Abstract: Aircraft engine exhaust systems enabling short aft fairings are described. An example turbofan engine exhaust system of an aircraft includes a primary nozzle having a leading edge and a trailing edge, and a heat shield coupled to an aft strut fairing. The heat shield has an upstream end and a downstream end. The downstream end of the heat shield is substantially coterminous with the trailing edge of the primary nozzle.

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: Systems and methods for cooling bleed air from an aircraft engine are described. An example system includes a housing to bifurcate airflow exiting a fan of an engine fan system, a pre-cooler assembly disposed within the housing to remove heat from the bleed air, and an inlet duct within the housing to direct the airflow to the pre-cooler assembly. The example system also includes at least one diverter duct within the housing and coupled to the inlet duct to divert the airflow around the pre-cooler assembly. The at least one diverter duct includes an exit directing the airflow into a fan duct of the engine fan system. The example system also includes at least one valve to control an amount of airflow through the inlet duct and an amount of airflow through the at least one diverter duct.

Abstract: Aircraft engine exhaust systems enabling short aft fairings are described. An example turbofan engine exhaust system of an aircraft includes a primary nozzle having a leading edge and a trailing edge, and a heat shield coupled to an aft strut fairing. The heat shield has an upstream end and a downstream end. The downstream end of the heat shield is substantially coterminous with the trailing edge of the primary nozzle.

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: Systems and methods for cooling bleed air from an aircraft engine are described. An example system includes a housing to bifurcate airflow exiting a fan of an engine fan system, a pre-cooler assembly disposed within the housing to remove heat from the bleed air, and an inlet duct within the housing to direct the airflow to the pre-cooler assembly. The example system also includes at least one diverter duct within the housing and coupled to the inlet duct to divert the airflow around the pre-cooler assembly. The at least one diverter duct includes an exit directing the airflow into a fan duct of the engine fan system. The example system also includes at least one valve to control an amount of airflow through the inlet duct and an amount of airflow through the at least one diverter duct.

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: 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: 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: 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: 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: 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: 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: A method and apparatus for draining fluid from a structure on an aircraft. The apparatus comprises a drainage tube, a housing, a number of inlet holes in the housing, and a number of outlet holes in the housing. The drainage tube has first end that connects to a structure on an aircraft and a second end opposite the first end. The housing connects to the structure. The drainage tube is located within the housing. Air flows into the housing during flight of the aircraft through the number of inlet holes in the housing. The air flows out of the housing during flight of the aircraft through the number of outlet holes. The air flowing into the housing through the number of inlet holes and out the housing through the number of outlet holes directs fluid out of the drainage tube and away from the structure during flight of the aircraft.

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: 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 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: A method and apparatus for draining fluid from a structure on an aircraft. The apparatus comprises a drainage tube, a housing, a number of inlet holes in the housing, and a number of outlet holes in the housing. The drainage tube has first end that connects to a structure on an aircraft and a second end opposite the first end. The housing connects to the structure. The drainage tube is located within the housing. Air flows into the housing during flight of the aircraft through the number of inlet holes in the housing. The air flows out of the housing during flight of the aircraft through the number of outlet holes. The air flowing into the housing through the number of inlet holes and out the housing through the number of outlet holes directs fluid out of the drainage tube and away from the structure during flight of the aircraft.