| 摘要 |
A propulsion arrangement suitable for an aircraft comprises a compressor, a (first) propulsion gas flow 19, and a (second) discharge gas flow 23, the discharge gas flow being at least partially bounded by the propulsion gas flow at the gas outlet. Ideally, a turbojet comprises a first propulsive flow 19 which flows through a compressor 9 and a combustor 13 before being exhausted by the turbine 11, and a second bypass flow 21 which travels through a duct 1 at the engine core / centre and enters the centre of the jet formed by the turbine exhaust. The bypass / secondary air may be purely ram air 21, or may have passed through the compressor / fan (see fig.2) before being introduced into the jet flow. The introduction of the flow into the jet reduces the velocity differential, and therefore reduces noise. An independent claim entails diverting jet air through the duct so as to provide thrust reversal. |
