GYROPLANE PREROTATION BY COMPRESSED AIR
A rotorcraft is disclosed. The rotorcraft may include a rotor having at least one tip nozzle, a compressor having an outlet for compressed air, and a network of conduits connecting the outlet of the compressor with the tip nozzle. In operation, the compressor may deliver a flow of compressed air to the tip nozzle. As the flow of compressed air exits the at least one tip nozzle, it may cause rotation of the rotor. This rotation may prerotate the rotor and shorten the take off distance required by the rotorcraft. Take off of the rotorcraft may be accomplished without ever adding fuel to the flow of compressed air to the tip nozzle.
1 . A method comprising:
selecting a rotorcraft comprising
at least one rotor having at least one tip nozzle,
at least one compressor having an outlet for compressed air, and
a network of conduits connecting the outlet of the at least one compressor with the at least one tip nozzle;
delivering, by the at least one compressor, a flow of compressed air to the at least one tip nozzle;
prerotating, by the flow of compressed air during the delivering, the at least one rotor;
ceasing, after the prerotating and before take off, the flow of compressed air to the at least one tip nozzle; and
taking off, by the rotorcraft, without the flow of compressed air to the at least one tip nozzle.
2 . The method of claim 1 , wherein the rotorcraft is a gyroplane.
3 . The method of claim 2 , wherein the at least one compressor comprises at least one jet engine.
4 . The method of claim 3 , wherein the flow of compressed air passing through the outlet corresponding to the at least one jet engine and into the network of conduits comprises exhaust gas from the at least one jet engine.
5 . The method of claim 3 , wherein the flow of compressed air passing through the outlet corresponding to the at least one jet engine and into the network of conduits comprises air bled from a compressor portion of the at least one jet engine.
6 . The method of claim 3 , wherein:
the at least one jet engine comprises a turbofan; and
the flow of compressed air passing through the outlet corresponding to the at least one jet engine and into the network of conduits comprises air from the fan of the turbofan.
7 . The method of claim 6 , wherein the flow of compressed air passing through the outlet corresponding to the at least one jet engine and into the network of conduits comprises substantially all of the air from the fan of the turbofan.
8 . The method of claim 2 , wherein the at least one compressor comprises at least one engine dedicated substantially exclusively to the generation of the flow of compressed air for one or more tip nozzles of the at least one tip nozzle.
9 . The method of claim 2 , wherein the at least one compressor is driven by a turboprop engine.
10 . The method of claim 9 , wherein the turboprop engine drives both the at least one compressor and a propeller.
11 . The method of claim 10 , further comprising a clutch selectively disengaging the at least one compressor from the turboprop engine.
12 . The method of claim 2 , wherein the rotorcraft further comprises a control system comprising at least one valve within the network of conduits.
13 . The method of claim 12 , wherein the ceasing comprises closing the at least one valve.
14 . The method of claim 2 , wherein the at least one compressor comprises a plurality of compressors.
15 . The method of claim 14 , wherein the at least one rotor comprises:
a hub; and
a plurality of rotor blades extending radially away from the hub, each rotor blade of the plurality of rotor blades having a tip nozzle of the at least one tip nozzle.
16 . The method of claim 15 , wherein the network of conduits comprises:
a plenum;
a plurality of incoming ducts, each connecting a different outlet of the plurality of compressors to the plenum;
outgoing ducting connecting the hub of the at least one rotor to the plenum; and
an interior conduit extending within each blade of the plurality of rotor blades to connect a tip nozzle corresponding thereto to the hub.
17 . A method comprising:
providing a rotorcraft comprising
at least one rotor having at least one tip nozzle,
at least one compressor having an outlet for compressed air, and
a network of conduits connecting the outlet of the at least one compressor with the at least one tip nozzle;
delivering, by the at least one compressor, a flow of compressed air to the at least one tip nozzle;
prerotating, by the flow of compressed air during the delivering, the at least one rotor; and
taking off, by the rotorcraft, without injecting fuel into the flow of compressed air.
18 . The method of claim 17 , further comprising ceasing, after the prerotating and before take off, the flow of compressed air to the at least one tip nozzle.
19 . The method of claim 17 , further comprising ceasing, after the taking off and in flight, the flow of compressed air to the at least one tip nozzle.
20 . The method of claim 17 , wherein the rotorcraft is a gyroplane.