Airplane Pilot's As Physicists

Bertie the Bunyip wrote:

He's a sockpuppet. A creation.

Who do you think he is a sock puppet for, MX?

wrote
Denny, this newsgroup is pretty effectively moderated by Bertie. The
Dudley man does a good job too.
\
Sadly, it has deteriorated to the current state.

People used to have real discussions about flying, instead of the constant
discord.

I long for the return of discussions where an idiot does not pervert every
thread, and all of the people that left, return.
--
Jim in NC

"Morgans" wrote in message
...

Sadly, it has deteriorated to the current state.

People used to have real discussions about flying, instead of the constant
discord.

Actually, I'm enjoying the tangental stuff that people like Dudley are
posting. Actual physics. Even if somebody appears to be trolling, it's
useful to hear experts articulate what we all pretty much know, plus I've
gotten at least two useful book recommendations out of the thread.

Maybe the OP is just a foil for the rest of us to talk about aerodynamics.
Works for me.

-c

On Oct 11, 12:15 am, "Morgans" wrote:
wrote Denny, this newsgroup is pretty effectively moderated by Bertie. The
Dudley man does a good job too.

\
Sadly, it has deteriorated to the current state.

People used to have real discussions about flying, instead of the constant
discord.

I long for the return of discussions where an idiot does not pervert every
thread, and all of the people that left, return.
--
Jim in NC

Hmm...I re-read my original 3 posts, two to rec.aviation.piloting, and
I do not see much perversion in them. I have recopied the most
controversial post for benefit of people in sci.physics.

If there is any perversion, it mostly came from susquent insults from
people who were upset by the idea that I might be reevaluating
backwash.

-Le Chaud Lapin-

Orginal Post Entitled "Backwash Causes Lift?" in
rec.aviation.piloting:

On Oct 2, 8:57 pm, Le Chaud Lapin wrote:
Hi,

Student pilot here, self-teaching using the Jeppensen Private Pilot
Kit after taking ground school.

I read in the book that combustion "creates" energy, which is
technically not true, but I decided to ignore it since the pictures
are sooo pretty.

Now, in Chapter 3, section about airfoils, it actually says:

"In addition to the lowered pressure, a downward-backward flow of air
also is generated from the top surface of the wing. The reaction to
this downwash results in an upward force on the wing which demnstrates
Newtons' third law of motion. This action/reaction principle also is
apparent as the airstream strikes the lwoer surface of the wing when
inclinded at a small angle (the angle of attack) to its direction of
motion. The air is forced downward and therefore causes an upward
reaction resulting in positive lift."

IMHO, the latter part of this paragraph is correct, but the former
part is wrong.

Obviously, any air above the wing can only result in a force downward
on top of the wing. The only force causing the plane to want to move
upward comes from beneath the wing. The effect of any air above the
wing is to cause rarefication above the wing, resulting in lower
pressure, thereby giving the 14.7lbs/in^2 (plus) to do its work. That
"reaction" coming from downward movement of air seems just plain silly
to me.

I am also inclined to take issue with the explanations of Bernouilli's
Principle which I see often in the literature, but that's a different
subject. [Note, I don't doubt Bernouilli's Principle, I just think
there is more to it than the way it is being described in context of
flying.]

-Le Chaud Lapin-

Denny writes:

Thank the lord that most of the lists I follow are moderated, and
unlike this one do not have this endless baloney going on...

Most moderated lists have nothing going on at all.

Mxsmanic wrote in
:

Denny writes:

Thank the lord that most of the lists I follow are moderated, and
unlike this one do not have this endless baloney going on...

Most moderated lists have nothing going on at all.


Much like yourself


Bertie

"CWatters" wrote in
:


"Le Chaud Lapin" wrote in message
ps.com...
I am trying to convince them that, if there is air on the inside of
the wing, it pushes against all sides of the inside of the wing,
including both top underside and bottom overside, and thereby
nullifying any effect it would have on the wing.

Correct.

Except that he is not trying to convince "them" of anything.

One guy used the air inthe ing thing as an analogy and wannabe troll boi
here is trying to make hay of it.



Bertie

Le Chaud Lapin wrote:

Hi All,

There is a long discussion ongoing in rec.aviation.piloting about what
causes lift on a plane. You can read from the link below. Please
note that about 80% of the post are mostly ad hominem attacks and
should be ignored. There are some small bits of real discussion.

http://groups.google.com/group/rec.a...11fa289cd7864a

I am an electrical engineer with experience in analag design and
software, with math and physics background that you would expect of an
electrical engineer.

There are many points made in the discussion, but I would like to
focus on one in particular for the sake of progress.

There are people in the pilot's group, who think that lift on a wing
is analyzed as such:

1. There is air on outside of top of wing that is pushing down, but
reduced because of aerodynamics.
2. The *inside* of the wing contains air pushing up against the
underside of top of wing .
3. Let us ignore that the same air inside the wing pushes down on the
overside of bottom part of wing.
3. The difference in pressure against the underside of the top wing on
the inside of wing and top of wing on outside, is what gives plane
lift.

Note that they ignore the pressure inside the wing that pushes
downward on the wing.

I am trying to convince them that, if there is air on the inside of
the wing, it pushes against all sides of the inside of the wing,
including both top underside and bottom overside, and thereby
nullifying any effect it would have on the wing. Lift is caused by a
difference in pressure between the underside of the bottom of the
wing, and the overside of the top of the wing.

I count 8-9 people in the group who are utterly convinced that I am
inept at physics, mathematics, etc.

Note that some of these people have been flying aircraft for years,
even decades, while I am still a student pilot.

Comments from anyone who knows physics welcome.

1) Acrobatic airplane wings are essentially symmetric in
cross-section. They fly equally well rightside-up or inverted. Angle
of attack is important.

2) Bernoulli's law is strictly a 2-D analysis.

3) Dr. Penelope Smith rigorously derived vortex shedding is a major
lift component in 3-D. Don't be Cessna behind a jumbo.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2

Uncle Al wrote in
:

Le Chaud Lapin wrote:

Hi All,

There is a long discussion ongoing in rec.aviation.piloting about
what causes lift on a plane. You can read from the link below.
Please note that about 80% of the post are mostly ad hominem attacks
and should be ignored. There are some small bits of real discussion.


http://groups.google.com/group/rec.a...wse_frm/thread
/b85a49e900a0c791/bb11fa289cd7864a#bb11fa289cd7864a

I am an electrical engineer with experience in analag design and
software, with math and physics background that you would expect of
an electrical engineer.

There are many points made in the discussion, but I would like to
focus on one in particular for the sake of progress.

There are people in the pilot's group, who think that lift on a wing
is analyzed as such:

1. There is air on outside of top of wing that is pushing down, but
reduced because of aerodynamics.
2. The *inside* of the wing contains air pushing up against the
underside of top of wing .
3. Let us ignore that the same air inside the wing pushes down on the
overside of bottom part of wing.
3. The difference in pressure against the underside of the top wing
on the inside of wing and top of wing on outside, is what gives plane
lift.

Note that they ignore the pressure inside the wing that pushes
downward on the wing.

I am trying to convince them that, if there is air on the inside of
the wing, it pushes against all sides of the inside of the wing,
including both top underside and bottom overside, and thereby
nullifying any effect it would have on the wing. Lift is caused by a
difference in pressure between the underside of the bottom of the
wing, and the overside of the top of the wing.

I count 8-9 people in the group who are utterly convinced that I am
inept at physics, mathematics, etc.

Note that some of these people have been flying aircraft for years,
even decades, while I am still a student pilot.

Comments from anyone who knows physics welcome.

1) Acrobatic airplane wings are essentially symmetric in
cross-section. They fly equally well rightside-up or inverted. Angle
of attack is important.

2) Bernoulli's law is strictly a 2-D analysis.

3) Dr. Penelope Smith rigorously derived vortex shedding is a major
lift component in 3-D. Don't be Cessna behind a jumbo.


Wow, you are a cut and paste genius Anthony.


Bertie

Uncle Al wrote in
:

Le Chaud Lapin wrote:

Hi All,

There is a long discussion ongoing in rec.aviation.piloting about
what causes lift on a plane. You can read from the link below.
Please note that about 80% of the post are mostly ad hominem attacks
and should be ignored. There are some small bits of real discussion.


http://groups.google.com/group/rec.a...wse_frm/thread
/b85a49e900a0c791/bb11fa289cd7864a#bb11fa289cd7864a

I am an electrical engineer with experience in analag design and
software, with math and physics background that you would expect of
an electrical engineer.

There are many points made in the discussion, but I would like to
focus on one in particular for the sake of progress.

There are people in the pilot's group, who think that lift on a wing
is analyzed as such:

1. There is air on outside of top of wing that is pushing down, but
reduced because of aerodynamics.
2. The *inside* of the wing contains air pushing up against the
underside of top of wing .
3. Let us ignore that the same air inside the wing pushes down on the
overside of bottom part of wing.
3. The difference in pressure against the underside of the top wing
on the inside of wing and top of wing on outside, is what gives plane
lift.

Note that they ignore the pressure inside the wing that pushes
downward on the wing.

I am trying to convince them that, if there is air on the inside of
the wing, it pushes against all sides of the inside of the wing,
including both top underside and bottom overside, and thereby
nullifying any effect it would have on the wing. Lift is caused by a
difference in pressure between the underside of the bottom of the
wing, and the overside of the top of the wing.

I count 8-9 people in the group who are utterly convinced that I am
inept at physics, mathematics, etc.

Note that some of these people have been flying aircraft for years,
even decades, while I am still a student pilot.

Comments from anyone who knows physics welcome.

1) Acrobatic airplane wings are essentially symmetric in
cross-section. They fly equally well rightside-up or inverted. Angle
of attack is important.

2) Bernoulli's law is strictly a 2-D analysis.

3) Dr. Penelope Smith rigorously derived vortex shedding is a major
lift component in 3-D. Don't be Cessna behind a jumbo.



Oops, sorry, friendly fire.


Bertie