Magnus Effect

If a wing is replaced by a rotating cylinder, with the forward surface
rotating upward, lift will be produced. The local air velocity is high on
top and low on the bottom. This upward force is known as magnus effect.

The information above comes from my helicopter handbook. The theory is used
to explain some helicopter principles, but caused me to wonder more about
it. Has anyone every produced an airplane using the magnus effect? If the
cylinder is rotating faster, I would expect that lift would be increased.
Does anyone know if there have been any writings and/or test aircraft? Not
much use with a glider, for obvious reasons - but the answer would make me a
bit smarter. I was not able to find much on the internet.

Thanks, Colin N12HS


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Have not seen such an aircraft.. but the principle of the "magnus effect"
can be seen in the flight path of a golf ball... ever watch a golf ball when
first hit.. start out low and then increase the climb rate before arcing
over ?.. I'm not talking about a golf ball hit with a pitching wedge... but
hit with the driver.. the spin imparted is the same as the rotating cylinder
described.. creating "lift" over the top of the ball... and yes.. all those
little divots in the ball (I forget what they are called) adds to the
lifting effect.

BT

"COLIN LAMB" wrote in message
nk.net...
If a wing is replaced by a rotating cylinder, with the forward surface
rotating upward, lift will be produced. The local air velocity is high on
top and low on the bottom. This upward force is known as magnus effect.

The information above comes from my helicopter handbook. The theory is
used
to explain some helicopter principles, but caused me to wonder more about
it. Has anyone every produced an airplane using the magnus effect? If
the
cylinder is rotating faster, I would expect that lift would be increased.
Does anyone know if there have been any writings and/or test aircraft?
Not
much use with a glider, for obvious reasons - but the answer would make me
a
bit smarter. I was not able to find much on the internet.

Thanks, Colin N12HS


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.775 / Virus Database: 522 - Release Date: 10/8/04

If a wing is replaced by a rotating cylinder, with the forward surface
rotating upward, lift will be produced. The local air velocity is high on
top and low on the bottom. This upward force is known as magnus effect.

The information above comes from my helicopter handbook.

News to me. I've been flying radio control helicopters and never heard of
this. Don't discredit me offhand, most full size rotor heads have no idea what
a pitch curve is or how many degrees they're pulling in fast foward flight
(FFF).

Generally what happens is that the rotor rotating forward generates more lift
because of relative wind. That generates a combined pitching and roll motion.
That rotation is around the vertical axis, the motion you're talking about is
about the lateral axis.

It seems to me that the magnus effect is best exampled by a spinning ball with
top spin, maybe like for golf or baseball. The lift contribution is generally
neglible.

Fire away! ;-)

Jim Vincent
N483SZ
illspam

Well, after asking the question, I found most of what I wanted. Just a
matter of putting the right words into a search engine.

For those who care, see an excellent report at
http://www.grc.nasa.gov/WWW/K-12/airplane/cyl.html

The formulas for lift of a cylinder is specified. An example is given that
has a 20 foot long cylinder of 2 feet diameter. At 100 mph, 236 rpm
rotation of the cylinder yields 1085 lb lift.

That seems to answer the question, since the energy required to rotate a 2
foot diameter cylinder which is 20 feet long would be substantial. And,
this would not provide any forward motion - just lift. Much easier to use a
simple, less complicated wing. But, it might be possible to build something
that actually flew.

Now I am a bit smarter.

Colin N12HS


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"COLIN LAMB" wrote in message
nk.net...
...Has anyone every produced an airplane using the magnus effect? If the
cylinder is rotating faster, I would expect that lift would be increased.
Does anyone know if there have been any writings and/or test aircraft?

Doesn't count as a real aircraft, but a Magnus effect vehicle was theorized
in the 1957 juvenile science fiction book Tom Swift and his Ultrasonic
Cycloplane:

http://www.series.net/swift/volume10.html

In the late 1970s the Van Dusen Development Company built a
subscale prototype rigid airship which rotated to produce lift
via the Magnus effect. They never built a full scale vehicle.

-- Joe D.

Speak for your own balls! Golf balls that is. Mine don't climb progressively
in a straight line ahead but they do swing impressivelly left or right!

:-)

The divots are called dimples by the way!

Ian


"BTIZ" wrote in message
news:MKldd.32193$bk1.30147@fed1read05...
Have not seen such an aircraft.. but the principle of the "magnus effect"
can be seen in the flight path of a golf ball... ever watch a golf ball
when first hit.. start out low and then increase the climb rate before
arcing over ?.. I'm not talking about a golf ball hit with a pitching
wedge... but hit with the driver.. the spin imparted is the same as the
rotating cylinder described.. creating "lift" over the top of the ball...
and yes.. all those little divots in the ball (I forget what they are
called) adds to the lifting effect.

BT

"COLIN LAMB" wrote in message
nk.net...
If a wing is replaced by a rotating cylinder, with the forward surface
rotating upward, lift will be produced. The local air velocity is high
on
top and low on the bottom. This upward force is known as magnus effect.

The information above comes from my helicopter handbook. The theory is
used
to explain some helicopter principles, but caused me to wonder more about
it. Has anyone every produced an airplane using the magnus effect? If
the
cylinder is rotating faster, I would expect that lift would be increased.
Does anyone know if there have been any writings and/or test aircraft?
Not
much use with a glider, for obvious reasons - but the answer would make
me a
bit smarter. I was not able to find much on the internet.

Thanks, Colin N12HS


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.775 / Virus Database: 522 - Release Date: 10/8/04

I understand that that is the limiting factor to helicopter forward
speed.( and why 'Airwolf' could never have worked ) At around 400 kph the
forward going blade starts to overcome the amount of control input available
to overcome the rolling effect.

Ian

"Jim Vincent" wrote in message
...

If a wing is replaced by a rotating cylinder, with the forward surface
rotating upward, lift will be produced. The local air velocity is high on
top and low on the bottom. This upward force is known as magnus effect.

The information above comes from my helicopter handbook.

News to me. I've been flying radio control helicopters and never heard of
this. Don't discredit me offhand, most full size rotor heads have no idea
what
a pitch curve is or how many degrees they're pulling in fast foward flight
(FFF).

Generally what happens is that the rotor rotating forward generates more
lift
because of relative wind. That generates a combined pitching and roll
motion.
That rotation is around the vertical axis, the motion you're talking about
is
about the lateral axis.

It seems to me that the magnus effect is best exampled by a spinning ball
with
top spin, maybe like for golf or baseball. The lift contribution is
generally
neglible.

Fire away! ;-)

Jim Vincent
N483SZ
illspam

COLIN LAMB wrote:
If a wing is replaced by a rotating cylinder, with the forward surface
rotating upward, lift will be produced. The local air velocity is high on
top and low on the bottom. This upward force is known as magnus effect.

The information above comes from my helicopter handbook. The theory is used
to explain some helicopter principles, but caused me to wonder more about
it. Has anyone every produced an airplane using the magnus effect? If the
cylinder is rotating faster, I would expect that lift would be increased.
Does anyone know if there have been any writings and/or test aircraft? Not
much use with a glider, for obvious reasons - but the answer would make me a
bit smarter. I was not able to find much on the internet.

Thanks, Colin N12HS


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.775 / Virus Database: 522 - Release Date: 10/8/04



It's possible to use the effect in an airplane, but
there is no concept of an angle of attack and the
L/D ratio is quite bad at low RPM.

You don't even neet an engine, the spin can be self-sustaining.
Experiment: Trow a strip of cardboard trough the air. If you get
it right, it will start to spin and glide at a L/D of about 1-2.

Regards,

Iwo

Joe replied:

In the late 1970s the Van Dusen Development Company built a
subscale prototype rigid airship which rotated to produce lift
via the Magnus effect. They never built a full scale vehicle.

Well, Joe, now that you mention it, there was a full scale model that did
fly. I had forgotten about that. It was called the CycloCrane and used
helium to obtain neutral buoyancy then rotated using the Magnus Effect for
lift. During the experiments, it was stored in the old blimp hangers at
Tillamook, Oregon. I recall the last flight was in about 1991 when it broke
up.

So, there was an aircraft that used the Magnus Effect - sort of.

Colin N12HS




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I understand that that is the limiting factor to helicopter forward
speed.( and why 'Airwolf' could never have worked ) At around 400 kph the
forward going blade starts to overcome the amount of control input available

I thought is was because the forward blade is approaching supersonic.

Jim Vincent
N483SZ
illspam