So this is an artists rendition of a possible implementation of one of DARPAS newest babies, the Discrotor copter.
The idea being to eliminate the speed limitations of rotor based aircraft by making the rotors retract into a disk at high speed, and thus circumventing the problems associated with rotor tips going supersonic.
OK, So my physics/aerodynamics may be a little rusty, but I’m missing the part about how efficiently the resulting disk is going to generate lift, even at high speed…
Info
www.theregister.co.uk/2008/09/05/darpa_disco_copter/
Concept renderings
www.vranek.ch/dragonfly.htm
If they could make it more into an elliptical airfoil, it could do okay.
…almost like the things the governator flew in ‘The 6th Day’…
Forget that its spinning, for a second, and think of the disk as being a wing. If the craft is moving forward fast enough, the disc should be able to provide lift on its own. To a first order approximation, it shouldn’t matter if the disk is rotating or not. But in reality, you’re going to get some really complicated surface effects with turbulent flow patterns. That’s some really hard physics. I won’t believe it until I see a prototype.
I always thought the speed limitation was due to the relative motion of the blades. As you increase forward speed, the retreating blade has less relative speed, thus less lift, while the approaching blades have increasing lift, making the copter unstable. Could be wrong on that, as I get my helio knowledge from Airwolf and Blue Thunder.
Will it take off?
DID anyone else notice the drawing having twin turbines just below the disk, where as the ,3d model doesn’t… I’m just going to go ahead and assume that they’re incorporated into the body of the aircraft and that’s why I don’t see them. Although I dont have any background in physics, I do know that any concept for a plane requires wind to be forces quickly under it’s wings. in this case, it would be under the disk if those turbines are actual there and under the aircraft where the other two might be. Also note that the drawing shows the turbines under the disk with a propeller at the end like any helicopter but the 3d design, replaces that.
It will stay on the drawing board.
It is just a cleverly shaped wing, that can spin.