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Gyrocopter rotor instead of canvas sail ?
- Thread starter CocoonCruisers
- Start date
Necroposting perhaps, but autogyro rotors for light sport airplanes are still going strong while there is little new when it comes to using them on sailing boats.
It seems Brabazon's Kestrel in the 30's followed by Alexander's fantastic skate sail some 6 years ago in this thread could need some follow up! There are small autogyro rotors, hubs and shafts reliable enough obviously, they are not overly heavy as compared to a sailing rig, and they have about the right amount of rotor disc area. On high a-o-a they work similar to a spinnaker with high lift and not so high L/D ratio, on small a-o-a they are like upwind sails with less lift and high L/D. No need to change sails when rounding the mark! And you basically have a wing sail, the full profile rotor-blade, that is not too large in cord to handle but still operate at reasonable high Re thanks to autorotation.
Questions: that of brakes that have been discussed in this thread e.g. in relationship to the Brabazon accident - do they have that on lightweight autogyros (no?). Doesn't autorotation just stop if you stop tilting the rotor away from the wind? Regarding the vibration of Alexander's ingenious skate-rotor: wouldn't that be controlled by what the autogyro constructors call "undersling" in the hub attachement?
I hope there is still some more interest for this!
It seems Brabazon's Kestrel in the 30's followed by Alexander's fantastic skate sail some 6 years ago in this thread could need some follow up! There are small autogyro rotors, hubs and shafts reliable enough obviously, they are not overly heavy as compared to a sailing rig, and they have about the right amount of rotor disc area. On high a-o-a they work similar to a spinnaker with high lift and not so high L/D ratio, on small a-o-a they are like upwind sails with less lift and high L/D. No need to change sails when rounding the mark! And you basically have a wing sail, the full profile rotor-blade, that is not too large in cord to handle but still operate at reasonable high Re thanks to autorotation.
Questions: that of brakes that have been discussed in this thread e.g. in relationship to the Brabazon accident - do they have that on lightweight autogyros (no?). Doesn't autorotation just stop if you stop tilting the rotor away from the wind? Regarding the vibration of Alexander's ingenious skate-rotor: wouldn't that be controlled by what the autogyro constructors call "undersling" in the hub attachement?
I hope there is still some more interest for this!
Paul Scott
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You’ve just got to love the Redwing class, influencing our Amati in a big way.Oh, cool !
So in 1933, King George V, who knew a lot about yachts, said "I have never seen a yacht sail so close to the wind". No videos found, but there is this tiny animated gif on Fiona Sinclair's site. The restored boat seems to live in the Cowes Classic Boat Museum - Wikipedia https://en.wikipedia.org/wiki/Classic_Boat_Museum now.
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