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: Disclosed herein are example variable flowpath casings for blade tip clearance control. An example casing for a turbine engine includes an annular substrate extending along an axial direction, the annular substrate including a first surface and a second surface that is radially inward relative to the first surface; an actuator structure coupled to the second surface of the annular substrate; and a smart structure cantilevered from the second surface of the annular substrate, the smart structure including: a support structure, a first region of the support structure coupled to the second surface of the annular substrate, a second region of the support structure coupled to the actuator structure; and a radially inward surface defining a variable surface, the support structure to move the variable surface in a radial direction.

Abstract: An air turbine starter (ATS) for starting an engine, having a stator including a housing having an inlet, an outlet, and a flow path extending between the inlet and the outlet and a rotor including a turbine member defining a rotating axis and having a set of blades at least partially disposed within the flow path. The ATS further including a bearing support structure disposed between the rotor and the stator comprising a first bearing support having a first stiffness (K1) and a second bearing support having a second stiffness (K2).

Abstract: Variable bleed valves with struts for aerodynamic stability are described. An apparatus described herein includes a variable bleed valve port, and a strut disposed within the variable bleed valve port, the strut defining a plane and a plurality of holes disposed perpendicularly to the plane, the plurality of holes disposed in a pattern to dampen an acoustic response associated with the variable bleed valve port.

Abstract: A gearbox assembly includes a first gear and a second gear. The first gear includes a plurality of first gear teeth. The second gear includes a plurality of second gear teeth. The plurality of first gear teeth and the plurality of second gear teeth mesh with each other as the first gear and the second gear rotate. A profile shape of at least one first gear tooth of the first gear is characterized by a total profile modification between 66 micrometers and 120 micrometers.

Abstract: A combustor for a gas turbine includes a dome structure including a dome-side swirler opening therethrough, and a deflector connected to the dome structure. The deflector includes a deflector-side swirler opening therethrough and a deflector-dome connecting member arranged at the deflector-side swirler opening. The deflector-dome connecting member is connected with the dome-side swirler opening via a snap-fit type connection.

Abstract: A hollow plank of a combustor liner defining a combustion chamber including an inner wall having a plurality of inner openings and one or more inner holes, an outer wall having one or more outer openings and a plurality of outer holes, a plurality of lateral walls coupled to the inner wall and the outer wall to define a cavity, and a partition wall connected to the plurality of lateral walls and dividing the cavity into a first sub-cavity and a second sub-cavity. The one or more outer openings communicate with the first sub-cavity and communicate through a plurality of tubes with the second sub-cavity. The plurality of inner openings communicate with the second sub-cavity and communicate with the first sub-cavity through one or more bypass tubes. The first sub-cavity or the second sub-cavity, or both, are frequency tuned to reduce combustion dynamic frequencies.

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: This disclosure is directed to cooling systems for turbomachine seal assemblies. The seal assemblies include stationary and rotating components and at least one interface between the stationary and rotating components. During operation of the turbomachine, the components of the seal assemblies generate heat, which is removed from the seal assembly by the cooling systems of this disclosure. In some examples, the cooling system includes a reservoir of lubricant that is distributed to a face of one of the components of the seal assembly. In other examples, the cooling system includes a lattice structure capable of retaining lubricant against the components of the seal assembly, or a pressurized jet of lubricant directed against the components of the seal assembly. The cooling systems can further include a combination of deflectors, hairpin members, and channels for distributing the lubricant to the components of the seal assemblies.

Abstract: A bearing support assembly to support one or more bearings on a shaft. The bearing support assembly includes a bearing support frame configured to be coupled to a static frame, a plurality of ribs connected to the bearing support frame, and a bearing support connected to the plurality of ribs and configured to support a bearing of the one or more bearings. The bearing support assembly has a non-axisymmetric stiffness around a circumference of the bearing support assembly.

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 liner at least partially defining a combustion chamber of the gas turbine engine, wherein the liner comprises a looped feature.

Abstract: Dual function links for gas turbine engine mounts are disclosed. An example apparatus for mounting a casing of a gas turbine engine to a pylon, the apparatus includes a first pin and a linkage including a first linkage portion including the first pin, a second linkage portion, the second linkage portion forming a first load path between the gas turbine engine and the pylon, the second linkage portion arranged with respect to the first linkage portion such that a gap prevents the first linkage portion from forming a second load path between the gas turbine engine and the pylon.

Abstract: A cooling system for a turbine engine. The turbine engine includes a compressor, a turbine, and a shaft that drivingly couples the compressor and the turbine. The cooling system includes one or more cavities of the compressor. The cooling system includes a shaft flowpath defined in the shaft. The shaft includes one or more shaft apertures that provide fluid communication between the shaft flowpath and the one or more cavities. Air passes through the one or more shaft apertures and the shaft flowpath during a shutdown of the turbine engine to cool the one or more cavities.

Abstract: An annular combustor includes a combustion liner defining a combustion chamber, the combustion liner having an outer liner and an inner liner and a plurality of dimples in the combustion liner. The combustion liner is characterized by a performance factor greater than or equal to one and less than or equal to seven. An engine includes the annular combustor.

Abstract: A seal assembly at a rotor-stator interface includes at least one non-contacting seal interface and at least one rub detection feature. The rub detection feature(s) is configured to generate a signal upon the rotor and the stator making contact at the rotor-stator interface and causing wear above a certain threshold at the rotor-stator interface. The seal assembly also includes at least one sensor arranged at the rotor-stator interface. The sensor is configured to sense the signal. The seal assembly further includes a controller communicatively coupled with the sensor(s). The controller is configured to receive the signal and estimate at least one of an amount and a location of the wear at the rotor-stator interface based on the signal.

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.