GAS TURBINE ENGINE WITH AXIAL MOVABLE FAN VARIABLE AREA NOZZLE

摘要

A turbofan engine includes a fan variable area nozzle includes having a first fan nacelle section and a second fan nacelle section movably mounted relative the first fan nacelle section. The second fan nacelle section axially slides aftward relative to the fixed first fan nacelle section to change the effective area of the fan nozzle exit area.

主权项

1. A turbofan engine comprising:
a fan section including a plurality of fan blades, the plurality of fan blades having a design angle of incidence; a gear train having a gear reduction ratio of greater than 2.5:1; a low pressure turbine configured to drive the plurality of fan blades through the gear train, the low pressure turbine having a pressure ratio greater than 5:1; a fan nacelle and a core nacelle, the fan nacelle at least partially surrounding the core nacelle; a fan bypass flow path defined between the core nacelle and the fan nacelle, and a bypass ratio greater than 10:1; a fan variable area nozzle in communication with the fan bypass flow path and defining a fan nozzle exit area between the fan nacelle and the core nacelle; and wherein the fan variable area nozzle is operable to vary the fan nozzle exit area in a plurality of flight conditions and maintain an angle of incidence of the plurality of fan blades in the plurality of flight conditions that is close to the design angle of incidence of the plurality of fan blades.