Abstract: A flexible panel assembly for a gas turbine engine selectively exhibits a range of positions to regulate exhaust of the engine.

Abstract: Systems and methods for altering airflow to gas turbine engines are provided. In this regard, a representative system includes a gas turbine engine inlet having a slat, the slat being movable between a retracted position and an extended position. In the extended position, the slat increases an effective diameter of the inlet compared to the diameter of the inlet when in the retracted position.

Abstract: Gas turbine engine systems involving tip fans are provided. In this regard, a representative gas turbine engine system includes: a multi-stage fan having a first rotatable set of blades and a second counter-rotatable set of blades, the first rotatable set of blades defining an inner fan and a tip fan; and an epicyclic differential gear assembly operative to receive a torque input and differentially apply the torque input to the first set of blades and the second set of blades.

Abstract: Gas turbine engines and related systems involving blade outer air seals are provided. In this regard, a representative blade outer air seal segment for a set of rotatable blades includes: a blade arrival end; and a blade departure end; each of the blade arrival end and the blade departure end being angularly offset with respect to a longitudinal axis about which the blades rotate.

Abstract: Gas turbine engine systems and related methods involving vane-blade count ratios greater than unity are provided. In this regard, a representative turbine stage for a gas turbine engine includes a first set of rotatable blades operative to be positioned downstream of and adjacent to a first set of vanes, a number of blades of the first set of blades being less than a number of vanes of the first set of vanes.

Abstract: Vacuum pressure systems are provided. In this regard, a representative vacuum pressure system includes: an inlet; and a linear actuator having a permanent magnet, a coil, an inner ferromagnetic core and an outer ferromagnetic core, the outer ferromagnetic core surrounding at least a portion of each of the permanent magnet, the coil, and the inner ferromagnetic core; the linear actuator being operative to exhibit relative motion between the permanent magnet and the coil responsive to an electrical current being applied to the coil such that the linear actuator forms vacuum pressure and draws fluid into the inlet.

Abstract: Systems and methods for positioning fairing sheaths are provided. In this regard, a representative method includes using vacuum pressure to assist in moving opposing portions of a fairing sheath away from each other.

Abstract: Repair methods involving conductive heat resistance welding includes repairing a crack of a gas turbine engine component using a conductive heat resistance welding technique and a welding technique other than conductive heat resistance welding.

Abstract: Methods for repairing abradable seals of gas turbine engines include providing an abradable seal component of a gas turbine engine, the seal component having a structural substrate; providing a first preform to restore the structural substrate; and providing a second preform to form an abradable layer of the component. Preforms include a multilayer stack having a first layer and a second layer.

Abstract: A nozzle assembly for a gas turbine engine includes a door axially slidable relative to a passage in communication with a secondary flow path to regulate the secondary flow though the passage.

Abstract: An air-blast fuel nozzle assembly includes a housing having an inner surface defining an interior chamber around a central axis. The inner surface terminates in an exit aperture. An air swirler pneumatically communicates with the interior chamber and has vanes operative to impart a swirling motion to air passing across the vanes and into the interior chamber. A fuel injection assembly includes a nozzle portion extending along the central axis and having a plurality of outlets circumferentially-arranged around the central axis that are directed into the interior chamber toward the inner surface of the housing. A shield extends radially outwardly from the nozzle portion upstream of the plurality of outlets. The shield extends between a base at the nozzle section and a free tip end such that the shield extends partially across the interior chamber toward the inner surface.

Abstract: Gas turbine engine systems involving I-beam struts are provided. In this regard, a representative strut assembly for a gas turbine engine includes a first I-beam strut having first and second flanges spaced from each other and interconnected by a web, the first strut exhibiting a twist along a length of the web.

Abstract: Gas turbine engine systems involving rotor bayonet coverplates and tools for installing such coverplates are provided. In this regard, a representative turbine assembly for a gas turbine engine includes: a turbine disk operative to mount a set of turbine blades; and a coverplate having an annular main body portion and a spaced annular arrangement of tabs extending radially inwardly from the main body portion with open-ended gaps being located between the tabs, the tabs being operative to secure an inner diameter of the coverplate to the turbine disk.

Abstract: Gas turbine engine systems involving cooling of combustion section liners are provided. A representative liner includes: an outer side, an inner side, an upstream end, and a downstream end, the outer side being configured to face away from a combustion reaction, the inner side being configured to face the combustion reaction; a cooling air channel, a portion of the cooling air channel being located proximate the downstream end; and cooling holes formed through the inner side of the liner, the cooling holes being in fluid communication with the cooling air channel such that cooling air provided to the cooling air channel is directed through the cooling holes and to the inner side of the liner such that at least a portion of the inner side of the liner receives cooling air despite a corresponding portion located on the outer side of the liner being obstructed from receiving cooling air.

Abstract: Systems and methods involving multiple torque paths of gas turbine engines are provided. In this regard, a representative spool assembly for a gas turbine engine, which incorporates a compressor, a turbine and a gear assembly, includes: a shaft operative to be driven by the turbine; a first spool segment operative to couple the shaft to the compressor; and a second spool segment operative to couple the shaft to the gear assembly. The first spool segment and the second spool segment are not coupled to each other.

Abstract: Platforms with curved side edges and gas turbine engine systems involving such platforms are provided. In this regard, a representative airfoil assembly for a gas turbine engine includes: a platform having a gas path side, a non-gas path side, a leading edge, a trailing edge, a first side edge extending between the leading edge and the trailing edge and exhibiting a first curve along a length thereof, and a second side edge extending between the leading edge and the trailing edge and exhibiting a second curve along a length thereof; and an airfoil extending from the gas path side of the platform; the platform and the airfoil exhibiting a unitary construction such that a continuous exterior surface blends from the airfoil to the platform.

Abstract: Gas turbine engine systems involving baffle assemblies are provided. In this regard, a representative baffle assembly for a gas turbine engine includes: a cooling plenum defining a cooling air path; and a baffle sized and shaped to extend between surfaces of the cooling plenum such that a cooling air path of reduced cross-section is formed between the baffle and the surfaces, the baffle being operative to increase a flow rate of cooling air as the cooling air directed to the cooling air path is redirected through the cooling air path of reduced cross-section.

Abstract: Gas turbine engine systems involving gear-driven variable vanes are provided. In this regard, a representative gas turbine engine system includes: a ring gear assembly operative to be mounted within an engine casing; and a vane module having a first vane airfoil and a first gear, the first gear being operative to engage the ring gear assembly such that movement of the ring gear alters a position of the first vane airfoil.

Abstract: Systems and methods involving localized stiffening of blades are provided. In this regard, a representative a gas turbine engine blade includes: a recess located in a surface of the blade; and material positioned at least partially within the recess such that the material provides a localized increase in stiffness of the blade.

Abstract: A swept turbomachinery blade for use in a cascade of such blades is disclosed. The blade (12) has an airfoil (22) uniquely swept so that an endwall shock (64) of limited radial extent and a passage shock (66) are coincident and a working medium (48) flowing through interblade passages (50) is subjected to a single coincident shock rather than the individual shocks. In one embodiment of the invention the forwardmost extremity of the airfoil defines an inner transition point (40) located at an inner transition radius rt-inner. The sweep angle of the airfoil is nondecreasing with increasing radius from the inner transition radius to an outer transition radius rt-outer, radially inward of the airfoil tip (26), and is nonincreasing with increasing radius between the outer transition radius and the airfoil tip.