Abstract: A variable area nozzle system for a turbofan gas turbine engine comprises a fan duct inner wall, a fan duct outer wall and a fan nozzle. The fan duct outer wall is disposed in radially-spaced relation to the fan duct inner wall. The fan nozzle defines at least a portion of the fan duct outer wall and has a nozzle aft edge defining a fan duct throat area relative to the fan duct inner wall. The fan nozzle is configured to move outwardly relative to the longitudinal axis during axial aft translation thereof in order to vary the fan duct throat area.

Abstract: The proposed adaptive exhaust nozzle features an innovative use of the shape memory alloy (SMA) actuators for actively control of the opening area of the exhaust nozzle for jet engines. The SMA actuators remotely control the opening area of the exhaust nozzle through a set of mechanism. An important advantage of using SMA actuators is the reduction of weight of the actuator system for variable area exhaust nozzle. Another advantage is that the SMA actuator can be activated using the heat from the exhaust and eliminate the need of other energy source. A prototype has been designed and fabricated. The functionality of the proposed SMA actuated adaptive exhaust nozzle is verified in the open-loop tests.

Abstract: A turbofan gas turbine engine (10) comprises a variable area exhaust nozzle (12) arranged at the downstream end of a casing (17). A control unit (66) analyses the power produced by the gas turbine engine (10), the flight speed of the gas turbine engine (1) and/or the altitude of the gas turbine engine (10). The control unit (66) configures the variable area nozzle (12) at a first cross-sectional area (70A) when the flight speed of the gas turbine engine (10) is less than a first predetermined value. The control unit (66) configures the variable area nozzle (12) at a second, smaller, cross-sectional area (70B) when the flight speed of the gas turbine engine (10) is greater than the first predetermined value and the power produced by the gas turbine engine (10) is greater than a second predetermined value.

Abstract: An eductor assembly is provided that includes a primary nozzle, a cooler plenum, and a surge plenum. In one embodiment, and by way of example only, the primary nozzle is configured to accelerate and discharge turbine exhaust gas therefrom and the cooler plenum surrounds the primary nozzle and includes at least a fluid inlet and a fluid outlet. The surge plenum partially surrounds the primary nozzle and the cooler plenum and includes at least a fluid inlet and a fluid outlet. The surge plenum fluid outlet axially aligns and is coterminous with the cooler plenum fluid outlet.

Abstract: A convergent/divergent nozzle for a gas turbine engine includes liners that are attached to the convergent flaps and seals. The liner is formed of two separate plates. By splitting the liner into two separate plates, a thermal break is provided between the two. Thermal stresses on a downstream plate are not as readily transferred to an upstream plate. External stresses on the upstream plate are not transferred as readily to the downstream plate. The two liner plate portions, and a separate backing plate all have faces that abut and are riveted together. These faces provide a flow blocker to maintain a lower pressure downstream of the flow blocker.

Abstract: A turbofan engine assembly is provided. The turbofan engine assembly includes a core gas turbine engine, a core cowl which circumscribes the core gas turbine engine, a nacelle positioned radially outward from the core cowl, a fan nozzle duct defined between the core cowl and the nacelle, and an inner core cowl baffle assembly positioned within the fan nozzle duct. The inner core cowl baffle assembly includes a first core cowl baffle coupled to a portion of the core cowl within the fan nozzle duct, a second core cowl baffle coupled to a portion of the core cowl and positioned a distance radially inward from the first core cowl baffle, and an actuator assembly configured to vary the throat area of the fan nozzle duct by selectively repositioning the second core cowl baffle with respect to the first core cowl baffle. A method for operating the turbofan engine assembly is also provided.

Abstract: A fan variable area nozzle (FVAN) includes a flap assembly which varies a fan nozzle exit area. The flap assembly generally includes a multiple of flaps, flap linkages and an actuator system. The actuator system radially and axially translates a drive ring relative an engine centerline axis. A slot within the drive ring receives the flap linkages to asymmetrically and symmetrically vary the fan nozzle exit area in response to movement of the drive ring.

Abstract: A method for operating a turbofan engine assembly including a core gas turbine engine is provided. The method includes varying an operating speed of the turbofan engine assembly from a first operating speed to a second operating speed. The method also includes selectively positioning a first arcuate portion and a second arcuate portion of a split cowl assembly to vary a throat area of a fan nozzle duct defined downstream from the core gas turbine engine to facilitate improving engine efficiency at the second operating speed. The split cowl assembly is downstream from the core gas turbine engine and inside the fan nozzle duct. A turbofan engine assembly and nozzle assembly are also provided.

Abstract: A turbofan engine includes a fan variable area nozzle having an axial overlapped nozzle assembly with a first fan nacelle section and a second fan nacelle section movably mounted relative the first fan nacelle section. The second fan nacelle section axially slides forward along the engine axis relative the fixed first fan nacelle section to change the effective area of the fan nozzle exit area.

Abstract: Integrated engine exhaust systems and methods for reducing drag and thermal loads are disclosed. In one embodiment, a propulsion system includes an engine installation configured to be mounted on a wing assembly of an aircraft. The engine installation includes an engine, and an exhaust system operatively coupled to the engine. The exhaust system includes at least one nozzle configured to exhaust an exhaust flow from the engine. The nozzle includes a variable portion configured to vary an exit aperture of the nozzle from a first shape to a second shape to change a flowfield shape of at least a portion of the nozzle flowfield proximate the wing assembly, thereby reducing at least one of drag and thermal loading on the wing assembly. In a further embodiment, the exhaust system includes an inner nozzle that exhausts a core exhaust flow, and an outer nozzle that exhausts a secondary exhaust flow, the outer nozzle having the variable portion configured to vary the exit aperture of the outer nozzle.

Abstract: A propulsive system for an aircraft including an auxiliary jet engine is integrated within a tail cone of a fuselage. Lateral air intakes include each one a scoop movable between a closed position and an opened position are associated with aerodynamic channels to supply with air the auxiliary jet engine. The aerodynamic channels meet at a common channel including a movable flap to balance air flows coming from the air intakes when the operation is not symmetrical.

Abstract: A turbofan engine includes a fan variable area nozzle having a rotationally overlapped nozzle assembly having a first tab section and a second tab section rotationally mounted relative to the first tab section. The rotationally overlapped nozzle assembly changes the physical area and geometry of the bypass flow path during particular flight conditions.

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 method of controlling mixing of a flow exiting a nozzle associated with a jet engine. The method may involve pivotally supporting a mixing structure forming a hinge device at a downstream edge of the nozzle. A shape memory alloy (SMA) element may be used to couple to the mixing structure. Heat may be generated by a flow exiting the nozzle to induce a phase change in the SMA element. The phase change may cause an axial length of the SMA element to constrict, to cause a pivoting movement of the mixing structure into a path of the flow exiting the nozzle.

Abstract: A fan variable area nozzle (FVAN) (42) includes a multiple of compact high power density electromechanical actuators (EMA) (56) located within a fan nacelle (34). Each EMA directly pitches an associated flap (48) or group of flaps between a converged position and a diverged position. The compactness of the EMA readily facilitates one-to-one flap mounting within the fan nacelle close to the relatively thin trailing edge (34 T) thereof yet provides the power density to meet FVAN power requirements.

Abstract: Jet engine nozzles with projections (e.g., chevrons) and injected flow, and associated systems and methods are disclosed. A method in accordance with one embodiment includes generating a first flow of gas with a jet engine, delivering the first flow through a nozzle having a trailing edge perimeter that includes multiple projections extending in an aft direction, and injecting a pressurized second flow of fluid into the first flow proximate to the projections. In other embodiments, other mixing enhancement devices (e.g., vortex generators) are carried by the projections. It is expected that the combination of the projections and the mixing enhancement devices will reduce engine exhaust noise levels below the levels achievable with either projections or injected flow individually.

Abstract: A high-bypass gas turbine engine includes a variable area fan nozzle with an acoustic system having an acoustic impedance.

Abstract: A thrust vectorable fan variable area nozzle (FVAN) includes a synchronizing ring, a static ring, and a flap assembly mounted within a fan nacelle. An actuator assembly selectively rotates synchronizing ring segments relative the static ring to adjust segments of the flap assembly to vary the annular fan exit area and vector the thrust through asymmetrical movement of the thrust vectorable FVAN segments. In operation, adjustment of the entire periphery of the thrust vectorable FVAN in which all segments are moved simultaneously to maximize engine thrust and fuel economy during each flight regime. By separately adjusting the segments of the thrust vectorable FVAN, engine trust is selectively vectored to provide, for example only, trim balance or thrust controlled maneuvering.

Abstract: A convergent/divergent nozzle for a gas turbine engine includes liners that are attached to the convergent flaps and seals. The liner is formed of two separate plates. By splitting the liner into two separate plates, a thermal break is provided between the two. Thermal stresses on a downstream plate are not as readily transferred to an upstream plate. External stresses on the upstream plate are not transferred as readily to the downstream plate. The two liner plate portions, and a separate backing plate all have faces that abut and are riveted together. These faces provide a flow blocker to maintain a lower pressure downstream of the flow blocker.

Abstract: A composite article includes a composite member, a flexible member and at least one shape memory material member. The composite member has longitudinally extending fibres in a matrix material. The at least one shape memory material member extends substantially parallel to the composite member and the flexible member is positioned between the composite member and the at least one shape memory material member to bond the at least one shape memory material member to the composite member. The composite article is particularly suitable for use as a tab for an exhaust nozzle of a turbofan gas turbine engine.

Abstract: A nozzle system includes a multitude of circumferentially distributed convergent flaps, divergent flaps and inter-flap seals which circumscribe an engine centerline and define the radial outer boundary of an exhaust gas path. Each divergent flap includes longitudinal sides having a set of extension which are located at different longitudinal stations such that the extensions on adjacent divergent flaps interfit when the nozzle is in a minimum dilated position yet provide support for the intermediate flap seal when the nozzle is in a maximum dilated position to thereby provide a relative increase in the nozzle area ratio range.

Abstract: A nozzle system includes a multitude of circumferentially distributed divergent seals that circumscribe an engine centerline. Each divergent seal includes an interface between a forward seal bridge bracket and an aft seal bridge bracket with a forward bridge support and an aft bridge support which provides axial and radial support for the divergent seals between adjacent divergent flaps. A divergent-convergent seal joint structure includes a horn and a fork. By having the forward bridge bracket retain the divergent seal in the axial direction, there is no need for axial sliding of the divergent seal relative to the divergent flap. The joint structure provides circumferential support as the axial and radial support are provided by the bridge-bracket interface.

Abstract: A quick change connection is provided for attaching a bracket and liner subassembly to convergent flaps and seals in an adjustable nozzle for a gas turbine engine. A threaded attachment member has a t-shaped head that is secured to prevent rotation by a washer. The washer is held in place in the convergent flaps and seals by spring fingers in a slot. By utilizing the washer, a simple threaded connection can be utilized even though the threaded attachment member must extend to a radially outer surface of the convergent flaps and seals, while a nut is threaded onto the threaded attachment member radially inwardly of the convergent flaps and seals. The washer prevents rotation of a head of the threaded attachment member, and thus allows the nut to be easily tightened to secure the components. This also facilitates maintenance as the threaded nut can be easily removed from the threaded attachment for replacement.

Abstract: Gas turbine engine systems involving variable nozzles with sliding doors are provided.

Abstract: The invention relates to an exhaust nozzle for a bypass turbomachine, the nozzle comprising a central body, a primary cowl surrounding the central body to define a primary channel, and a secondary cowl surrounding the primary cowl to define a secondary annular channel, the secondary cowl comprising a stationary portion and a movable portion disposed to extend the stationary portion and capable of moving longitudinally upstream and downstream relative to the stationary portion and relative to the primary cowl so as to vary the exhaust section and/or the throat section of the nozzle, the stationary portion of the secondary cowl presenting a plurality of spaced-apart repetitive patterns disposed extending its trailing edge, and the movable portion of the secondary cowl including in its outside surface a plurality of indentations of shapes complementary to the patterns of the stationary portion.

Abstract: Gas turbine engine systems involving flexible panels are provided. In this regard, a representative flexible panel assembly for a gas turbine engine includes: a flexible panel operative to define at least one of a throat area and an exit area of a nozzle of a gas turbine engine, the panel being further operative to selectively exhibit a range of positions to regulate exhaust of the engine.

Abstract: A turbofan engine starting system includes a core nacelle housing (12), a compressor (16) and a turbine (18). The core nacelle is disposed within a fan nacelle (34). The fan nacelle includes a turbofan (20). A bypass flow path (B) downstream from the turbofan is arranged between the two nacelles. A controller (50) is programmed to manipulate the nozzle exit area (A) of the bypass flow path to facilitate startup of the engine. In one example, the controller manipulates the nozzle exit area using hinged flaps (42) in response to an engine shutdown condition. The flaps open and close to adjust the nozzle exit area and the associated bypass flow rate, the mass flow rate of the air through the cave nacelle and the rotational speed of the compressor rotar (14).

Abstract: The proposed adaptive exhaust nozzle features an innovative use of the shape memory alloy (SMA) actuators for actively control of the opening area of the exhaust nozzle for jet engines. The SMA actuators remotely control the opening area of the exhaust nozzle through a set of mechanism. An important advantage of using SMA actuators is the reduction of weight of the actuator system for variable area exhaust nozzle. Another advantage is that the SMA actuator can be activated using the heat from the exhaust and eliminate the need of other energy source. A prototype has been designed and fabricated. The functionality of the proposed SMA actuated adaptive exhaust nozzle is verified in the open-loop tests.

Abstract: An aircraft gas turbine engine exhaust nozzle basesheet includes longitudinally extending plurality of basesheet segments. Each of the basesheet segments includes a panel body between segment leading and trailing edges and slidable sealing joints with slidingly un-restrained center surfaces between adjacent segment leading and trailing edges. Segmented first and second basesheet side edges first and second segment side edges of the basesheet segments respectively. Slidably sealingly engaged overlapping flanges at the segment leading and trailing edges include tacked together transversely spaced apart first and second distal ends of the overlapping flanges. Leading and trailing edge ribs supporting the overlapping flanges are clipped together with longitudinally spaced apart and transversely extending forward and aft slits in retainers.

Abstract: The thrust of a rocket motor can be varied to optimize Nozzle Pressure Ratio (NPR) using a design that allows for adjusting the relative position of a plug and a combustion chamber exit. The plug or the exit may be attached to an adaptive control system for position modification. The relative position of the plug and exit may be adjusted to optimize NPR to account for changing propellant flow and/or changing ambient pressure.

Abstract: An exhaust nozzle assembly includes a plurality of interfitting flap assemblies that are moveable between a maximum area ratio and a minimum area ratio. Each of the pluralities of flap assemblies includes a slot and a wing. The wing fits within an adjacent slot of an adjacent flap assembly. Each of the flap assemblies includes a divergent element that provides a specific geometric shape forming the trailing edge surfaces. The flap element is attached to the divergent element and extends to a static structure. The flap element and the divergent element combine to form a continuous faceted outer surface of the exhaust nozzle assembly substantially void of gaps throughout the range of motion between the maximum and minimum area ratios.

Abstract: Extendible exhaust nozzle bell for rocket engine of aircraft or spacecraft includes a first part with smaller diameter fixedly arranged on motor of engine and a second part with larger diameter arranged in flexible manner with respect to first part. In a front stowed position, second part is located surrounding first part closer to the rocket motor and, in a rear operating position, first part is arranged further away from the rocket motor. A closed volume that can be acted on by a gaseous fluid causes an extension of the second part of the exhaust nozzle bell from the stowed position into the operating position. The closed volume is formed at least in part by a deformable rolling bellows arrangement coupled between the flexibly arranged second part of the exhaust nozzle bell and a fixed part of the rocket engine or of the aircraft or spacecraft.

Abstract: A nozzle assembly for thrust or thrust vector control of a rocket or ramjet, comprising an elongated nozzle housing and a pair of vane members mounted for pivotal movement within a central portion of the nozzle housing. The vane members extend vertically or transversely between the upper and lower portions of the nozzle housing near the forward portion thereof, and extend longitudinally in the nozzle housing from the forward end portion thereof to a point near the rear end portion thereof. The vane members are pivotable about axes disposed between the forward and rear ends thereof, and are movable between an open position wherein they are in substantially parallel relation and a closed position wherein their forward ends are in engagement with each other and their rear ends are in engagement with the adjacent inner surface of the nozzle housing.

Abstract: A turbofan engine includes a core nacelle housing a spool having a turbine. A turbofan is arranged upstream from the core nacelle and is coupled to the spool. A fan nacelle surrounds the turbofan and core nacelle. A bifurcation supports the core nacelle relative to the fan nacelle and extends radially between the nacelles. The core and fan nacelles provide a bypass flow path receiving bypass flow from the turbofan. In the example, the nacelles provide a fixed nozzle exit area. The bifurcation includes an inlet that is in communication with a passage. The passage is selectively opened and closed by a valve to provide air from the inlet to a vent opening near the nozzle exit area. By opening the valve, the nozzle exit area is effectively increased to provide increased bypass flow through the turbine engine.

Abstract: Nozzles that offer shape variability to maintain or purposely change the pressure drop across the throat are obtained by constructing the nozzles with components that change their shape, angle, or curvature in response to temperature changes that occur during the flow of combustion products through the nozzle. The temperature change may be the gradual heating of the nozzle wall from hot combustion gases, and the shape change may result in a decrease in the throat diameter or an expansion of the throat diameter. A decrease in throat diameter will be useful when the depletion of propellant as burning proceeds causes a drop in the pressure or flow rate of the combustion gas and there is a need to compensate for this drop to maintain the pressure drop across the throat. An increase in throat diameter will be useful when an initial high thrust is no longer needed and depletion of the fuel by itself is insufficient to lower the thrust to its desired reduced level.

Abstract: A bracket for attaching a liner to the divergent flaps and seals in a gas turbine engine convergent/divergent nozzle includes a rivet connection. There is clearance between a rivet and an opening in the bracket. This clearance allows for thermal expansion in both an axial and a radial invention.

Abstract: A turbine engine nozzle assembly has an upstream flap and a downstream flap pivotally coupled thereto for relative rotation about a hinge axis. An actuator linkage is coupled to the flaps for actuating the nozzle between a number of throat area conditions. First and second mode struts respectively restrict rotation of the downstream flap in first and second directions.

Abstract: A system for controlling a position of jet engine exhaust mixing tabs includes a plurality of exhaust mixing tabs spaced apart from one another and extending from a lip of an exhaust nozzle of a jet engine nacelle adjacent a flow path of an exhaust flow emitted from the exhaust nozzle. Each of the exhaust mixing tabs are constructed to be controllably deformable from a first position adjacent the flow path to a second position extending into the flow path of the exhaust flow in response to a control signal applied to each of the exhaust mixing tabs. In the first position, the exhaust mixing tabs either have no affect on the thrust produced, or increase the momentum (thrust) of the exhaust flow exiting from the exhaust nozzle. In the second position, that is, the “deployed” position, the exhaust mixing tabs are deformed to extend into the flow path. In this position the exhaust mixing tabs promote mixing of the exhaust flow with an adjacent air flow.

Abstract: Varying the flowsection for air leaving the fan as a function of flying conditions. According to the invention, the nozzle has a ring of deformable panels arranged close to its trailing edge, each panel having a dual-strip type structure made up of two materials presenting different coefficients of expansion, together with controlled heater means that are thermally coupled to the set of panels.

Abstract: The jet engine of the invention comprises an exhaust nozzle of variable section, comprising at least one flap pivot mounted about a pin, the pin being joined to the fixed structure of the jet engine via two braces each comprising a bore for housing the pin, the flap being pivot commanded by an actuating cylinder, connected to two fasteners which each comprise a bore through which the pin passes and about which they rotate. The jet engine is characterized by the fact that the pin, the bores of the braces and bores of the fasteners are arranged so that the contacts between the pin with the bore walls of the braces and with the bore walls of the fasteners are made over convex surfaces. Therefore, when in operation, in the event of pin bending the contact surfaces follow this convex shape and are suitably distributed.

Abstract: A gas turbine propulsion engine reheat system having a variable area exhaust nozzle comprising a nozzle area control system including means for accelerating increases of nozzle area

Abstract: A variable-section turbomachine nozzle comprises a plurality of moving flaps, and a moving flap control system comprising control levers each associated with a respective moving flap, the control levers comprising both controlled levers that are actuated directly by actuators, and follower levers that are actuated by the controlled levers via transmission links. When the nozzle is at rest, the flaps associated with the follower levers present a radial offset relative to the flaps associated with the controlled levers.

Abstract: An aircraft, gas turbine engine, controller and trim system for neutralizing pitching moments caused by power changes and consequent changes in engine thrust. Several expedients are disclosed, utilizing either thrust vectoring or automatic aircraft trim augmentation in response to thrust variations, made either by throttle setting changes caused by a pilot or a flight management control (FMC)/autopilot system.

Abstract: A propulsion system with a pintle for variable thrust is constructed such that the pintle contains a shaft at its fore end which passes through an opening in the thrust chamber wall and extends into a boss on the outside surface of the thrust chamber. A dynamic seal that maintains the pressurization of the thrust chamber while allowing movement of the pintle is positioned inside the boss, between the pintle shaft and the boss, and actuation of the pintle is achieved by a rack affixed to the fore end of the pintle and a gear that engages the rack. The dynamic seal, rack and gear are thus external to the thrust chamber, providing the thrust chamber with a compact external envelope, a greater thermal standoff, or both.

Abstract: A variable area fan nozzle for use with a gas turbine engine system includes a nozzle section that is movable between a plurality of positions to change an effective area associated with a bypass airflow through a fan bypass passage of a gas turbine engine. A protective coating is disposed on the nozzle section and resists change in the effective area of the nozzle section caused by environmental conditions.

Abstract: An actuator arrangement comprises an actuator having a rotatable drive input, a motor, and a drive transmission arrangement for transmitting rotary drive from the motor to the rotatable drive input of the actuator, wherein the transmission arrangement includes a telescopic drive coupling.

Abstract: A convergent turbojet exhaust nozzle comprising a ring of hinged flaps made up of controlled flaps and of follower flaps disposed in alternation and co-operating at their upstream ends with a peripheral sealing gasket arranged at the outlet from an afterburner channel, each flap being made out of a ceramic-matrix composite material, and at its upstream end, each flap being made integrally with bearing means for bearing against the above-mentioned peripheral gasket, and with spherical-joint means between their upstream ends.

Abstract: A vectorable nozzle includes convergent and divergent sections and a throat therebetween. Heightwise spaced apart upper and lower walls outwardly bound a nozzle flowpath and extend aftwardly through the convergent and divergent sections from the nozzle inlet to the nozzle outlet. The upper wall includes triangular left and right side convergent upper panels pivotably mounted to a triangular convergent upper ramp in the convergent section along left and right side convergent angled hinge lines respectively. The upper wall further includes triangular left and right side divergent upper panels pivotably attached to a triangular divergent upper ramp in the divergent section along left and right side divergent angled hinge lines respectively. The left and right side convergent upper panels are in sealing engagement with the left and right side divergent upper panels along left and right side upper interfaces, respectively.

Abstract: A variable area nozzle comprising a concentric support and a plurality of convexly contoured self sealing vanes is disclosed and claimed. The vanes are circumferentially and rotatably mounted to the concentric support forming a nozzle infinitely positionable between a first position corresponding to a minimum area nozzle and a second position corresponding to a maximum area nozzle. A closer, which is preferably a shape memory alloy (SMA), urges the nozzle toward the first position corresponding to a minimum area nozzle. Periodically spaced openers act between adjacent vanes to urge the nozzle to a second position corresponding to a maximum area nozzle.

Abstract: The invention relates to a variable-section flow mixer for a double-flow turbojet for a supersonic airplane, the mixer comprising a central body, a primary cover, a secondary cover, and a nozzle extending the secondary cover. The nozzle has a plurality of external-air admission openings having mounted therein lobes that are movable between two positions: a closed position in which they close the openings; and a deployed position in which they disengage said openings and deploy into the nozzle so as to allow external air to be admitted. All of the lobes present a common azimuth component in a common direction, and the mixer further includes a plurality of longitudinal grooves occupying at least a portion of the central body, all of the grooves presenting a common azimuth component in a common direction that is opposite to the direction of the azimuth component of the lobes.