US Patent 7299621 Three-spool by-pass turbojet with a high by-pass ratio

The invention relates to aerodynamically matching the rear fan of a turbojet having two fans and a low-pressure compressor at the front of the intermediate casing, said fans being driven by two independent shafts. Said compressor is disposed between the blades of the two fans and includes at least one ring of rotor blades around the periphery of a wheel driven by the drive shaft for the front fan, and at least two grids of stator vanes disposed on either side of the ring of rotor blades and inside a grid carrier ring. A stationary outer grid and a stator of variable pitch connect the ring to the fan casing.