Abstract: A turbofan engine includes fan section including a plurality of fan blades, a gear train, a low spool including a low pressure turbine and a low pressure compressor, the low pressure turbine driving the plurality of fan blades through the gear train, and a high spool including a high pressure turbine driving a high pressure compressor. A fan nacelle at least partially surrounds a core nacelle to define a fan bypass flow path. A fan variable area nozzle is in communication with the fan bypass flow path and defines a fan nozzle exit area between the fan nacelle and the core nacelle. The fan variable area nozzle varies the fan nozzle exit area.

Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, a fan section including a plurality of fan blades, a gear train, a low pressure turbine driving the fan section through the gear train, 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 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. The fan variable area nozzle includes a first fan nacelle section and a second fan nacelle section, the second fan nacelle section movably mounted relative the first fan nacelle section and moveable axially along an engine axis of rotation relative the first fan nacelle section, defining an auxiliary port that extends between the first fan nacelle section and the second fan nacelle section.

Abstract: A turbofan engine includes fan section including a plurality of fan blades, a gear train, a low spool including a low pressure turbine and a low pressure compressor, the low pressure turbine driving the plurality of fan blades through the gear train, and a high spool including a high pressure turbine driving a high pressure compressor. A fan nacelle at least partially surrounds a core nacelle to define a fan bypass flow path. A fan variable area nozzle is in communication with the fan bypass flow path and defines a fan nozzle exit area between the fan nacelle and the core nacelle. The fan variable area nozzle varies the fan nozzle exit area.

Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, a fan section including a plurality of fan blades, a gear train, a low pressure turbine driving the fan section through the gear train, 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 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. The fan variable area nozzle includes a first fan nacelle section and a second fan nacelle section, the second fan nacelle section movably mounted relative the first fan nacelle section and moveable axially along an engine axis of rotation relative the first fan nacelle section, defining an auxiliary port that extends between the first fan nacelle section and the second fan nacelle section.

Abstract: A method of designing a turbofan engine according to an exemplary aspect of the present disclosure includes, among other things, providing a fan section including a plurality of fan blades, providing a low pressure turbine driving the plurality of fan blades through a gear train, providing a fan nacelle and a core nacelle, the fan nacelle at least partially surrounding the core nacelle, providing a fan bypass flow path defined between the core nacelle and the fan nacelle, and providing 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.

Abstract: A turbofan engine includes fan section including a plurality of fan blades, a gear train, a low spool including a low pressure turbine and a low pressure compressor, the low pressure turbine driving the plurality of fan blades through the gear train, and a high spool including a high pressure turbine driving a high pressure compressor. A fan nacelle at least partially surrounds a core nacelle to define a fan bypass flow path. A fan variable area nozzle is in communication with the fan bypass flow path and defines a fan nozzle exit area between the fan nacelle and the core nacelle. The fan variable area nozzle varies the fan nozzle exit area.

Abstract: A nacelle assembly for a high-bypass gas turbine engine includes a fan variable area nozzle movable relative a fan nacelle to vary a fan nozzle exit area to reduce a fan instability.

Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, a fan section including a plurality of fan blades, the plurality of fan blades having a fixed stagger angle and a design angle of incidence, a low pressure turbine driving the plurality of fan blades through a gear train, a fan nacelle and a core nacelle extending along an engine axis of rotation, the fan nacelle at least partially surrounding the core nacelle and the plurality of fan blades, a fan bypass flow path defined between the core nacelle and the fan nacelle, the core nacelle contoured along the fan bypass flow path with respect to the engine axis of rotation, and a fan variable area nozzle in communication with a controller and with the fan bypass flow path, and defining a fan nozzle exit area between the fan nacelle and the core nacelle.

Abstract: A gas turbine engine includes a fan section with twenty (20) or less fan blades and a fan pressure ratio less than about 1.45.

Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, a fan section including a plurality of fan blades, the plurality of fan blades having a fixed stagger angle and a design angle of incidence, a low pressure turbine driving the plurality of fan blades through a gear train, a fan nacelle and a core nacelle extending along an engine axis of rotation, the fan nacelle at least partially surrounding the core nacelle and the plurality of fan blades, a fan bypass flow path defined between the core nacelle and the fan nacelle, the core nacelle contoured along the fan bypass flow path with respect to the engine axis of rotation, and a fan variable area nozzle in communication with a controller and with the fan bypass flow path, and defining a fan nozzle exit area between the fan nacelle and the core nacelle.

Abstract: A turbofan engine includes fan section including a plurality of fan blades, a gear train, a low spool including a low pressure turbine and a low pressure compressor, the low pressure turbine driving the plurality of fan blades through the gear train, and a high spool including a high pressure turbine driving a high pressure compressor. A fan nacelle at least partially surrounds a core nacelle to define a fan bypass flow path. A fan variable area nozzle is in communication with the fan bypass flow path and defines a fan nozzle exit area between the fan nacelle and the core nacelle. The fan variable area nozzle varies the fan nozzle exit area.

Abstract: A method of designing a turbofan engine according to an exemplary aspect of the present disclosure includes, among other things, providing a fan section including a plurality of fan blades, providing a low pressure turbine driving the plurality of fan blades through a gear train, providing a fan nacelle and a core nacelle, the fan nacelle at least partially surrounding the core nacelle, providing a fan bypass flow path defined between the core nacelle and the fan nacelle, and providing 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 afterward relative to the fixed first fan nacelle section to change the effective area of the fan nozzle exit area.

Abstract: A nacelle assembly for a high-bypass gas turbine engine includes a fan variable area nozzle axially movable relative the fan nacelle to define an auxiliary port to vary a fan nozzle exit area and adjust a pressure ratio of the fan bypass airflow during engine operation.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.