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 mixing tube with multiple shapes is provided, allowing additional injection of gas in order to keep the flow detached from the second shape in an ascent phase and to bring about, in a descent phase, a controlled detachment as a result of the change of slope between the two shapes. A propulsion nozzle for an engine of a spacecraft or aircraft is provided including such a mixing tube and a method for controlling the speed transition of the propulsion gases in such a nozzle in accordance with the altitude. Also, a method is provided for vectorising the thrust in such a nozzle by radial and asymmetrical injection of gas and a control method which prevents re-attachment of the jet to the second shape of such a propulsion nozzle for an engine of a spacecraft when it is in the take-off or landing phase.

A mixing tube with multiple shapes is provided, allowing additional injection of gas in order to keep the flow detached from the second shape in an ascent phase and to bring about, in a descent phase, a controlled detachment as a result of the change of slope between the two shapes. A propulsion nozzle for an engine of a spacecraft or aircraft is provided including such a mixing tube and a method for controlling the speed transition of the propulsion gases in such a nozzle in accordance with the altitude. Also, a method is provided for vectorising the thrust in such a nozzle by radial and asymmetrical injection of gas and a control method which prevents re-attachment of the jet to the second shape of such a propulsion nozzle for an engine of a spacecraft when it is in the take-off or landing phase.

A nacelle includes at least a first cowling which at least partially defines an inlet of the nacelle and which at least partially defines an outlet of the nacelle. The first cowling can include a unitary portion that extends continuously from the inlet to the outlet. The nacelle also includes a second cowling that at least partially defines the inlet and which translates relative to the first cowling. The nacelle can include a third cowling that at least partially defines the outlet and translates relative to the first cowling.

A nacelle includes at least a first cowling which at least partially defines an inlet of the nacelle and which at least partially defines an outlet of the nacelle. The first cowling can include a unitary portion that extends continuously from the inlet to the outlet. The nacelle also includes a second cowling that at least partially defines the inlet and which translates relative to the first cowling. The nacelle can include a third cowling that at least partially defines the outlet and translates relative to the first cowling.

A variable area fan nozzle assembly for a turbofan engine includes a nacelle having an aft edge and a translating thrust reverser sleeve with a trailing edge. The thrust reverser sleeve is movably disposed aft of the nacelle's aft edge and is movable between a forward position and an aft position. A translating fan nozzle having a forward edge is movably disposed behind the trailing edge, and is movable between a stowed position and a deployed position. An upstream bypass flow exit is defined between the trailing edge and the forward edge when the fan nozzle is in the deployed position. An extendable actuation system is configured to move the fan nozzle between the stowed position and the deployed position.

A flow vectoring turbofan engine employs a fixed geometry fan sleeve and core cowl forming a nozzle incorporating an asymmetric convergent/divergent (con-di) and/or curvature section which varies angularly from a midplane for reduced pressure in a first operating condition to induce flow turning and axially symmetric equal pressure in a second operating condition for substantially axial flow.

A flow vectoring turbofan engine employs a fixed geometry fan sleeve and core cowl forming a nozzle incorporating an asymmetric convergent/divergent (con-di) and/or curvature section which varies angularly from a midplane for reduced pressure in a first operating condition to induce flow turning and axially symmetric equal pressure in a second operating condition for substantially axial flow.

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.