Abstract: Conventional commercial engine exhaust systems are defined with axi-symmetric surfaces (e.g., conical or nearly conical surfaces), which create an annular exhaust for the fan (bypass) nozzle of roughly constant duct-height around the circumference. In one example configuration, the fan sleeve has been sheared upward (towards the wing or pylon) causing a larger area and duct height near the pylon relative to the portion away from the pylon. For a given thrust generated by the turbofan engine housed in the nacelle, the shear toward the pylon mount realigns the thrust in the direction of flight which may, in some examples, reduce noise experienced downstream of the turbofan engine and decreases fuel consumed in the engine core.

Abstract: Conventional commercial engine exhaust systems are defined with axi-symmetric surfaces (e.g., conical or nearly conical surfaces), which create an annular exhaust for the fan (bypass) nozzle of roughly constant duct-height around the circumference. In one example configuration, the fan sleeve has been sheared upward (towards the wing or pylon) causing a larger area and duct height near the pylon relative to the portion away from the pylon. For a given thrust generated by the turbofan engine housed in the nacelle, the shear toward the pylon mount realigns the thrust in the direction of flight which may, in some examples, reduce noise experienced downstream of the turbofan engine and decreases fuel consumed in the engine core.

Abstract: Conventional commercial engine exhaust systems are defined with axi-symmetric surfaces (e.g., conical or nearly conical surfaces), which create an annular exhaust for the fan (bypass) nozzle of roughly constant duct-height around the circumference. In one example configuration, the fan sleeve has been sheared upward (towards the wing or pylon) causing a larger area and duct height near the pylon relative to the portion away from the pylon. For a given thrust generated by the turbofan engine housed in the nacelle, the shear toward the pylon mount realigns the thrust in the direction of flight which may, in some examples, reduce noise experienced downstream of the turbofan engine and decreases fuel consumed in the engine core.

Abstract: Auxiliary power unit inlet apparatus and methods are disclosed. An example apparatus includes an aircraft including a fuselage, the fuselage including an air inlet including a first sub-inlet and a second sub-inlet separated from the first sub-inlet; and a door coupled along the air inlet to enable air to separably flow into the first sub-inlet and the second sub-inlet, the door to deter the air from flowing between the first sub-inlet and the second sub-inlet.

Abstract: Pre-cooler inlet ducts that utilize active flow-control and systems and methods including the same are disclosed herein. The systems include a pre-cooler inlet duct for a jet engine that is configured to receive a pre-cooler air stream and to direct the pre-cooler air stream into a heat exchanger. The pre-cooler inlet duct includes a flow-directing surface, which defines at least a portion of the pre-cooler inlet duct, and an active flow-control device. The active flow-control device is located to modify a boundary layer fluid flow within a boundary layer adjacent the flow-directing surface to resist separation of the boundary layer from the flow-directing surface when the pre-cooler air stream flows through the pre-cooler inlet duct. The methods include methods of resisting boundary layer separation in the pre-cooler inlet duct by flowing the pre-cooler air stream across the flow-directing surface and modifying the boundary layer with the active flow-control device.

Abstract: In one example, a strut for mounting a jet engine to a wing of an aircraft includes a plurality of engine mounts and a space frame truss supported from the wing and including front and aft portions, the front portion being coupled to and supporting the engine mounts, the aft portion extending upwardly and rearwardly from an aft end of the front portion. By removing the aft end of the strut from the core exhaust zone of the engine, substantial reductions in the weight and drag of the strut, and a corresponding increase in the specific fuel consumption of the associated aircraft may be achieved.

Abstract: A core cowl for a turbofan engine may include a plurality of valleys formed in an outer surface of the core cowl. Each valley may include a convex portion upstream of a concave portion, and may be configured to disrupt a shock cell exiting a fan nozzle of the turbofan engine. Associated methods for reducing turbofan engine noise are also described.

Abstract: Thrust recovery outflow valves for aircraft are disclosed. An example thrust recovery outflow valve includes a flow control member having a first aerodynamic surface and a second aerodynamic surface to define at least a portion of a fluid flow passageway between an inlet and an outlet of the thrust recovery outflow valve. A first portion of the first aerodynamic surface and a first portion of the second aerodynamic surface provides a converging profile between the inlet and a throat of the fluid flow passageway. A second portion of the first aerodynamic surface and a second portion of the second aerodynamic surface provides a diverging profile between the throat and the outlet of the fluid flow passageway. The fluid flow passageway is positioned at a small angle relative to an outer surface of an aircraft to enable fluid exiting the fluid flow passageway to provide a thrust recovery vector oriented substantially parallel to the outer surface of the aircraft and opposite a direction of drag.

Abstract: A turbine engine nozzle can include a primary outer wall extending from an engine core area to an annular wall terminus that surrounds an engine tail cone, to form a core nozzle. The turbine engine nozzle also includes a single engine core cowl extending from the engine core area to an annular cowl terminus to form a core compartment vent nozzle. The core compartment vent nozzle exhausts air from a core compartment in a trailing edge between the single engine core cowl and the primary outer wall.

Abstract: In one example, a strut for mounting a jet engine to a wing of an aircraft includes a plurality of engine mounts and a space frame truss supported from the wing and including front and aft portions, the front portion being coupled to and supporting the engine mounts, the aft portion extending upwardly and rearwardly from an aft end of the front portion. By removing the aft end of the strut from the core exhaust zone of the engine, substantial reductions in the weight and drag of the strut, and a corresponding increase in the specific fuel consumption of the associated aircraft may be achieved.

Abstract: A thrust reverse variable area nozzle system for a nacelle of an aircraft engine system may include a reverse thrust opening disposed in the nacelle, and a thrust reverser door pivotally movable relative to the nacelle for selectively covering the reverse thrust opening, wherein the thrust reverser door is pivotally movable between a first position for completely covering the reverse thrust opening, a second position for partially uncovering a forward portion of the reverse thrust opening and discharging a bypass airflow through the forward portion of the reverse thrust opening in a forward direction, and a third position for partially uncovering an aft portion of the reverse thrust opening and discharging the bypass airflow through the aft portion of the reverse thrust opening in an aft direction.

Abstract: A gas turbine engine exhaust nozzle comprises a housing having an aft end that terminates in a row of chevrons. At least one surface of the housing has scalloped root regions proximate bases of adjacent chevrons. The scalloped root regions have a reduced thickness relative to the rest of the aft end.

Abstract: In one example embodiment, a strut for mounting a jet engine to a wing of an aircraft includes a plurality of engine mounts and a space frame truss supported from the wing and comprising front and aft portions, the front portion being coupled to and supporting the engine mounts, the aft portion extending upwardly and rearwardly from an aft end of the front portion. By removing the aft end of the strut from the core exhaust zone of the engine, substantial reductions in the weight and drag of the strut, and a corresponding increase in the specific fuel consumption of the associated aircraft may be achieved.

Abstract: A gas turbine engine exhaust nozzle comprises a housing having an aft end that terminates in a row of chevrons. At least one surface of the housing has scalloped root regions proximate bases of adjacent chevrons. The scalloped root regions have a reduced thickness relative to the rest of the aft end.

Abstract: Thrust recovery outflow valves for aircraft are disclosed. An example thrust recovery outflow valve includes a flow control member having a first aerodynamic surface and a second aerodynamic surface to define at least a portion of a fluid flow passageway between an inlet and an outlet of the thrust recovery outflow valve. A first portion of the first aerodynamic surface and a first portion of the second aerodynamic surface provides a converging profile between the inlet and a throat of the fluid flow passageway. A second portion of the first aerodynamic surface and a second portion of the second aerodynamic surface provides a diverging profile between the throat and the outlet of the fluid flow passageway. The fluid flow passageway is positioned at a small angle relative to an outer surface of an aircraft to enable fluid exiting the fluid flow passageway to provide a thrust recovery vector oriented substantially parallel to the outer surface of the aircraft and opposite a direction of drag.

Abstract: 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.

Abstract: In one example embodiment, a strut for mounting a jet engine to a wing of an aircraft includes a plurality of engine mounts and a space frame truss supported from the wing and comprising front and aft portions, the front portion being coupled to and supporting the engine mounts, the aft portion extending upwardly and rearwardly from an aft end of the front portion. By removing the aft end of the strut from the core exhaust zone of the engine, substantial reductions in the weight and drag of the strut, and a corresponding increase in the specific fuel consumption of the associated aircraft may be achieved.

Abstract: Auxiliary power unit inlet apparatus and methods are disclosed. An example apparatus includes an aircraft including a fuselage, the fuselage including an air inlet including a first sub-inlet and a second sub-inlet separated from the first sub-inlet; and a door coupled along the air inlet to enable air to separably flow into the first sub-inlet and the second sub-inlet, the door to deter the air from flowing between the first sub-inlet and the second sub-inlet.

Abstract: Auxiliary power unit inlet apparatus and methods are disclosed. An example apparatus includes an air inlet for an aircraft including a first air flow path and a second air flow path. The first air flow path is immediately adjacent the second air flow path. The first air flow path is at least partially separated from the second air flow path by a first panel. The example apparatus includes a door hingably coupled adjacent the air inlet. The door includes a second panel extending from an interior surface of the door to substantially prevent air from flowing across the interior surface between the first air flow path and the second air flow path.

Abstract: A turbine engine nozzle can include a primary outer wall extending from an engine core area to an annular wall terminus that surrounds an engine tail cone, to form a core nozzle. The turbine engine nozzle also includes a single engine core cowl extending from the engine core area to an annular cowl terminus to form a core compartment vent nozzle. The core compartment vent nozzle exhausts air from a core compartment in a trailing edge between the single engine core cowl and the primary outer wall.