Airplane Pilot's As Physicists

"Morgans" wrote in news:EKUOi.35$KS3.30
@newsfe03.lga:


"Randy Poe" wrote

BS and more BS.
***********************
And another sock puppet is born. Sheesh.

Nah, he's not a sock. just someone who isn't up to speed on aerodynamics
that Anthony sucked in with a crosspost.


His sock didn't work so he's looking for reinforcements elsewhere.

Told you it would get good!


Bertie

Randy Poe writes:

As I said, I lean toward the angle-of-attack arguments now. Take
a flat rectangle, tilt it into the wind. The wind blows against the
front which is also the bottom, not the back/top. So the
forces are on the bottom.

The essential feature of an airfoil is that it twists the flow of air as it
passes (or as the airfoil passes through still air, which is equivalent, and
that's how it works in airplanes). The air is accelerated downward, and this
engenders an equal and opposite force that is lift.

So how does a wing produce lift? By twisting air downwards, creating a
downwash. Accelerating a mass of air downwards tends to accelerate the wing
upwards, and there's your lift.

The theory gets more complicated when you try to explain exactly how and why
airfoils twist an airflow. Just looking at a flat board with a positive angle
of attack, you'd think that it would twist the air, and that's exactly what it
does. But the devil is in the details.

Fortunately, aviators don't have to know or care about the details. All they
need to know is that a wing with a positive angle of attack (and below the
stall angle) will generate lift.

Lift, like so many other phenomena in physics, can be analyzed and explained
in a number of different, equally valid ways, depending on one's point of
view. All analyses and explanations converge on the same reality. Of course,
some explanations of lift are just plain incorrect, and unfortunately a few of
them are quite widespread.

Mxsmanic wrote in
:

Randy Poe writes:

As I said, I lean toward the angle-of-attack arguments now. Take
a flat rectangle, tilt it into the wind. The wind blows against the
front which is also the bottom, not the back/top. So the
forces are on the bottom.

The essential feature of an airfoil is that it twists the flow of air
as it passes (or as the airfoil passes through still air, which is
equivalent, and that's how it works in airplanes). The air is
accelerated downward, and this engenders an equal and opposite force
that is lift.

So how does a wing produce lift? By twisting air downwards, creating
a downwash. Accelerating a mass of air downwards tends to accelerate
the wing upwards, and there's your lift.

The theory gets more complicated when you try to explain exactly how
and why airfoils twist an airflow. Just looking at a flat board with
a positive angle of attack, you'd think that it would twist the air,
and that's exactly what it does. But the devil is in the details.

Fortunately, aviators don't have to know or care about the details.
All they need to know is that a wing with a positive angle of attack
(and below the stall angle) will generate lift.

Lift, like so many other phenomena in physics, can be analyzed and
explained in a number of different, equally valid ways, depending on
one's point of view. All analyses and explanations converge on the
same reality. Of course, some explanations of lift are just plain
incorrect, and unfortunately a few of them are quite widespread.





Nope


Bertie

"Mxsmanic" wrote in message
...
The essential feature of an airfoil is that it twists the flow of air as
it
passes (or as the airfoil passes through still air, which is equivalent,
and
that's how it works in airplanes). The air is accelerated downward, and
this
engenders an equal and opposite force that is lift.

Nope. That wouldn't explain how wing sections for tailless planes work. The
sections for those curve up towards the trailing edge. The leading edge
produces lift but the trailing edge produces a _downward_ force to counter
the pitching moment. Example section...

http://www.desktopaero.com/appliedae...image13_43.gif

"CWatters" wrote in
:


"Mxsmanic" wrote in message
...
The essential feature of an airfoil is that it twists the flow of
air as
it
passes (or as the airfoil passes through still air, which is
equivalent,
and
that's how it works in airplanes). The air is accelerated downward,
and
this
engenders an equal and opposite force that is lift.

Nope. That wouldn't explain how wing sections for tailless planes
work. The sections for those curve up towards the trailing edge. The
leading edge produces lift but the trailing edge produces a _downward_
force to counter the pitching moment. Example section...

http://www.desktopaero.com/appliedae...mages/image13_
43.
gif





Good point.

The porblem with this guy is (and it's just one guy with a handful of
sockpuppets) is that he ses some discrepencies in how bernoulli is
explained and has concluded that it must be incorrect since there is
"disagreement amongst the experts"

A good analogy here would be the eeedjit creationists who grasp at the
straws presented by the minor scuffles occuring within the evolutionary
sciences.


Bertie

Bertie the Bunyip wrote:
"CWatters" wrote in
:

"Mxsmanic" wrote in message
...
The essential feature of an airfoil is that it twists the flow of
air as
it
passes (or as the airfoil passes through still air, which is
equivalent,
and
that's how it works in airplanes). The air is accelerated downward,
and
this
engenders an equal and opposite force that is lift.
Nope. That wouldn't explain how wing sections for tailless planes
work. The sections for those curve up towards the trailing edge. The
leading edge produces lift but the trailing edge produces a _downward_
force to counter the pitching moment. Example section...

http://www.desktopaero.com/appliedae...mages/image13_
43.
gif





Good point.

The porblem with this guy is (and it's just one guy with a handful of
sockpuppets) is that he ses some discrepencies in how bernoulli is
explained and has concluded that it must be incorrect since there is
"disagreement amongst the experts"

A good analogy here would be the eeedjit creationists who grasp at the
straws presented by the minor scuffles occuring within the evolutionary
sciences.


Bertie

This is exactly how I see this as well. This character and his puppets
are playing out a conversation with themselves (one person) designed to
capitalize on the few simple misconceptions concerning Bernoulli that
are common knowledge among the professional aviation community and have
been "corrected" years ago.
Unfortunately for this forum, there are still a few old textbooks
hanging around out there reflecting these misconceptions. This, coupled
with the fact that there are individual pilots out here (from the GA
community mostly) who apparently lack the formal physics knowledge to
take on someone whose sole intent is to discredit them by cleverly using
the remaining confusion in the community concerning Bernoulli against them.
The REAL rub in this situation is that the idiot doing this, from what I
have seen in his posting, has very little knowledge HIMSELF about the
lift issue and is totally wrong in critical areas of his argument.
It's an unfortunate situation designed by a person who seems to pleasure
himself by what he's doing.
Personally I wouldn't give this idiot the time of day. His understanding
of Bernoulli is much worse than those with whom he has engaged. Those
who are on to him he avoids, only taking glancing shots at them knowing
he won't be answered directly.
It's a shame really....but what the hell, it's Usenet!!
:-)))

--
Dudley Henriques

On Oct 10, 7:06 am, Bertie the Bunyip wrote:
"CWatters" wrote :

"Mxsmanic" wrote in message
.. .
The essential feature of an airfoil is that it twists the flow of
air as
it
passes (or as the airfoil passes through still air, which is
equivalent,
and
that's how it works in airplanes). The air is accelerated downward,
and
this
engenders an equal and opposite force that is lift.

Nope. That wouldn't explain how wing sections for tailless planes
work. The sections for those curve up towards the trailing edge. The
leading edge produces lift but the trailing edge produces a _downward_
force to counter the pitching moment. Example section...

http://www.desktopaero.com/appliedae...mages/image13_
43.
gif

Good point.

The porblem with this guy is (and it's just one guy with a handful of
sockpuppets) is that he ses some discrepencies in how bernoulli is
explained and has concluded that it must be incorrect since there is
"disagreement amongst the experts"

A good analogy here would be the eeedjit creationists who grasp at the
straws presented by the minor scuffles occuring within the evolutionary
sciences.

Bertie

Obviously, pilots AND the airplanes they fly are just plain too
stoopid to fall.

"Scientists Refute Gravity with New "Intelligent Falling" Theory"
http://www.theonion.com/news/index.php?issue=4133&n=2

Jim Deutch (JimboCat)
--
The Japanese tried coating airplane wings with teflon, but could never
come up with a good nonstick flying plan.

CWatters writes:

Nope. That wouldn't explain how wing sections for tailless planes work. The
sections for those curve up towards the trailing edge. The leading edge
produces lift but the trailing edge produces a _downward_ force to counter
the pitching moment. Example section...

http://www.desktopaero.com/appliedae...image13_43.gif

The first thing I saw in this image was "Angle of attack 5.50." Case closed.

Mxsmanic wrote in
:

CWatters writes:

Nope. That wouldn't explain how wing sections for tailless planes
work. The sections for those curve up towards the trailing edge. The
leading edge produces lift but the trailing edge produces a
_downward_ force to counter the pitching moment. Example section...

http://www.desktopaero.com/appliedae...ges/image13_43
.gif

The first thing I saw in this image was "Angle of attack 5.50." Case
closed.


Nope


Bertie

"Mxsmanic" wrote in message
...
CWatters writes:

Nope. That wouldn't explain how wing sections for tailless planes work.
The
sections for those curve up towards the trailing edge. The leading edge
produces lift but the trailing edge produces a _downward_ force to
counter
the pitching moment. Example section...


http://www.desktopaero.com/appliedae...image13_43.gif

The first thing I saw in this image was "Angle of attack 5.50." Case
closed.

So what's that got to do with anything. You can simulate the performance of
a section at any AOA you like. Try it yourself at AOA = 0 degrees. You might
be surprised.