A system and method of an airflow control system for a vehicle is described herein. The airflow control system (100) includes an airflow housing (120) defining an airflow passageway (125) extending between a bypass opening (122) and an intake outlet (124). The airflow housing also defines a duct opening (126) positioned between the bypass opening (122) and the intake outlet (124). The intake outlet (124) may be in fluid communication with an engine intake (12) of the vehicle such that air passes from the bypass opening (122) and/or the duct opening (126) to the engine intake (12). The airflow control system (100) also includes a movable duct (160) movably connected to the airflow housing (120) to selectively allow or prevent air passage through the duct opening (126) and into the engine intake (12), and further includes a bypass door (140) movably connected to the airflow housing (120) to selectively allow or prevent air passage through the bypass opening (122) and into the engine intake (12).

A system and method of an airflow control system for a vehicle is described herein. The airflow control system (100) includes an airflow housing (120) defining an airflow passageway (125) extending between a bypass opening (122) and an intake outlet (124). The airflow housing also defines a duct opening (126) positioned between the bypass opening (122) and the intake outlet (124). The intake outlet (124) may be in fluid communication with an engine intake (12) of the vehicle such that air passes from the bypass opening (122) and/or the duct opening (126) to the engine intake (12). The airflow control system (100) also includes a movable duct (160) movably connected to the airflow housing (120) to selectively allow or prevent air passage through the duct opening (126) and into the engine intake (12), and further includes a bypass door (140) movably connected to the airflow housing (120) to selectively allow or prevent air passage through the bypass opening (122) and into the engine intake (12).

There is disclosed a fan assembly including a fan rotor including a hub and fan blades. The fan blades have a leading edge and a trailing edge. A fan stator downstream of the fan rotor relative to a direction of an airflow through the fan assembly. The fan stator includes vanes extending between radially inner ends and radially outer ends. A flow recirculation circuit has an inlet downstream of the vanes of the fan stator and an outlet upstream of the vanes. A recirculation rotor has a plurality of airfoils circumferentially distributed around the axis and located in the flow recirculation circuit. The recirculation rotor is rotatable about the axis within the recirculation circuit. A method of operating the fan assembly is also disclosed.

There is disclosed a fan assembly including a fan rotor including a hub and fan blades. The fan blades have a leading edge and a trailing edge. A fan stator downstream of the fan rotor relative to a direction of an airflow through the fan assembly. The fan stator includes vanes extending between radially inner ends and radially outer ends. A flow recirculation circuit has an inlet downstream of the vanes of the fan stator and an outlet upstream of the vanes. A recirculation rotor has a plurality of airfoils circumferentially distributed around the axis and located in the flow recirculation circuit. The recirculation rotor is rotatable about the axis within the recirculation circuit. A method of operating the fan assembly is also disclosed.

Disclosed is a method for using an aircraft turbojet engine comprising an air inlet comprising a plurality of rectifier vanes, each rectifier vane being mounted such that it can move between a retracted position to assist the thrust phase and a deployed position in which the rectifier vane protrudes from the inner wall in a radially inward direction in order to rectify the reverse air flow of the inner wall to assist a thrust-reverse phase, in which method at least one rectifier vane is in the retracted position during a turbojet engine thrust phase, the method comprising, during a thrust-reverse phase of the turbojet engine, a step of moving the rectifier vane to the deployed position.

Disclosed is a method for using an aircraft turbojet engine comprising an air inlet comprising a plurality of rectifier vanes, each rectifier vane being mounted such that it can move between a retracted position to assist the thrust phase and a deployed position in which the rectifier vane protrudes from the inner wall in a radially inward direction in order to rectify the reverse air flow of the inner wall to assist a thrust-reverse phase, in which method at least one rectifier vane is in the retracted position during a turbojet engine thrust phase, the method comprising, during a thrust-reverse phase of the turbojet engine, a step of moving the rectifier vane to the deployed position.

Systems and methods for adjusting a variable geometry mechanism of an engine are described herein. An engine control request indicative of a desired output power for the engine is monitored. A rate of change of the engine control request is determined. The rate of change is compared to a threshold. Responsive to determining that the rate of change is beyond the threshold, a transient bias map is applied to a steady-state schedule to generate a variable geometry mechanism request indicative of a target position for the variable geometry mechanism. The variable geometry mechanism is adjusted toward the target position according to the variable geometry mechanism request.

Systems and methods for adjusting a variable geometry mechanism of an engine are described herein. An engine control request indicative of a desired output power for the engine is monitored. A rate of change of the engine control request is determined. The rate of change is compared to a threshold. Responsive to determining that the rate of change is beyond the threshold, a transient bias map is applied to a steady-state schedule to generate a variable geometry mechanism request indicative of a target position for the variable geometry mechanism. The variable geometry mechanism is adjusted toward the target position according to the variable geometry mechanism request.

An inlet duct for use with an engine is presented. The invention includes a duct structure, at least one spike disposed along an interior surface of the duct structure, and an inlet throat formed by one or more apexes disposed along an equal number of spikes. The inlet throat corresponds to the minimum cross-sectional area through which airflow passes as otherwise allowed by the maximal obstruction formed by the apex(es) within the duct structure. Each spike is bounded by a longitudinal ridge and a lateral ridge along an upper end and a base along a lower end. The longitudinal ridge and the lateral ridge intersect at the apex. In preferred embodiments, the longitudinal ridge is at least partially non-linear so as to properly conform to the interior surface of the duct structure. The portion of each spike upstream of the inlet throat functions primarily as a supersonic diffuser. The portion of each spike downstream of the inlet throat functions primarily as a subsonic diffuser. Airflow is isentropically compressed and then expanded within the inlet duct so that greater-than-subsonic flow at an input end is reduced to subsonic flow at an output end.

Aspects of the invention regard an aircraft including: a gas turbine engine, the gas turbine engine including an intake, a nacelle, and gas turbine engine components located radially inside the nacelle; and an aircraft structure. The intake of the gas turbine engine is mounted to the aircraft structure in a manner such that its position can be adjusted. The nacelle and the gas turbine engine components located radially inside the nacelle are rigidly mounted to the aircraft structure. Other aspects of the invention regard a gas turbine engine and a method for adjusting the input of air flowing into a gas turbine engine.