pull away from the ribs?

Air pressure from inside the wing pushing up on it more than the air
above is pushing down...

For a couple of seconds, perhaps.

Wings aren't typically hermetically sealed.

Let me take a wild guess he you did physics for an uundergraduate
degree. Is that right?

Brian W

Steve Hix wrote:
In article ,
brian whatcott wrote:

Alan Baker wrote:

Interesting comment: what would YOU call it when the fabric on the upper
wing surface wants to pull away from the ribs?
Air pressure from inside the wing pushing up on it more than the air
above is pushing down...

For a couple of seconds, perhaps.

Wings aren't typically hermetically sealed.

Let me take a wild guess he you did physics for an uundergraduate
degree. Is that right?

Brian W

I'll take Physics Majors for $500, Alex!

In article ,
brian whatcott wrote:

Alan Baker wrote:


Interesting comment: what would YOU call it when the fabric on the upper
wing surface wants to pull away from the ribs?

Air pressure from inside the wing pushing up on it more than the air
above is pushing down...



Let me take a wild guess he you did physics for an uundergraduate
degree. Is that right?

Brian W

No. But it doesn't matter.

If the fabric is moving upward, it can only be because there is more
pressure on its bottom surface than there is on its top surface.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

Alan Baker wrote:
In article ,
brian whatcott wrote:

Alan Baker wrote:

Interesting comment: what would YOU call it when the fabric on the upper
wing surface wants to pull away from the ribs?
Air pressure from inside the wing pushing up on it more than the air
above is pushing down...


Let me take a wild guess he you did physics for an uundergraduate
degree. Is that right?

Brian W

No. But it doesn't matter.

If the fabric is moving upward, it can only be because there is more
pressure on its bottom surface than there is on its top surface.


I'm kind of curious about how that higher pressure got on the bottom
of that wing though...

In article ,
cavelamb wrote:

Alan Baker wrote:
In article ,
brian whatcott wrote:

Alan Baker wrote:

Interesting comment: what would YOU call it when the fabric on the upper
wing surface wants to pull away from the ribs?
Air pressure from inside the wing pushing up on it more than the air
above is pushing down...


Let me take a wild guess he you did physics for an uundergraduate
degree. Is that right?

Brian W

No. But it doesn't matter.

If the fabric is moving upward, it can only be because there is more
pressure on its bottom surface than there is on its top surface.


I'm kind of curious about how that higher pressure got on the bottom
of that wing though...

If the curvature of the upper surface lowers the pressure, then even if
the pressure on the lower surface is just the ambient pressure, it will
be *higher* than the upper surface.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg

Alan Baker wrote:
In article ,
brian whatcott wrote:

Alan Baker wrote:

Interesting comment: what would YOU call it when the fabric on the upper
wing surface wants to pull away from the ribs?
Air pressure from inside the wing pushing up on it more than the air
above is pushing down...


Let me take a wild guess he you did physics for an uundergraduate
degree. Is that right?

Brian W

No. But it doesn't matter.

If the fabric is moving upward, it can only be because there is more
pressure on its bottom surface than there is on its top surface.


It seems that you are uncomfortable with the entire concept of suction.
For example, how do you suppose suction cups work?
Or how about a suction pump that happens to be limited to a 30 ft lift?

Well duh, it's also atmospheric pressure that enables suction pumps and
suction cups etc., etc. Yes indeed , but it's an academic issue at
the junior high level, isn't it?

Brian W

brian whatcott wrote:
Alan Baker wrote:
In article ,
brian whatcott wrote:

Alan Baker wrote:

Interesting comment: what would YOU call it when the fabric on the
upper wing surface wants to pull away from the ribs?
Air pressure from inside the wing pushing up on it more than the air
above is pushing down...


Let me take a wild guess he you did physics for an uundergraduate
degree. Is that right?

Brian W

No. But it doesn't matter.

If the fabric is moving upward, it can only be because there is more
pressure on its bottom surface than there is on its top surface.


Have you ever seen the top surface of a fabric covered wing?

The skin does not bulge upwards.

Not usually anyway.