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.

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.

A variable area exhaust nozzle defining an actual area ratio for a gas turbine engine that includes a shroud assembly having a fixed shroud and an adjustable cowl, an adjustable plug, a nozzle adjustment assembly, and a controller configured to receive data indicative of an operating speed of the gas turbine engine; determine a target area ratio based at least in part on received data indicative of the operating speed of the gas turbine engine; and operate the nozzle adjustment assembly to selectively adjust at least one of the adjustable cowl or the adjustable plug such that the actual area ratio is substantially equivalent to the target area ratio.

A variable area exhaust nozzle defining an actual area ratio for a gas turbine engine that includes a shroud assembly having a fixed shroud and an adjustable cowl, an adjustable plug, a nozzle adjustment assembly, and a controller configured to receive data indicative of an operating speed of the gas turbine engine; determine a target area ratio based at least in part on received data indicative of the operating speed of the gas turbine engine; and operate the nozzle adjustment assembly to selectively adjust at least one of the adjustable cowl or the adjustable plug such that the actual area ratio is substantially equivalent to the target area ratio.

A rotating detonation engine can include an annular combustion chamber, an adjustable exhaust nozzle, and a nozzle actuator arrangement. The annular combustion chamber can have repetitive high frequency combustion and can include an outlet. The nozzle can be coupled to that outlet to receive exhaust reactants expelled therefrom. The nozzle can include elongated fins arranged in a conical shape having inner surfaces, outer surfaces, and distal ends. The fins can include outer and inner sets of fins, can contract toward a closed position, and can expand toward an open position. Distal ends of the fins can define a nozzle outlet having variable diameters. The nozzle actuator arrangement can have fin adjusters that adjust the fins between the closed and open positions when power is applied to a power transmitter coupled to the fin adjusters during engine operations.

A variable-section nozzle for an aircraft nacelle includes a deformable portion of which is movable between a narrow section position and a wide section position. In particular, the variable-section nozzle includes piezoelectric actuators and a controller to control the piezoelectric actuators in order to displace the deformable portion between the narrow and wide section positions. The piezoelectric actuators can be disposed on at least one faces of the deformable portion or be disposed end-to-end to form actuating rods.

A variable-section nozzle for an aircraft nacelle includes a deformable portion of which is movable between a narrow section position and a wide section position. In particular, the variable-section nozzle includes piezoelectric actuators and a controller to control the piezoelectric actuators in order to displace the deformable portion between the narrow and wide section positions. The piezoelectric actuators can be disposed on at least one faces of the deformable portion or be disposed end-to-end to form actuating rods.

A control system for a variable area fan nozzle (VAFN) is disclosed. The VAFN may have a plurality of petals and may be for use with a gas turbine engine. The control system may include a primary system configured to acquire primary data indicative of an operating condition of the VAFN, a secondary system configured to acquire secondary data indicative of a current operating condition of the gas turbine engine, and a control module in operative communication with the primary system and the secondary system. The control module may be configured to: determine a nozzle area of the VAFN based at least in part on the primary data, adjust the determined nozzle area based on the secondary data, and position the plurality of petals according to the adjusted nozzle area.

A control system for a variable area fan nozzle (VAFN) is disclosed. The VAFN may have a plurality of petals and may be for use with a gas turbine engine. The control system may include a primary system configured to acquire primary data indicative of an operating condition of the VAFN, a secondary system configured to acquire secondary data indicative of a current operating condition of the gas turbine engine, and a control module in operative communication with the primary system and the secondary system. The control module may be configured to: determine a nozzle area of the VAFN based at least in part on the primary data, adjust the determined nozzle area based on the secondary data, and position the plurality of petals according to the adjusted nozzle area.

For gains in terms of aerodynamic performance levels, an aircraft engine assembly includes a turbomachine, a fastening strut for the turbomachine, and at least one foldable ventilator cover which surrounds the turbomachine and which includes: a first cover sector which includes a first end portion which is mounted so as to be articulated to the fastening strut, along a first articulation axis, and a second cover sector which includes a first end portion which is mounted so as to be articulated to a second end portion of the first cover sector, along a second articulation axis parallel with the first articulation axis. The second end portion is mounted so as to be guided at one side and the other thereof by a thrust inverter cover of the engine assembly and an air inlet structure of this assembly, respectively.