Abstract: A laser unit includes a laser beam source for generating a laser beam along a laser beam centerline. A beam tube surrounds at least a portion of the beam centerline. A beam aperture is located at an exit of the tube. A final beam optical lens is mounted within the tube upstream of the aperture. A gas purging means flows purge gas into the tube between the lens and the aperture. A converging section of the tube is located between the lens and the aperture. At least one telescoping section in the tube is located between the lens and the aperture in the converging section of the tube. The lens has a focal number less than 8 and may be less than 7 and down to about 5. A gas knife located between the aperture and the focal point of the lens is used for flowing a large volume of clearing gas across the laser beam between the aperture and the focal point.

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: An aircraft engine turbine frame includes a first structural ring, a second structural ring disposed co-axially with and radially spaced inwardly of the first structural ring about a centerline axis. A plurality of circumferentially spaced apart struts extend between the first and second structural rings. Forward and aft sump members having forward and aft central bores are fixedly joined to forward and aft portions of the turbine frame respectively. A frame connecting means for connecting the engine to an aircraft is disposed on the first structural ring. The frame connecting means may include a U-shaped clevis. The frame may be an inter-turbine frame axially located between first and second turbines of first and second rotors of a gas turbine engine assembly. An axial center of gravity of the second turbine passes though or very near a second turbine frame bearing supported by the aft sump member.

Abstract: An aircraft gas turbine engine includes a low pressure turbine having 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 by low pressure inner and outer shafts, respectively. At least one of the low pressure first and second turbine blade rows is interdigitated with an adjacent pair of one of the turbine blade rows. At least one row of non-rotatable low pressure vanes is disposed across the low pressure turbine flowpath between a non interdigitated adjacent pair of one of the turbine blade rows.

Abstract: A gas turbine engine aspirating face seal includes a rotatable engine member and a non-rotatable engine member and a leakage path therebetween. Annular generally planar rotatable and non-rotatable gas bearing face surfaces circumscribed about a centerline are operably associated the rotatable and non-rotatable engine members respectively. Radially inner and outer tooth rings axially extend away from a first one of the rotatable and non-rotatable gas bearing face surfaces across the leakage path and towards a second one of the gas bearing face surfaces. A pull off biasing means is used for urging the inner and outer tooth rings axially away from the second one of the gas bearing face surfaces. The rotatable engine member may be a side plate mounted on a rotor disk and the non-rotatable engine member is mounted on a translatable piston axially movably supported on a stationary face seal support structure.

Abstract: An annular hanger for supporting an annular wall element from a gas turbine engine annular outer casing is circumscribed about a centerline extending in opposite first and second axial directions and has an annular first hook extending in the first axial direction from said body section and an annular second hook extending in the second axial direction. One of the hooks has circumferentially spaced apart tabs extending equal axial lengths from the body section and corresponding notches circumferentially disposed between a corresponding adjacent pair of the tabs. The annular hanger is used to support at least in part a wall element from the outer casing as part of a bayonet mount. The bayonet mount further includes a bayonet slot on one of the casing and the wall element and the hanger tabs are received within the bayonet slot.

Abstract: A gas turbine engine cooling system for providing cooling air to engine components includes a core engine and, in downstream serial flow relationship, a high pressure compressor, a combustor, and high pressure turbine. A first flowing system is used for flowing a portion of the pressurized air to a heat exchanger to cool the pressurized air and provide the cooling air and a second flowing system is used for flowing a first portion of the cooling air to a compressor impeller operably connected to a compressor disk of the high pressure compressor for boosting pressure of the first portion of the cooling air. A second portion of the cooling air is supplied to turbine cooling. The heat exchanger may be a fuel to air heat exchanger for cooling the portion of the pressurized air from the first flowing means with fuel.

Abstract: A method for manufacturing an integrally bladed rotor includes fixturing a plurality of blade blanks having radially inwardly facing blade conical surfaces into a segmented blade ring assembly circumscribed around an axis. A rotor ring having a radially outwardly facing ring conical surface circumscribed around the axis is rotated to a contact speed. The rotor ring is fictionally engaged under an axially applied weld load with the blade ring assembly to effect a conical inertia weld along the mating blade conical surfaces and ring conical surface. The integrally bladed rotor includes a plurality of airfoils circumferentially distributed about and integral with a rim. The airfoils extend radially outwardly from respective airfoil bases on a radially outer flowpath surface of the rim to airfoil tips. A conical inertia weld is located between the airfoil tips and a radially inwardly facing rim surface of the rim.

Abstract: An aircraft gas turbine engine is provided with low observable fan features which reduce the radar signature of the engine and its aircraft. An aircraft gas turbine engine fan section has in direct serial flow relationship an inlet having fixed high swirl angle inlet guide vanes, a first stage of first fan rotor blades, a stage of first variable angle stator vanes, and a fan bleed. The inlet guide vanes are angled to block the linear line of sight of the rotating fan blades through the inlet and include a RAM treatment which preferably is a coating of a radar absorbing material on the surface of the inlet guide vanes. The exemplary embodiment has a multi-stage fan section with the mid-stage fan bleed disposed between the first and second stages of fan rotor blades.

Abstract: A filtered air vent has a housing with an inlet and outlet, at least one set of spaced apart airflow control elements extending across the housing elements, spaces between the elements, and a pleated filter disposed within the housing. The filter has alternating first and second pleats that open up in opposite first and second directions, respectively. In one exemplary embodiment of the invention, at least a portion of the pleats that open in a first one of the directions are disposed across the spaces between the elements. The filter may be made from a washable filter material such as, for example, woven polypropylene. The elements in one embodiment of the invention are rotatable blades of a damper disposed within the housing and each of the blades are disposed within a corresponding one of the pleats that open in the second direction.

Abstract: A gas turbine engine rotor disk has a number of annular hubs circumscribed about a centerline and each of the hubs is connected to a disk rim by a web. A plurality of circumferentially spaced apart circular arc dovetail slots are disposed through the rim. Circumferentially extending annular burst slots extend radially through the rim into the dovetail slots between each adjacent pair of the webs. The fan blades have circular arc dovetail roots disposed within the circumferentially spaced apart circular arc dovetail slots. A one piece spinner attached to a forward extension of the disk at a location between a tip and an axially aft spinner end of the spinner. Non-integral platforms circumferentially disposed between the fan blades. A booster spool is connected to the rotor disk by a mounting plate therebetween and the platforms are radially retained to the disk and mounting plates by pins through holes in mounting lugs depending radially inwardly from the platforms.

Abstract: An aircraft gas turbine engine assembly includes an inter-turbine frame axially located between high and low pressure turbines. Low pressure turbine has counter rotating low pressure inner and outer rotors with low pressure inner and outer shafts which are at least in part rotatably disposed co-axially within a high pressure rotor. Inter-turbine frame includes radially spaced apart radially outer first and inner second structural rings disposed co-axially about a centerline and connected by a plurality of circumferentially spaced apart struts. Forward and aft sump members having forward and aft central bores are fixedly joined to axially spaced apart forward and aft portions of the inter-turbine frame. Low pressure inner and outer rotors are rotatably supported by a second turbine frame bearing mounted in aft central bore of aft sump member. A mount for connecting the engine to an aircraft is located on first structural ring.

Abstract: An annular disk side plate for a gas turbine engine rotor assembly includes an annular plate hub and an annular plate shaft extension extending axially forwardly from the plate hub. A plate web extends radially outwardly from the plate hub and a plate rim extends radially outwardly from the plate web. In the exemplary embodiments of the invention illustrated herein, the plate rim is canted aftwardly from the plate web. One or more annular sealing ridges extend aftwardly from the plate rim. The side plate further includes an anti-rotation means for preventing rotation of the disk side plate relative to the disk such as a circumferential row of radially extending circumferentially spaced apart tabs. Cooling air apertures or holes extend axially through the plate web. A rotor assembly further includes an annular rotor disk comprising a disk hub and an annular disk shaft extension extending axially forward from the disk hub.

Abstract: A method for laser shock peening an article by simultaneously firing low energy first and second laser beams to form pairs of longitudinally spaced apart first and second laser shock peened spots that are on opposite sides of the article, simultaneously laser shock peened, and transversely offset from each other. Each of the low energy first and second laser beams having a level of energy of between 1-10 joules.

Abstract: A method to laser shock peen articles such as a gas turbine engine rotor blade with first and second oblique laser beams to form pairs of longitudinally spaced apart first and second laser shock peened elliptical spots that are on opposite sides of the article or blade and transversely offset from each other. The oblique laser beams are fired at a portion of the leading or trailing edges of the blade at first and second oblique angles with respect to opposite surfaces of the edge. Another method laser shock peens the leading and trailing edges of gas turbine engine integrally bladed rotors and disks that are blocked by other rows of blades by firing the laser beams at compound angles such that the beams are aimed at the first and second oblique angles with respect to the surfaces of the edge and at a third oblique angle with respect to a rotor axis.

Abstract: A method for single sided laser shock peening an article includes laser shock peening a laser shock peening surface on a first side of the article while maintaining an opposite second surface on a back side of the article in acoustic communication with a shock attenuating material. The second surface is opposite the laser shock peening surface. The shock attenuating material is a material that does not allow tensile waves to be reflected back off the back side through the article. The shock attenuating material may be a liquid metal and the article made from a titanium alloy. One such article is a gas turbine engine airfoil of an integrally bladed disk and the surfaces may be on an edge of the airfoil. The shock attenuating material may be one that dissipates compressive waves or reflects back compressive shock waves caused by the laser shock peening.

Abstract: A method of laser shock peening a metallic part by firing a laser on a coated laser shock peening surface of the part which has been covered with an explosive coating containing at least one explosive ingredient. Two or more explosive ingredients having different shock sensitivities may be used and the laser beam is fired with sufficient power to explode at least some amount of each of the explosive ingredients.

Abstract: An annular gas turbine engine combustor liner has a single piece annular shell circumscribed about a first axis of revolution. The shell has a hot side and a cold side, an annular dilution hole section, and a plurality of asymmetrical cylindrical dilution holes extending through the section. Pockets are circumferentially interdigitated between the dilution holes and extend into the shell from the cold side such that the pockets form dilution hole bosses between the pockets through which the dilution holes extend. Each of the dilution holes is circumscribed about a second axis of revolution which is not parallel to the first axis of revolution. The liner may further include forward and aft annular cooling nuggets located forward and aft of the dilution hole section and having annular film cooling slots which are open in the axially aftwardly direction.

Abstract: A gas turbine engine outlet guide vane assembly has annular inner and outer end walls, a flowpath between the inner and outer end walls, outlet guide vanes radially disposed between the inner and outer end walls, and boundary layer energizing means for energizing boundary layers using secondary flow to mix free stream flow into the boundary layers along the inner and outer end walls and suction and pressure sides of the vanes. The boundary layer energizing means includes having the vanes circumferentially leaned in a direction that the suction sides face. The boundary layer energizing means also includes swept leading and/or trailing edges of the vanes that extend radially between the inner and outer end walls. The swept leading and/or trailing edges may be curved inwardly into the vanes from the outer end walls to leading and/or trailing edge points respectively between the end walls.

Abstract: A torque shaft assembly includes a hollow tube with a central axis disposed between and fixedly connected to first and second crankshafts at first and second distal ends, respectively, of the tube for movement of an array of connecting members such as push rods. A hollow interior of tube between the first and second crankshafts is filled with a sufficient quantity of flowable inertia material or damping media to absorb vibratory energy by friction during operation of the engine. The hollow interior is preferably filled with a quantity of damping media to a level by volume of about 98% and a preferred flowable inertia material is round steel shot. A plurality of spaced-apart clevises are fixedly attached to a tube wall on an outer surface of the tube wall surrounding the hollow interior. Each clevis includes connection means disposed away from the wall outer surface for connection with an actuator for movement of the array of adjustable devices such as variable stator vanes.