Hybrid RotorWing Design Transitions From Fixed To Rotary Wing Mid-Flight 86
cylonlover writes "Attempts to combine the vertical take-off and landing (VTOL) capabilities of a helicopter with the high-speed flight and long range capabilities of a fixed-wing aircraft have been tackled in a number of different ways – from tiltrotor designs, such as the V-280 Valor and Project Zero, to fixed rotor aircraft that transition from vertical to horizontal flight, such as the SkyTote and Flexrotor. Australian company StopRotor Technology has taken a different approach with its Hybrid RotorWing design concept which features a main rotor that switches from fixed rotor to fixed wing in mid air."
Re:It's just an autogyro (Score:4, Informative)
Autogyros are very old tech.
From TFA "The design features a powered main rotor" so no, not an autogyro.
Re:Harrier? (Score:5, Informative)
A bit different. The rough rotor equivalent of the Harrier is a tiltrotor design, where the rotor rotates from a position where it generates vertical thrust (for takeoff) to one where it generates horizontal thrust (for flight).
This design instead stops the rotor when in horizontal flight, fixing it at an angle perpendicular to the fuselage so it becomes a wing generating lift. Then forward thrust is provided by separate, flight-only engines mounted in a conventional manner. When the plane wants to land again, the rotor stops being a wing, and starts spinning again in a helicopter style, to provide vertical thrust.
Re:Harrier? (Score:5, Informative)
Is this like the Harrier, where the motor switches from vertical to horizontal?
No, it is a helicopter where you stop the rotor and then use it as a wing for flying straight ahead with a traditional propellor. There is a typo in the summary.
This design would necessitate that the airfoil be symetrical along the long axis. Think VW Beatle shaped [wikipedia.org] rather than teardrop-shaped like a typical NACA airfoil [wikipedia.org]. This is probably a lot less efficient than a normal airfoil. Locking the airfoil would also be tricky- The rotor must come to a stop, so upwards lift is basically 0. At the same time, there is no wing for the front propeller to work on. Or worse, a wing oriented in the wrong direction. If they make a full-scale version, I hope the test pilot is single without any kids.
Re:Harrier? (Score:5, Informative)
A bit different. The rough rotor equivalent of the Harrier is a tiltrotor design, where the rotor rotates from a position where it generates vertical thrust (for takeoff) to one where it generates horizontal thrust (for flight).
You are thinking of the V-22 Osprey. [wikipedia.org] The Harrier uses a jet engine and ducting to direct the jet blast downward. There are no tilting rotors.
Re:The 6th Day (Score:5, Informative)
Though at least these guys seem to have worked out how to stop the thing from sinking like a stone during rotor transition though, which is a welcome feature.
I don't know, the flight path from their simulation video looks a lot like it drops like a stone for a while:
1) Fly along in "airplane mode" with the rotor fixed perpendicular to the body, acting like a wing - regular amount of lift being generated
2) lift the nose until the airflow is perpendicular to the bottom of the rotor - not much lift being generated now
3) unlock the rotor so that the wind can start it rotating like an autogyro - starts to provide significant amount of lift
4) apply power to the rotor and get into helicopter mode - regular amount of lift being provided.
Step #2 looks a bit like falling.
Going the other way
1) Fly in helicopter mode, moving forward at a fast clip - regular amount of lift being provided
2) Lift the nose to get airflow perpendicular to the bottom of the rotor -
3) Stop the rotor and get it fixed perpendicular to the body - not much lift being generated now
4) drop the nose to get the airflow over the now fixed wing - regular amount of airplane lift.
Step #3 looks a whole lot like falling.
Saw this in Popular Science 25 years ago... (Score:5, Informative)
Yep, I remember this too. I even found the site of someone who claims to have created it. [nemontel.net] But you and he are off by 10 years - it was July 1987. [google.com]
Re:The 6th Day (Score:4, Informative)
http://en.wikipedia.org/wiki/Sikorsky_S-72 [wikipedia.org]