Abstract: A propulsion system for an aircraft includes a rotor and a nacelle fairing that extends around the rotor in relation to an axis. The nacelle fairing includes an upstream portion forming an inlet section of the nacelle fairing as well as a downstream portion, a downstream end of which forms an outlet section of the nacelle fairing. The downstream portion includes radially inner and outer walls, both of which are made of a deformable shape memory material. The wall has independently actuatable piston actuator mechanisms, each actuator mechanism being actuatable independently of the others and being designed to cooperate with means built into an inner surface of the wall to deform the wall in a radial direction in relation to the axis under the effect of a predetermined displacement command.

Abstract: 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.

Abstract: In a convergent-divergent flap pair for a turbojet engine nozzle of the variable-geometry convergent-divergent type, the convergent flap and the divergent flap include respective cooling-air ducts connected to one another through air passage openings formed in respective contact surfaces of the convergent flap and of the divergent flap arranged facing one another.

Abstract: Flexible aft cowls are disclosed. In some examples, an aircraft engine having a flexible aft cowl is disclosed. In some examples, the aircraft engine comprises an aft cowl having a flexible portion defining a throat area adjacent an engine core nozzle of the aircraft engine. In some examples, the flexible portion to move radially between a first radial position in response to pressure within a nacelle not exceeding a pressure threshold and a second radial position in response to pressure within the nacelle exceeding the pressure threshold. In some examples, the throat area defined by the flexible portion is greater when the flexible portion is in the second radial position than when the flexible portion is in the first radial position.

Abstract: A variable exhaust nozzle for use with a gas turbine engine includes an outer shroud and an inner plug that can move relative to the outer shroud. The relative movement of the inner plug and the outer shroud changes the shape of the variable exhaust nozzle from one that converges in area to one that converges and then diverges in area.

Abstract: A bell-mouth scoop assembly includes an actuator comprising a plurality of hinge members configured to rotate in unison about a respective hinge axis of rotation from a first stowed position to a second deployed position and at least one linkage arm extending outwardly from at least one of the plurality of hinge members. The bell-mouth scoop assembly further comprises a bell-mouth panel comprising a panel longitudinal centerline and pivotably coupled to each linkage arm, in the first stowed position the bell-mouth panel (configured to conform to an outer surface of the with the panel longitudinal centerline aligned about a circumference of the flow discharge nozzle, in the second deployed position the bell-mouth panel configured to extend away from the outer surface of the flow discharge nozzle with the longitudinal centerline aligned parallelly with the nozzle centerline.

Abstract: A divergent flap seal includes a flap seal body with a spine, the flap seal body manufactured of a non-metallic material. A mount is engaged with the spine at the dovetail interface and a resilient member at the dovetail interface.

Abstract: A thrust reverser is disclosed. The thrust reverser includes a frame, a first reverser door pivotally mounted to the frame, a second reverser door pivotally mounted to the frame and a hybrid exhaust duct. A first trailing edge of the first reverser door forms a portion of an exit plane of the thrust reverser and a second trailing edge of the second reverser door merges into the hybrid exhaust duct.

Abstract: Methods and apparatus for sealing variable area fan nozzles of jet engines are disclosed. An apparatus in accordance with the teachings of this disclosure includes a frame and a seal to be coupled to the frame. The seal to enclose petals of a variable area fan nozzle to substantially prevent airflow between the petals.

Abstract: A method of managing a gas turbine engine includes the steps of detecting an airspeed and detecting a fan speed. A parameter relationship is referenced related to a desired variable area fan nozzle position based upon at least airspeed and fan speed. The detected airspeed and detected fan speed is compared to the parameter relationship to determine a target variable area fan nozzle position. An actual variable area fan nozzle position is adjusted in response to the determination of the target area fan nozzle position and at least one threshold.

Abstract: An inlet diffuser for a jet engine and methods for mixing boundary layers of air in compact inlet diffusers with high offset and high aspect ratio apertures are disclosed. The inlet diffuser includes an inlet diffuser body that includes elongate structures that are configured to allow a first portion of boundary layer air located between the elongate structures to flow within a channel, restrict the first portion of boundary layer air from flowing across either elongate structure, and allow a second portion of boundary layer air located outboard of the elongate structures to flow across the elongate structures and into a region of internal volume inward of the channel, wherein the second portion of boundary layer air is pushed away from the internal surface of the diffuser body by the elongate structures as the second portion of boundary layer air flows across the elongate structures in an inboard direction.

Abstract: A turbofan engine is disclosed which includes a nacelle assembly, having an interior surface for directing airflow, and a flow disruptor positioned on the interior surface upstream of the fan, the flow disruptor extending towards the axis a height greater than the anticipated boundary layer height of the airflow. A turbofan engine which includes an array of circumferentially disposed flow disruptors extending from a fan case inner surface is also disclosed. A method of mitigating fan flutter in a gas turbine engine by generating a circumferential asymmetrically in the airflow, upstream of the fan, is also described.

Abstract: A variable-geometry ducted fan may include an air duct having a longitudinal axis, the air duct including an inlet of the variable-geometry ducted fan, a fan rotatably mounted within the air duct downstream from the inlet, the fan including fan blades defining a fan area, and a variable-area nozzle coupled to the air duct downstream from the fan, the variable-area nozzle including an exhaust of the variable-geometry ducted fan having a variable exhaust area.

Abstract: A seal system for a turbomachine, in particular a gas turbine, which includes a first component (10A, 10B), a second component (20), a flap (30) for sealing a gap between the first and second components, and a leaf spring, which includes a first leg (41) and a second leg (42), in a mounting state in which the flap and the second component do not contact each other, a projection of an abutment area (11) of the first component (10A, 10B), against which the first leg (41) is supported via the flap (30), is situated perpendicularly to a contact line (K) through at least two contact points of the first leg (41) with the flap (30), at least partially within a bearing surface (A) of the first component (10A, 10B), against which the second leg (42) of the pretensioned leaf spring is supported.

Abstract: In various embodiments, a cowl actuation system may comprise a cowl, an actuator, a bell crank, and a guide arm. The cowl may be configured to modulate at least a portion of the exhaust flow of a gas turbine engine. The bell crank may have a first end and a second end. The first end may be operatively coupled to the actuator. The second end may be operatively coupled to the cowl. The bell crank may be configured to pivot about a first point located between the first end and the second end. The first point may also be located along a diameter. The guide arm may have a third end and a fourth end. The third end may be mounted to a second point. The fourth end may be operatively coupled to the cowl. The second point may be located along the diameter.

Abstract: An exhaust gas diffuser for a gas turbine engine whose inlet geometry can be selectively controlled to change the angular orientation of the diffuser at the location where the exhaust gas exits the last stage row of blades of the turbine section of the gas turbine engine. An end portion of the gas diffuser proximate the last stage row of blades can include one or more actuated sections that are independently controlled to change the angular orientation of the inlet geometry of the diffuser. In one embodiment, the angular orientation of the actuated sections is set at the manufacturing level for the service location of the engine. In another embodiment, the angular orientation of the actuated sections is selectively controlled based on the operating conditions of the engine. In another embodiment, the angular orientation of the actuated sections is controlled by pneumatic pressure from a compressor section of the engine.

Abstract: An exhaust nozzle for a gas turbine engine includes a gas path liner connected to an interior surface of an exhaust nozzle flap. The gas path liner includes a liner backbone that extends along a liner axis, and a plurality of liner panels sequentially connected to the liner backbone along the axis.

Abstract: An assembly is provided for an aircraft propulsion system. The assembly includes a first component, a second component and a seal assembly configured to seal a gap between the first and the second components. The seal assembly includes a metal spring seal element and an elastomeric seal element. The metal spring seal element is mounted to the first component. The metal spring seal element is sealingly engaged with the second component. The elastomeric seal element is mounted to the metal spring seal element. The elastomeric seal element is sealingly engaged with the second component.

Abstract: A thrust reverser for a nacelle of an aircraft turbojet engine includes at least one movable thrust reverser cowl, a means for locking the cowl, a variable section outlet nozzle, and at least one actuator including an actuator rod. The thrust reverser is provided with a resilient coupler comprising a body which is rigidly connected to the thrust reverser cowl and a resilient return and abutment device that engages with the actuating rod of the actuator such as to resiliently return the nozzle to a neutral position. The return device is calibrated such that, when the cowl is unlocked, the return device opposes the relative movement of the actuating rod relative to the cowl, such as to enable the movement of the cowl and the nozzle, and when the cover is locked, the actuator drives the actuating rod against the return device to enable the movement of the nozzle.

Abstract: An exhaust nozzle for a gas turbine engine according to an example of the present disclosure includes, among other things, a duct having a first surface and a second surface extending about a duct axis to define an exhaust flow path, and at least one effector positioned along the first surface. The at least one effector is pivotable about an effector axis to vary a throat area of the exhaust flow path. The at least one effector tapers along the effector axis. A method of exhaust control for a gas turbine engine is also disclosed.

Abstract: A nacelle is disclosed. The nacelle may include an inner fixed structure (“IFS”) comprising a first half, the first half comprising a central barrel portion, wherein the first half includes a first member that extends radially outward from the central barrel portion and a second member that extends radially outward from the central barrel portion radially opposite the first member, a first support structure overlaid by a first composite material that extends axially along a confluence between the central barrel portion and the first member, the first support structure configured to contact a second half comprising a second central barrel portion, and a second support structure overlaid by a second composite material that extends axially along the confluence between the central barrel and the second member, the second support structure configured to contact the second half.

Abstract: Provided are methods and systems for measuring and controlling nozzle areas of variable area fan nozzles. A control system attached to a nozzle may include a cable having one end connected to a linear displacement measuring device, such as a string potentiometer. The other end of the cable may be connected to a petal. A reference portion of the cable extends across multiple petals of the nozzle and, in some embodiments, substantially parallel to the nozzle circumference. The linear displacement measuring device measures any changes in the length of this reference portion as the petals actuate outwardly or inwardly during operation of the nozzle. The output of the linear displacement measuring device may be used to control actuators that move the petals. In some embodiments, potentiometer's output may be combined with one or more outputs from other sensors, such as a linear variable differential transducer and/or thermocouple.

Abstract: Systems and methods for influencing thrust of a gas turbine engine are disclosed. A system includes a plurality of pipes positioned at an exhaust nozzle of the gas turbine engine. Each one of the plurality of pipes includes: an inlet inside the exhaust nozzle; an outlet inside the exhaust nozzle; and an intermediate portion outside the exhaust nozzle.

Abstract: A gas turbine engine including an outlet guide vane and a bifurcation fairing is disclosed. The outlet guide vane is located in a bypass duct of the gas turbine engine downstream of a fan and is of aerofoil form. The bifurcation fairing traverses the radial extent of the bypass duct and has an upstream end that blends into a trailing edge of the outlet guide vane. The bifurcation fairing includes a scoop protruding outwards from its side corresponding to a pressure side of the upstream outlet guide vane. The scoop includes a forward facing inlet leading to a delivery conduit extending inside the bifurcation fairing for delivery in use of bypass air to one or more components of the gas turbine engine.

Abstract: A divergent flap seal includes a flap seal body with a spine, the flap seal body manufactured of a non-metallic material. A mount is engaged with the spine at the dovetail interface and a resilient member at the dovetail interface.

Abstract: A variable area fan nozzle comprising an array of rigid petals and a petal actuation system comprising left and right assemblies, each assembly comprising: a multiplicity of tracks attached to or integrally formed with respective petals; a curved pivoting ring segment; an actuator coupled to the ring segment; and a multiplicity of sets of cam followers spaced along the ring segment and aligned with respective tracks. Each ring segment is pivotable between first and second angular positions depending on how the state of the actuator changes. As one ring segment pivots in one direction, one set of cam followers exert inward forces on the tracks to deflect petals inward; as that ring segment pivots in the other direction, another set of cam followers exert outward forces on the tracks to deflect petals outward.

Abstract: A variable area fan nozzle comprising an array of hinged rigid petals and a petal actuation system in which the principle of actuation is realized by changes in shape (i.e., deformation) of the actuators rather than by movement of cooperating mechanical parts. Because these actuators have no rotating or sliding mechanical components, wear and associated maintenance are reduced. Each deformable actuator has a portion made of shape memory alloy that has been trained to change shape in a specific manner when heated to a temperature above a transition temperature. In addition, each shape memory alloy actuator is shaped to act as a fairing to reduce aerodynamic drag.

Abstract: An aircraft nacelle comprising a first duct secured to an air intake and a second duct secured to a powerplant, the first duct comprising an exterior surface and an end portion connected to the second duct. The nacelle includes a hollow section piece in contact with the exterior surface of the first duct which extends over at least part of the circumference of that end portion of the first duct that is connected to the second duct.

Abstract: Embodiments may include an actuation system for an exhaust nozzle of a gas turbine engine. The actuation system may comprise a plurality of flap assemblies including a plurality of convergent flaps movable between first and second convergent positions and a plurality of divergent flaps movable between first and second divergent positions. Each of the plurality of divergent flaps may extend from a respective one of the plurality of convergent flaps. The system may further include a first sync ring rotatably carried by an engine body and configured to synchronously move the divergent flaps between the first and second divergent positions and a second sync ring rotatably carried by the engine body and configured to synchronously move the convergent flaps between the first and second convergent positions. A method may translate rotation of the sync ring to movement of a vehicle surface between radially outward and inward positions.

Abstract: A fuel nozzle assembly including a conduit defining a fuel inlet and a fuel outlet and being operable to convey a fuel stream comprising a solid particulate fuel entrained in a fluid. The conduit has a flow area defined by an interior surface of the conduit. A first flow deflector and a second flow deflector extend inwardly from the interior surface. The first flow deflector and the second flow deflector are positioned to disrupt a velocity profile of the flow stream established upstream of the conduit.

Abstract: An inner structure for a nacelle for an aircraft turbofan includes a plurality of active and passive movable portions. Each active movable portion can drive adjacent passive movable portions such that the inner structure has a nominal first position, a second position and a third position. In the second position, the active movable portions project beyond by the passive movable portions toward the outside of the inner structure after the active mobile portions have driven the passive mobile portions. In the third position, the active movable portions project beyond the passive movable portions toward the inside of the inner structure after the active mobile portions have driven the passive mobile portions. The present disclosure also relates to a nacelle having an outer structure and such an inner structure.

Abstract: Systems and methods for influencing thrust of a gas turbine engine are disclosed. A system includes a plurality of pipes positioned at an exhaust nozzle of the gas turbine engine. Each one of the plurality of pipes includes: an inlet inside the exhaust nozzle; an outlet inside the exhaust nozzle; and an intermediate portion outside the exhaust nozzle.

Abstract: A liner assembly includes a plurality of flaps arranged about a central axis and operable to move relative to the central axis. Each of the plurality of flaps defines a forward end and an aft end, lateral sides, and an inner surface and an outer surface relative to the central axis. Each of the plurality of flaps has a thickness between the inner surface and the outer surface, and thickness varies in a lateral direction between the lateral sides.

Abstract: A gas turbine engine test cell has a turbine detuner capable of recovering kinetic energy from exhaust gases emitted by a gas turbine engine while also detuning the exhaust flow to reduce unwanted infrasound. The gas turbine engine test cell includes a test cell building, a thrust frame for mounting the gas turbine engine, and the turbine detuner disposed downstream of the thrust frame for extracting energy from the exhaust gases of the gas turbine engine when in operation. The turbine detuner has an inlet for receiving the exhaust gases, a kinetic energy recovery mechanism (e.g. stator and rotor) for converting the kinetic energy of the exhaust gases into rotary power, and an outlet through which de-energized exhaust gases are emitted after being de-energized by the kinetic energy recovery mechanism. By eliminating the augmentor, the test cell is more compact. The turbine detuner not only reduces infrasound but also recovers otherwise wasted energy.

Abstract: A latch assembly for securing a nacelle portion of a gas turbine engine includes first and second nacelle flow structures that define a portion of a bypass flowpath. A seal is engageable between the first and second nacelle flow structures. A latch is rotatable about a pivot between latched and unlatched positions. The latch maintains the seal in engagement with the first and second nacelle flow structures in the latched position. A method of opening a nacelle flow structure includes the steps of pivoting a latch from a latched position to an unlatched position, and unlatching a first nacelle flow structure relative to a second nacelle flow structure in response to the latch pivoting step.

Abstract: A diffuser (30) expanding a gas flow (F) upstream of a heat recovery steam generator (32) of a combined cycle power plant (34). An outer wall (44) of the diffuser includes a smoothly lofted backward facing step (46) effective to fix a location of a flow recirculation bubble (56) under conditions conducive to flow separation. The step has a varying step height (Hpeak, HvaIley) about a circumference of the step edge (62). The varying step height segments the recirculation bubble into small cells (66) located downstream of each peak (58) of the step height and reducing a reattachment length (L) of the bubble, thereby facilitating a reduction of the overall length of the diffuser.

Abstract: A nacelle for a turbofan propulsion system that extends along a centerline includes a forward cowling and an aft cowling. To improve the fit of a turbofan propulsion system in the space between the wing and ground of a fixed-wing aircraft, the aft cowling of the nacelle is modified. The aft cowling has a non-circular cross-sectional geometry disposed in a plane substantially perpendicular to the centerline. The non-circular cross-sectional geometry includes a radially recessed section disposed between first and second curved sections. The first and the second curved sections each have a radius that is greater than a radial distance between the centerline and a center point of the radially recessed section.

Abstract: A turbofan engine (10) employs a flow control device (41) that changes an effective exit nozzle area (40) associated with a bypass flow path (B) of the turbofan engine. A spool (14) couples a fan (20) to a generator (52). The turbofan emergency power system includes a controller (50) that communicates with the flow control device (41). Upon sensing an emergency condition, the controller manipulates the flow control device to reduce the effective nozzle exit area (40) of the bypass flow path, which chokes the flow through the bypass flow path thereby increasing the rotational speed of the fan. In this manner, the generator is driven at a higher rotational speed than if the flow through the bypass flow path was not choked, which enables a smaller generator to be utilized.

Abstract: An apparatus installed on an aircraft, comprising: a sleeve or duct having a trailing lip area; a plurality of petals arranged side by side with gaps therebetween, one end of each petal being attached or pivotably coupled to the lip area; and a plurality of elastomeric seals configured and disposed to close the gaps between adjacent petals. Each elastomeric seal comprises a first portion that moves with a portion of a first petal that is in contact therewith, a second portion that moves with a portion of a second petal that is in contact there, and a third portion which is stretched as the first and second petals move further apart from each other. Petal deflection is actuated by a system comprising a flexible member, a motor, a shaft driven by the motor, and an arm projecting from the shaft. One end of the flexible member is attached to the arm, the flexible member being movable to deflect the petals inward in response to a shaft rotation.

Abstract: An external flap connection assembly for a turbine engine nozzle has a track frame, a slider track, and an external flap. The external flap is removably connected to the slider track via a retaining member which has a slider block.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a nacelle assembly that includes an inlet lip section and an inlet internal diffuser section downstream of the inlet lip section. A variable area fan nozzle is positioned near an aft segment of the nacelle assembly, the variable area fan nozzle adaptable to move between a first position having a first discharge airflow area and a second position having a second discharge airflow area greater than the first discharge airflow area. At least one boundary layer control device is positioned near one of the inlet lip section and the inlet internal diffuser section. A controller is configured to move the variable area fan nozzle from the first position to the second position and to actuate the at least one boundary layer control device to introduce an airflow in response to an operability condition.

Abstract: A gas turbine jet noise reduction apparatus including a variable geometry gas turbine engine nozzle comprising a circumferentially distributed array of nozzle flap panels supported for alternate collective splaying and gathering motion, with the collective splaying motion of the flap panels being from a narrow position defining a minimum cross-sectional area at a nozzle exit plane, to a wide position defining a maximum cross-sectional area at the nozzle exit plane. A plurality of nozzle seal panels is supported in a circumferentially distributed array within the array of nozzle flap panels. A seal panel actuator is operatively engageable with the seal panels to deflect the seal panels radially inward into respective deployed positions to reduce jet noise by increasing exhaust stream mixing with ambient air.

Abstract: An exemplary nozzle having a variable internal exhaust area for a gas turbine engine can have a plurality of flap trains extending around a periphery of the gas turbine engine. Each flap train can include a convergent flap pivotally attached to an engine body and a divergent flap pivotally attached to the engine body downstream of the convergent flap. The nozzle can further have a fluid circuit in communication with the convergent and divergent flaps and configured to pivot the convergent and divergent flaps between a radially inward position and a radially outward position.

Abstract: A fan variable area nozzle (FVAN) includes a flap driven through a cable which circumscribes the fan nacelle. The cable is strung through a multiple of flaps to define a flap set of each circumferential sector of the EVAN. An actuator system includes a compact high power density electromechanical actuator which rotates a spool to deploy and retract the cable and effectively increase or decrease the length thereof between the spool and a fixed attachment to increase and decrease the fan nozzle exit area.

Abstract: A turbofan engine includes an engine core and a ducted fan assembly, with the ducted fan assembly including an annular cowling and a dilating fan duct nozzle. The nozzle includes continuous nozzle sections with intermeshing tiles. The tiles include drive tiles that are pivotal between nominal and dilated positions and driven tiles that intermesh with the drive tiles and shift with the drive tiles between the positions. The intermeshing tiles cooperatively adjust an orifice size of the nozzle by shifting between the positions and thereby affect the thrust and noise developed by the ducted fan assembly.

Abstract: A multi-layered honeycomb structure adapted to reduce and/or eliminate thermal deformation is disclosed herein. In some embodiments, walls of the honeycomb structure comprise a first layer, optionally, a second layer, and a core layer adjacent to the first layer or between the first and second layers. The first and second layers may be compositions of Inconel or other high strength materials. The core layer may be copper or another thermally conductive material. The core layer is adapted to transmit heat between a first region of a structure and a second region. In this manner, heat can be transferred from the heated region to an unheated region, thereby reducing the temperature difference between the regions and thus the amount of thermal deformation.

Abstract: A fluid dynamic device (100) for directing fluid flow to generate thrust comprising a thrust control shroud (130) disposed about a central axis (210) of said fluid dynamic device (100) for directing a fluid flow between an upstream fluid intake region (220) and a downstream fluid exit region (222), forming a fluid exit area, of said shroud (130) to generate thrust wherein a displacement of said fluid exit region (222) of said shroud (130) with respect to said central axis (210) results in a translation of said fluid exit area (222) such that the level of shear stress induced in that part of the shroud (130) disposed laterally to the direction of translation of the shroud (130) is minimized.

Abstract: An exhaust nozzle flap for a turbine engine may include an exhaust nozzle flap linkage, an exhaust nozzle flap panel and a mounting pin. The linkage may include a first linkage segment that extends longitudinally from a linkage end to a second linkage segment, and a mounting aperture that extends transversely through the second linkage segment. The panel may include a first panel segment that extends longitudinally from a panel end to a second panel segment. The first panel segment may be pivotally engaged with the first linkage segment. The mounting pin may extend through and move transversely within the mounting aperture, and may be connected to the second panel segment.

Abstract: An exhaust nozzle flap for a turbine engine may include an exhaust nozzle flap linkage, an exhaust nozzle flap panel and a mounting pin. The linkage may include a first linkage segment that extends longitudinally from a linkage end to a second linkage segment, and a mounting aperture that extends transversely through the second linkage segment. The panel may include a first panel segment that extends longitudinally from a panel end to a second panel segment. The first panel segment may be pivotally engaged with the first linkage segment. The mounting pin may extend through and move transversely within the mounting aperture, and may be connected to the second panel segment.

Abstract: A variable area fan nozzles comprising an array of rigid petals hinged to a lip area at the downstream end of a thrust reverser sleeve (or half-sleeve). In one embodiment, the actuation system comprises a rotatable ring segment, a drive system for rotating the ring segment, a plurality of cams attached or integrally formed with the ring segment, a plurality of cam followers, and a plurality of petal linkages which operatively couple the petals to the cam followers. This actuation system controls the deflection of the petals, thereby controlling the amount of opening and the rate at which the fan nozzle throat area changes. Each cam may have forward- and rearward-facing camming surfaces that interact with the cam followers to force the petals to pivot outward or inward respectively.