| 摘要 |
<p>The nozzle comprises a duct 17(c), a plurality of movable flaps 38,43 for varying the geometry of the nozzle, one or more openings 59 and a pair of rotatably mounted mutually confronting doors 61. The doors 61 are mounted 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. The reduced pressure downstream of the throat induces ambient air through the openings 59 into the gas flow path through the nozzle. (Fig.2, not shown). In this way the infrared emission of the gas plume exiting from the nozzle is suppressed by the cool air. <IMAGE></p> |
