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What were the advantages and why was it never produced?

Spinning wing airliner diagram

FreeMan
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TesterMen Tester
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    complexity I guess – ratchet freak Nov 07 '14 at 12:02
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    What makes you think there were any advantages? – Jamiec Nov 07 '14 at 14:00
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    It seems to me that the gyroscopic forces would be massive for such a big drum. Modern airplanes go through tires very often because they skid when initially touching the pavement. Pre-spinning the wheels to reduce skidding has proven to be infeasible because even the relatively small wheels have produced gyroscopic forces making maneuverability more difficult whilst landing. – Keavon Nov 09 '14 at 06:40
  • This made me think, though, that perhaps a sort of cloth skin could go over the outside of the wing and be rotated so that there isn't a heavy cylinder, but instead a light piece of cloth that would wrap and spin around the wing. This would also provide more surface area to catch the air and the wings would still be functional in the case that the power source spinning this stops functioning. It could even be used just at takeoff for more lift, allowing for lift-off in shorter distances. This seems much more feasible in this way. – Keavon Nov 09 '14 at 06:50
  • Applicable: http://www.fanwing.com/

    One of the claimed benefits is extremely low stall speed. I have no idea, I just saw the site a few months ago and recognized your drawing above as what the site was promoting.

     – Calphool Feb 24 '15 at 23:00
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    There are a lot of designs like the spinning wing and aerodyne that work just fine but which rely completely on having power for lift. That's a deal breaker because engines quit. Any design that MUST have power for lift will never be a primary system for any flying aircraft. The only reason we use helicopter is autorotation. We're it not for that, helicopters would be suicidal. Another example of 99% great killed by 1% deal breaking suck. – TechZen Jun 02 '15 at 22:16

1 Answers1

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Some earlier prototypes of spinning-wing aircraft were produced but none were successful. The design has some very serious disadvantages. One of the main issues appears to be undesirable gyroscopic effects.

Production

... why it was never produced?

Several full-scale prototype aircraft with rotating Magnus-effect wings seem to have been produced:

  • 921-V - Plymouth. 1930.
  • X772N - Union Aircraft Co. 1931.

It may be that 921-V is the only one to have flown, crashing after one flight.

enter image description here The Flettner airplane

Built in 1930 (USA), the 921-V is reported to have been flown at least once - ending it's short career with a crash landing. Three cylinders with disks performing as winglets driven by a separate engine. Information on this design needed! It's probably the only aircraft equipped with cylinder wings which made it into the air.

From Pilotfriend.com

In practice the effect can be less efficient than conventional alternatives

In the early 1920's the force from a rotating cylinder was used to power a sailing ship. The idea, proposed by Anton Flettner of Germany, was to replace the mast and cloth sails with a large cylinder rotated by an engine below deck. The idea worked, but the propulsion force generated was less than the motor would have generated if it had been connected to a standard marine propeller!

From NASA

Advantages

What were the advantages?

The article referenced suggests

More wing lift and less drag are the major aims of aviation’s researchers. Maybe the Magnus Wing will supply the answers ... The ship is powered by a conventional gas-turbine jet engine, while the drums are revolved by a separate piston engine. Small wings, heavy loads and quick take-offs would be its great advantages.

Disadvantages

The developer of a working model wrote about a few of the disadvantages (try a google translation of that page for more):

  1. If the cylinder rotation accidentally becomes slow or stops, its lift disappears completely. This plane will never be able to glide.

  2. If a gust blows from backside during a slow flight (takeoff or landing), the cylinder wings generate a down force.

  3. The spinning cylinder wings generate a strong gyro effect, which makes it difficult for the plane to change its attitude.

See video and comments.

NASA did some experiments with rotating-cylinders for flaps (not main lift source)

OV-10 with rotating cylinder flaps

They concluded

These experiments demonstrated on the one hand the effectiveness of such a high lift system but on the other hand the weakness in handling qualities due to the gyroscopic forces in such an aircraft configuration.

From A review of the Magnus effect in aeronautics

The US Army also carried out a study of the use of the Magnus effect in aircraft VIEW AND PRELIMINARY EVALUATION OF LIFTING HORIZONTAL-AXIS ROTATING-WING AERONAUTICAL SYSTEMS

enter image description here

It is difficult to pick out a simple conclusion as the study looked at a wide variety of systems. For rotating cylinders in wing (RCIW) they wrote

Such systems do not appear to have merit as STOL devices.

flyingfisch
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RedGrittyBrick
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  • Thanks @RedGrittyBrick again, you're the one which answers almost all of my question professional and good – TesterMen Tester Nov 07 '14 at 16:12
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    Great answer! You have made this page the definite source for Magnus effect planes on the whole Internet. – Peter Kämpf Nov 07 '14 at 17:54
  • I would add that Magnus-effect wings don't seem to provide better efficiency. Induced drag would still be the same (and it is inversely proportional to wing span, so making the wing shorter only makes things worse) and being thicker it does not look like they should have lower form drag. – Jan Hudec Nov 07 '14 at 18:47
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    Couldn't you counter the gyroscopic forces with another cylinder inside the first one spinning in the opposite direction? The article seems to claim that turbulence would be reduced or even eliminated. Wouldn't the extra difference between the top and bottom airflow speeds increase turbulence? – CJ Dennis Nov 08 '14 at 03:11
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    @CJDennis: I think you could, see Dynamics of counter-rotating flywheels. That adds a lot to complexity and weight. You'd need much stronger framework and bearings to keep the two cylinders separate as the aircraft banked, yawed or pitched up or down. Any failure might be spectacular. – RedGrittyBrick Nov 08 '14 at 10:45
  • This has blown my mind! I love the idea of a magnus effect jet too! I might be getting the angular momentum vector wrong, but won't the spinning cylinders dampen the effect of turbulence on the airframe? – shortstheory Nov 08 '14 at 17:39
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    @shortstheory: It probably would make things worse, gyroscopic effect. To dampen a force, the reaction force would have to oppose the action force. With gyroscopes, the reaction force is orthogonal to the action force and the axis of rotation. With this arrangement, the axis of rotation is pitch so the gyroscope couples roll and yaw. – MSalters Nov 11 '14 at 10:11
  • Note that the prototype YOV-10A pictured above was housed at the Yankee Air Museum at Willow Run Airport in Michigan, US until it was destroyed by fire October 9, 2004. http://www.ov-10bronco.net/news_detail.cfm?NewsID=319 – Ed Griebel Nov 17 '14 at 20:58