Abstract: In accordance with at least one aspect of this disclosure, a composite rotor includes a first rotor portion defining a first rotational axis and having a first magnet therein and a second rotor portion defining a second rotational axis and having a second magnet therein. A stator portion is disposed radially between the first rotor portion and the second rotor portion. The first rotor portion and the second rotor portion are formed of composite filaments and/or composite tape, and the composite filaments and/or composite tape are wrapped in both a first direction and a second direction different from the first direction relative to the first and second rotation axes.

Abstract: In accordance with at least one aspect of this disclosure, a method includes installing a welding tool into a repair tool holder, ultrasonic welding a repair sheet to a part to be repaired with the welding tool, removing the welding tool from the repair tool holder, installing a machining tool into the repair tool holder, and ultrasonic machining a portion of the repair sheet that is welded to the part to be repaired to match an a predetermined geometry of the part to be repaired with the machining tool.

Abstract: An airfoil for a gas turbine engine including an airfoil body extending between a leading edge and a trailing edge and between a pressure side and a suction side. The airfoil body includes a strut portion extending from the leading edge and a flap portion extending from the trailing edge. The flap portion is pivotable relative to the strut portion. A flexible skin surrounds both the strut portion and the flap portion on both the pressure side and the suction side.

Abstract: In accordance with at least one aspect of this disclosure, a method includes installing a welding tool into a repair tool holder, ultrasonic welding a repair sheet to a part to be repaired with the welding tool, removing the welding tool from the repair tool holder, installing a machining tool into the repair tool holder, and ultrasonic machining a portion of the repair sheet that is welded to the part to be repaired to match an a predetermined geometry of the part to be repaired with the machining tool.

Abstract: A gear system, having: first and second ground gear; a drive shaft disposed along a rotation axis of the gear system and configured to rotate about the rotation axis; and an output gear supported by the first and second ground gear and configured to rotate by engagement between a wave generator portion of a drive shaft, a wave generator bearing, a flex spline, the output gear and the first and second ground gear, the output gear defining: an output gear body; and first and second output arms respectively extending radially outward from opposite sides of the output gear body to respectively define first and second radial inner ends and radial outer ends of the first and second output arms, so that the first and second radial outer ends are disposed on a radial axis that extends through a radial center of the gear system.

Abstract: A stator for an electrical machine can include a plurality of windings, each forming a coil and end connections. The stator can include a first potting material having a first viscosity and a first thermal conductivity. The first potting material can be disposed on each coil and fills gaps between each coil. The stator can include a second potting material different from the first potting material and having a second viscosity and a second thermal conductivity. The second viscosity can be higher than the first viscosity and the second thermal conductivity is higher than the first thermal conductivity. The second potting material can be disposed on each of the end connections to provide increased thermal conductivity from the end connections.

Abstract: A combustor for a detonation engine includes a radially outer wall extending along an axis; a radially inner wall extending along the axis, wherein the radially inner wall is positioned at least partially within the radially outer wall to define an annular detonation chamber having an inlet for fuel and oxidant and an outlet; a cooling flow passage defined along at least one of the radially outer wall and the radially inner wall and comprising at least two axially spaced cooling flow passage sections, whereby a different cooling rate can be implemented in the at least two axially spaced cooling flow passage sections.

Abstract: A heat exchanger includes a body, a plurality of first flow channels defined in the body; and a plurality of second flow channels defined in the body. The second flow channels are fluidly isolated from the first flow channels. The first flow channels and second flow channels are arranged in a checkerboard pattern.

Abstract: A stator includes a stator hub, a plurality of stator teeth extending from stator hub that define a stator slot and at least one winding disposed in the stator slot, the winding including a cooling passage formed therein through. The cooling passage is connected to an inlet plenum and an outlet plenum. The stator can also include coil separators tint include cooling passages.

Abstract: A header for an electric machine that include a stator core and one or more windings that include coolant passages formed therein. The header includes an inlet to receive a coolant, an outlet though which the coolant exits the header, an inlet plenum fluidly connected to the inlet, and an outlet plenum fluidly separated from the inlet plenum and fluidly connected to the outlet. The inlet and outlet plenums each have a varying cross section that varies from a top of the header as compared to a bottom of the header.

Abstract: A method of manufacturing a composite vessel assembly (20) includes the steps of filling a first chamber defined by a first liner (28,30,32) with a first granulated material (96) through a first orifice (98) in the first liner. A vacuum is then applied to the first chamber, and the first orifice is plugged. The first liner may then be enveloped with a first layer (84) for structural rigidity followed by relief of the vacuum.

Abstract: A composite pressure vessel assembly includes a plurality of lobes, each of the lobes having at least one interior wall and at least one curved wall, the plurality of lobes being positioned in a side by side arrangement and extending in a longitudinal direction from a first end to a second end. Also included is a plurality of end caps disposed at the ends of the lobes, wherein the plurality of lobes and end caps are formed of at least one fiber-reinforced polymer. A method of manufacturing a composite pressure vessel assembly is provided. The method includes forming a plurality of lobes consisting of at least one fiber-reinforced polymer. The method also includes forming a main body with the plurality of lobes, the lobes disposed in a side by side arrangement.

Abstract: Aircraft electric motors are described. The electric motors include an annular rotor sleeve having an inner wall, a connecting wall, and an outer wall, wherein the inner wall, the connecting wall, and the outer wall define a U-shaped channel configured to receive a U-shaped magnet structure and a sleeve inner cavity defined radially inward from the inner wall, a hub connector extending radially inward from the inner wall into the sleeve inner cavity, a hub arranged in the sleeve inner cavity and fixedly connected to the hub connector, wherein the hub is configured to rotate with rotation of the rotor sleeve, and a U-shaped magnet structure arranged within the U-shaped channel of the rotor sleeve. At least one of the rotor sleeve, the hub connector, and the hub are formed from a composite material.

Abstract: Aircraft electric motors are described. The aircraft electric motors include a cooling system comprising an annular heat exchanger, a motor housing arranged radially inward from the heat exchanger, the motor housing defining a rotor-stator cavity and a gear assembly cavity, a rotor sleeve arranged within the rotor-stator cavity, a gear assembly arranged within the gear assembly cavity, a first shaft operably coupled to the rotor sleeve and configured to be rotationally driven by the rotor sleeve to drive rotation of a portion of the gear assembly, and a second shaft operably coupled to the gear assembly and configured to be rotationally driven by the gear assembly.

Abstract: A combustor for a detonation engine includes a radially outer wall extending along an axis; a radially inner wall extending along the axis, wherein the radially inner wall is positioned at least partially within the radially outer wall to define an annular detonation chamber having an inlet for fuel and oxidant and an outlet; a cooling flow passage defined along at least one of the radially outer wall and the radially inner wall and comprising at least two axially spaced cooling flow passage sections, whereby a different cooling rate can be implemented in the at least two axially spaced cooling flow passage sections.

Abstract: A fuel cell assembly including a fuel cell stack having a first stack end and a second stack end, a first end plate located at the first stack end, and a second end plate located at the second stack end. The fuel cell stack being interposed between the first end plate and the second end plate. The fuel cell assembly including a compliant assembly extending from a first end to a second end located opposite the first end. The compliant assembly is configured to anchor together the fuel cell stack, the first end plate, and the second end plate. The compliant assembly include a rod extending from a first rod end to a second rod end. The compliant assembly also includes a connector body secured to the rod at or proximate the first rod end and an anchoring mechanism secured to the connector body.

Abstract: An airfoil for a gas turbine engine including an airfoil body extending between a leading edge and a trailing edge and between a pressure side and a suction side. The airfoil body includes a strut portion extending from the leading edge and a flap portion extending from the trailing edge. The flap portion is pivotable relative to the strut portion. A flexible skin surrounds both the strut portion and the flap portion on both the pressure side and the suction side.

Abstract: A method for deep roll peening a workpiece includes deep roll peening a workpiece by moving the workpiece along a feed path through multiple groups of opposed rollers that are arranged in series. Each group of opposed rollers includes a rim that defines a workpiece engagement surface that exerts a deep roll peening force on the workpiece. A deep roll peening system includes multiple groups of opposed rollers. Each of the opposed rollers is rotatably mounted and has a rim that defines a workpiece engagement surface. The workpiece engagement surfaces are spaced apart from each other by a gap. The groups are arranged in series such that the gaps define a feed path for receiving a workpiece into serial contact with the workpiece engagement surfaces.

Abstract: A method for machining a ceramic workpiece includes providing a sonotrode that has a transducer and a horn arranged along an axis, and the horn has helical slots and terminates at a tip, bringing the tip into proximity of the ceramic workpiece and providing an abrasive media to a work zone around the tip, using the transducer to produce ultrasonic vibration that axially propagates down the horn and causes axial vibration at the tip, and the helical slots convert a portion of the axial vibration to torsional vibration at the tip, and the axial vibration and the torsional vibration causing the abrasive media to abrade the ceramic workpiece in the work zone and thereby remove a localized portion of the ceramic workpiece.

Abstract: A gas turbine engine includes a fan section, a compressor section, and a turbine section. The fan section has a plurality of vane assemblies spaced circumferentially about an engine axis. The vane assemblies each include an airfoil extending between a leading edge and a trailing edge, a control rod extending through the airfoil, and a mechanism driven by the control rod to change the shape of the airfoil. A vane system for a gas turbine engine is also disclosed.