The Impossibility of Flying Heavy Aircraft Without Training

Heck no. It just does so with no *net* downward momentum of air. In
other words, the upward momentum ahead of the wing is equal to the
downward momentum at the rear of the wing.

What upward momentum? The air starts out still, and infinitely wide
wing comes flying through it, when all is done air has to have been
deflected downwards, at the very least to satisfy Newton.

Behind the wing, air is moving downwards, there is higher pressure below
the wing's path, and lower pressure above the wing's path. The air will
recover, as the pressure equalizes (eventually pushing down on the
earth's surface and up into the lower pressure region)

Infinite wings have no downwash, yet provide lift. By *definition*,
downwash is caused by wingtip vortices.

Well, then an infinite wing ought to have something that is not called
downwash, but keeps Newton happy. Call it downflow, call it pressure
bounce.. but it's something.

Jose
--
Money: what you need when you run out of brains.
for Email, make the obvious change in the address.

What upward momentum? The air starts out still, and infinitely wide
wing comes flying through it,

As the wing approaches, the air starts moving up, eagerly anticipating
the meeting. Called "upwash".

Well, then an infinite wing ought to have something that is not
called
downwash, but keeps Newton happy. Call it downflow, call it pressure
bounce.. but it's something.

Newton is happy. The high pressure air on the bottom of the airfoil
pushes on the airfoil, the airfoil pushes back

Anyway, I'm just the messenger. The idea that there is no net downward
momentum of infinite airfoils is stated in a number of aerodynamics
books.

As the wing approaches, the air starts moving up, eagerly anticipating
the meeting. Called "upwash".

Not disputing, just trying to learn... but... the way I see it (and I'm
not an aeronautical engineer)

.... why does the air start moving up? AFAIK, lifting fairies don't push
the air around; that's not in their contract.

The way I see it, the high pressure air below the wing causes air to be
displaced out from below the wing, and some of that pushes out ahead of
the wing, pusing the air in front of the wing up out of the way. So,
before the wing itself meets the air, the air is in an upwashing state.
Then the leading edge meets the upwashing air and gains some lift from
momentum transfer...

However, in front of the upwashing air, the air is undisturbed. This is
the initial state of the air - upwashing is somehow caused by the wing's
approach.

When the wing passes through the air, the air is forced downward as it
follows the wing's angle of attack, since it can't go through the wing.

After the wing has passed, the downward moving air slows down (to a
stop?) as it compresses the air below it, helping to create the upwash
in front of the wing.

In another scenario, what happens in a long ducted fan? The blades are
just wings going round and round providing lift in the direction of the
duct, the duct prevents wingtip vortices, and air gets sucked in one end
and pushed out the other end. Is this not analogous to a wing "pushing
air down"?

Jose
--
Money: what you need when you run out of brains.
for Email, make the obvious change in the address.

In article . net, Richard Lamb
says...

According to Shafer "Lift is caused by Lift Demons.
These little, invisible demons hold on to the leading and trailing edges of
the aircraft and lift it into the air by flapping their wings (so, in a
reductionist sense, lift is actually caused by feathers).

First honest thing I've read in this thread. Lift is caused by feathers is a
known scientific fact and I can prove it .

Take a 10 # Canada goose and it will fly very nicely. Now pluck all the feathers
and then watch this now naked Goose do high speed taxi's with it's little naked
wings flapping wildly. The Goose sans feathers cannot fly so the answer is
obvious to those who take the time the think about it. The average goose has 2
pounds of feathers so therefore for every pound of feathers you can lift 5# of
goose. Therefore I propose that we build a man carrying mechanical Goose to
prove this phenomena.

We can start small with say an Ultralight version with a gross weight of 600#.
We would need only about 120 # of feathers. We will need to fund this all
important project so I'll be accepting donations...cash only .

Later well do a project on how speed is caused ,you'll be amazed how it works.A
small clue is electromagnetic plasma pulses rectified by an alum pyramid shaped
hat. Don't forget to send money ...

Lift Faries?? Pure bunk!! It's feathers my boy feathers!!

Count Clipper

"ChuckSlusarczyk" wrote ...
First honest thing I've read in this thread. Lift is caused by feathers is
a
known scientific fact and I can prove it .

I hate to get involved in these "what causes lift" threads but this is
nonsense. An ostrich after all, with all it's feathers, CAN'T FLY. I
already stated a couple weeks ago that flight is magic. A well known fact.
Such silliness as "feathers" and "lift demons" is just an attempt to avoid
being burnt at the stake by the fearful masses.

Rich

ChuckSlusarczyk wrote:

First honest thing I've read in this thread. Lift is caused by feathers is a
known scientific fact and I can prove it .

Take a 10 # Canada goose and it will fly very nicely. Now pluck all the feathers
and then watch this now naked Goose do high speed taxi's with it's little naked
wings flapping wildly. The Goose sans feathers cannot fly so the answer is
obvious to those who take the time the think about it. The average goose has 2
pounds of feathers so therefore for every pound of feathers you can lift 5# of
goose. Therefore I propose that we build a man carrying mechanical Goose to
prove this phenomena.

We can start small with say an Ultralight version with a gross weight of 600#.
We would need only about 120 # of feathers. We will need to fund this all
important project so I'll be accepting donations...cash only .

Later well do a project on how speed is caused ,you'll be amazed how it works.A
small clue is electromagnetic plasma pulses rectified by an alum pyramid shaped
hat. Don't forget to send money ...

Lift Faries?? Pure bunk!! It's feathers my boy feathers!!

Count Clipper

Have you been drinking muzzle loader again???

Tony

("ChuckSlusarczyk" wrote)
Therefore I propose that we build a man carrying mechanical Goose to prove
this phenomena.


So, after the test flight, how do you get down from your mechanical goose?


Montblack
Minnesota State Bird - The Common Loon

upwashing is somehow caused by the wing's approach.

On one level you can say it's a consequence of the bound vortex around
the wing. Not satisfying? I agree, but that's about as far as most
aerodynamics books go in providing an intuitive answer.

In another scenario, what happens in a long ducted fan? Is this
not analogous to a wing "pushing air down"?

You aren't the first to pose that question and it's a good one. Here
are some things which are unsupported by anything that I've read:
There is at least one dis-analogy (new word) that I can think of.
With a wing, it creates a low pressure area and then is gone; whatever
happens to that low pressure area is irrelevant. The air that rushes
into it has no effect on the wing. A fan, however, creates a
permanent low pressure area in front of the airplane, which creates a
flow from front to back which doesn't exist for a wing.

"Jim Macklin" wrote in message
news:uX8Lf.104268$4l5.39451@dukeread05...
It was sad and never should have been allowed to happen.
Some people knew what was planned, many escaped, but the
world was unwilling to stop Hitler. Hope we don't make the
same error again.


We are making the same error again. If you look at the political tactics
used by the Nazis in their rise to power, some of them ring a bell in a
recent presidential campaign.

1. Attendees at Nazi rally were carefully screened and only Nazi supporters
were allowed in.

Bush political speechs had a screened audience and only known Bush
supporters were allowed to attend.

2. Hitler pointed at jews and gypsies as the source of all the problems in
the world of the third reich.

Bush points at "terrorists"

3. The Nazi party evaded the German Democratic constitution and evaded the
law to protect citizens from jews and gypsies.

Bush evades the law and eavesdrops on american citizens when the only
reason to evade the law is to keep the courts from knowing who and how many
people he is eavesdropping on and what he is doing with the information.

4. The Nazi propaganda minister proved the validity of the "big lie." If
you lie blatantly enough and often enough and do so on all of the public
media a significant portion of the population will believe the lie.

Bush always tell the truth even when he contradicts himself. Right.

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )

( don't call me guys. someone may be listening after this post! :-)

"Greg Esres" wrote in message
oups.com...
An infinitely wide wing has no wingtips. You suggest it could not
provide lift.

Heck no. It just does so with no *net* downward momentum of air. In
other words, the upward momentum ahead of the wing is equal to the
downward momentum at the rear of the wing.


Disagree. There is a *net* downward momentum of air. Otherwise there is no
lift. However the downward momentum for any finite section of the infinite
wing is infinitesimal. Note, however, that even though in Calculus 100 we
assume that an infinitesimal is approximately equal to zero and can be
ignored, it is only approximately to zero and only very very near zero.

While zero times any number is still zero, almost zero times infinity is
NOT zero. Ergo, the downwash is not zero either.



I've read the "wingtip vortices provide lift" papers,

I'm not proposing that.

the wing causes downwash which provides lift (action-reaction) and
=that= creates vortices.

Infinite wings have no downwash, yet provide lift. By *definition*,
downwash is caused by wingtip vortices.

No. wingtip vortices are caused by downwash. Infinite wings don't have
wingtip vortices because they don't have ends, not because they don't have
downwash.

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )