| 摘要 |
An exhaust nozzle for a gas turbine aero-engine comprising a duct 17(c), a plurality of movable flaps 38,43 for varying the geometry of the nozzle, one or more forwardly and outwardly directed openings 59 located upstream of the flaps 38,43 and a pair of mutually confronting doors 61 each of which is mounted for rotation about an axis extending transverse to the length of the duct 17(c). The doors 61 are located relative to the duct 17(c) and the openings 59 so that, in a first position, they obturate the openings 59 and mutually confronting surfaces 67 of the doors define therebetween part of the gas flow path through the nozzle, and the doors 61 are movable to a second position, upstream of the first position, where they uncover the openings 59, define, at their upstream ends 68, a reduced area throat for the gas flow path through the nozzle. In the second position the doors 61 also define a divergent part of the gas flow path immediately downstream of the said throat. The reduced pressure downstream of the throat induces ambient air through the openings 59 into the gas flow path through the nozzle. Means 28,35,36 are provided for moving the flaps 38,43 to accommodate the increased gas flow through the nozzle when the said openings 59 are uncovered. In this way the infrared emission of the gas plume exiting from the nozzle is suppressed by the cool air.
|
