Abstract: A gas turbine engine includes a casing, a rotor assembly rotatably mounted within the casing, the rotor assembly comprising a forward rotor portion defining a forward rotor cavity and an aft rotor portion defining an aft rotor cavity, the aft rotor cavity being fluidly isolated from the forward rotor cavity, and a cooling system. The cooling system includes a forward cooling fluid supply, a forward supply line providing fluid communication between the forward cooling fluid supply and the forward rotor cavity, an aft cooling fluid supply, an aft supply line providing fluid communication between the aft cooling fluid supply and the aft rotor cavity, and a flow control system fluidly coupled to the forward supply line and the aft supply line for regulating a flow of forward cooling fluid and a flow of aft cooling fluid.

Abstract: Variable sleeve clearance control systems for gas turbine engines are disclosed. An example variable sleeve clearance control system for a gas turbine engine includes a sleeve comprising a first end and a second end, the first end of the sleeve coupled to a first spring that biases the sleeve inward, and the second end of the sleeve coupled to a second spring that biases the sleeve outward, a proximity sensor to measure a clearance width, and a controller for each of the first and second springs, the controller to obtain the measured clearance width from the proximity sensor and determine a response of the first and second springs.

Abstract: Disclosed herein are example variable flowpath casings for blade tip clearance control. An example casing for a turbine engine includes a first annular substrate extending along an axial direction, the first annular substrate defining a cavity at a radially inward surface of the first annular substrate, a second annular substrate positioned at least partially within the cavity of the first annular substrate, and a tension belt extending circumferentially around a periphery of the second annular substrate.

Abstract: Disclosed herein are example variable flowpath casings for blade tip clearance control. An example casing for a turbine engine includes a first annular substrate extending along an axial direction; a second annular substrate positioned radially inward relative to the first annular substrate, the second annular substrate movably coupled to the first annular substrate; and an actuator coupled to the second annular substrate such that a force applied by the actuator moves the second annular substrate relative to the first annular substrate to adjust a tip clearance.

Abstract: A combustor includes an inner liner and an outer liner defining a combustion chamber. The inner liner includes an inner mesh structure, and a plurality of inner planks mounted to the inner mesh structure. The outer liner includes an outer mesh structure, and a plurality of outer planks mounted to the outer mesh structure. Each of the plurality of inner planks and outer planks includes an inner wall, an outer wall, and lateral walls defining a cavity to allow circulation of airflow within the cavity to cool down the inner wall.

Abstract: A self-cleaning conduit for a hydrocarbon fluid. The conduit includes a tube and a mesh. The tube has an interior surface defining a flow passage for the hydrocarbon fluid. The mesh is positioned within the flow passage to abut the interior surface and movable along the interior surface to break-up deposits on the interior surface. The mesh is characterized by a mesh activation parameter (MAP) from one ten thousandths to six tenths.

Abstract: A self-cleaning conduit for a hydrocarbon fluid. The conduit includes a tube and a movable sleeve. The tube has an interior surface defining a flow passage for the hydrocarbon fluid. The movable sleeve is positioned within the flow passage to abut the interior surface and is movable along the interior surface in response to a change in an operating characteristic of the conduit to break-up deposits on the interior surface.

Abstract: A combustor including a skeleton structure. The combustor further includes at least one liner operably coupled to the skeleton structure to at least partially define a combustion chamber, and a plurality of first planks mounted to a first side of the at least one liner and a plurality of second planks mounted to a second side of the at least one liner. The combustor also includes at least one dilution hole structure provided with a portion of the skeleton structure, and including at least one dilution hole configured to allow fluid to pass therethrough into the combustion chamber.

Abstract: A combustor includes an inner liner and an outer liner defining a combustion chamber. The inner liner includes an inner mesh structure, a plurality of hot side planks mounted to a hot side of the inner mesh structure, and a plurality of cold side planks mounted to a cold side of the inner mesh structure. The outer liner includes an outer mesh structure, a plurality of hot side planks mounted to a hot side of the outer mesh structure, and a plurality of cold side planks mounted to a cold side of the outer mesh structure. The combustor further includes a plurality of clips configured to couple the plurality of hot side planks and the plurality of cold side planks to a plurality of structural elements of the inner mesh structure and the outer mesh structure.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed. A shroud assembly of a gas turbine engine includes: a first shroud arm having a first end and a second end, the first end to couple to an outer wall and the second end to couple to a first shroud pad, and a second shroud arm having a first end and a second end, the first end to couple to the outer wall and the second end to couple to a second shroud pad, at least one of the first shroud pad or the second shroud pad to move radially outward toward the outer wall in response to a rotor blade contacting the at least one of the first shroud pad or the second shroud pad.

Abstract: A combustor for a gas turbine engine, the gas turbine engine defining a longitudinal centerline extending in a longitudinal direction, a radial direction extending orthogonally outward from the longitudinal centerline, and a circumferential direction extending concentrically around the longitudinal centerline, the combustor including: a forward liner segment; an aft liner segment disposed downstream from the forward liner segment relative to a direction of flow through the combustor, the forward and aft liner segments at least partially defining a combustion chamber; and a fence disposed between the forward and aft liner segments, wherein the fence extends in the circumferential direction, and wherein the fence extends into the combustion chamber along the radial direction.

Abstract: A support assembly for a bearing of a gas turbine engine includes a shaft extending along an axial direction. The support assembly includes an outer race positioned radially exterior to the bearing such that the outer race supports the bearing. Additionally, the support assembly includes a shape memory alloy damper positioned radially exterior to the outer race and at least partially supporting the outer race. Moreover, the shape memory alloy damper includes a plurality of sleeves. One or more sleeves of the plurality of sleeves include a shape memory alloy material.

Abstract: A check valve assembly for a supply pipe. The check valve assembly includes a hinge pin, a first flapper, and a second flapper. The first flapper is pivotally coupled to the second flapper with the hinge pin. The check valve assembly also includes a stopper located between the first flapper and the second flapper. The stopper is configured to limit movement of the first flapper and the second flapper. The check valve assembly further includes a plate assembly located downstream of the stopper. The plate assembly is configured to break vortices formed in a fluid flow across the first flapper and the second flapper.

Abstract: This disclosure is directed to seal assemblies for a turbomachine. The seal assemblies include stationary and rotating components and at least one interface between the stationary and rotating components. In some examples, seal assembly includes a runner coupled to a rotating shaft and a sealing element coupled to a stationary engine housing. The seal assembly can also include a spring element located between the sealing element and the stationary engine housing, which allows the relative position between the runner and the sealing element to be adjusted while the turbomachine engine is in operation. Some seal assemblies include damping elements positioned between the sealing element and the fixed engine housing to slow the motion of the sealing element relative to the runner to reduce the risk of inadvertent contact between the runner and the sealing element.

Abstract: An insulation assembly for use in a gas turbine engine is provided. The insulation assembly defines a hot side and an insulated side and includes: a heat shield layer positioned proximate the hot side; and a thermal absorption layer positioned proximate the insulated side, the thermal absorption layer comprising a phase change material, the insulation assembly defining an air gap positioned between the heat shield layer and the thermal absorption layer.

Abstract: A dome-deflector assembly for a gas turbine includes a dome, a deflector, and at least one dome-deflector connecting assembly that includes a connecting member connecting the dome and the deflector together with a cavity being defined between the dome and the deflector. The connecting member extends through the deflector and has a first end arranged at a hot surface side of the deflector and a second end arranged to connect with the dome. The dome-deflector connecting assembly is configured to provide a flow of cooling air from the cavity to the hot surface side of the deflector to cool the first end of the connecting member on the hot surface side of the deflector.

Abstract: A combustor for a gas turbine has a combustor liner including an outer liner and an inner liner, a combustion chamber being defined between the outer liner and the inner liner. The combustion chamber includes a primary combustion zone at an upstream end of the combustion chamber. The combustor also includes an outer liner expanded primary volume portion, and a secondary outer liner portion. One of the outer liner expanded primary volume portion and the secondary outer liner portion is movable to adjust a volume of the primary combustion zone by opening and closing access to the outer liner expanded primary volume portion so as to increase and to decrease the volume of the primary combustion zone.

Abstract: A differential gearbox assembly for a turbine engine having a fan shaft and a drive shaft. The differential gearbox assembly includes an epicyclic gear assembly coupling the fan shaft to the drive shaft. The epicyclic gear assembly includes a sun gear, a planet gear constrained by a planet carrier, and a ring gear. The sun gear is coupled to the drive shaft and the planet carrier is coupled to the fan shaft. The sun gear, the planet gear, and the ring gear all rotate about the drive shaft. The differential gearbox assembly includes an electric machine assembly that includes an input coupled to the epicyclic gear assembly. The electric machine assembly provides mechanical power to the fan shaft through the epicyclic gear assembly.

Abstract: A combustor for a gas turbine engine includes a forward liner segment having an aft end portion. The forward liner segment at least partially defines a primary combustion chamber. The combustor further includes an aft liner segment having a forward end portion. A channel is defined between the forward liner segment and the aft liner segment. The channel directs a stream of dilution air in a counter-flow or reverse direction with respect to combustion gases flowing from the primary combustion chamber during operation of the combustor.

Abstract: This disclosure is directed to seal assemblies for a turbomachine. The seal assemblies include stationary and rotating components and at least one interface between the stationary and rotating components. The seal assembly further includes a self-lubricating lattice element made of carbon or a carbon-based material. The self-lubricating lattice element may have a porous and compressible microstructure capable of retaining a liquid substance. During engine operation, the self-lubricating lattice element can compress and expel some portion of the liquid substance to form a liquid-containing layer between the rotating and stationary components of the seal assembly. Also described herein are self-lubricating wear sleeves for use in other portions of the turbomachine.