Abstract: An improved containment structure for use with turbomachinery, such as turbofan engines. A casing is provided with at least one impact resistant section of a thickness sufficient to resist being pierced upon impact by a blade. The impact resistant section has a smoothly contoured thickness along its axial length and is free from features likely to cause a local failure in the event of impact by a blade released from a rotating disk.

Abstract: A rotor blade for a turbine engine including a blade root section and an airfoil section which extends radially outward along a radial line RAS from the blade root section, is described. The radial line RAS extends at an angle relative to a plane extending across a top surface of the platform, rather than normal, or perpendicular, to such plane. As a result, and during a blade out event, an over turning moment is generated in a root of the airfoil section. The overturning moment facilitates bending the airfoil section reducing damage to the stator.

Abstract: A preferred embodiment of said present invention is a gas turbine engine blade root shim for use between a composite blade root and a wall of a slot for receiving the root in a rotor of the engine. An exemplary embodiment of the shim includes a longitudinally extending base having distal first and second transversely spaced apart ends, first and second longitudinally extending legs acutely angled inwardly towards the base from the first and second ends, and first and second low coefficient of friction coatings on first and second outwardly facing surfaces of the first and second legs, respectively. Among coatings suitable for use in the present invention are polytetrafluoroethylene powder dispersed in a resin binder and other coatings which include polytetrafluoroethylene.

Abstract: A control unit in accordance with an exemplary embodiment of the present invention includes a multiplicity of regulators (Ki) and generates an output corresponding to blended and tuned actuator values. More particularly, and in the exemplary embodiment, the control unit includes a plurality of regulators (Ki), and each regulator (Ki) corresponds to a mode of operation or operating conditions. Each regulator (Ki) is configured to receive engine parameters as input and to generate output values for at least one actuator command uj. Respective gain schedulers are coupled to each regulator (Ki), and each scheduler receives, as input, an operating point which corresponds to at least one of a power setting parameter and an inlet temperature or pressure. Based on the operating point, each scheduler selects a gain to supply to its respective regulator (Ki).

Abstract: A preferred embodiment of the present invention is a gas turbine engine rotor assembly having axially spaced apart forward and aft disks circumferentially disposed about an axis. The forward disk has an aftwardly extending annular forward arm and the aft disk has a forwardly extending annular aft arm. Forward and aft flanges are located at forward and aft ends of the forward and aft arms respectively. Forward and aft pluralities of aligned forward and aft bolt holes extending axially through the forward and aft flanges respectively. A scalloped annular ring having a plurality of circumferentially spaced apart tabs with spaces therebetween is disposed between the flanges. A plurality of ring bolt holes extend axially through the plurality of circumferentially spaced apart tabs such that corresponding ones of the ring, forward, and aft bolt holes are axially aligned.

Abstract: A deswirler system for a centrifugal compressor of a gas turbine engine that improves overall engine performance as a result of exhibiting significantly reduced friction losses. The deswirler system generally entails an annular-shaped manifold having an inlet configured to receive radially-outward flowing gas from a diffuser of the compressor, an outlet configured to discharge the gas in an axial downstream direction, and an arcuate passage therebetween. The deswirler system further includes a plurality of deswirler vanes directly within the arcuate passage and closely coupled to the diffuser.

Abstract: A multi-layer seal and washer that provide a seal between a vane stem and a casing in a turbine engine are disclosed. The seal and washer are fabricated from materials such as Teflon fibers and glass fibers and are impregnated with a polyimide resin. The seal and washer are durable and have a low coefficient of friction.

Abstract: A coupling assembly for connecting the aft end of an air duct to the compressor rear shaft in a gas turbine engine includes a retaining ring disposed in the central bore of the compressor rear shaft. The retaining ring has a first set of tabs extending axially therefrom, and the air duct has a second set of tabs extending axially from its aft end. The aft end of the air duct is disposed in the bore and positioned relative to the retaining ring so that the first set of tabs intermeshes with the second set of tabs.

Abstract: A support structure for a gas turbine engine includes a support arm (214, 216) extending between a low pressure shaft (202) and a rotor. The support arm includes a fuse (220) having a low failure point. A high pressure stub shaft (270) axially and radially supports the low pressure shaft (202) after fuse failure. An axial gap (A) between a portion of the low pressure shaft and the stub shaft permits movement of the low pressure shaft after fuse failure. A radial gap (B) between the stub shaft (270) and the low pressure shaft (202) allows radial deflection of the low pressure rotor system after fuse failure.

Abstract: A seal includes a seal ring with a circumferential split defining a gap. An arcuate bridge extends across the gap and nests in the seal ring. The bridge includes an anchor end which engages the seal ring solely in friction to restrain differential circumferential movement therebetween. The bridge also includes a slip end engaging the seal ring on an opposite side of the gap with less friction than the anchor end to permit differential circumferential movement therebetween.

Abstract: A compressor stator includes a casing having a circumferentially extending slot therein in which are mounted a plurality of vane sectors. Each sector includes a plurality of vanes extending between outer and inner bands, with each outer band being mounted in the slot. A plurality of tabs are ranged in interlocked pairs between the outer bands and casing for unloading adjacent sectors from each other.

Abstract: A turbine casing supports a row of nozzle vanes through which are flowable hot combustion gases. A baffle surrounds the casing to define a cooling duct. A nacelle surrounds the turbine casing to define a bay having an inlet for receiving bay air, and an outlet for discharging the air. The cooling duct includes an inlet which receives the bay air for flow along the turbine casing for selective cooling thereof.

Abstract: A retainer which, in an exemplary embodiment of the invention, is used in a gas turbine engine inter-stage seal assembly to retain an annular seal ring flange of a seal ring against an annular platform flange extending radially inwardly from an inner platform of an annular nozzle stage having nozzle vanes. The retainer includes a body having a central portion through which a bore is formed around a bore axis and a central tab extends radially outwardly from the central portion with respect to the bore axis. First and second arms, respectively, extend in opposite respective first and second tangential directions, with respect to the bore axis, away from the central portion and each other. Axial spacers extend aftwardly from first and second free ends of the first and second arms, respectively and anti-rotation feet with rounded ends depend from the first and second free ends in an opposite direction from which the central tab extends.

Abstract: A recirculation passageway for a turbine engine provides stall protection in a booster by directing high pressure airflow from a flow path of the booster to the passageway. The high pressure airflow loses energy and decreases in pressure while traveling through the passageway until re-entry into the booster flow path. The airflow recirculates in the passageway until the airflow is discharged through a high pressure compressor.

Abstract: A platform for a turbofan gas turbine engine that does not limit the rotation capability of adjacent fan blades in the event one of the fan blades is impacted by a foreign object. The platform includes a structural body portion and an integrally formed flowpath surface portion. The structural body portion has a contour that matches that of the adjacent fan blades. The flowpath surface portion defines a pair of wings that extend laterally beyond the structural body portion. The wings are frangible so as to break off if an adjacent fan blade rotates in response to an ingestion event. The platform is made from a composite material using a resin transfer molding process.

Abstract: A method and fixture assembly for assisting in the matching and assembly of components of a variable stator vane assembly of a gas turbine engine. The method generally entails a stator vane configured to be assembled to a casing with a spacer. The vane has a surface at a perimeter thereof and a seat offset from the surface. The spacer to which the vane is to be assembled has first and second surfaces offset relative to each other, the first surface being adapted to engage the seat of the vane and the second surface adapted to face the surface of the vane. The vane is installed within an opening in the casing so that a first sealing member is between the casing and the vane, the casing is between the first sealing member and a second sealing member, and the seat extends through the opening. A fixture is then mounted to the vane so that the casing and the first and second sealing members are clamped between the fixture and the vane under a load.

Abstract: The present invention provides a sealing apparatus for sealing leakage around a trunnion assembly of a gas turbine engine variable vane rotatably supported by an engine casing. The apparatus includes a trunnion of the variable vane rotatable about a trunnion axis, radially spaced apart inner and outer casing bores circumscribed about the trunnion axis and disposed radially outward of the engine centerline through the casing, and the trunnion rotatably disposed within the inner and outer casing bores. The inner bore is wider than the outer bore forming an annular shoulder with a planar radially inwardly facing shoulder surface. An annular recess in the trunnion has a planar radially inwardly facing recess surface substantially co-planar with the shoulder surface.

Abstract: A wall first portion of an article is provided with reduced tensile stress, of an amount less than that which can result in cracking of the wall, with an elongated opening through the wall first portion. The opening separates areas of a wall first portion and extends generally toward a wall second portion under a lower or different stress.

Abstract: An airfoil blade measuring apparatus includes an airfoil blade engagement system and a measuring system. The airfoil blade engagement system rotates the mounted airfoil blade to a position to be measured, and elevates the airfoil blade to permit the entire airfoil blade to be easily measured. The measuring system includes a blade engagement tool which positions the airfoil blade, a limit switch, two alignment slides, and a measuring slide including a plurality of laser displacement sensors, which are positioned via a computer controlled motor.

Abstract: A blade containment structure for turbomachinery, such as a high bypass turbofan engine. The blade containment structure includes a first casing member having a wall that defines an inner containment shell that immediately surrounds the blades of the turbomachine, and a second casing member assembled to the first casing member. The second casing member has a wall that defines an outer containment shell that surrounds the inner containment shell, such that a cavity is defined by and between the inner and outer containment shells. The first casing member is formed from a high-toughness material such as steel or a nickel-base alloy, while the second casing member is formed from a lower-weight and potentially lower-toughness material as compared to the material of the first casing member.