Patent ID: 6179225
Filing Date: 2001-01-30
Classification: F02K

Abstract:
In an axially symmetric, variable area and converging exhaust nozzle for an aircraft turbojet engine, the nozzle including a ring of inner hot flaps pivotally mounted at their upstream ends to the downstream end of conical shell fixedly located at an inner outlet area of the nozzle and actuatable by a first set of actuators between radially inward and outward positions, and a ring of outer cold flaps located radially outwardly of and downstream of the hot flaps, said cold flaps pivotally connected at their upstream ends to annular assembly located between the conical shell and an outer cowl extending around the outlet area of the nozzle, said cold flaps movable between radially inner and outer pivoted positions by a second set of actuators carried by the annular assembly to vary a terminal nozzle outlet area located within the cold flaps, the improvement comprising:said cold flaps each comprising an inner and outer skin radially separated from each other to define a longitudinal airflow channel between them and converging toward each other as they approach their trailing ends, the inner skin including orifices providing communication between the airflow channel and the nozzle flow area, and said inner skin carrying a pivot hinge connecting the cold flap to the annular assembly;said outer skin being aligned with a downstream end of the outer cowl when the cold flaps are in a forward retracted location and longitudinally separated from a downstream end of the outer cowl when the cold flaps are in a rearward extended position:said outer skin in the extended position defining an ambient fresh air scoop leading to said air flow channel;a third actuator arrangement for moving said actuator assembly and cold flaps between longitudinally separated retracted and extended positions.