Abstract: A two dimensional gas turbine engine exhaust nozzle includes transversely spaced apart upper and lower convergent and divergent flaps and extending longitudinally in a downstream direction and between two widthwise spaced apart sidewalls. The divergent flaps have inwardly facing upper and lower flap surfaces defining together with the sidewalls at least a part of an exhaust stream flowpath therebetween. The upper and lower flap surfaces have respective upper and lower apexes wherein the upper apex is axially spaced apart and aft of the lower apex. The upper divergent flap has an expansion ramp diverging away from the nozzle axis. The ramp extends aftwardly from the upper apex and aftwardly of a trailing edge of the lower divergent flap. The upper and lower divergent flaps are operably movable to block a line of sight along the nozzle axis through an exit of the nozzle during engine operation.

Abstract: A short take off and vertical landing (STOVL) nozzle for a jet aircraft provides thrust reversing and thrust vectoring functions using two pairs of flaps. Each flap is independently actuated and controlled to allow for numerous exhaust gas exit configurations. A two dimensional or rectangular center plug extends across the nozzle throat region to allow one pair of flaps to selectively engage the plug for STOVL operation.