http://www.flightglobal.com/blogs/fl...lutionary.html

Well...

Interesting... I can see how it could very stable. You have that entire rotor spinning to provide centrifical stability. I can definitely see that it'd need larger than normal rudder area, a larger rudder would be needed to overcome the centrifical effect of that long cylinder spinning.

It'd be very quite, too. Not just because the model is electric, but you have a really big blades spinning relatively slowly, I'd think there wouldn't be a whole lot of cavitation. (At slow rotating speeds, that is.) I wonder if the blades could be made more efficient if the center of the blade cylinder was filled in, not hollow. I'm think there could be a lot of air turbulance incide the blade area that could be robbing power.

I think it'd definitely have a definitive upper power/speed limit. As the blade spins faster, I could see where it'd cavitate the air more. (the same as paddlewheel boats cavitate the water at higher rotating speeds.)

A - VERY - OLD idea resurfaces!

I wonder how well it flies/glides dead-stick.

good point pkh, one of the characteristics of a UAV is its big long wings so the UAV can loiter without much thrust from the motor.

It seemed very fun to fly that thing! But I really dont understand how it works, it makes no sense to me. Someone please explain?[:-]

It is a variation on a very old design called a "Cyclogyro".

See: [link=http://en.wikipedia.org/wiki/Cyclogyro]Click me![/link]

The helicopter generates lift by spinning the "wing" very fast to get airflow over it and generate lift. I believe this is the same concept, except tiny fan fins are acting as the "wing", spinning and generating lift and thrust.

I figure this thing can probably do it's own form of "auto-gyroing" down for a dead stick landing, but I believe this is very high drag design, so it probably won't have much of a glide ratio.

It's a cool idea, but for a UAV, you could use a hand-launched glider, which would take-off in a small area, and it would have a very good glide ratio, and very little drag, so it would require much less power to keep it in the air for extended periods of time. If you just want VTOL and hovering ability, you might as well just use a heli. The only advantage I see this fan-wing has over a heli is it's probably more stable and much easier to fly than a heli.

Thanks for the information guys!
Anyone know if something like that is available at hobby shops? I really want something like that, but if they are available I`m sure they are expensive!

Wow. It would take about 10 safety officers to keep my fingers out fo those blades !

if you want one of those, i want one of these
http://www.youtube.com/watch?v=bCJ70Fr1umA

I gotta admit, the VTOL was cool...

I particalarily like how smoothly it lifted off and landed... And how accurately it landed.... I'm thinking the gyroscopic effect of the prop helped the stabilitiy. Odd that the body didn't start to spin opposite of the prop...

None-the-less... Very cool...

It looked to me as though the bottom of the rotor was masked. That means there are no retreating blades.And even if there were any, they'd be the same on both sides of the aircraft. It's the retreating blade stall problem that limits the top speed of helicopters.Also, the blades probably don't need to flap.
(When a helicopter is moving forwards, the rotor blade that's also going forwards has a much higher airspeed than the one "retreating". As they have to have the same lift, the retreating blade has to operate at a higher angle of attack. Thus the blade flaps from a low angle of attack to a high one and back again every rotation. When the airspeed of the helicopter becomes very high, the retreating blade develops such an angle of attack that it stalls. Gyroscopic forces then come into play. Rather than rolling to the side, the rotor disc pitches up violently and cuts off the tail of the helicopter!!)

That fan wing is no speed plane, and the speeds we're talking about here, a heli can hold it's own. I believe a heli can easily go as fast as that fan wing, maybe even faster. Plus, a heli can hover and fly backwards, sideways, etc., which the fan wing cannot do. I still don't see much of an advantage of the fan wing over a heli, except for a little more inherent stability.