Variable fan exhaust area nozzle for aircraft gas turbine engine with

Abstract

A structure to provide a variable nozzle for the fan air flow of a turbofan aircraft gas turbine engine with the nozzle being defined by the exit throat area defined by the aft edge of a trailing edge portion of the fan cowl and the core engine housing. A trailing edge cowl portion is slidably positioned in a rearwardly opening annular cavity in the aft end of the fan cowl for reciprocal axial translation between a deployed position to provide an enlarged exit throat area to provide enhanced performance of the aircraft engine during take off and climb to a cruising altitude and a stowed position to provide an optimum exit throat area for cruise condition of the engine. The trailing edge portion is sealably secured within the core cowl cavity to preclude any air leakage from the fan air stream of the fan duct around the trailing edge portion. A unique dual slider and track arrangement is provided to permit the variable nozzle to be translated aft simultaneously with and/or independently of a translating cowl portion of the fan cowl which may form a portion of a blocker door/cascade thrust reverser structure. The trailing edge portion includes sound attenuation treatment on its inner surface for exposure which when deployed enhances the sound attenuation capability of the nacelle system. The variable nozzle may also be used to advantage with other thrust reverser systems such as a four pivoting door structure positioned in the fan cowl.