Abstract: A bladed rotor and a hub rotor for a gas turbine are provided. A bladed rotor may comprise a rotor interface comprising a radially inward surface, wherein the rotor interface comprises a constant diameter zone; and a reduced stress zone located adjacent to and aft of the constant diameter zone. A hub rotor may comprise a hub interface comprising a radially outward surface, wherein the hub interface comprises, a constant diameter zone, and a reduced stress zone located adjacent to and aft of the constant diameter zone.

Abstract: A stage of a fan for a gas turbine engine may include a rotor blade and a stator vane disposed aft of the rotor blade. A baffle may be coupled to the stator vane. The baffle may define a secondary airflow path from aft of the stator vane to forward of the rotor blade. The baffle may further define the secondary airflow path from aft of the stator vane to forward of the stator vane.

Abstract: A combination fuel-oil and air-oil heat exchanger comprising: a first heat exchanger section that has an oil circulation path and a fuel circulation path thermally coupled to the oil circulation path; a second heat exchanger section that has an oil circulation path and an air circulation path thermally coupled to the oil circulation path; an oil coupling path that couples an oil circulation path outlet of the first heat exchanger section to an oil circulation path inlet of the second heat exchanger section to establish a combined oil circulation path; an oil path by-pass valve that selectively diverts oil from the combined oil circulation path to an outlet of the oil path by-pass valve; and a fuel path by-pass valve that selectively diverts fuel from the fuel circulation path of the first heat exchanger section to an outlet of the fuel path by-pass valve.

Abstract: A blade retainer clip for retaining a foot of a turbine blade in a shoe of a turbine disc of a turbine wheel includes: a clip shank that fits into a mating slot in the blade foot; a protuberance along a central portion of the clip shank that fits into a mating recess along the mating slot in the blade foot; a clip heel on one end of the clip shank that engages a heel of the blade foot and a heel of the disc shoe that expands radially from at least opposite sides of the clip shank; and a clip toe that extends beyond a toe of the disc shoe that is deformable to contact at least the toe of the disc shoe.

Abstract: A blade retention system for retaining a foot of a turbine blade in a shoe of a turbine disc of a turbine wheel includes: a hook on a heel end of the blade foot that protrudes from a bottom of the blade foot to engage a heel end of the turbine disc shoe; and a compound fillet that engages the hook with the bottom of the blade foot.

Abstract: A middle support member is used to provide axial support and control to the tie shaft. The middle support member includes a high pressure compressor coupling nut that applies a preload that allows the high pressure compressor stack to be installed separately from the high pressure turbine rotor through a kickstand.

Abstract: A brazed end cover assembly for a gas turbine combustor using Au-Ni braze is disclosed. The end cover assembly may include an end cover with openings, a flow insert, first and second gaps between the end cover and the flow insert, and first and second braze joints formed at the first and second gaps, wherein the braze materials used comprises Au and Ni. A method of brazing a flow insert into an end cover is also disclosed. The method may include providing an end cover and a flow insert with first and second gaps therebetween; applying a braze material to an outer surface of the flow insert, wherein the braze material comprises Au and Ni; inserting the flow insert into the end cover; heating the assembly to a brazing temperature for some time; and cooling the resulting brazed assembly to room temperature.

Abstract: A seal for a gas turbine engine and a gas turbine engine employing such a seal are disclosed. More specifically, the engine includes a knife edge seal which is better able to withstand the extremely high temperatures and mechanical loads to which gas turbine engine components are increasingly subjected. By moving the knife edge seal to the aft hub and cantilevering its angle off of vertical, thermal and mechanical loads are balanced and thus thermal mechanical fatigue life is improved while low cycle fatigue is maintained.

Abstract: A diffuser seal for an aft end of a high pressure compressor of a gas turbine engine is disclosed. The diffuser seal includes a flow guide carrier coupled to the diffuser case. The flow guide carrier is also coupled to a static seal. The static seal engages a rotary seal and permits air flow through the static and rotary seals in the aft direction. The flow guide carrier is also coupled to a fairing and a fairing/hub support. The flow guide carrier supports the fairing in a spaced-apart position with respect to the rear hub so that air flowing through the static and rotary seals passes between a forward surface of the fairing and the rear hub. The fairing/hub support extends forward from the flow guide support and engages an aft surface of the fairing thereby limiting movement of the rear hub and fairing in the aft direction. This design helps to prevent parts or debris from piercing the rear hub and entering the high pressure turbine in the even of a fan blade-out or fan blade-off event.

Abstract: An apparatus and method to automate the process of measuring and verifying trace gas levels such as oxygen and dewpoint inside a retort used to coat or heat treat substrates are provided. The apparatus may include an integrated measuring system, and an operator interface. The method may include coupling the apparatus to the retort in which the substrate is coated or heat treated, activating the integrated measuring system to measure and verify atmospheric conditions within the retort, and providing operator access to process parameters and status through the operator interface. The measurement and verification system may be completely autonomous.

Abstract: A gas turbine engine has a variable overall pressure rate (“OPR”). The engine includes a high pressure compressor having at least a primary stage having a set of primary rotors and a secondary stage having a set of secondary rotors. A clutch is provided to selectively engage the secondary rotors with the primary rotors. Engagement of the clutch may be controlled based on the vehicle travel mode, such as disengaging during a takeoff mode to reduce turbine entry temperature and engaging during a loiter mode to increase OPR.

Abstract: A method of indicating low oil level of lubrication oil for a gas turbine engine automatically eliminates false low oil readings due to temperature-induced lubrication oil shrinkage and operation-induced changes in lubrication oil level.

Abstract: A compression pump for an engine is provided. The pump may include a first impeller operatively coupled to a main shaft of the engine, a first inlet configured to at least partially receive bypass airflow, and a first outlet configured to direct compressed air to a thermal management system.

Abstract: A by-pass turbofan gas turbine engine, has a by-pass fan, a generally annular core engine duct, a generally annular by-pass duct situated in a generally coaxial relationship with the core engine duct coupled to the by-pass fan, an upstream axial compressor coupled to the core engine duct, a downstream radial compressor coupled to the upstream compressor, a generally annular recuperator with a cool side inlet coupled to the downstream compressor, a generally annular combustor coupled to a cool side outlet of the recuperator, a radial turbine coupled to the combustor and a warm side inlet of the recuperator coupled to the radial turbine, at least one exhaust nozzle coupled to a warm side outlet of the recuperator that discharges into the by-pass duct and a propelling nozzle coupled to the by-pass duct.

Abstract: A twin lubrication oil tank filling system with a single oil fill port that prevents overfilling of both a primary oil tank and a secondary oil with a gravity fill system by directing oil primarily into the secondary oil tank by means of a special oil diverter, a float valve for the secondary oil tank that closes when the oil level in the secondary tank reaches a full level to cause additional oil flow to pour into the primary oil tank and a float valve for the primary oil tank that closes when the oil level in the primary tank reaches a full level.

Abstract: An exhaust duct system for a gas turbine engine that mounts within a tail cone of an aircraft, comprises an exhaust exit that exits one side of the tail cone offset from the axial centerline of the tail cone and an exhaust duct that couples the engine to the offset exhaust exit, with a straight section of the exhaust duct extending from the exhaust exit for a length that corresponds to at least one diameter of the exhaust duct.

Abstract: A recirculating lubrication system for a gas turbine engine comprises: a storage reservoir for storing a quantity of lubrication oil for the engine; an operating reservoir for supplying lubrication oil for the engine; a transfer valve with an inlet coupled to an outlet of the storage reservoir and an outlet coupled to an inlet of the operating reservoir to transfer the quantity of lubrication oil from the storage reservoir to the operating reservoir before starting the engine; and a pump for circulating the transferred lubrication oil through at least one engine bearing and back to the operating reservoir.

Abstract: A method of compensating for load-induced twisting of a gear assembly under load that includes a gear on a gear shaft, bearings on each side of the gear that support the gear shaft and a carrier fastened to a stationary support surface that mounts a proximal one of the bearings near the stationary support surface and mounts a distal one of the bearings away from the stationary support surface. The method includes the steps of determining the twisting deflection of a distal bearing axis of rotation for the distal bearing relative to a proximal bearing axis of rotation for the proximal bearing and offsetting the position of the distal bearing axis of rotation relative to the proximal bearing axis of rotation in the carrier opposite the determined deflection under no gear loading.

Abstract: A calibration artifact for an inspection system is provided. The calibration artifact comprises a base adapted for placement within a holding fixture of an inspection system during calibration, a sphere operatively connected to the base, and a light source operatively connected to the base. The base, the sphere, and the light source are removable from the inspection system after calibration.

Abstract: Embodiments of a cover plate and material blank for forming the cover plate may include features and characteristics to accommodate tolerance issues in a turbine vane assembly. In one embodiment, the cover plate is formed from a material blank configured to provide the cover plate with a flexible flange area that can be secured to the turbine vane assembly. The flange area may have a range of motion that may be responsive to an installation force, which effectively modifies the configuration of the cover plate to such degree as to seal the cover plate to the turbine vane assembly.