Abstract: Systems and methods for reducing the potential for riser backfilling during investment casting are provided. In this regard, a representative method for performing investment casting includes: providing a mold having an opening communicating with an interior, the interior having a part cavity and a riser; providing an insert; and using the insert to form a physical barrier to reduce a potential for molten metal to backfill into the riser while the molten metal is introduced into the interior of the mold via the opening.

Abstract: Accessory gearboxes and related gas turbine engine systems are provided. In this regard, a representative accessory gearbox for a gas turbine engine is operative to be driven by rotational energy extracted from the gas turbine engine and imparted to the gearbox by multiple tower shafts.

Abstract: Systems and methods for transient liquid phase bonding are described herein. Embodiments of these systems and methods utilize sandwich interlayers to produce stronger, more homogeneous bonds than currently possible. These sandwich interlayers have a middle bonding layer sandwiched between two outer bonding layers. The middle bonding layer is a different composition, and may even be a different form, than the outer bonding layers. In embodiments, these sandwich interlayers may be used to join a single crystal material to a polycrystalline material to make a gas turbine engine component, such as an integrally bladed rotor.

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: Systems and methods involving variable throat area vanes are provided. In this regard, a representative gas turbine engine includes: a vane extending into a gas flow path and having: an interior operative to receive pressurized air; a pressure surface portion; and a first port communicating between the interior and pressure surface portion, the first port being operative to receive the pressurized air from the interior and emit the pressurized air, wherein the emitted pressurized air displaces the gas flow path such that a throat area defined, at least in part, by the vane is modified.

Abstract: Artifacts, methods of creating such artifacts and methods of using such artifacts are provided. In this regard, an exemplary embodiment of a method for creating an artifact for quantifying measurement accuracy of non-contact sensors included in optical three-dimensional (3-D) measuring systems, comprises: fabricating an artifact using a base material; and coating the artifact with an approximately uniform coating of dry film lubricant.

Abstract: A method for evaluating three-dimensional (3-D) coordinate system measurement accuracy of an optical 3-D measuring system using targeted artifacts is provided. In this regard, an exemplary embodiment of a method for evaluating 3-D coordinate system measurement accuracy using targeted artifacts comprises: taking a series of measurements from different positions and orientations using target dots on a targeted artifact with an optical 3-D measuring system; and calculating measurement errors using the series of measurements. An exemplary embodiment of a targeted artifact used with the method includes a base and target dots located on the base.

Abstract: Gas turbine engines and related systems involving blade outer air seals are provided. In this regard, a representative blade outer air seal assembly for a gas turbine engine includes: an annular arrangement of outer air seal segments, each of the segments having ends, the segments being positioned in an end-to-end orientation such that each adjacent pair of the segments forms an intersegment gap therebetween, each intersegment gap being defined, at least partially, by a first recess and a first protrusion, the first protrusion being sized and shaped to be received by the first recess, one of the first recess and the first protrusion being located on an end of a first segment of an adjacent pair of the segments, another of the first recess and the first protrusion being located on an end of a second segment of the adjacent pair of the segments.

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 engines and related systems involving air-cooled vanes are provided. In this regard, a representative vane for a gas turbine engine includes: an airfoil having a leading edge, a pressure surface, a trailing edge and a suction surface; and a cooling air channel; the suction surface being formed by an exterior surface of a first wall portion and an exterior surface of a second wall portion, the first wall portion spanning a length of the suction surface between the second wall portion and the trailing edge; the cooling air channel being defined, at least in part, by an interior surface of the first wall portion, the first wall portion exhibiting a thickness that is thinner than a thickness exhibited by the second wall portion.

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: System and methods involving pattern molds are provided. In this regard, a representative system includes a mold assembly unit having a movable fixture holder operative to engage a portion of a pattern mold and position the pattern mold for assembly.

Abstract: Gas turbine engines and related systems involving offset hub struts are provided. In this regard, a representative bearing assembly for a gas turbine engine includes: a bearing operative to support a rotatable shaft; an annular hub positioned about the bearing; and an annular array of struts extending radially outwardly from the hub, at least two of the struts being positioned in different planes, the planes being oriented transversely with respect to the rotatable shaft. The method of assembling the struts by mounting first and second pluralities of struts, each plurality in a common plane, between the hub and the turbine exhaust case, with the second plurality of struts longitudinally offset from the first plurality of struts.

Abstract: Gas turbine engine systems involving mechanically alterable vane throat areas are provided. In this regard, a representative vane for a gas turbine engine includes: a leading edge; a trailing edge; a suction side surface extending between the leading edge and the trailing edge; a cavity having an aperture located in the suction side surface; and a barrel located within the cavity and being moveable therein such that movement of the barrel alters an extent to which the barrel protrudes through the aperture.

Abstract: Organic matrix composite components, systems using such components, and methods for manufacturing such components are provided. In this regard, a representative organic matrix composite component includes: an organic matrix composite; a layer of aluminum applied to the organic matrix composite; and a wear resistant coating applied to the aluminum layer.

Abstract: Gas turbine engine systems involving cooling of combustion section liners are provided. In this regard, 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, at least a portion of the cooling air channel being located in a vicinity of 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 directly receiving cooling air.

Abstract: Gas turbine engine systems involving integrated fluid conduits are provided. In this regard, a representative engine casing for a gas turbine engine includes: a casing wall; and a fluid conduit integrated into the casing wall.

Abstract: Gas turbine engine systems involving hydrostatic face seals are provided. In this regard, representative compressor assembly for a gas turbine engine includes a compressor having a hydrostatic seal formed by a seal face and a seal runner.

Abstract: Feather seals and gas turbine engine systems involving such seals are provided. In this regard, a representative feather seal for a gas turbine engine includes: an elongate body portion; and a locating tab extending longitudinally along the body portion and extending outwardly therefrom.

Abstract: Shaft trim balancing devices, related systems and methods are provided. In this regard, an representative device for trim balancing a rotatable shaft includes: an intermediate section being annularly shaped and having terminating ends spaced from each other in an uncompressed state of the device; and first and second sets of counterweights extending longitudinally from opposing sides of the intermediate section.