rotating cylinder wing

[flybike]

I saw a picture here a while back, it looked like the wing was a cylinder. It takes advantage of the same force that makes a baseball curve, I think its called the Magnus Effect? Does anyone have experience with these, or a website to look at? Thanks, Hans

[TomM]

Here's a simple page without the math.

http://www.howstuffworks.com/airplane4.htm

Years ago, Model Airplane News had a construction article about it. I think it used a 400 motor to spin the wing and it had paddles on it.

Tom

[CharleyRexom]

In the early 60's as a kid I had a rotating wing kite. At both ends of the styrofoam wing were discs of the same diameter as the wing chord. It used two strings attached to bushings at each side. It was quite manueverable and flew well, but needed good breeze.
Powered kites work, so why not a rotating wing? Sounds like a fun quest!

Charley

[Jim Petro]

Back in the atic of my mind I remember a discussion of the Magnus effect in college (about '59) and a German who rigged some on a motorcycle to assist jump/ glides over obstacles. In the discussion it was detemined that lift and control were good in a magnus assisted wing but the thickness and gyroscopic effects created lots of frontal drag and adverse control affects. The Kite looks like the only practical use.

[tharold]

I seem to recall someone powered a small ship with 2vertical rotating cylinders in place of sails. Not
of practical use but there is a family of airfoils that
can be derived by considering the streamlines around a
rotating cylinder in a free stream. I forget the name
but it was mostly of pedagogical value.

[SJ]

Look at this cool video !

http://bornholm.adsl.dk/modelfly/files/sto.mpa

[max z]

Found another example that was flown at one of the Dutch-German Inter-Ex fly-ins for experimental planes. Looks like this one is following the kite concept closely. Must have flown, as evidenced by another picture of it in full flight.

Max.

[Tony Oliver]

Here's another - freeflight this time - from 1964/5 Aeromodeller Annual.
This links with Charley's kite. I had one in the 1950s - it was towed and flew like a kite as he says - called the 'Revojet' as far as I can remember.

Tony

[MrThermal]

I have built (and love to fly) UFO Rotor kites. They are 2 identical circles compressed into elipse's and mounted at right angles to each other. The horiz. wing is mounted to a shaft w/bearings and bridles strings.
Mine are silver mylar double-sticked to 4mm f/glas rods. Look awesome in full sunlight.
Only problem is.... the lift/drag ratio is one/one so they only fly at ~45 deg. ... untill a thermal comes by, then almost vertical. They do need 10-15 mph wind and will fly in 35mph if you have strong enough line (75-100lb).
Anyone interested ...do a search for UFO Rotor Kite and should end up at Anthony's site (he has great pictures and plans)

[schoey]

The best example of this is at Fan wing (http://www.fanwing.com) . As far as I know its just plain old Bernoulli effect that does this, a simple exp can be done to show it,
1 get a big rubber band and cut it so you have one long strip,
2 tie a ribbon to one end,
3 wrap the ribbon around a light cardboard cyl (toilet paper roll works well)
4 fix the end of the rubber band on a table and stretch it out holding on to the cyl,
5 let it go and see what happens.
The bernoulli effect also contributes to lift on an aerofoil.
Grant

[flybike]

I am going to have to try that, grant. Another thing to try- take the insides out of a bic pen. Launch the tube with your fingers depressing it on a table. Should get 2-3 second flight times.:) Just wondering, why is the engine mounted with so much up thrust? Thanks for the replies. Hans

[Ron van Sommeren]

Originally posted by max z
Must have flown, as evidenced by another picture of it in full flight.
@Max
One of these flies in our club. An old 10cc Webra blackhead, lots of drag, hardly any speed. A crowd pleaser: 'How the h*** will that ever fly'?

Met vriendelijke groet, Ron van Sommeren

[CharleyRexom]

Many of the indoor / parkflyer light weight designs such as the IFO were not practical 10 years ago, so we either dismissed them as crack pot designs or ignored them completley. The Park Hawk is another example that wasn't feasible. To me, the rotating cylinder wing has the same aura about it.

Like ornithopters, it may not be effecient, but it is interesting. Call it a novelty, but I would build one if someone engineered a reasonable design.

Charley

[Viper Pilot]

Flying Models Magazine November 2002 issue has an article on a C/L rotating winged plane.
Check it out. Very interesting design. Includes a great write-up on the theory behind it, too.

VP

[Matthew Allen]

I saw the fan wing in Q&EFI (I think). Looks cool. Those videos are neat. It makes a really weird noise. it actually seems to have a remarkable amount of power.

[Tim Green]

For those of you who think negative pressure on the top of a wing can lift it (the Bernoulli does it all club) - try this experiment ...

Get an object capable of holding a vacuum. This object must also be capable of being quickly opened without placing force on the object. Place object onto ground, with the seal facing up. Cause object's seal to be quickly removed.

You'll notice that the object doesn't leap skyward, even though it's less than atmospheric pressure is pulling air into the top of the object.

But what about Bernoulli? Well, apparently Bernoulli is misapplied as an explanation of lift. Sure the pressure on the top of a wing is less than atmospheric, but that's not lifting the wing up.

Nothing in the world, can suck itself skyward, without expelling air earthward.

[Regecide]

Another thing to try!
Get a beer bottle, preferably a long neck, make sure it's dry and place a wad of tissue in the neck, then try and blow the tissue into the bottle. It don't work
I think it's bernoullies principle but I could be wrong

[FlightofSong]

The rotating-wing models and kites shown in this thread don't really use the magnus effect. The magnus effect actually involves a smooth sylinder rotating in a flow, and isn't really applicable to airplane lift because of the issue of drag and weight. Magnus himself build the boat that was mentioned with the two cylinders. By varying the rotation rate of the cylinders, he could maneuver the boat without a rudder, and the boat was capable of sailing very close to the wind due to the lack of a stall on the "sails".

The rotating wing effect is more akin to the behavior of an autogyro, but in a different axis. It's also very similar to the concept of a cycloidal propeller.

[Daddio]

So why couldn't you just power the rotor-thing-a-ma-wing-thing?
D²

[Lancair]

Tim, anyone who, as you put it, belongs to the Bernouli does it all club, doesnt think that a negative pressure sucks the wing up. Your little example is very wrong and fatally flawed. There is no vacumm.
In the "Bernouli does it all club" we believe that the relatively low pressure above the wing, only allows the relatively high pressure on the lower side of the wing to more easily push the wing up. Not be sucked up by some mysterious force.
Try this one.

Get a strip of paper about 2 inches wide and 6-10 long. Hold one narrow end at each side in each hand. Now holding the paper parrallel to the gound in your fingers, allowing the rest to droop down, gently bring your hands to your lips and blow lightly just above the piece of paper. WOW something lifted that piece of paper, if you did it right and didnt use cardboard type paper, try using airmail writing paper.
If you want a laymans terms description of how bernouli was RIGHT then just ask.
Bascially: Static + Dynamic = Constant

Lancair

[andyberner]

for those interested in the specifics of lift generation, this discussion covers the ground pretty thoroughly... http://www.twitt.org/miller.htm#topleft

Andy

[Tomas Dunker]

I'm thinking of building a RC model aeroplane with rotating cylinder wing.
Do you know where I can buy plans (drawing, blueprint)?

Do you think it's possible to scale up the Turbo Max (se pictures) and install RC and a outrunner?
The best, I think, is to find a drawing!

//Tomas Dunker
Sweden

[MarkusN]

...there is a family of airfoils that
can be derived by considering the streamlines around a
rotating cylinder in a free stream. I forget the name
but it was mostly of pedagogical value.
Those were the Joukovski airfoils. The original Ka6 had one of these at the wing tip.

And it being only of paedagogocal value... Not really. The computer simulations of airflow still use a pieced-together Joukowski transformation to calculate pressure distribution over a wing. (No wing section is a pure Joukowski-airfoil anymore, but short pieces are sufficiently close.)


On the Bernoulli Club: Ther sure is still a lot of Horror Vacui around. The low pressure field over the wind does indeed accelerate a mass of air earthwards, so the two concepts are not mutually exclusive at all.

[Tom Harper]

Hans,

Zaics Model Aeronautic Yearbook 1964-65 has a discussion of Magnus effect aircraft and several plans for models.

The Magnus effect is interesting for models but it presents some odd problems. A Magnus rotor sets up a chordwise irrotational vortex like any wing. But think of issues like airflow in a lateral slip or a stall. Not like a curved plate. Could be interesting to investigate.

There was a full size aircraft made in 1930s and promoted by Butler Ames. It had a 300HP Wright J6 engine to drive the propeller and an 85HP American Cirrus engine to drive the wing rotors. It was a pontoon plane. Ames got the use of a navy barge for 11 days to test the craft. I have not found any record of the results. There are fragments under the name Pilgrim if you want to try searches. Probably never got off the water.

The definitive work on Magnus application is Fletner - The Story of the Rotor. Anton Fletner modified three grain ships to use the rotor - Buckau, Baden Baden, Barbara. They were employed in the grain trade and one even sailed into New York harbor.

The advantage of the rotor was ease of handling. The 'sails' were trimmed by simply changing the rotation rate of the rotor. It was cheaper to manufacture, maintain and use than cloth sail. However, it was not competitive with steam.

I believe Fletner went on to produce the first tactical, military helicopter.

Tom

[macboffin]

So why couldn't you just power the rotor-thing-a-ma-wing-thing?
D² Been done in model form, with what look like heavily reflexed wings rotating on a central spar. Variation on a kite which gets resurrected every few years as " an innovation", last appearance in Britain I remember was called a "Wirblewing". Loads of drag, a difficult engineering exercise if much more than a few ounces or much more than 18 inches span. A novelty, but of no practical flight use, apart from crowd's "Wow" factor, like a Dog-house or "witch on broomstick".

[nmasters]

Holy zombie thread, Batman!

Here's a picture of that Flettner rotor plane (http://flight-monster.com/wiki/index.php/Bild:RotorFlugzeug.jpg) . It's a completely different concept than the model Tomas Dunker shows though. That model is typical of rotary kites, like Macboffin said. It's a savonius rotor (http://www.cit.gu.edu.au/~anthony/kites/rotor/rolloplane/) , one of the less efficient types (something like 15%) of windmill but easy to make (http://best-breezes.squarespace.com/journal/2006/1/7/rotor-kites-move-from-toy-novelty-to-high-tech-power-generation.html) and apparently good enough for kites and whirligigs.

A Flettner rotor is capable of producing a lot more lift (CL >9 acording to the NACA) than any un-powered system but, of course, it is a powered lift system and therefor kind of complicated. I've never heard of one actually flying but there are probably lots of reel things that I haven't seen

--Norm

[Tom Harper]

Norm,

LOL - bad pun!

The Savonius Rotor came under Fletner's patent. He worked with Savonius and made the same comment as you did in your post above. Too much drag and to little lift. But, it was self powered and was used on small windmills.

Many years ago (1959) there was a Fletner windmill at the north end of Grapevine pass just out of L.A.. Anybody been there lately?

Here is another picture of the aircraft. Looks like the same platform. All of the photos must be from the rear since the nose was over water.

With the materials available today and with brushless motors and Lipos, it might be worth a try. You get two little outrunners and that old SS fuse and a couple of rocket body tubes and..............

Tom

[nmasters]

That explains why both rotors are mentioned together so often. Last night I remembered that I had seen a Flettner rotor on a real airplane. It's an OV-10 Bronco and the rotor is submerged in the wing (http://rexresearch.com/aero/1aero.htm#thompson) at the flap hinge. The page has pictures from several old patents so it takes a while if your on dialup. Than NACA report I mentioned is TN-209

--Norm

[Tom Harper]

Norm,

Neat link.

I like the 'Cornelius Free Wing'. There has been some discussion of the design on these forums. It might make sense for aerial photogaphy. I'd try one but there are too many unfinished projects on the bench ahead of it.

Tom

[50+AirYears]

There was also an earlier RC rotor wing design in one of the (Senior Moment-forgot the author's name: Had the book on circular airflow as part of the series) yearbooks sold through the AMA on-line store. I have a copy of it somewhere in my files.

[MarkusN]

Last night I remembered that I had seen a Flettner rotor on a real airplane. It's an OV-10 Bronco and the rotor is submerged in the wing (http://rexresearch.com/aero/1aero.htm#thompson) at the flap hinge. The page has pictures from several old patents so it takes a while if your on dialup. Than NACA report I mentioned is TN-209
I'd consider that a boundary layer control device (like slats, BL suction, blowing slots and slotted flaps), rather than a full blown Flettner rotor, but then again the whole Flettner rotor can be considered a boundary layer control lifting device.

[Tom Harper]

There are some polars in the Zaic Yearbook. The X axis is:

(Rotor surface velocity) / (Aircraft Velocity)

Seems to me that Fletner recommended 30 ft per second.

The chart shows the dramatic benefit of a cylinder over the Biconvex section. However the double curves commonly used are not true Savonius sections. Fletner points out that they must be separated and overlap. That's the magic. It offers a new avenue for investigation.

The polars and Fletner's illustration are below:

[Flyingwingbat1]

That biconvex section looks fascinating for tumblewings. I'm going to try some things with it this weekend. It looks like a rotational equivalent to those impulse-bucket water wheels (i.e. air going in the forward facing end provides a "double kick" for rotational purposes.)

Thanks for the pic, Tom

[Tom Harper]

Flyingwingbat1,

Keep us informed on your results.

Tom

[Tom Harper]

Since support of the rotor is an issue, why not revive the Custer Channel wing as a support.

Maybe I gotta lay off the coffee.

[50+AirYears]

I remember having a couple of those rotor wing kites. Never got one to fly more than a couple minutes, nor over about 20' altitude.

I now remember that the copy of a plan for a powered version I mentioned earlier came out of one of the Zaic yearbooks. It's heck :mad: :( :censored: getting old, couldn't remember Zaic even with several other posts mentioning his name.

[Flyingwingbat1]

Well, after building a paper model I found that the bi-convex section spins reasonably well, BUT, it's too complicated and heavy for use as a walkalong tumblewing. I wouldn't discount it for use in powered fanwings, though.

[50+AirYears]

Veddy Interestink! While inventorying my plan collection, I came across an old plan set, Hobby Helper's #357, from the March 1957 Air Trails, or whatever the progression may have been by that time. It is a control line Fletner rotory wing plane, for a small engine, designed by one Roy Clough, Jr, who still is a rather prolific designer of unusual model aircraft in CL, FF, and RC. I've seen his designs in Air Trails, MAN, Science Mechanics, Mechanix Illustrated, among others.

[Terry S]

My boy had one of those tumble wing kites, worked great, wobbled a bit from side to side at low level but when high i just tied it to a tent peg and left it up there.

Terry

[Tomas Dunker]

Do you mean this>> http://www.rcgroups.com/forums/showpost.php?p=8132038&postcount=22

Anyone know where to get a plan/drawing to a model with "rotating cylinder wings"? (I don't mean a heli or autogyro)

[50+AirYears]

Check the Model Airplane News plan service. Or maybe Flying Models. I believe they have a plan for a Flettner wing job designed by Roy Clough, published sometime in the last few years. Also, there is at least one in one of the Frank Zaic year books. Not sure which one. I have the book someplace in storage.

[Tomas Dunker]

Look what I found>>

http://209.196.57.92/ME2/dirmod.asp?sid=&nm=&type=EcomBB&mod=E%2DCommerce%3A%3AProduct+Catalog&mid=D30FB4BBE3764A5694C4972616B7262A&tier=3&id=9E2EB5E04DA7403097808B0EA88B01AA

Rotorplane! The text is fine but I think the picture is a bit crazy, or..?

[JRuggiero]

Back in 1951 I had one of those Flettner wing kites. It flew great.

Jim R

[50+AirYears]

I have noticed over the years that the MAN editors sometimes have a bit of trouble getting the right pictures with their plan ads. Probably somebody should mention this to their reps at the MAN booth at Toledo or other trade shows. Luckily, I don't notice them making the same kind of mistakes in the mag. Although I think I've seen some errors in the captions on a couple issues of the mag they put out for the electric and back yard fliers.

They didn't seem to make these mistakes back when they were a full feature model airplane magazine and the catalogue waspaper/snail mail.

At least, when I've ordered plans from them, they've always sent me the correct plans, usually within a week.

[50+AirYears]

Just found a clipping in one of my old notebooks for another .049 control line Flettner plan. Back 40 years or more ago, when I was in high school, to satisfy my mom, I clipped articles from my collection of model airplane mags and glued or taped them into notebooks and put the balance of the mags in the trash. Wish I still had some of those mags now.

Anyway, this clipping is from an old Air Trails or American Modeler, or one of that progression. The only hint of who might have designed it were the initials PDG, which I believe was Paul del Gato, who was both a pretty prolific designer himself, and also I think did quite a bit of drawing up other people's designs for publication.

Boy, with some of those old articles scanned into jpeg and printed out with a program like Tile Print, there are so many possibilities.

So many planes, so little time!