| 摘要 |
<p>A two-stage mixer ejector concept ("TSMEC") (10) is disclosed for suppressing the noise emanted by jet aircraft. This TSMEC was designed to help older engines (12) meet the stringent new federal noise regulations in the United States of America, known as "Stage III". In an illustrated embodiment, the TSMEC comprises: a lobed engine nozzle (18) attached to the rear of a turbofan engine (12); a short shroud (20) that straddles the exit end of the engine nozzle; two rings (30, 32) of convergent/divergent primary and secondary lobes within the engine nozzle shroud; and a ring (26) of accurate gaps that preceed the shroud and the second nozzle ring. The lobes (30,32) are complimentary shaped to rapidly mix the turbine's hot exhaust flow with cooler air including entrained ambient air, at supersonic speed. This drastically reduces the jet exhaust's velocity and increases jet mixing, thereby reducing the jet noise. <IMAGE></p> |
