Abstract: A fuel control system for a gas turbine engine includes logic that is used to facilitate enhanced compressor stall margin when the engine is operating in potential icing conditions is described. The fuel control system is coupled to at least one fuel regulator within the engine, and receives input from a plurality of sensors coupled to the engine. More specifically, the system receives input from environmental sensors, as well as inputs representing compressor inlet temperature, compressor discharge pressure, and corrected core engine speed. Furthermore, the fuel control system also receives input from the other engine fuel regulators.

Abstract: A method facilitates replacing a portion of a gas turbine engine combustor. The combustor includes a combustor liner and a wire-wrapped cowl assembly that includes an inner cowl and an outer cowl. The method comprises cutting through the wire-wrapped cowl assembly upstream from fastener openings used to couple the inner and outer cowls to the combustor liner, removing a portion of the cowl assembly from the combustor, and coupling a replacement cowl to the portion of the existing cowl assembly that is downstream from the cut, wherein the replacement cowl includes an inner annular portion, an outer annular portion, and a plurality of circumferentially-spaced radial ligaments extending therebetween.

Abstract: A method enables a variable vane assembly for a gas turbine engine to be coupled to an engine casing. The variable vane assembly includes a bushing assembly and at least one variable vane that includes a platform and a vane stem. The method comprises coupling a first bushing to the engine casing in a press fit, coupling a second bushing to the variable vane, and coupling the variable vane to the engine casing such that at least a portion of the first bushing is between the engine casing and the second bushing, and such that at least a portion of the second bushing is between the first bushing and the vane stem.

Abstract: A stiffener system includes a stiffener and a fastener means. The stiffener includes an extruded body that includes a plurality of projections. The stiffener couples to the apparatus to facilitate increasing a structural integrity of the apparatus. The fastener means secures the stiffener to the apparatus.

Abstract: A gas turbine engine rotor disk assembly includes a disk having an annular hub circumscribed about a centerline. An annular web extends radially outwardly from the hub to an annular rim. A plurality of dovetail slots extend generally axially through the rim. A plurality of cooling air slots extending generally radially through the rim and are skewed circumferentially with respect to the centerline and slanted axially aftwardly with respect to a normal radius perpendicular to the centerline. In the exemplary embodiment, each cooling air slot has parallel side walls skewed circumferentially with respect to the centerline and an aft wall extending between the side walls and slanted axially aftwardly with respect to the normal radius. The side walls are skewed circumferentially about 5 degrees with respect to the centerline and the aft wall is slanted axially aftwardly about 18 degrees with respect to the normal radius.

Abstract: A flowpath wall is provided for bounding hot combustion gases in a gas turbine engine. The wall includes opposite outer and inner surfaces and a plurality of cooling holes extending therebetween. A thermal barrier coating is bonded to the outer surface and covers blind the holes thereat.

Abstract: A method for fabricating a nozzle for a gas turbine engine facilitates extending a useful life of the nozzles. The nozzle includes an airfoil. The method includes forming the airfoil to include a suction side and a pressure side connected at a leading edge and a trailing edge such that a cooling cavity and a cooling circuit are defined within the airfoil, wherein the suction side and the pressure side extend radially between a tip and a root. The method also includes forming a plurality of cooling slots within the airfoil that extend from the cooling circuit towards the airfoil trailing edge, and forming a control vane within the cooling circuit to facilitate maintaining a substantially constant cooling effectiveness within the cooling circuit.

Abstract: A method enables a gas turbine engine positioned within a module to be operated. The engine includes an inlet and an exhaust, and the module includes an inlet area, an exhaust area, and an engine area extending therebetween and housing the engine. The exhaust area includes an exhaust duct and an outlet. The engine is operated such that inlet air is routed through the module inlet and into the engine inlet, wherein exhaust gases are discharged through the module exhaust duct and substantially perpendicularly from the gas turbine engine. The exhaust gases are discharged from the module outlet in a direction that is at least ninety degrees offset from exhaust gases flowing within the exhaust duct. Cooling fluid is discharged from the module engine area through a cooling system exhaust, such that the discharged fluid flows through the cooling system exhaust and around the module exhaust area.

Abstract: A method enables a gas turbine engine variable bypass valve system to be assembled. The method comprises positioning a unison ring circumferentially within the gas turbine engine such that the unison ring is radially outward from a structural frame, coupling at least one bellcrank to the unison ring, such that the unison ring is radially supported only by said at least one bellcrank, and coupling the at least one bellcrank to a bellcrank support that is coupled to the structural frame.

Abstract: A gas turbine engine combustor can downstream of a pre-mixer has a pre-mixer flowpath therein and circumferentially spaced apart swirling vanes disposed across the pre-mixer flowpath. A primary fuel injector is positioned for injecting fuel into the pre-mixer flowpath. A combustion chamber surrounded by an annular combustor liner disposed in supply flow communication with the pre-mixer. An annular trapped dual vortex cavity located at an upstream end of the combustor liner is defined between an annular aft wall, an annular forward wall, and a circular radially outer wall formed therebetween. A cavity opening at a radially inner end of the cavity is spaced apart from the radially outer wall. Air injection first holes are disposed through the forward wall and air injection second holes are disposed through the aft wall. Fuel injection holes are disposed through at least one of the forward and aft walls.

Abstract: A combustor for a gas turbine engine operates with high combustion efficiency, and low nitrous oxide emissions during engine operations. The combustor includes at least one trapped vortex cavity, a fuel delivery system including two fuel circuits, and a fuel spray bar assembly. A pilot fuel circuit supplies fuel to the trapped vortex cavity and a main fuel circuit supplies fuel to the combustor. The fuel spray bar assembly includes a spray bar and a heat shield. The spray bar is sized to fit within the heat shield. The heat shield includes aerodynamically-shaped upstream and downstream sides.

Abstract: An aircraft gas turbine engine includes high and low pressure turbines having respective counter rotatable low pressure inner and outer rotors with low pressure inner and outer shafts in part rotatably disposed co-axially within a high pressure rotor and drivingly connected to first and second fan blade rows and first and second boosters respectively. A bypass duct radially bounded by a fan casing and an annular radially inner bypass duct wall surrounds the boosters axially located between the first and second fan blade rows. The engine has a high pressure compressor operable to produce an overall pressure ratio in a range of about 40-65 and a fan inlet hub to tip radius ratio in a range between 0.20 and 0.35, a bypass ratio in a range of 5-15, an operational fan pressure ratio in a range of 1.4-2.5, and a sum of operational fan tip speeds in a range of 1000 to 2500 feet per second.

Abstract: A turbofan engine includes a row of fan blades disposed upstream from a row of stator vanes, and is powered by a core engine. The fan blades are serrated for mixing wakes therefrom to attenuate fan noise.

Abstract: A butterfly valve for a gas turbine engine includes a valve shaft and a valve disk. The valve disk has a centerline axis that extends through the valve disk. The valve disk also includes a shaft opening, an outer periphery, an outer surface, a first side, and a second side. The first side is opposite the second side. The shaft opening extends through the valve disk adjacent the centerline axis, and is sized to receive the valve shaft therein. The disk outer surface extends over the first and second sides, and is tapered between the outer periphery and the centerline axis over at least one of the disk first and second sides.

Abstract: A method enables a duct to be coupled to a gas turbine engine casing. The method comprises extending a first inner tube support member circumferentially around the duct, such that a radially inner side of the first inner tube support is against the duct, and wherein the first inner tube support member has a substantially curved cross sectional profile extending between the radially inner side of the first inner tube support, and a radially outer side of the first inner tube support. The method also comprises extending an outer tube support member circumferentially around the first inner tube support member such that the outer tube support member is against the first inner tube support member outer surface, and coupling the outer tube support member to the gas turbine engine casing.

Abstract: A low pressure turbine section for an aircraft gas turbine engine includes a low pressure turbine flowpath and counter rotatable low pressure inner and outer shaft rotors having inner and outer shafts, respectively. The low pressure inner and outer shaft rotors include low pressure first and second turbine blade rows disposed across the turbine flowpath and drivingly connected to first and second fan blade rows, respectively. The first low pressure turbine blade rows are disposed downstream of the second low pressure turbine blade rows along said low pressure turbine flowpath. Rows of non-rotatable low pressure vanes are disposed across the low pressure turbine flowpath between the first low pressure turbine blade rows and between the second low pressure turbine blade rows. An annular vaneless gap may be located between an aftmost row of the second low pressure turbine blade rows and a forwardmost row of the first low pressure turbine blade rows.

Abstract: A coupling used to transfer fluid between two conduits includes a seal arrangement that permits an inner sleeve to move axially and angularly without fluid leaking from the coupling. The coupling also includes a pair of coupling members coupled to the inner sleeve, around each end of the inner sleeve. The inner sleeve includes tapered ends sized to receive a seal including a spherical lip. Each coupling member includes a tapered end that compresses each seal during assembly of the coupling. The seal spherical lips maintain sealable contact between the inner sleeve and the coupling first and second members.

Abstract: The present invention provides a weep plug for an oil sump having a central vent passage and one or more weep passages parallel to the central passage. The weep passages allow oil to flow back into the sump where it may be recovered.

Abstract: A turbine engine shroud segment, preferably a low ductility material, for example a ceramic matrix composite, comprises a segment body extending between body circumferential ends. The body includes a body radially inner surface arcuate at least circumferentially, and a body radially outer surface from which a plurality of hooks extend generally radially outwardly. Each hook comprises a generally radially outwardly extending hook arm with a generally axially extending hook end having a generally radially inner surface in spaced apart juxtaposition with a portion of the body radially outer surface. Such body outer surface includes at least two body contact surfaces each matched in shape and in juxtaposition at least at body circumferential ends with a cooperating hanger contact surface. The radially inner surface of each hook end includes a hook end contact surface matched in shape with a cooperating hanger contact surface at least in a circumferential middle portion of such surface.

Abstract: A trunnion support for a variable-position stator vane in a turbomachine. The stator vane includes an upper trunnion and a lower trunnion to allow the stator vane to be pivoted about a longitudinal axis. The lower trunnion is supported in a bushing that is carried in an opening provided in an annular stator vane carrier ring. The bushing is longitudinally split and is installed in the carrier ring while in a laterally compressed condition so that when installed in the carrier ring the bushing bears against the carrier ring opening in which it is positioned. When the carrier ring material expands with rising temperature, the pre-stress in the bushing will cause it to expand to maintain tight frictional engagement between the bushing and the opening and thereby prevent relative rotation between the bushing and the carrier ring to minimize wear of the carrier ring material.