Airplane Pilot's As Physicists

Le Chaud Lapin wrote in
ups.com:

On Oct 16, 3:47 am, "Androcles" wrote:
"Le Chaud Lapin" wrote in
glegroups.com...
: On Oct 15, 7:54 pm, "Androcles" wrote:
: "Le Chaud Lapin" wrote in
ooglegroups.com...
: : On Oct 15, 6:42 pm, "Gatt" wrote:
: : "Le Chaud Lapin" wrote in
: messagenews:1192488325.423647.30120
@i38g2000prf.googlegroups.com..
: .
: :
: : I read last night in another piloting book, again, that the
: : common
: belief
: : about the dynamics of airfoils is wrong,
: :
: : Yeah? Which one?
: :
: : I'd have to go back to bookstore to find the name.
:
: AHAHAHAHAHAHA!
: Or back to sleep to dream again...
:
: Barry Schiff, in "The Proficient Pilot", "An AOPA Book", writes on
: page 2:
:
: "There is, for example, this amusing fable: "Air flowing above the
: wing has a greater distance to travel (because of camber) than air
: flowing beneath the wing. Therefore, air above the wing must travel
: faster so as to arrive at the wing's trailing edge at the same time
: as air flowing underneath. This is pure nonsense."

Since it is true Schiff must be a raving lunatic. Maybe you don't
understand that travelling the greater path in the same time involves
a greater speed.

Perhaps you could explain in detail what you mean by this last
statement. I am sure that there are plenty of people here would would
like, for once, that a pilot explains what s/he means by this.



What's it matter? Yo'll never be a pilot. Any math that wil enable you
to dial up for home delivered pizza and escargot should suffice. #



Bertie

Le Chaud Lapin wrote in
oups.com:

On Oct 16, 5:01 am, "BDS" wrote:
"Le Chaud Lapin" wrote

Therefore, one could conclude that the vitriolic attacks against me
personally for broaching the subject might be a sign of something
deeper, perhaps the attackers' distaste for having the topic openly
discussed.

And yet still, after my 1st post, after more than 600 replies
cummulative, not one pilot has dared answered the question why the
bottom paper rises.

[Yawn] Perhaps no one here is interested in discussing this with you
and going out of their way to help you to learn because of your
abrasive and insulting approach. I think you will find that pilots
with a considerable amount of experience no longer feel like they
have anything to prove, so the "insulting challenge" approach does
not work with them. IOW, they are not interested in trying to
impress you.

What about my orignial post is abrasive and insulting?



Bwawahwhahwhahwhahwhahhwhahwhahwwhahwhahwhahhwhahw hahwwhahwhahwhahhwhahw
hahwwhahwhahwhahhwhahwhahwwhahwhahwhahhwhahwhahwwh ahwhahwhahhwhahwhahwwh
ahwhahwhahhwhahwhahwwhahwhahwhahhwhahwhahwwhahwhah whahhwhah



Bertie

On Oct 16, 6:31 am, Thomas wrote:
On 9 Oct, 21:08, Le Chaud Lapin wrote:
You may want to check out my web pageshttp://www.physicsmyths.org.uk/bernoulli.htm
andhttp://www.physicsmyths.org.uk/drag.htm for a closer examination
of the physics behind the aerodynamic lift and drag.

The main point I am making there is that it is physically nonsense to
claim that changing merely the tangential velocity of the air stream
relative to the surface would in any way produce a resultant force (at
least for a non-viscous gas).

What one needs for a pressure change
(and thus a force) on the surface is a change in the numbers and/or
the velocity of the molecules hitting it, i.e. it is only the vertical
component of the velocity that is relevant here. Only this can produce
the lift for an airfoil, either because of the increased number of
collisions on the lower side or the decreased number of collisions on
the upper side (both situations lead to a lift).

I agree, but there are some that seem to think the contrary, as you
know, with the Coanda effect.
http://en.wikipedia.org/wiki/Coand%C4%83_effect

What is troubling about many of these theories is that, at the precise
moment where the reader is most alert in anticipation of the meat of
the explanation, the hand-waving begins. In the link above, the clause
entitled Causes, it is written:

"The effect of a spoon apparently attracting a flow of water is caused
by this effect as well, since the flow of water entrains gases to flow
down along the stream, and these gases are then pulled, along with the
flow of water, in towards the spoon, as a result of the pressure
differential. "

Hmmm...."and these gases are then pulled"...

pulled? By what?

And it should be
obvious that for this to be the case, one must either have the lower
side of the wing facing to a certain degree into the airstream, and/or
the upper side facing to a certain degree opposite to the airstream.
This is why one either needs a certain 'angle of attack' or a
correspondingly shaped airfoil. And it should be obvious that in order
to have an asymmetric force (i.e. a higher upward than downward force)
one needs the surfaces of the airfoil to be orientated in some way
asymmetrical relatively to the airstream. So a perfectly symmetrical
airfoil (front to back) at a zero angle of attack (like I indicated in
Fig.1 on my pagehttp://www.physicsmyths.org.uk/bernoulli.htm) should
not produce any lift as the upward force (from the rear part) is
exactly equal to the downward force (from the front part). All that
would happen is that the wing experiences an anti-clockwise torque.
This is the reason why the rear part of the wing (behind the apex)
must always have a larger surface than the front part. At least I have
yet to see an airfoil where this is not the case and where it can be
used at a zero angle of attack.
(the Bernoulli principle is in direct contradiction to this as it
would also predict a lift for a perfectly symmetric airfoil in this
sense).

I just read both your web pages.

BTW, your explanation of d'Alembert's Paradox and the blow-over-paper-
attached-to-table experiment could both use diagrams. I am trying the
blow over the paper experiment now and I am not sure if I am doing it
as you described. Could you provide a more vivid description so I can
make sure?

-Le Chaud Lapin-

"Le Chaud Lapin" wrote in message
ups.com...
: On Oct 16, 3:47 am, "Androcles" wrote:
: "Le Chaud Lapin" wrote in
glegroups.com...
: : On Oct 15, 7:54 pm, "Androcles" wrote:
: : "Le Chaud Lapin" wrote in
: ooglegroups.com...
: : : On Oct 15, 6:42 pm, "Gatt" wrote:
: : : "Le Chaud Lapin" wrote in
: : oglegroups.com...
: : :
: : : I read last night in another piloting book, again, that the
common
: : belief
: : : about the dynamics of airfoils is wrong,
: : :
: : : Yeah? Which one?
: : :
: : : I'd have to go back to bookstore to find the name.
: :
: : AHAHAHAHAHAHA!
: : Or back to sleep to dream again...
: :
: : Barry Schiff, in "The Proficient Pilot", "An AOPA Book", writes on
: : page 2:
: :
: : "There is, for example, this amusing fable: "Air flowing above the
: : wing has a greater distance to travel (because of camber) than air
: : flowing beneath the wing. Therefore, air above the wing must travel
: : faster so as to arrive at the wing's trailing edge at the same time as
: : air flowing underneath. This is pure nonsense."
:
: Since it is true Schiff must be a raving lunatic. Maybe you don't
: understand that travelling the greater path in the same time involves
: a greater speed.
:
: Perhaps you could explain in detail what you mean by this last
: statement. I am sure that there are plenty of people here would would
: like, for once, that a pilot explains what s/he means by this.

Really?
Ok, for plenty of cretins such as yourself...

Travelling 70 miles (distance) in one hour (duration of time)
is a speed of 70 mph by definition.
100 miles (the greater distance) in the same time (1 hour)
is 100 mph.
100 mph is faster than 70 mph.
People unaware of this simple fact are prone to getting
speeding tickets and losing their license.
Aircraft pilots are even more aware of it than motorists,
using their stop watches to compute distance.

In this video the air moves MUCH faster over the top of the wing
than it does over the bottom:
http://www.youtube.com/watch?v=KCcZyW-6-5o

Now you can go back to sleep and dream of Barry Schiff and
his "nonsense".

On Oct 16, 9:53 am, "Gatt" wrote:
Barry Schiff, in "The Proficient Pilot", "An AOPA Book", writes on
page 2:

"There is, for example, this amusing fable: "Air flowing above the
wing has a greater distance to travel (because of camber) than air
flowing beneath the wing. Therefore, air above the wing must travel
faster so as to arrive at the wing's trailing edge at the same time as
air flowing underneath. This is pure nonsense."

Like I said. Upper camber is a conspiracy by the aluminum manufacturers to
sell more metal... Bournoulli was a shill.

You wrote repeatedly that lack of attention to detail (mostly due to
my spelling errors) indicated lack of understangind, was not becoming
of a critical thinker, etc...yet you keep making spelling errors
youself.

I never disputed Bernoulli's Principle, not once. I said that there
was a lot of hand-waving going on when pilots uttered greater/lesser/
camber/Bernoulli in the same sentence.

Bernoulli's principle is correct.

That the camber influences lift is correct.

But how the camber influences lift has nothing to do with greater
distances traveled, IMO.

-Le Chaud Lapin-

On Oct 16, 10:20 am, "Androcles" wrote:
"Le Chaud Lapin" wrote in oglegroups.com...
: On Oct 16, 3:47 am, "Androcles" wrote:
: "Le Chaud Lapin" wrote in
glegroups.com...
: : On Oct 15, 7:54 pm, "Androcles" wrote:
: : "Le Chaud Lapin" wrote in
: ooglegroups.com...
: : : On Oct 15, 6:42 pm, "Gatt" wrote:
: : : "Le Chaud Lapin" wrote in
: : oglegroups.com...
: : :
: : : I read last night in another piloting book, again, that the
common
: : belief
: : : about the dynamics of airfoils is wrong,
: : :
: : : Yeah? Which one?
: : :
: : : I'd have to go back to bookstore to find the name.
: :
: : AHAHAHAHAHAHA!
: : Or back to sleep to dream again...
: :
: : Barry Schiff, in "The Proficient Pilot", "An AOPA Book", writes on
: : page 2:
: :
: : "There is, for example, this amusing fable: "Air flowing above the
: : wing has a greater distance to travel (because of camber) than air
: : flowing beneath the wing. Therefore, air above the wing must travel
: : faster so as to arrive at the wing's trailing edge at the same time as
: : air flowing underneath. This is pure nonsense."
:
: Since it is true Schiff must be a raving lunatic. Maybe you don't
: understand that travelling the greater path in the same time involves
: a greater speed.
:
: Perhaps you could explain in detail what you mean by this last
: statement. I am sure that there are plenty of people here would would
: like, for once, that a pilot explains what s/he means by this.

Really?
Ok, for plenty of cretins such as yourself...

Travelling 70 miles (distance) in one hour (duration of time)
is a speed of 70 mph by definition.
100 miles (the greater distance) in the same time (1 hour)
is 100 mph.
100 mph is faster than 70 mph.
People unaware of this simple fact are prone to getting
speeding tickets and losing their license.
Aircraft pilots are even more aware of it than motorists,
using their stop watches to compute distance.

In this video the air moves MUCH faster over the top of the wing
than it does over the bottom:
http://www.youtube.com/watch?v=KCcZyW-6-5o

I just looked at this video.

What you wrote and what this video demonstrates are two entirely
different things. There is no reason to say that the air moving above
the wing must meet beneath the wing.

I keep hearing people say,

"The air moves faster, therefore Bernoulli's Principle must be
invoked."

The thesis of what I have been saying all along can be seeing in an
inversion of this sentence.

"It is Bernoulli's principle that causes the air to flow faster."

In particular, it is the pressure gradient that causes the air in the
contstriction to flow faster. This same pressure gradient exists
above a wing in an air craft, and it has nothing to do with the
distance traveled. The camber of the wing is carefully designed my
airfcraft manufacturers to incudes, as much as possible, this pressure
gradient, at a particular speed, but *with* the conflicting
requirement that resulting drag must be reduced. This is why I said
earlier that pressure at the front of the wing is not necessarily bad.
It is desirable, but it also causes some laminar drag. Intuitively,
one can see what the edge must not be made sharp - doing that would
elimate the very pressure that is need to bring about the pressure
gradient.

Now you can go back to sleep and dream of Barry Schiff and
his "nonsense".

-Le Chaud Lapin-

"Bertie the Bunyip" wrote


What's it matter? Yo'll never be a pilot. Any math that wil enable you
to dial up for home delivered pizza and escargot should suffice. #

Are you kidding? He doesn't have a job to provide enough money for
escargot.

The only escargot he is going to see is from the snails he plucks out of the
river!

Mmmmmm!
--
Jim in NC

"Le Chaud Lapin" wrote in message
ups.com...
: On Oct 16, 10:20 am, "Androcles" wrote:
: "Le Chaud Lapin" wrote in
oglegroups.com...
: : On Oct 16, 3:47 am, "Androcles" wrote:
: : "Le Chaud Lapin" wrote in
: glegroups.com...
: : : On Oct 15, 7:54 pm, "Androcles" wrote:
: : : "Le Chaud Lapin" wrote in
: : ooglegroups.com...
: : : : On Oct 15, 6:42 pm, "Gatt" wrote:
: : : : "Le Chaud Lapin" wrote in
: : :
oglegroups.com...
: : : :
: : : : I read last night in another piloting book, again, that
the
: common
: : : belief
: : : : about the dynamics of airfoils is wrong,
: : : :
: : : : Yeah? Which one?
: : : :
: : : : I'd have to go back to bookstore to find the name.
: : :
: : : AHAHAHAHAHAHA!
: : : Or back to sleep to dream again...
: : :
: : : Barry Schiff, in "The Proficient Pilot", "An AOPA Book", writes on
: : : page 2:
: : :
: : : "There is, for example, this amusing fable: "Air flowing above the
: : : wing has a greater distance to travel (because of camber) than air
: : : flowing beneath the wing. Therefore, air above the wing must
travel
: : : faster so as to arrive at the wing's trailing edge at the same
time as
: : : air flowing underneath. This is pure nonsense."
: :
: : Since it is true Schiff must be a raving lunatic. Maybe you don't
: : understand that travelling the greater path in the same time
involves
: : a greater speed.
: :
: : Perhaps you could explain in detail what you mean by this last
: : statement. I am sure that there are plenty of people here would would
: : like, for once, that a pilot explains what s/he means by this.
:
: Really?
: Ok, for plenty of cretins such as yourself...
:
: Travelling 70 miles (distance) in one hour (duration of time)
: is a speed of 70 mph by definition.
: 100 miles (the greater distance) in the same time (1 hour)
: is 100 mph.
: 100 mph is faster than 70 mph.
: People unaware of this simple fact are prone to getting
: speeding tickets and losing their license.
: Aircraft pilots are even more aware of it than motorists,
: using their stop watches to compute distance.
:
: In this video the air moves MUCH faster over the top of the wing
: than it does over the bottom:
: http://www.youtube.com/watch?v=KCcZyW-6-5o
:
: I just looked at this video.
:
: What you wrote and what this video demonstrates are two entirely
: different things. There is no reason to say that the air moving above
: the wing must meet beneath the wing.

What do you think it meets, water?



:
: I keep hearing people say,
:
: "The air moves faster, therefore Bernoulli's Principle must be
: invoked."

That's right.

:
: The thesis of what I have been saying all along can be seeing in an
: inversion of this sentence.
:
: "It is Bernoulli's principle that causes the air to flow faster."

Oh sure... and it is falling that causes gravity and losing that
causes cretins to buy lottery tickets.

As the other person said, your entertainment value is zero.

*plonk*

"BDS" wrote

Please do. Might I suggest you try a different approach when you ask
someone for help?

Too late. Everyone knows that he is not worth the dynamite it would take to
blow him to H*ll and back.
--
Jim in NC

On Oct 16, 11:04 am, "Androcles" wrote:
"Le Chaud Lapin" wrote in
: In this video the air moves MUCH faster over the top of the wing
: than it does over the bottom:
: http://www.youtube.com/watch?v=KCcZyW-6-5o
:
: I just looked at this video.
:
: What you wrote and what this video demonstrates are two entirely
: different things. There is no reason to say that the air moving above
: the wing must meet beneath the wing.

What do you think it meets, water?

BTW, there is nothing in that video about airplane wings. It only
shows Bernoulli's principle using smoke stacks, hanging balls, piece
of paper, etc. At no point do I see any demonstration of air above
and below having disparity in speed, unless you count the book.

-Le Chaud Lapin-