Why Airplanes Fly - Voids Above A Planar Sheet
Le Chaud Lapin
The title of this post implies that I know why airplanes fly. I
don't, not completely at least. But I do know that I have read a lot
of "official" explanations that are just plain wrong.
Before I begin my exposition about what keeps the plane afloat, I
would like anyone who care to participate in this discussion to do a
couple of simple experiments. This will get us all on the same page
(no pun intended, heh):
We are all familiar with the "blow-over-sheet-of-paper" trick to
illustrate Bernouilli's principle. That trick is actually has more
going on than Bernouilli's princinple, but I am going to avoid talking
about it until we can all at least agree on the concepts of voids and
pressures.
Let us do an experiment that uses not one but two sheets of paper.
EXPERIMENT 1:
Take two sheets of paper. Superpose one on top of the other on a
desk, perfectly aligned. Then carefully grab the edges of the top
sheet with both hands, gripping the edges between your palms, but
making sure to keep the top sheet as close to the bottom sheet as
possible, including the edges. The closer, the better. It helps to
grab long-wise, not short-wise. Try to grab as much edge as possibe.
Now take a breath...
In one quick motion, yank up the top sheet. Watch what happens to the
bottom sheet. It follows the top sheet for a brief moment.
EXPERIMENT 2:
Do the same as EXPERIMENT 1, but be creative. Instead of simply
yanking upward, move in a nice fluid-but-fast motion all around the
room. If you are careful, you should be able to make some nice,
gracious curves, keeping the bottom sheet intact. Some of you might
find it hard to believe, but with the right contraption, you could
actually keep two pieces of cardboard stuck together like this,
dragging one with the other all over the room, even though there is no
glue or any other adhesive binding the two.
There is one important lesson to be learned from these experiments,
especially the 1st. Bernoulli's Principle has nothing to do with
this. Bernoulli's principle has to do with air flow that is
*coplanar* with the surface under discussion. Bernoulli's principle
has to do with gases that are flowing in a direction that is
perpendicular to the normal vector of the surface over which it flows.
When you yank the top paper to lure the bottom paper, you are moving
in a direction that is *colinear* to this normal vector. Simply
stated, if you do not move sideways *at all*, but only outward, away
from the paper, you will STILL cause the bottom sheet to follow.
I will leave it to the reader to explain why the bottom sheet follows
the top sheet. ;)
-Le Chaud Lapin-
Bertie the Bunyip
news:1191463474.6...@19g2000hsx.googlegroups.com:
> Hi,
>
> The title of this post implies that I know why airplanes fly. I
> don't, not completely at least. But I do know that I have read a lot
> of "official" explanations that are just plain wrong.
>
> Before I begin my exposition about what keeps the plane afloat, I
> would like anyone who care to participate in this discussion to do a
> couple of simple experiments.
Good grief..
Bertie
>
RandyL
is.........
$$$$$$$
> There is one important lesson to be learned from these experiments,<
Yes there is. You are an idiot.
Randy L.
--
"When making an emergency off-field landing at night,
turn on your landing light just prior to touchdown.
If you don't like what you see, then turn off the landing lights."
"Le Chaud Lapin" <jaibu...@gmail.com> wrote in message
news:1191463474.6...@19g2000hsx.googlegroups.com...
> Hi,
(snip)
> -Le Chaud Lapin-
>
VZ/res0zhra
"RandyL" <rl...@cableone.net> wrote in message
news:13g9m0q...@corp.supernews.com...
OK -- everyone has been dancing all around this. The thing that keeps an
airplane
up is the WINGS! Once again, more slowly---------the
WWWIIIIIINNNNNGGGGSSSS!
No wings - no flying. With no wings you don't have an airPLANE, you have a
rocket (or a bomb,
depending on which way it's going). Any bee knows this. Most birds know this
and they have bird brains. :)
Tina
flying, I'd enjoy knowing how these 'experiments' are related.
Are you suggesting that a table top under the paper is in any way
representative of what goes on in a dynamic airfoil?
Are you really educated as an engineer?
Le Chaud Lapin
> If "Getting on the same page" means learning some of the physics of
> flying, I'd enjoy knowing how these 'experiments' are related.
>
> Are you suggesting that a table top under the paper is in any way
> representative of what goes on in a dynamic airfoil?
Well I was trying to illustrate what goes on between the two sheets of
paper, but I guess a table will do. Technically, if you place one
sheet of paper on top a table, and yank up hard on the paper, there
will be a tendency for the table to lift off the ground, but since the
mass of table is so great, the net pressure upward on table is not
enough to counteract gravity so the table remains at rest (actually,
at a quantum level it does not completely "not move", but for our
purpose we can say that it doesn't).
So I used two sheets of paper because the bottom paper will rise.
So yes, I believe this experiment illustrates an important phenomenon
in aerodynamics. It is not the only phenomenon that plays a role, but
it has one, nevertheless. The decriptions of lift that I read in
flight books seem to ignore it. This weekend I am going to download
material on aerodynamics and read what it says.
There is another experiment that could demonstrate this principle more
dramatically, using an actual airplane wing:
SMOKING CIGARETTES/AIRPLANE WING EXPERIMENT:
I would take an airplane wing, and mount it rails that can move in the
forward and aft directions along what would be the longitudinal axis
of the airplane if if the wing were so attached. Then I would take a
bunch of cigarettes, light them, and hang them up-side-down from a
high ceiling above the wing of the aircraft. The wing would have an
exaggerated AoA, say 30%, no flaps, displaced slightly so that it is
ahead of the hanging cigarettes, but so that the cigarettles cannot
touch. The cigarettes would be lit so that stream of smoke floats
upward.
Then I would use a tremendous force applied to move the wing forward
along the rails, say, by linear induction motor, or whatever, to move
the wing forward, being careful that the apparutus doing so is already
ahead of the wing and connected by steel wire to minimize interference
effects.
You would see that, if the impulse is great enough, not only would the
smoke be diverted from upward and moved in the direction that the wing
went (forward), but the hanging cigarettes themselves would move.
If flat pressure sensors were mounted above the wing, close to the
trailing edge, they would show a momentary decrease in pressure.
If flat pressure sensors were mounted below the wing, close to the
trailing edge, they would show a momentary increase in pressure.
After the force stops, there would be relaxation where the
rarefication above the wing and compression below the wing are
elminiated by flows due to the pressure gradient.
In a real airplane, this is what is happening, but because the the
wing is constantly moving foward, the rarefication above the wingg and
the compression below the wing are never quite normalized by to normal
atmosphere.
The downwash above wing is due to air rushing in to fill the void.
SMOKING CIGARETTE/HARD-COVER BOOK EXPERIMENT:
There is an similar, not-as-dramatic experiment you can do at home
that is closely related to experiment above. Let a piece of stiff
cardboard be your wing. Hold it from the side at an angle of attack,
as above, but don't rest your arm on top of a table. That would
create a boundary condition beneath the wing. Light a cigarette and
inverted so that it is the hot part is near the top of the wing, so
where in middle between leading and trailing edge. Get your arm out of
the way of the void that is about to be created. Now, in one quick
motion, move the cardboard forward. Notice the tremendous net impulse
force that is generated on the cardboard. The smoke will follow.
These things are happening in flight, along with Bernoulli.
> Are you really educated as an engineer?
Yes, electrical/software.
-Le Chaud Lapin-
BDS
"Le Chaud Lapin" <jaibu...@gmail.com> wrote...
Are you crazy?! Do you know what cigarettes cost these days??!!
BDS
Robert M. Gary
> Hi,
>
> The title of this post implies that I know why airplanes fly. I
> don't, not completely at least. But I do know that I have read a lot
> of "official" explanations that are just plain wrong.
Or just buy the book "Aerodynamics for Naval Aviators" and look at the
pictures.
-Robert
Le Chaud Lapin
What will I see?
-Le Chaud Lapin-
Dudley Henriques
What will I see????
The collective knowledge of the finest aerodynamics minds since the dawn
of aviation. ANA is the "bible" for anyone from Astronauts to Student
Pilots. It's not written for the casual user however.
I'm sure from what I've been reading of your posts that you might
perhaps have something you would like to see changed in the book to
reflect a more accurate text.
If you would like to do this, please email me and I'll put you in touch
with the right people at the Naval Test Pilot School at Patuxant NAS.
--
Dudley Henriques
John Godwin
> What will I see?
Lots of pictures which is probably all you can comprehend.
--
Bob Moore
> If you would like to do this, please email me and I'll put you
> in touch with the right people at the Naval Test Pilot School at
> Patuxant NAS.
Dudley...just what was your association with the school? Since
you were not a military pilot, you could not have had "Orders"
to the school. Did you perhaps "pay" your way through the course?
I seem to remember that there was such a provision at one time.
Or...perhaps you worked for a corporation under contract to the
government?
Bob Moore
Naval Aviator 15753
Le Chaud Lapin
> -----BEGIN PGP SIGNED MESSAGE-----
>
> From: Le Chaud Lapin <jaibudu...@gmail.com>
>
> >> Are you really educated as an engineer?
>
> >Yes,
>
A student's education is not the responsibility of the institut ion.
True understanding has been and always will be ultimately the
responsibility of the student.
-Le Chaud Lapin-
ManhattanMan
Me thinks that reply by LCB, and others like it, have Mx written all over
it... :)
Dudley Henriques
I am not a Naval Aviator. That title is reserved for the finest pilots
in the world. I'm simply a civilian pilot who happened to be a fair
stick in prop fighters given access. This access has been formed through
years of friendship and involvement with the flying military.
I flew the T38 at TPS under special arrangement by Admiral Francis
Taylor Brown and Tex Birdwell, Cmdr of the school. I have also flown at
Strike Aircraft Test Directorate at Pax as a guest of that organization.
I also narrated the demonstration of the prototype YF17 Cobra for Hank
Choteau's demonstration of the aircraft for the Navy at Pax as well as
narrating the annual Navy Air Show at Pax.
I've also flown with the Canadian Snowbirds as a guest pilot of that
organization doing an aerobatic evaluation on their Tutors.
I'm simply now and always have been a "friend" of the military and
specifically of TPS.
You know Moore, if you spent a bit less time trying to discredit me and
a bit more simply engaging me on a slightly more friendly basis, you and
I might actually get along. I have done something for you I have not
done for anyone else I've encountered on Usenet. After you requested of
me by private email some "proof" from someone other than myself who
could actually testify to my ability as a pilot, I offered to send you a
copy of the official debrief notes written by the IP assigned to fly
back seat for my T38 flights by TPS but never heard from you on that score.
You may still have access to that information if you desire.
Personally, if you desire to see this information, I will send it to you
and seek no further contact with you on these forums.
If my word on these matters isn't good enough for you to accept, I would
see no future in any further dialog with you.
You're choice; you can have the debrief notes, or you can stop this
constant under posting of me requesting backup information on me.
All the best to you,
--
Dudley Henriques
ManhattanMan
> Me thinks that reply by LCB,
LCB??? Try LCL.......
Le Chaud Lapin
> You know Moore, if you spent a bit less time trying to discredit me and
> a bit more simply engaging me on a slightly more friendly basis, you and
> I might actually get along.
If eveyone in this group would simply take the advice that you just
wrote, I think it would be a better group. I have been here only a
few days, and I count no less than 7 insults by people I have never
known.
I imagine these individuals as being overweight and constipated,
reading my posts, debating whether they should take a laxative or fire
off an insult, the latter choice leaving them in the same state they
were before they read my post.
-Le Chaud Lapin-
P.S. I am going to get that book btw.
Gatt
"Le Chaud Lapin" <jaibu...@gmail.com> wrote in message
news:1191463474.6...@19g2000hsx.googlegroups.com...
> Before I begin my exposition about what keeps the plane afloat, I
> would like anyone who care to participate in this discussion to do a
> couple of simple experiments.
HAHAHAA!!!
Jeez, not again...
-c
Dudley Henriques
A little more tact and just a bit less aggressiveness might be helpful
in making your Usenet aviation experience more satisfying considering
the experience levels ranging in decades rather than mere hours you will
find on these forums.
--
Dudley Henriques
Gatt
> So yes, I believe this experiment illustrates an important phenomenon
> in aerodynamics. It is not the only phenomenon that plays a role, but
> it has one, nevertheless. The decriptions of lift that I read in
> flight books seem to ignore it.
Subsequently, all the airplanes are falling from the sky.
I recommend building an airplane sometime. The ultimate way to prove your
theory is to be like the Wright Brothers; build it and fly it.
Folks on this forum have logged hundreds of thousands if not millions of
collective hours and all of them have put their asses on the line based on
the aerodynamic principles in books, so you're not going to get much respect
here if you want everybody to do experiments just to discuss to your
otherwise-unproven theories. Some people here have built their own planes,
or engineered airplanes, or maintained them so -their- science is
sufficiently proven. All the discussions and textbooks and usenet theories
in the world aren't worth your first solo flight around the pattern. That
demonstrates that the aerospace engineers proved their wing design and that
the pilots here proved their ability to manipulate that technology. That's
what it takes.
About once a month somebody comes in here and wants to talk about how
aerospace science is all wrong but the thing is, none of 'em ever seems to
have flown an airplane. If you don't do their math for them just the way
they want you to, however, somehow it's all the pilots and plane builders
out here who don't know what they're talking about.
I think your theory would be great put into practice on an experimental
aircraft. I promise you, if you fly it they will come. Best of luck to
you.
-c
Gatt
> If eveyone in this group would simply take the advice that you just
> wrote, I think it would be a better group. I have been here only a
> few days, and I count no less than 7 insults by people I have never
> known.
>
> I imagine these individuals as being overweight and constipated,
What you should imagine are pilots who risk their lives countless times
between wings that are proven to work being told to do experiments by
somebody who challenges proven technology and expects everybody to do
experiments just to indulge your accusation that basically everything they
know about aerodynamics is wrong.
It's sort of like an IT guy telling Marines how to fight a war. Probably
not going to get you invited to the NCO's club.
Don't take it personally. It just is. If you were the first person to come
in here and do it they'd probably go easier, but, alas, you're not.
If you have questions about aerodynamic science, perhaps you should first
ask those who use it on a regular basis rather than coming in an suggesting
their understanding of their area of expertise is deficient. Or AT least let
people know you're a pilot, builder or aerodynamics professional.
-c
Dan_Thom...@yahoo.com
> The cigarettes would be lit so that stream of smoke floats
> upward.
Can cigarettes be lit so that the smoke flows downward?
> If flat pressure sensors were mounted below the wing, close to the
> trailing edge, they would show a momentary increase in pressure.
We've been told for years by people who do wind-tunnel
experiments that the pressure on the bottom is not increased. Again,
it's not intuitive. We're feeling drag, not an increase in pressure.
If we hold a funnel (a version of a converging duct) with the big end
to the wind, we'll find accelerating airflow in it, decreasing
pressure, decreasing temperature, and drag that makes us think that
the pressure in it is increasing.
The air below is moving downward, something that could be
measured by an airspeed indicator, but that doesn't mean pressure is
increased. It means that the air has dynamic pressure now because it's
moving, and if it's moving its static pressure has decreased.
Better get building this thing. Get back to us as to the
pressure readings under the wing.
Dan
Dan
Le Chaud Lapin
> What you should imagine are pilots who risk their lives countless times
> between wings that are proven to work being told to do experiments by
> somebody who challenges proven technology and expects everybody to do
> experiments just to indulge your accusation that basically everything they
> know about aerodynamics is wrong.
Not true. I do not recall any "accusation that basically everything
they know about aerodynamics is wrong." I wrote that there are some
things in the Jeppensen book that are just plain wrong, as is the
explanation of action/reaction with regard to downwash.
> It's sort of like an IT guy telling Marines how to fight a war. Probably
> not going to get you invited to the NCO's club.
What has IT got to do with a war? My writings were very specific,
involving aerodynamics.
> Don't take it personally. It just is. If you were the first person to come
> in here and do it they'd probably go easier, but, alas, you're not.
Things would go a lot easier if people would focus on the physics and
ease up on the ad hominem attacks.
> If you have questions about aerodynamic science, perhaps you should first
> ask those who use it on a regular basis rather than coming in an suggesting
> their understanding of their area of expertise is deficient. Or AT least let
> people know you're a pilot, builder or aerodynamics professional.
I did. The answer was "yes, the book is right, and you are wrong."
-Le Chaud Lapin-
Gatt
> On Oct 4, 4:46 pm, "Gatt" <g...@damnnearwiley00.com> wrote:
>>expects everybody to do
>> experiments just to indulge your accusation that basically everything
>> they
>> know about aerodynamics is wrong.
>
> Not true. I do not recall any "accusation that basically everything
> they know about aerodynamics is wrong." I wrote that there are some
> things in the Jeppensen book that are just plain wrong, as is the
> explanation of action/reaction with regard to downwash.
Oh, nevermind, everybody. It's the same guy with a new handle. It's
Jeppesen, and, do you have any idea how many people are successfully flying
with what they learned from the Jeppesen books? Are you one of them?
> What has IT got to do with a war? My writings were very specific,
> involving aerodynamics.
What I'm saying is, until you prove your aerodynamics with something more
than two sheets of paper, nobody gives a damn. Here's a hint: We don't fly
sheets of paper or plywood. If you think it can be done, all you have to do
is build an airplane and demonstrate it.
> I did. The answer was "yes, the book is right, and you are wrong."
Accept it and move on. Don't just change your handle and try again.
-c
Le Chaud Lapin
> "Le Chaud Lapin" <jaibudu...@gmail.com> wrote in messagenews:1191535344.0...@n39g2000hsh.googlegroups.com...
> Oh, nevermind, everybody. It's the same guy with a new handle. It's
My handle has been the same for over a decade.
> Jeppesen, and, do you have any idea how many people are successfully flying
> with what they learned from the Jeppesen books? Are you one of them?
Not yet. I will continue to study my Jeppesen book. That does not
mean that I will blindly accept everything I read.
> > What has IT got to do with a war? My writings were very specific,
> > involving aerodynamics.
>
> What I'm saying is, until you prove your aerodynamics with something more
> than two sheets of paper, nobody gives a damn. Here's a hint: We don't fly
> sheets of paper or plywood. If you think it can be done, all you have to do
> is build an airplane and demonstrate it.
>
> > I did. The answer was "yes, the book is right, and you are wrong."
>
> Accept it and move on. Don't just change your handle and try again.
My handle has been the same for over a decade.
And I will do as I please, thanks.
-Le Chaud Lapin-
Matt Whiting
... Charlie Brown.
Matt Whiting
> Le Chaud Lapin wrote:
>> On Oct 4, 12:48 pm, "Robert M. Gary" <N70...@gmail.com> wrote:
>>> On Oct 3, 7:04 pm, Le Chaud Lapin <jaibudu...@gmail.com> wrote:
>>>> The title of this post implies that I know why airplanes fly. I
>>>> don't, not completely at least. But I do know that I have read a lot
>>>> of "official" explanations that are just plain wrong.
>>> Or just buy the book "Aerodynamics for Naval Aviators" and look at the
>>> pictures.
>>>
>>> -Robert
>>
>> What will I see?
>>
>> -Le Chaud Lapin-
>>
>
> What will I see????
>
> The collective knowledge of the finest aerodynamics minds since the dawn
> of aviation. ANA is the "bible" for anyone from Astronauts to Student
> Pilots. It's not written for the casual user however.
Can us nonNaval aviators still read it? :-)
Matt
Dudley Henriques
Absolutely! Accurate information is accurate information to
all.....well, ALMOST all anyway!! :-))
--
Dudley Henriques
Bertie the Bunyip
Teh book is right.
Bertie
Crash Lander
news:1191463474.6...@19g2000hsx.googlegroups.com...
> Hi,
>
> The title of this post implies that I know why airplanes fly. I
> don't, not completely at least. But I do know that I have read a lot
> of "official" explanations that are just plain wrong.
If one does not know the correct answer, how can one even suggest that a
proposed answer is in fact wrong?
Crash Lander
--
Straight and Level Down Under.
http://www.straightandleveldownunder.net/
Dudley Henriques
> "Le Chaud Lapin" <jaibu...@gmail.com> wrote in message
> news:1191463474.6...@19g2000hsx.googlegroups.com...
>> Hi,
>>
>> The title of this post implies that I know why airplanes fly. I
>> don't, not completely at least. But I do know that I have read a lot
>> of "official" explanations that are just plain wrong.
>
> If one does not know the correct answer, how can one even suggest that a
> proposed answer is in fact wrong?
> Crash Lander
Hold on a minute. My wife will know this one!!!!
:-)
--
Dudley Henriques
ManhattanMan
Oh gawd, yours too?
If you answer a question in the woods, and your wife isn't there, are you
still wrong? :)
Dudley Henriques
Absolutely! A constant is a constant!!!!
:-)
--
Dudley Henriques
Matt Whiting
If you have to ask you wife, then you are wrong by definition! :-)
Matt
Tina
> >news:1191463474.6...@19g2000hsx.googlegroups.com...
> >> Hi,
>
> > If one does not know the correct answer, how can one even suggest that a
> > proposed answer is in fact wrong?
> > Crash Lander
>
> Hold on a minute. My wife will know this one!!!!
> :-)
>
> --
may be a reasonaable assumption -- but don't make it about M Mx.
Crash Lander
news:dbGdnTp6WbHyFJja...@rcn.net...
>> If one does not know the correct answer, how can one even suggest that a
>> proposed answer is in fact wrong?
>> Crash Lander
>
>
> Hold on a minute. My wife will know this one!!!!
> :-)
>
> --
> Dudley Henriques
You sold your set of Encyclopaedias too then? I had no use for mine, as the
wife knows everything.
Dudley Henriques
LCL is a rabbit. I don't know about Mx. He could also be a rabbit
according to Bertie the Bunyip.
Are we still an aviation forum? I'll have to ask my wife :-))
--
Dudley Henriques
Dallas
> You sold your set of Encyclopaedias too then? I had no use for mine, as the
> wife knows everything.
Yup CL... sometimes yer priceless.
:-)
--
Dallas
Dallas
> I would point out the underlying assumption is LCL is married. That
> may be a reasonaable assumption -- but don't make it about M Mx.
Nope, sorry Tina... that's an incorrect assumption.
From LCL in RAS: "[No, I don't have a girlfriend]."
--
Dallas
Crash Lander
news:1c26bsxy2oav3$.qp30cjjm8789$.dlg@40tude.net...
> Nope, sorry Tina... that's an incorrect assumption.
>
> From LCL in RAS: "[No, I don't have a girlfriend]."
>
> --
> Dallas
Not necessarily Dallas. I don't have a girlfriend either. My wife won't
allow it!
Dallas
> Not necessarily Dallas. I don't have a girlfriend either. My wife won't
> allow it!
Got me twice in less that an hour! CL you're on fire.
LOL.
--
Dallas
Ron
wrote:
I will first admit I haven't done the experiments outlined in Lapin's
posts. I will second admit that airplanes do fly. Thirdly I will
admit there are many very good reference books on "why" airplanes fly.
The key word here is "why". The fact that people can design and build
a machine that flies, means they have mastered the elements of design
that allow an aircraft to fly. It doesn't mean they know "why" it
flies. There are accepted theories, disproved theories, questionable
theories and unproven theories, but they are all theories.
Le Chaud Lapin has posted some experiments that in their present form
exhibit some interesting characteristics. Whether or not these
characteristics can be extrapolated to winged aircraft remains to be
seen. Certainly further, much more complex, testing would have to be
done. However, that fact should not provoke the kind of vitriolic
attacks I've seen in this forum. Just because someone posts something
outside the box of conventional thinking is no reason to attack them.
Ron Kelley
Bertie the Bunyip
> On Oct 4, 5:20 pm, "Gatt" <g...@damnnearwiley00.com> wrote:
>> "Le Chaud Lapin" <jaibudu...@gmail.com> wrote in
>> messagenews:1191535344.0...@n39g2000hsh.googlegroups.com...
>> Oh, nevermind, everybody. It's the same guy with a new handle.
>> It's
>
> My handle has been the same for over a decade.
>
>> Jeppesen, and, do you have any idea how many people are successfully
>> flying with what they learned from the Jeppesen books? Are you one
>> of them?
>
> Not yet. I will continue to study my Jeppesen book. That does not
> mean that I will blindly accept everything I read.
Wel, if you do ever leave your bedroom and take a flying lesson that will
turn out to be some CO2 pumped into the atmosphere for nothing.
At least your instructor will make enough to supersize off you.
Bertie
>
>
>
>
Le Chaud Lapin
> I will first admit I haven't done the experiments outlined in Lapin's
> posts. I will second admit that airplanes do fly. Thirdly I will
> admit there are many very good reference books on "why" airplanes fly.
> The key word here is "why". The fact that people can design and build
> a machine that flies, means they have mastered the elements of design
> that allow an aircraft to fly. It doesn't mean they know "why" it
> flies. There are accepted theories, disproved theories, questionable
> theories and unproven theories, but they are all theories.
>
> Le Chaud Lapin has posted some experiments that in their present form
> exhibit some interesting characteristics. Whether or not these
> characteristics can be extrapolated to winged aircraft remains to be
> seen. Certainly further, much more complex, testing would have to be
> done. However, that fact should not provoke the kind of vitriolic
> attacks I've seen in this forum. Just because someone posts something
> outside the box of conventional thinking is no reason to attack them.
> Ron Kelley
Thanks Ron.
Given the ratio of ad hominem attacks I have experienced in my first
few days here versus true exploration, I was beginning to wonder if
the 10 people or so who have been responding are representative of
this group, since they do seem to generate the most messages. I saw
your post about 30 seconds after and concluded that perhaps they are
not.
-Le Chaud Lapin-
Jim Logajan
> Given the ratio of ad hominem attacks I have experienced in my first
> few days here versus true exploration, I was beginning to wonder if
> the 10 people or so who have been responding are representative of
> this group, since they do seem to generate the most messages. I saw
> your post about 30 seconds after and concluded that perhaps they are
> not.
First, I finally found time to read your initial post to this thread. It is
true that all the explanations you've read over the years are not quite
right - that is due to the nature of fluid dynamics. Except for some
trivial examples, the mathematics can't be solved except by numeric
approximation methods. The Bernoulli theorem for example assumes a pre-
existing streamline. It does not actually provide the all-important
streamlines! Otherwise the theorem does take account of all the applicable
conservation laws - but not in a form that can shed much insight into lift
(IMHO).
As to the response you've seen - well, I have some theories but if they are
correct there is nothing I can do, except possibly indirectly. Such as
making this post.
I think for the purposes of piloting that one does not need to know the
Navier-Stokes equations. Because quite honestly the real explanation of
lift is to be found in the differential equations (or integral form)
governing mass continuity, momentum, and energy. All those simple
explanations are just that - simple and obviously incomplete. Rest assured
you're correct in your observations on the inadequate explanations - but
don't make the mistake of assuming a simple _and_ accurate one must exist,
if only you think hard enough on it.
If you are interested in some books on the subject I'd be happy to make
some suggestions.
Bertie the Bunyip
@w3g2000hsg.googlegroups.com:
Except we both know that isn't what you are doing.
Bertie
Le Chaud Lapin
> Le Chaud Lapin <jaibudu...@gmail.com> wrote:
> I think for the purposes of piloting that one does not need to know the
> Navier-Stokes equations.
That's true.
> Because quite honestly the real explanation of
> lift is to be found in the differential equations (or integral form)
> governing mass continuity, momentum, and energy.
Yes, I agree.
> All those simple
> explanations are just that - simple and obviously incomplete. Rest assured
> you're correct in your observations on the inadequate explanations - but
> don't make the mistake of assuming a simple _and_ accurate one must exist,
> if only you think hard enough on it.
I never thought that my explanation was complete or accurate. I
offered it because, IMO, it has a sificant influence on airfoil
dynamics. But after reading several books that ignore the partial
vacuum, and one book that was wrongly employing Newton's thereom...
[which is intolerable on any grounds, let alone aerodynamics], I had
to read more.
In his book, "The Proficient Pilot", on page 8, Barry Schiff writes:
"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."
In his book Learning to Fly With Rod Machado, on page 70, Rod Machado
writes:
"Because air flowing over the wing bends, it is forced to travel a
greater distance than the air flowing underneath. Because it travels a
greater distance, the bent air must move faster on its journey over
the wing. It's this relative increase in wind speed above the wing
that lowers pressure and productes lift."
Since I was new to piloting, I asked a few pilots if they understood
aerodynamics about an airfoil, and they all said yes. The reason they
gave is the one that Rod Machado gave. I asked the older pilots if
they knew who Barry Schiff was, and they said yes. I asked them if
they realized that Barry Schiff did not think that was the reason, and
they said I was mistaken, that Barry Schiff would never be as confused
as I seemed to be about flying. I asked them if they knew who Rod
Machado was. They said yes. I asked them if they thought that Rod
Machado and Barry Schiff would agree. They said yes. I asked them if
they were 100% certain, and they said yes.
Thus began my earnest interest in aerodynamics. I had always been
interested in flying, but this accelerated the interest quite a bit.
I took a sheet of paper and blew over it, the trick that we've all
done, and it went up of course, but I suspected that the reason it
went up was not the reason that was being given by so many people.
I visited a few aero/astro departments online, and while no one is
going to argue with the mathematics of field theory...I did get the
feeling that there were experts in the field saying the opposite
things. So before digging into the math [afterall, there is nothing
wrong with math], I decided to refresh my understanding of Bernoulli's
theorem from my old physics book, and while reading that book, it
occured to me that Barry Schiff's view is more likely right than
not...that is, until I read his explanation of relationship between
Newton and downwash on the next 2 pages of his book. I found a couple
of other books that gave the explanation of downwash that was
similar. Most importantly, I also notice that there was a ***HUGE***
amount of hand-waving going on, far more than one would expect in a
field that has been researched for over a century. I still need to
find a book that I can trust.
I went to the WWW and started reading more aero-astro excerpts, and
concluded that not only is theory still in flux, the experts do not
even agree on the basics. The very basics. Huge amounts of money had
been spent on wind-tunnels. But after all that, I could not get two
experts to agree on the basics. And this was a not simply a matter of
different styles, using integral instead of differential form of
equations, for example, or, deciding where to put a constant, as we
electrical engineers do in our expressions of the Fourier
integrals...there was *fundamental* disgreement about what causes lift
on an airplane.
I asked one of the pilot's again..."How sure are you that the aviation
world understands the basics?" He said he was very sure. He started
rattling off things about NASA.
I begin to imagine airflow over a wing and concluded that pinching at
front of wing must be very important, more important than one would
think, reading the explanations. I also concluded that a glider
should have wings that are very long but with a short cord, which aslo
turned out to be true. I then revisited my physics book...and it
_appeared_ that the application of Bernoulli to flying is wrong in
many contexts, but I decided to not discuss that just yet because it
would be too controversial.
I ask one of the pilots if he thought rarefication had anything to do
with it. He said, "No, it's all Bernoulli." I asked him what would
happen if I did the paper experiment, the one mentioned in my OP, and
he did not know, but said it does not matter because a piece of paper
is not a wing and it does not fly through the air. I asked him if he
understood why the paper would move, and he said, again, it does not
matter. I asked him if he saw any relation between my paper experiment
and the movement of a airfoil, and he said, finally, no, there is
none, because it is all Bernoulli.
I asked a CFI one last time, and he too said it was all Bernoulli,
precisely the argument that Barry Schiff refutes in his book.
So I started imagining, with no mathematics, what goes on with fluids
around surfaces, which lead me to these various experiments.
> If you are interested in some books on the subject I'd be happy to make
> some suggestions.
Sure.
-Le Chaud Lapin-
Gatt
"Ron" <r...@never.org> wrote in message
news:iufbg3p82p65voh55...@4ax.com...
> However, that fact should not provoke the kind of vitriolic attacks I've
> seen in this forum. Just because someone posts something
> outside the box of conventional thinking is no reason to attack them.
The same person posted the same sort of stuff a month or so ago under a
different name, and hasn't acknowledged that he's the same guy.
The vitriol is because it's intellectually dishonest to come in and approach
the group as if you're new to the discussion, and then make reference to
something from a thread that was discussed a month ago.
Additionally, there's a difference between coming in and posting out of the
box versus coming in and suggesting that all the textbooks are wrong. If he
wants less vitriol he'll approach our common understanding of aerodynamic
science with a little more respect when among our own community.
-c
Bertie the Bunyip
news:1191593607.4...@r29g2000hsg.googlegroups.com:
> On Oct 5, 1:11 am, Jim Logajan <Jam...@Lugoj.com> wrote:
>> Le Chaud Lapin <jaibudu...@gmail.com> wrote:
>> I think for the purposes of piloting that one does not need to know
>> the Navier-Stokes equations.
>
> That's true.
>
>> Because quite honestly the real explanation of
>> lift is to be found in the differential equations (or integral form)
>> governing mass continuity, momentum, and energy.
>
> Yes, I agree.
>
>> All those simple
>> explanations are just that - simple and obviously incomplete. Rest
>> assured you're correct in your observations on the inadequate
>> explanations - but don't make the mistake of assuming a simple _and_
>> accurate one must exist, if only you think hard enough on it.
>
> I never thought that my explanation was complete or accurate. I
> offered it because, IMO, it has a sificant influence on airfoil
> dynamics.
Ooow! Write Nasa quick! Your research is obviously going to enable the next
critical leap in aeronautical sciences!
Bwawahwhhahwhahwhahwhahwhahwhahwhahawh!
Bertie
Le Chaud Lapin
> The same person posted the same sort of stuff a month or so ago under a
> different name, and hasn't acknowledged that he's the same guy.
>
> The vitriol is because it's intellectually dishonest to come in and approach
> the group as if you're new to the discussion, and then make reference to
> something from a thread that was discussed a month ago.
I have never assumed any other alias on USENET other than the one that
I a currently using in the 20 years I have been using the Internet.
-Le Chaud Lapin-
Le Chaud Lapin
Correction:
Several years ago due to problems with email, I used a different
alias. But beyond that, my aliases has always been the same.
In any case, I have never assumed any alias other than the one that I
am currently using in this group, because I've only recently begun to
post in this group.
-Le Chaud Lapin-
Bertie the Bunyip
Snort!
Bertie
>
>
Bertie the Bunyip
Yeh, right.
Bertie
Gatt
> In any case, I have never assumed any alias other than the one that I
> am currently using in this group, because I've only recently begun to
> post in this group.
Fair enough. Just understand then that on occasion somebody comes in here
claiming that their physics trumps established, documented science, and
usually these people don't actually fly airplanes.
Of course, actually flying airplanes is only relevant because 1) this is a
"piloting" newsgroup and 2) lots of people come out on the internet claiming
to prove or disprove everything, such as 9/11 conspiracies, but they have
nothing to show for it.
Somebody else posted a link to the SR-71 Blackbird flight manual. I
daresay, the people who developed that understood aviation a whole hell of a
lot better than most engineers, and so whatever science they used to derive
that design (and the P-38, and the U-2) is good enough for me. To suggest
that the likes of Kelly Johnson's understanding of aerodynamics is flawed in
a pilot's forum is going to be met with hostility by many here. Especially
if your tone, delivery and style conspicuously match that of people who have
previoulsy challenged aviation here.
-c
Jim Logajan
> The same person posted the same sort of stuff a month or so ago under
> a different name, and hasn't acknowledged that he's the same guy.
What name might that be?
george
>
> You sold your set of Encyclopaedias too then? I had no use for mine, as the
> wife knows everything.
Unless of course you have a teenager in the house.
Then even the wife has a 99% error rate
:-)
Robert M. Gary
> Le Chaud Lapin <jaibudu...@gmail.com> wrote innews:1191521212.4...@r29g2000hsg.googlegroups.com:
>
> > What will I see?
>
> Lots of pictures which is probably all you can comprehend.
hehehe, that actually isn't how I meant it. I find that many of the
pictures in the book do an excellent job of describing stall
progression. I've been known to pick up my copy and just thumb through
the pictures on occassion.
-robert
Matt Whiting
> I never thought that my explanation was complete or accurate. I
> offered it because, IMO, it has a sificant influence on airfoil
> dynamics. But after reading several books that ignore the partial
> vacuum, and one book that was wrongly employing Newton's thereom...
> [which is intolerable on any grounds, let alone aerodynamics], I had
> to read more.
Newton had only one theorem? Wow, I always thought he had several...
Matt
muff528
"Matt Whiting" <whi...@epix.net> wrote in message
news:ggzNi.191$2n4....@news1.epix.net...
Not many are familiar with Newton's 4th Law --- "One Fig to a Cookie"
TP
Mxsmanic
> I recommend building an airplane sometime. The ultimate way to prove your
> theory is to be like the Wright Brothers; build it and fly it.
>
> Folks on this forum have logged hundreds of thousands if not millions of
> collective hours and all of them have put their asses on the line based on
> the aerodynamic principles in books ...
But they have not built airplanes, as you suggest (with a few rare exceptions,
and even then they did not design them).
> About once a month somebody comes in here and wants to talk about how
> aerospace science is all wrong but the thing is, none of 'em ever seems to
> have flown an airplane.
Flying an airplane wouldn't help, although designing one (successfully) would.
Mxsmanic
> Given the ratio of ad hominem attacks I have experienced in my first
> few days here versus true exploration, I was beginning to wonder if
> the 10 people or so who have been responding are representative of
> this group, since they do seem to generate the most messages.
Those who engage rapidly in personal attacks are the most active posters, but
are not necessarily representative. Personal attacks are very easy to
construct and thus can be launched very quickly. Rational argument or debate
is much more difficult.
Mxsmanic
> Especially
> if your tone, delivery and style conspicuously match that of people who have
> previoulsy challenged aviation here.
I have never seen anyone challenge aviation here. I have seen people refuse
to be intimidated by the yelping alpha dogs and playground bullies, but that's
quite different.
Gatt
"Jim Logajan" <Jam...@Lugoj.com> wrote in message
news:Xns99C066CCE3B2...@216.168.3.30...
Don't remember. IIRC he was babbling about how Bournouli was wrong and how
upper camber is irrelvant. Do you remember?
-c
Mxsmanic
> I am not a Naval Aviator. That title is reserved for the finest pilots
> in the world.
There might be some Air Force pilots who disagree with that.
> You know Moore, if you spent a bit less time trying to discredit me and
> a bit more simply engaging me on a slightly more friendly basis, you and
> I might actually get along.
You dislike personal attacks?
> You're choice; you can have the debrief notes, or you can stop this
> constant under posting of me requesting backup information on me.
Or he can continue to attack you.
Mxsmanic
> If eveyone in this group would simply take the advice that you just
> wrote, I think it would be a better group. I have been here only a
> few days, and I count no less than 7 insults by people I have never
> known.
>
> I imagine these individuals as being overweight and constipated,
> reading my posts, debating whether they should take a laxative or fire
> off an insult, the latter choice leaving them in the same state they
> were before they read my post.
They are simply the typical males of USENET who have more testosterone than
intellect and behave accordingly. It is a type of background noise that never
goes away, so one must learn to ignore it.
Mxsmanic
> A little more tact and just a bit less aggressiveness might be helpful
> in making your Usenet aviation experience more satisfying considering
> the experience levels ranging in decades rather than mere hours you will
> find on these forums.
Claims of experience are valueless on USENET, because anyone can make claims.
The only way to earn respect is to demonstrate competence, not to merely claim
it. Credentials are a dime a dozen in this venue.
Mxsmanic
> What you should imagine are pilots who risk their lives countless times
> between wings that are proven to work being told to do experiments by
> somebody who challenges proven technology and expects everybody to do
> experiments just to indulge your accusation that basically everything they
> know about aerodynamics is wrong.
But that would not be accurate.
It's more a matter of aggressive males who are highly insecure concerning
their ignorance of many things and try to conceal their ignorance with puerile
personal attacks. The only words they cannot utter are "I don't know."
> It's sort of like an IT guy telling Marines how to fight a war. Probably
> not going to get you invited to the NCO's club.
What about Marines telling IT guys how to program computers?
> Don't take it personally. It just is. If you were the first person to come
> in here and do it they'd probably go easier, but, alas, you're not.
No, that doesn't matter. The behavior is always the same, and it is as
predictable as clockwork, and as unavoidable as the tide.
> If you have questions about aerodynamic science, perhaps you should first
> ask those who use it on a regular basis rather than coming in an suggesting
> their understanding of their area of expertise is deficient. Or AT least let
> people know you're a pilot, builder or aerodynamics professional.
Using something is not the same as understanding it, as so many accidents in
aviation prove.
Mxsmanic
> Things would go a lot easier if people would focus on the physics and
> ease up on the ad hominem attacks.
Not for people who don't understand the physics and dread admitting it. For
them, personal attacks are about the only option.
Gatt
"Jim Logajan" <Jam...@Lugoj.com> wrote in message
news:Xns99C066CCE3B2...@216.168.3.30...
Hey, I found it: It's under the thread "John Travolta Sues His Home
Airport" circa August 10.
The person's exact words were "Camber does not produce lift" and he quoted a
NASA site that contradicted him. He also said
"Many pilots don't understand that angle of attack is everything. That's
why many of them get into trouble in unusual situations. "
I'll give you guys ONE guess who that person was, and you probably don't
need a hint, but he's undoubtedly the most accomplished Flight Simulator
pilot on the newsgroup.
-c
Gatt
> On Oct 4, 4:46 pm, "Gatt" <g...@damnnearwiley00.com> wrote:
> Not true. I do not recall any "accusation that basically everything they
> know about aerodynamics is wrong." I wrote that there are >some things in
> the Jeppensen book that are just plain wrong, as is the explanation of
> action/reaction with regard to downwash.
Wow, Lapin. For somebody who wrote: "In any case, I have never assumed any
alias other than the one that I
am currently using in this group, because I've only recently begun to post
in this group," your statement sure sounds AWFUL similar to:
"A wing creates a downward acceleration called downwash which contributes to
lift." - MXManiac
"Hint: the same thing applies to your "downwash theory of lift"." - Doug
Semler to MX, August 3, in the thread "John Travolta Sues His Home Airport.
-ALSO-
"Things would go a lot easier if people would focus on the physics and ease
up on the ad hominem attacks." -Lapin
"Perhaps if they were less obsessed with the poster and concentrated more
on the topic such anomalies would not arise." - MXManiac, 8/4/2007
"My handle has been the same for over a decade." - Laupin
"I have never assumed any other alias on USENET other than the one that I am
a currently using ..." - Laupin
"But beyond that, my aliases has always been the same."
(AliasES? AliasES have always been the same? I'm not Sherlock Holmes here,
but I SWEAR you've been saying your handle has been the same for over a
decade.)
-c
Tina
LCL's posting history you'll find groups and technology far different
than our resident jerk. I agree there are common characteristics, but
i do not think MX is capable of isolating the two distinct patterns
I'm seeing.
I've admited many times I'm not a pilot so don't attempt to speak with
authority on piloting techniques, but I am the resident shrink. In
this matter the odds are you're in error.
Jim Logajan
> Most importantly, I also notice that there was a ***HUGE***
> amount of hand-waving going on, far more than one would expect in a
> field that has been researched for over a century. I still need to
> find a book that I can trust.
How much math are you willing to deal with?
If you can handle some calculus, then probably the least expensive book I
know of that may fit the bill is:
"Theoretical Aerodynamics" by L. M. Milne-Thomson.
Paperback edition is available from Dover Press.
> I went to the WWW and started reading more aero-astro excerpts, and
> concluded that not only is theory still in flux, the experts do not
> even agree on the basics. The very basics. Huge amounts of money had
> been spent on wind-tunnels. But after all that, I could not get two
> experts to agree on the basics. And this was a not simply a matter of
> different styles, using integral instead of differential form of
> equations, for example, or, deciding where to put a constant, as we
> electrical engineers do in our expressions of the Fourier
> integrals...there was *fundamental* disgreement about what causes lift
> on an airplane.
I have no idea what web sites you have visited - all I can say is that
there is _no_ dispute among experts on the very basics. Aerodynamic
models are now run routinely on computers - the field is known as
Computational Fluid Dynamics (CFD) - which would hardly be possible if
the very basics were still in dispute!
> I asked one of the pilot's again..."How sure are you that the aviation
> world understands the basics?" He said he was very sure. He started
> rattling off things about NASA.
NASA is an excellent and authoritative source and you'll be very pleased
to discover they have web pages that address the VERY SAME COMPLAINTS you
have about many of the bogus explanations of lift that are floating
around. Here are two of the most relevant pages you should read:
http://www.grc.nasa.gov/WWW/K-12/airplane/bernnew.html
Excerpt from the above:
"Arguments arise because people mis-apply Bernoulli and Newton's
equations and because they over-simplify the description of the problem
of aerodynamic lift. The most popular incorrect theory of lift arises
from a mis-application of Bernoulli's equation."
http://www.grc.nasa.gov/WWW/K-12/airplane/wrong1.html
Excerpt from the above:
"There are many theories of how lift is generated. Unfortunately, many of
the theories found in encyclopedias, on web sites, and even in some
textbooks are incorrect, causing unnecessary confusion for students.
The theory described on this slide is one of the most widely circulated,
incorrect explanations. The theory can be labeled the "Longer Path"
theory, or the "Equal Transit Time" theory."
> So I started imagining, with no mathematics, what goes on with fluids
> around surfaces, which lead me to these various experiments.
It is a great idea to experiment - even with things others already
understand. I do it too.
>> If you are interested in some books on the subject I'd be happy to
>> make some suggestions.
>
> Sure.
In addition to the above, there are a couple of other (expensive, alas)
books I would suggest:
"Introduction to Flight" by John D. Anderson, Jr.
Contains a history of the science of flight and also goes into details on
some of the more common mistakes people make in explanations of lift. I
do not own this book, but others also give it great reviews.
"Fundamentals of Aerodynamics" by John D. Anderson, Jr.
A well regarded, though mathematical, text on the subject. I do not own
this book either, but I expect it is good, based on my knowledge of the
next book I mention:
"Computational Fluid Dynamics" By John D. Anderson.
I bought and read through this book a couple years ago and it does a
great job of introducing CFD. I mention it here only because it is how I
know the style and quality of Anderson's writing to confidently recommend
two of his other books (above) that I have not read! He carefully disects
and explains each of the differential equations of the various types used
for computational modeling, among the many things covered.
Jim Logajan
Sounds vaguely familiar - but no specifics come to mind.
Jim Logajan
> Hey, I found it: It's under the thread "John Travolta Sues His Home
> Airport" circa August 10.
>
> The person's exact words were "Camber does not produce lift" and he
> quoted a NASA site that contradicted him. He also said
> "Many pilots don't understand that angle of attack is everything.
> That's why many of them get into trouble in unusual situations. "
>
> I'll give you guys ONE guess who that person was, and you probably
> don't need a hint, but he's undoubtedly the most accomplished Flight
> Simulator pilot on the newsgroup.
Oh - I rarely read his posts, so that may be why I missed it.
Viperdoc
physician.
His disdain for those with experience, training, or degrees is simply a
reflection of his own lack of the same. An attempt at engaging him in a
reasonable discourse will rapidly degenerate into a meaningless interchange
where he will attempt to demonstrate his superior knowledge and intellect,
despite the fact that he has neither.
Viperdoc
Viperdoc
Le Chaud Lapin
> How much math are you willing to deal with?
I am comfortable with graduate-level mathematics. :)
> If you can handle some calculus, then probably the least expensive book I
> know of that may fit the bill is:
>
> "Theoretical Aerodynamics" by L. M. Milne-Thomson.
> Paperback edition is available from Dover Press.
Dover. I will assume it is cheap and take a look.
> I have no idea what web sites you have visited - all I can say is that
> there is _no_ dispute among experts on the very basics.
Well, someone should have told me that Rob Machado and Barry Schiff
are not experts. I did read once that Rod Machado has a Ph.D. in
aviation science, and the foreword to Barry Schiff's book is by Ernest
K. Gann, whom I presumed from his credentials is highly respected in
field. Yet Rob Machado and Barry Schiff said the exact opposite,
Barry clearly stating that what Rob stated was non-sense. Note that
there were not talking about something esoteric how precipitation
beings as condensation on nuclei...they have different opinions on the
most basic phenemenon that _any_ student fascinated with flying would
be inclinded to ask: "Why does the plane stay in the air?" Then we
have Jeppesen, a leaders in edcuation of GA. You would think that,
with such a fine product (no sarcasm meant), that they would have
people whom they trust, experts, at the very high-end of academia, who
could verify what's in the text. But what is in my Jeppensen book and
what Barry Schiff wrote is wrong.
Now I could have gone to some university in the U.S., Germany, France,
and found someone with stratospheric credentials in aero-astro, but
after seeing one expert say that the other is wrong, and then seeing
an incorrect application of Newton's law (yes I still believe it's
incorrect), I had to put on the brakes.
> Aerodynamic
> models are now run routinely on computers - the field is known as
> Computational Fluid Dynamics (CFD) - which would hardly be possible if
> the very basics were still in dispute!
Hmm...how shall I say this. It is very similar to what Ron said in my
defense.
In any field of research, there is mind and hand. For artists in the
field, there are those who have a proclivity to use hand more than
mind, and there are those who have a proclivity to use mind more than
hand. In any case, there are typically multiple paths to discovery,
one major path relying heavily on the imagination, the other path
relying on experimentation. Typically there is a combination. Based
on the small amount of the field of aerodynamcis I have seen so far,
and the disputes and inconsistencies, I would not be surprised if
there is an enormous amount of money being spent on experimentation.
Granted, experimentation is very necessary to validate (or invalidate)
what was conceived, but in many fields, there are researchers who
adopt the brute force approach, not completely, but much more than
someone who, lacking $100's of millions in funding would.
> > I asked one of the pilot's again..."How sure are you that the aviation
> > world understands the basics?" He said he was very sure. He started
> > rattling off things about NASA.
>
> NASA is an excellent and authoritative source and you'll be very pleased
> to discover they have web pages that address the VERY SAME COMPLAINTS you
> have about many of the bogus explanations of lift that are floating
> around. Here are two of the most relevant pages you should read:
I will read that...but there seems to be a contradiction of what you
are saying. OTOH, you're saying that there is no disputes amond
experts. On the other hand, you're saying that other people
(institutions) are complaining about the same thing.
> http://www.grc.nasa.gov/WWW/K-12/airplane/bernnew.html
>
> Excerpt from the above:
> "Arguments arise because people mis-apply Bernoulli and Newton's
> equations and because they over-simplify the description of the problem
> of aerodynamic lift. The most popular incorrect theory of lift arises
> from a mis-application of Bernoulli's equation."
Ok, I just read that entire page, and yes, it is comforting to see
that NASA is at least dispelling the myth that is being put forth by
Jeppensen's book and Rod Machado's book. I guess Barry Schiff was
right.
> Excerpt from the above:
> "There are many theories of how lift is generated. Unfortunately, many of
> the theories found in encyclopedias, on web sites, and even in some
> textbooks are incorrect, causing unnecessary confusion for students.
Entirely unnecessary.
> The theory described on this slide is one of the most widely circulated,
> incorrect explanations. The theory can be labeled the "Longer Path"
> theory, or the "Equal Transit Time" theory."
>
> > So I started imagining, with no mathematics, what goes on with fluids
> > around surfaces, which lead me to these various experiments.
>
> It is a great idea to experiment - even with things others already
> understand. I do it too.
Oh, I plan to.
> In addition to the above, there are a couple of other (expensive, alas)
> books I would suggest:
>
> "Introduction to Flight" by John D. Anderson, Jr.
> Contains a history of the science of flight and also goes into details on
> some of the more common mistakes people make in explanations of lift. I
> do not own this book, but others also give it great reviews.
>
> "Fundamentals of Aerodynamics" by John D. Anderson, Jr.
> A well regarded, though mathematical, text on the subject. I do not own
> this book either, but I expect it is good, based on my knowledge of the
> next book I mention:
>
> "Computational Fluid Dynamics" By John D. Anderson.
> I bought and read through this book a couple years ago and it does a
> great job of introducing CFD. I mention it here only because it is how I
> know the style and quality of Anderson's writing to confidently recommend
> two of his other books (above) that I have not read! He carefully disects
> and explains each of the differential equations of the various types used
> for computational modeling, among the many things covered.
A lot of J. D. Anderson.
Another note:
On my way to and from a party tonight, I thought in more detail about
Bernoulli's theorem, and I am more certain that not that I understand
the venturi tube, why the fluids, move, the distribution of pressures,
etc. Bernoulli's theorem is, indeed, at work over an airfoil, but is
has nothing to do with the descriptions that are being put forward by
the incorrect texts [really nothing]. All that business about one
side being longer is *not* the reason.
I guess the most important thing I learned from this experiences is
that, if it is true that the field of aerodynamics is fully-cooked,
the experts need to tell everyone else so that they stop printing (as
late as 2006) erroneous information in textbooks about the very
basics.
-Le Chaud Lapin-
Bertie the Bunyip
news:pjjdg3l3gidlfl0j3...@4ax.com:
> Gatt writes:
>
>> I recommend building an airplane sometime. The ultimate way to prove
>> your theory is to be like the Wright Brothers; build it and fly it.
>>
>> Folks on this forum have logged hundreds of thousands if not millions
>> of collective hours and all of them have put their asses on the line
>> based on the aerodynamic principles in books ...
>
> But they have not built airplanes, as you suggest (with a few rare
> exceptions, and even then they did not design them).
I have.
>
>> About once a month somebody comes in here and wants to talk about how
>> aerospace science is all wrong but the thing is, none of 'em ever
>> seems to have flown an airplane.
>
> Flying an airplane wouldn't help, although designing one
> (successfully) would.
>
You haven't done either, fjukkktard
Bertie
Bertie the Bunyip
news:4njdg3tkemulv68qj...@4ax.com:
Actualy, with you , either would be impossible.
You have the one redeeming feature of being a reliable target, though. A
bit like a Whack A Mole
Bertie
Bertie the Bunyip
news:f2kdg3d4t59f9i0vt...@4ax.com:
How can it be an attack if you don' care a whit for anyone's opinion?
You're an idiot.
Bertie
Bertie the Bunyip
news:f6kdg3l810hglnk0h...@4ax.com:
Bullshit, you ignore nothing, wannabe boi
Bertie
Bertie the Bunyip
news:18kdg3103gm0se8fe...@4ax.com:
So, ardly anyone makes claims of experience. They relate experiences, but
make few claims.
You , OTOH...
Bertie
Bertie the Bunyip
news:p9kdg3plibke9a0g0...@4ax.com:
> Gatt writes:
>
>> What you should imagine are pilots who risk their lives countless
>> times between wings that are proven to work being told to do
>> experiments by somebody who challenges proven technology and expects
>> everybody to do experiments just to indulge your accusation that
>> basically everything they know about aerodynamics is wrong.
>
> But that would not be accurate.
>
Anyd you are a liar.
Bertie
Bertie the Bunyip
news:2fkdg3lf5s32t0gla...@4ax.com:
I undertand physics quite well, and obviously much better than you ,
fjukkwit.
Bertie
Bertie the Bunyip
news:irjdg394020km9ksu...@4ax.com:
> Gatt writes:
>
>> Especially
>> if your tone, delivery and style conspicuously match that of people
>> who have previoulsy challenged aviation here.
>
> I have never seen anyone challenge aviation here.
You're an idiot.l
Bertie
Bertie the Bunyip
news:afdc24efd5f6044d...@dizum.com:
> -----BEGIN PGP SIGNED MESSAGE-----
>
> From: Tina <tbake...@gmail.com>
>
>>Gatt, I think you're wrong about the dual id. If you take a look at
>>LCL's posting history you'll find groups and technology far different
>>than our resident jerk. I agree there are common characteristics, but
>>i do not think MX is capable of isolating the two distinct patterns
>>I'm seeing.
>
> OK, I had to look at LCL's other posting history.
>
> MX is a failed computer programmer. Does that explain the other
> "groups"?
>
> It's hard to change one's writing style.
>
> MX and LCL use the same phrases and argument progression.
>
> 1) "I've got all the answers"
> 2) "Like most people, especially those who have spent their lives
> studying a subject, you are confused"
> 3) "Here's a quote that, when taken out of context, says I'm right"
> 4) "Here's a stupid and irrelevant question for you"
> 5) "Do your own research to support my claims"
> 6) "You're picking on me because I'm smarter than all of you and you
> don't like it"
>
> That pretty much sums up every exchange with MX and also the recent
> appearance of LCL.
>
> Dollars to donuts they're the same idiot.
I agree. This is clasic sockpuppetry, Tina. Fascinating phenomenon you
really aren;t going to get a better view of than in usenet.
Keep watching, it gts better.
Bertie
Morgans
"Gatt" <ga...@damnnearwiley00.com> wrote
> Hey, I found it: It's under the thread "John Travolta Sues His Home
> Airport" circa August 10.
>
> The person's exact words were "Camber does not produce lift" and he quoted
> a NASA site that contradicted him. He also said
> "Many pilots don't understand that angle of attack is everything. That's
> why many of them get into trouble in unusual situations. "
>
> I'll give you guys ONE guess who that person was, and you probably don't
> need a hint, but he's undoubtedly the most accomplished Flight Simulator
> pilot on the newsgroup.
Bingo. As I said, even without proof, it is obvious.
Anyone else notice that the increase of the chad's posts were directly
inversely proportional to MX's?
Doesn't take a rocket scientist.
--
Jim in NC
Mxsmanic
> Well, someone should have told me that Rob Machado and Barry Schiff
> are not experts.
It's best not to worry too much about credentials or hearsay.
> Then we
> have Jeppesen, a leaders in edcuation of GA. You would think that,
> with such a fine product (no sarcasm meant), that they would have
> people whom they trust, experts, at the very high-end of academia, who
> could verify what's in the text. But what is in my Jeppensen book and
> what Barry Schiff wrote is wrong.
Jeppesen probably depends on credentials, like so many other entities and
people. It's easier to go by credentials than to test actual qualifications.
If someone has fancy credentials, he may get the job, even if he doesn't
actually know the answers.
> Now I could have gone to some university in the U.S., Germany, France,
> and found someone with stratospheric credentials in aero-astro, but
> after seeing one expert say that the other is wrong, and then seeing
> an incorrect application of Newton's law (yes I still believe it's
> incorrect), I had to put on the brakes.
Lift is bizarre because it's easy to use and very reliable and practical, and
the overall principle is easy to understand correctly, but it's very difficult
to analyze in detail. But that is true of many things in the physical world:
the more closely you look at them, the more confusing they become.
> In any field of research, there is mind and hand. For artists in the
> field, there are those who have a proclivity to use hand more than
> mind, and there are those who have a proclivity to use mind more than
> hand. In any case, there are typically multiple paths to discovery,
> one major path relying heavily on the imagination, the other path
> relying on experimentation. Typically there is a combination. Based
> on the small amount of the field of aerodynamcis I have seen so far,
> and the disputes and inconsistencies, I would not be surprised if
> there is an enormous amount of money being spent on experimentation.
> Granted, experimentation is very necessary to validate (or invalidate)
> what was conceived, but in many fields, there are researchers who
> adopt the brute force approach, not completely, but much more than
> someone who, lacking $100's of millions in funding would.
Not understanding aerodynamics doesn't prevent you from developing elaborate
computer models, it just prevents you from developing models that produce
accurate answers. Just running something through a computer doesn't validate
it.
> A lot of J. D. Anderson.
Everyone has his favorite "experts."
> I guess the most important thing I learned from this experiences is
> that, if it is true that the field of aerodynamics is fully-cooked,
> the experts need to tell everyone else so that they stop printing (as
> late as 2006) erroneous information in textbooks about the very
> basics.
There are still many mysteries in aerodynamics, as in so many other areas of
physical reality. It seems unlikely that human beings could have gone for
thousands of years understanding almost nothing of the subject and then
suddenly could have progressed to omniscience in a single century.
Dudley Henriques
I can't believe the sheer inaccuracy of this person's posting.
He openly, aggressively and pedantically I might add, presents a counter
statement to a non existing premise......a premise that he has
misinterpreted to boot :-)
His comment is totally moot, as the statement he is countering assumes
experience simply EXISTS, rather than implying it has been STATED.
--
Dudley Henriques
Bertie the Bunyip
news:IbOdnU7XAc6fKJra...@rcn.net:
Did you ever write for Abbot and Costello? ;)
Bertie
Dudley Henriques
You mean the "who's on first; what's on second" routine? Perfect for
this guy :-))
--
Dudley Henriques
Bertie the Bunyip
news:bpteg3lnt5c3n4vhf...@4ax.com:
> Le Chaud Lapin writes:
>
>> Well, someone should have told me that Rob Machado and Barry Schiff
>> are not experts.
>
> It's best not to worry too much about credentials or hearsay.
>
>> Then we
>> have Jeppesen, a leaders in edcuation of GA. You would think that,
>> with such a fine product (no sarcasm meant), that they would have
>> people whom they trust, experts, at the very high-end of academia,
>> who could verify what's in the text. But what is in my Jeppensen
>> book and what Barry Schiff wrote is wrong.
>
> Jeppesen probably depends on credentials,
Actualy, they rely on pilots, which you are not.
Bertie
Bertie the Bunyip
I think we'll put him on third. "I dunno" is on third, isn't he/
Bertie
Dudley Henriques
"I think so" is on third :-)
--
Dudley Henriques
Bertie the Bunyip
OK, well that won't do. I've never heard anthony say anything like "I
think so"
Bertie
>