Abstract: A turbomachine, a computing system for a turbomachine, and a method for overspeed protection are provided. The turbomachine includes a first rotor assembly interdigitated with a second rotor assembly together operably coupled to a gear assembly. A plurality of sensors is configured to receive rotor state data indicative of one or more of a speed, geometric dimension, or capacitance, or change thereof, or rate of change thereof, relative to the first rotor assembly or the second rotor assembly. A controller executes operations including receiving rotor state data from the plurality of sensors; comparing rotor state data to one or more rotor state limits; and contacting one or more of the first rotor assembly or the second rotor assembly to a contact surface adjacent to the respective first rotor assembly or the second rotor assembly if the rotor state data exceeds the rotor state limit.

Abstract: The variable pitch propeller assembly includes a hub. The variable pitch propeller assembly also includes a plurality of propeller blade assemblies spaced circumferentially about the hub. Each of the plurality of propeller blade assemblies configured to rotate a respective propeller blade. The variable pitch propeller assembly also includes a hydraulic fluid port assembly integrally formed and including at least three hydraulic fluid ports configured to receive respective flows of hydraulic fluid from a stationary hydraulic fluid transfer sleeve. The variable pitch propeller assembly also includes a pitch actuator assembly coupled in flow communication with at least three hydraulic fluid ports through respective hydraulic fluid transfer tubes. The pitch actuator coupled to the plurality of propeller blade assemblies to selectively control a pitch of the propeller blades. The pitch actuator assembly includes a travel stop configured to limit a rotation of at least one of the pitch actuator assemblies.

Abstract: A propulsion system of an aircraft has at least one unducted fan and at least one ducted fan, the at least one unducted fan and the at least one ducted fan being powered by an electric power source and rotatable between a vertical thrust position and a forward thrust position, and a controller configured to distribute electrical power between the at least one unducted fan and the at least one ducted fan. During a first mode when the at least one unducted fan and the at least one ducted fan are in the vertical thrust position, the controller is configured to distribute the electrical power between the plurality of unducted fans and the plurality of ducted fans such that the at least one unducted fan is a primary source of thrust.

Abstract: A turbomachine equipped with an embedded electric machine having a segmented and movable stator is provided. In one aspect, a turbomachine defines a radial direction and includes a rotating component, actuators, and an electric machine. The electric machine includes a rotor assembly rotatable with and operatively coupled with the rotating component. The electric machine also includes a stator assembly having a stator split into stator segments. Each one of the stator segments is movable by one of the actuators between a first position and a second position along the radial direction, the stator segments each being closer to the rotor assembly along the radial direction when in the first position than when in the second position.

Abstract: A method for operating a hybrid electric propulsion system of an aircraft, the hybrid electric propulsion system comprising a turbomachine, an electric machine coupled to the turbomachine, and a propulsor coupled to the turbomachine, the method comprising: operating the turbomachine to drive the propulsor; receiving data indicative of a failure condition of the hybrid electric propulsion system; and extracting power from the turbomachine using the electric machine to slow down one or more rotating components of the turbomachine in response to receiving the data indicative of the failure condition.

Abstract: The present disclosure is directed to a gas turbine engine including a first turbine frame defining one or more first struts extended along a radial direction and a turbine rotor assembly. The turbine rotor assembly defines a rotatable drum surrounding a reduction speed reduction assembly and coupled thereto. The turbine rotor assembly includes a first turbine rotor and a second turbine rotor each disposed on one or more bearing assemblies. The first turbine frame defines a first supply conduit through the first strut providing a flow of fluid to the speed reduction assembly and one or more of the bearing assemblies. The first turbine frame further defines a first scavenge conduit providing an egress of at least a portion of the flow of fluid from one or more of the bearing assemblies.

Abstract: The present application relates to a frictional damper, a frictional damper assembly and method for installing the frictional damper. The frictional damper comprises a split ring; and a disk spring positioned against the split ring and tensioned by the split ring in an installed state.

Abstract: An electric machine is provided. The electric machine defines a centerline and includes: a stator assembly; a rotor assembly rotatable relative to the stator assembly about the centerline; and an actuator coupled to the rotor assembly, the stator assembly, or both for moving the rotor assembly, the stator assembly, or both along the centerline between a first position and a second position, the rotor assembly positioned closer to the stator assembly when in the first position than when in the second position.

Abstract: A gas turbine engine includes a core turbine engine and a fan mechanically coupled to the core turbine engine. The fan includes a plurality of fan blades, each fan blade defining a base and an inner end along a radial direction of the gas turbine engine. The fan also includes a hub covering the base of each of the plurality of fan blades. Further, the fan includes one or more bearings for supporting rotation of the plurality of fan blades. The one or more bearings define a fan bearing radius along a radial direction of the gas turbine engine. Similarly, the hub defines a hub radius along the radial direction of the gas turbine engine. The ratio of the hub radius to the fan bearing radius is less than about three, providing for desired packaging of the various components within the fan of the gas turbine engine.

Abstract: The variable pitch propeller assembly includes a hub. The variable pitch propeller assembly also includes a plurality of propeller blade assemblies spaced circumferentially about the hub. Each of the plurality of propeller blade assemblies configured to rotate a respective propeller blade. The variable pitch propeller assembly also includes a hydraulic fluid port assembly integrally formed and including at least three hydraulic fluid ports configured to receive respective flows of hydraulic fluid from a stationary hydraulic fluid transfer sleeve. The variable pitch propeller assembly also includes a pitch actuator assembly coupled in flow communication with at least three hydraulic fluid ports through respective hydraulic fluid transfer tubes. The pitch actuator coupled to the plurality of propeller blade assemblies to selectively control a pitch of the propeller blades. The pitch actuator assembly includes a travel stop configured to limit a rotation of at least one of the pitch actuator assemblies.

Abstract: An engine includes: a first rotating component; a second rotating component separate from the first rotating component; and an electric machine, the electric machine including a first rotor rotatable with the first rotating component; a second rotor rotatable with the second rotating component; and a stator assembly arranged between the first rotor and the second rotor, the stator assembly including a first set of windings arranged adjacent to the first rotor, a second set of windings arranged adjacent to the second rotor, and a non-ferromagnetic inner housing arranged between the first set of windings and the second set of windings.

Abstract: Aspects of the present invention disclose a method for ordering rows of a table based on access statistics. The method includes one or more processors adding a respective tracking mechanism to the attribute of each respective instance of the set of rows of the table of the database. The method further includes adding a tracking mechanism to the respective instances of the set of rows. The method further includes gathering access data of the respective tracking mechanism of the attribute of each respective instance of the set of rows. The method further includes determining each respective instance of an attribute value that corresponds to the access data of the respective tracking mechanism of each respective instance of the set of rows. The method further includes ordering each respective instance of the set of rows of the table based at least in part on the respective instances of the attribute values.

Abstract: An aircraft defines a vertical direction and includes a fuselage and a propulsion system comprising a power source and a plurality of vertical thrust electric fans driven by the power source. A wing extends from the fuselage. The plurality of vertical thrust electric fans are arranged along a length of the wing along a lengthwise direction of the wing. The wing comprises a diffusion assembly along the lengthwise direction of the wing and includes a first diffusion member positioned downstream of at least one of the plurality of vertical thrust electric fans. The first diffusion member defines a curved shape relative to a longitudinal direction of the aircraft. The longitudinal direction is generally perpendicular to the lengthwise direction of the wing.

Abstract: A method is provided for maintaining a gas turbine engine installed on an aircraft, the gas turbine engine including an electric machine mounted at least partially inward of a core air flowpath of the gas turbine engine. The method includes removing a rotor mount connecting a rotor of the electric machine to a rotary component of the gas turbine engine; removing a stator mount connecting a stator of the electric machine to a stationary component of the gas turbine engine; and removing in situ the electric machine.

Abstract: A method of masking data includes disabling, by one or more processors of a computer system, operation of a data structure that includes at least one data index. The method includes masking, by the one or more processors of the computer system, the data structure in a table with an isomorphic function, and enabling, by the one or more processors of the computer system, operation of the data structure.

Abstract: Methods, computer program products, and systems are presented. The method computer program products, and systems can include, for instance: running an application on one or more computing node, the application providing user access to a database; receiving by the application registration data from a user for registering the user into a service; in response to the receiving the registration data from the user, generating a user schema that defines access rights of the user to the database, wherein the generated user schema includes a set of shared data structure objects instantiated in a storage system associated to the application, and a set of private data structure objects.

Abstract: A computer-implemented method for unambiguously identifying entities in a database system may be provided. The method comprises storing data items as records with different attributes in a table of a database, storing naming rules for selected combinations of the attributes of the data items, and prioritizing the naming rules. The method also comprises determining a hash value for each of the selected combinations of the attributes of the data items, and identifying duplicate data items using the determined hash values and the prioritized naming rules.

Abstract: An aircraft includes a fuselage; a propulsion system including a power source and a vertical thrust electric fan driven by the power source; and a wing extending from the fuselage. The vertical thrust electric fan is positioned on or within the wing, the wing including a diffusion assembly movable between a first position and a second position and positioned at least partially downstream of the vertical thrust electric fan when in the second position, the diffusion assembly including a first member and a second member, the second member movable generally along the vertical direction relative to the first member such that the first member and second member together define at least in part an exhaust flowpath for the first vertical thrust electric fan when the diffusion assembly is in the second position.

Abstract: An aircraft includes a fuselage; a propulsion system including a power source and a plurality of vertical thrust electric fans driven by the power source; and a wing extending from the fuselage. The plurality of vertical thrust electric fans are arranged along the wing, the wing including one or more components being moveable to selectively expose the plurality of vertical thrust electric fans, the wing further including a diffusion assembly positioned downstream of at least one vertical thrust electric fan of the plurality of vertical thrust electric fans, the diffusion assembly defining a diffusion area ratio greater than 1:1 and less than about 2:1.

Abstract: An aircraft includes a fuselage; a propulsion system including a power source and a plurality of vertical thrust electric fans driven by the power source; and a wing extending from the fuselage. The plurality of vertical thrust electric fans are arranged along a length of the wing, the wing including a variable geometry assembly moveable generally along a horizontal direction between a forward thrust position and a vertical thrust position, the variable geometry assembly at least partially covering at least one vertical thrust electric fan of the plurality of vertical thrust electric fans when in the forward thrust position and at least partially exposing the at least one vertical thrust electric fan when in the vertical thrust position.