January 31st 08, 03:56 PM
posted to rec.aviation.piloting
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MythBusters airplane on a conveyor belt
Dudley Henriques wrote in
:
Bertie the Bunyip wrote:
Dudley Henriques wrote in
:
Bertie the Bunyip wrote:
Dudley Henriques wrote in
:
Bertie the Bunyip wrote:
Dudley Henriques wrote in
:
Bertie the Bunyip wrote:
WingFlaps wrote in
news:ddef2011-7cca-4e5e-b5a8-
:
On Jan 31, 12:34 pm, "Robert M. Gary"
wrote:
On Jan 30, 1:36 pm, Peter Clark
wrote:
For those interested in such things, the MythBusters show
titled
"Airplane on a Conveyor Belt" is in TVGuide to air tonight
at
9pm
Eastern US on Discovery/Discovery HD.
Yea, I had the TiVo searching for it for the last few weeks.
I
see
that its set to record soon (I never actually pay attention
to
when
a show is on anymore). I'm looking forward to it. To me the
interesting part will not be the experiment but the premise.
Do some believe that an airplane generates lift as a result
of the speed of the wheels? -Robert
I'd be interested in knowing whether they can detect the
actual
lift
derived from the wheels spinning as the plane lifts off...
Well, you could do it in a wind tunnel!
There was a time in the 30's when a rotating cylinder was seen
as
the
future of the wing. I think maybe even a few were built! I'm
pretty
sure I have an old Popular aviation with a few pics of a fairly
unsucessful prototype..
But a little spinning wheel isn't going to give you much..
Bertie
Actually you can still do it.
Really? I thought there might have been a physics watershed back
there
in the late ffties!
We could check this out with Ken, but I'm pretty sure it will work
without him :-)))
I used a spinning cylinder all the time
in my discussions on aerodynamics. It makes a perfect example
when getting into lift. A cylinder not rotating in a free stream
airflow
has no lift as the stagnation points are neutral. The airstream
flows
over the cylinder equally; no Bernoulli...no Newton.
Now spin the cylinder clockwise to the airstream.
Walla......instant
lift! You get it all in one simple demonstration. You get upwash
and
downwash. That's circulation. (Newton) You get increased local
velocity over the top of the cylinder and decreased local
velocity under it. That's Bernoulli!
The whole shegang is Magnus effect. It's a wonderful way to get
into
wings, golf balls, curve balls...the whole magilla :-))
Excellent. What kind of contraption do you use to demonstrate?
Bertie
Just a tin can, a blackboard and chalk, some finger pointing and a
good
gift of gab :-))
OK You don't actually spin the can in front of a fan or anything
then?
I have located a very olp plan for a rubber powered cylindrical
wing model if anyone want me to post it I will.
Bertie
The Naval Test Pilot School used to have a neat demonstration film
set up with a smoke generator and a fan coupled with a cylinder that
was both static and synamically capable that was shot in Schlieren
format that did the trick nicely, but in a pinch, I always found the
blackboard
and chalk thing did just as well.
The trick with audio visuals is that the emphasis is really on the
instructor and how he/she uses the training aid rather than the
training
aid itself. It's amazing what you can get across to people with the
right gift of gab :-))
I usually resort to drawing on the back of beer mats, myself.
Bertie
I've done that myself many times giving ground school at an old bar
across the street from one of the airports I used to operate out of
:-)
Actually, a lot of good stuff gets done this way. Ed Heinemann from
Douglas jotted down the initial design for the A4 Skyhawk on a table
napkin.
He he. Yeah. A lot of our aircraft paperwork ends up with strange
scribbles on the back too.
Bertie
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