In article 1454525a-4a26-432c-a550-42e437fb2070
@f11g2000vbx.googlegroups.com, , Dudley
Henriques says...

On May 23, 4:40*am, Dave Doe wrote:
In article , , Private
says...











"Dave Doe" wrote in message
...
In article ,
, Mxsmanic says...

Dave Doe writes:

So a wing generates as much lift upside down? *

Absolutely..........without question! The EXACT same explanation of
lift creation is in play on an inverted wing as on the upright wing.
Applies to barn doors as well.
Newton= 100% Bernoulli= 100%.
Dudley Henriques

We're talking lift here mate - that's in the upwards direction!

If you are right, I'd expect to see planes with the airfoil upsidedown
(with the increased camber on the bottom), but that's not the case (and
I'm talking about the *wings* here, not the horizontal stabiliser

However, I'm getting what you're saying - and will now argue with my
mate that an airfoil is simply a more *efficient* device (vs. a barn
door).

He has not disagreed that:
* All wings (barn door or airfoil) create lift by deflecting
(accelerating) air (which has mass), down. Simple. F=ma.
* An airfoil produces lift by Newtonian mechanics in the same way as a
barn door (angle of attack), *but* ...
* An airfoil has increased camber over the top surface - and the air
flowing around that is pulling air down - a low pressure area is created
(and the air is accelerated over the wing (lets not go into the air
particles meet up, same as the bottom fallacy - and nor are either of us
arguing over that)).

I think you have explained though, that the Bernoulli effect occurs with
a barn door too at an angle of attack - however it is a lot less
*efficient* without that camber (which will continue to 'suck' air down
- as the camber continues to change direction - and therefore drag the
viscous air around it with it). I hope you'll agree with that.

In my reading up of the Bernoulli principle on various pages, it seems
to me that one of it's most important uses is that is often used as an
accurate *means* by which lift is calculated.

It should be an interesting argument - and many thanks for your replies.
I won't reply to your other responses - don't think it's necessary.

--
Duncan.