Abstract: Systems and methods of aircraft thrust management are provided. For example, a propulsion system for an aircraft comprises a fuel cell assembly comprising a fuel cell, a turbomachine, and a controller comprising memory and one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the propulsion system to perform operations including receiving data indicative of a propulsion system thrust discrepancy and modifying an output of the fuel cell in response to receiving data indicative of the propulsion system thrust discrepancy. Modifying the fuel cell output may include modifying output products, an electrical power output, or both of the fuel cell to balance the thrust provided by the propulsion system.

Abstract: Damping devices, turbomachines, and methods of damping vibration are provided. For example, a damping device for damping vibration of a shaft rotatable about an axis of rotation is provided. The damping device defines radial and axial directions. The damping device comprises a bearing, a housing, and a damper element. The housing and damper element define a cavity therebetween for receipt of a damping fluid. The cavity has a length along the axial direction that is curved away from the axis of rotation. As another example, a turbomachine comprising a shaft rotatable about an axis of rotation includes a damping device positioned annularly about the shaft. The damping device comprises a housing and a damper element defining a cavity therebetween for receipt of a damping fluid that has a curved shape. The cavity is curved in a plane extending along the radial and axial directions and including the axis of rotation.

Abstract: An imaging system and method acquires non-contrast images of a region of interest in a body and determines an entrance criterion based on the non-contrast images. The entrance criterion dictates conditions in which to begin acquiring contrast imaging exposures of the region of interest. An amount of a contrast agent is measured in one or more locations in the imaged body subsequent to acquiring the non-contrast images. The system and method determine that the one or more conditions of the entrance criterion are met based on the amount of the contrast agent that is measured in the imaged body, and acquire one or more contrast images of the region of interest in the imaged body responsive to determining that the one or more conditions of the entrance criterion are met.

Abstract: A clearance control assembly for a gas turbine engine that defines an axial direction and a radial direction and includes a stage of rotor blades and a shroud hanger. The assembly includes a case configured to be positioned outward along the radial direction from the stage of rotor blades when installed in the gas turbine engine. The case is further configured to be engaged with the shroud hanger at a first location when installed in the gas turbine engine. The assembly also includes a baffle positioned outward along the radial direction from the case to define a chamber therebetween. The baffle has a forward end and an aft end. The forward end of the baffle is engaged with the case to form a first seal and the aft end of the baffle is engaged with the case to form a second seal. The baffle, the case, or both define an inlet to allow a fluid to enter the chamber and the case defines an outlet to allow the fluid to exit the chamber.

Abstract: An airfoil is provided defining a spanwise direction, a chordwise direction, a root end, a tip end, a leading edge end, and a trailing edge end. The airfoil includes: a leading edge extending from the leading edge end; a body extending along the spanwise direction between the root end and the tip end, the body including a plurality of cavity walls defining a plurality of cavities, each of the plurality of cavities having an inlet located at the leading edge; and a porous face sheet positioned on at least one inlet of the plurality of cavities.

Abstract: A combustor for a gas turbine engine has a combustor liner that has a cold surface side and a hot surface side, the liner defining an upstream end and a downstream end, and a dilution opening through the combustor liner. The dilution opening includes a main dilution hole portion having an upstream edge and a downstream edge, a notched portion disposed at the upstream edge and extending upstream from the upstream edge, the notched portion being in fluid communication with the main dilution hole portion, and a slotted portion disposed at the downstream edge and extending downstream of the downstream edge, the slotted portion being in fluid communication with the main dilution hole portion.

Abstract: A propulsion system is provided including: a gas turbine engine including a combustion section having a combustor; and a modular fuel cell assembly. The modular fuel cell assembly includes: a first fuel cell string comprising a first processing unit and a first fuel cell stack, the first fuel cell stack comprising a first fuel cell defining an outlet configured to provide output products from the first fuel cell to the combustor; and a second fuel cell string comprising a second processing unit and a second fuel cell stack, the second fuel cell stack comprising a second fuel cell defining an outlet configured to provide output products from the second fuel cell to the combustor.

Abstract: A control system for an engine operatively coupled with a propeller and methods for controlling an engine operatively coupled with a propeller are provided. In one example aspect, the control system includes a controller and an electric propeller governor. The electric propeller governor includes a motor operatively coupled with a flyweight governor spring. The motor is communicatively coupled with the controller. The controller is operable to receive data indicative of the speed of the propeller, determine if the measured speed exceeds a propeller speed threshold, and if the threshold is exceeded, the controller is configured to change a propeller speed set point. Particularly, the controller can cause the motor to change the preload on the flyweight governor spring, which in turn causes adjustment of the propeller speed set point. In this way, propeller speed overshoot is prevented during fast acceleration of the engine.

Abstract: A heat exchanger is provided. The heat exchanger includes a first wall manifold. The heat exchanger further includes a second wall manifold spaced apart from the first wall manifold. The heat exchanger further includes a plurality of vanes that extend generally circumferentially between the first wall manifold and the second wall manifold. The heat exchanger further includes a plurality of fluid circuits defined within the heat exchanger. Each fluid circuit in the plurality of fluid circuits includes an inlet channel portion and an outlet channel portion defined within the first wall manifold. A return channel portion defined within the second wall manifold. At least one passage portion of a plurality of passage portions defined within each vane of the plurality of vanes. The at least one passage portion extends between the return channel portion and one of the inlet channel portion and the outlet channel portion.

Abstract: A method for providing overspeed protection for a gas turbine engine having an engine shaft includes monitoring, via an overspeed protection system, a torque of the engine shaft. The method also includes determining, via the overspeed protection system, at least one additional condition of the engine shaft. Further, the method includes determining, via the overspeed protection system, an overspeed condition of the gas turbine engine when the torque of the engine shaft drops below a torque threshold and the at least one additional condition of the engine shaft is indicative of the gas turbine engine being in an operational state. Thus, the overspeed condition is indicative of an above normal rotational speed of the engine shaft. In addition, the method includes initiating a shutdown procedure for the gas turbine engine in response to the determined overspeed condition to reduce the rotational speed of the engine shaft.

Abstract: A method of additively manufacturing three-dimensional objects, and/or a method of controlling one or more irradiation parameters of the energy beam system, may include determining an irradiation setting using an irradiation control model and outputting an irradiation control command to an energy beam system based at least in part on the irradiation setting. The irradiation control model may be configured to determine the irradiation setting based at least in part on a power density factor and/or an irradiation vector factor. The irradiation control command may be configured to change one or more irradiation parameters for additively manufacturing a three-dimensional object. An additive manufacturing system may include an energy beam system and a control system that includes an irradiation controller. The irradiation controller may include a control module configured to perform such a method.

Abstract: An approach for facilitating mechanical and electrical connection of electric machines and electrical components in an electrical system using connectors with quick connect/disconnect electrical connectors is disclosed. Each quick connect/disconnect electrical connector can be placed on the end of an electrical power distribution cable that connects with an electric machine or electrical component. The electric machines and electrical components and the electrical power distribution cables can have hollow coolant passages formed therein to receive cooling fluid from a cooling device for direct cooling of the electric machines, electrical components and the electrical power distribution cables.

Abstract: An additive manufacturing machine may include a beam source, a process chamber, a beam column operably coupled to the process chamber and/or defining a portion of the process chamber, and a gaseous ionization detector disposed about the beam column. The gaseous ionization detector may be configured to detect elementary particles corresponding to an ionizing gas ionized by an energy beam from the beam source. A method of additively manufacturing a three-dimensional object may include determining data from a gaseous ionization detector disposed about a beam column of an additive manufacturing machine, and additively manufacturing a three-dimensional object using the additive manufacturing machine based at least in part on the data from the gaseous ionization detector.

Abstract: Systems and methods for compacting components are provided. In one exemplary aspect, a component is positioned between a first tool portion and a second tool portion of a compaction tool. A sandwich structure is positioned between the first tool portion and the component. The sandwich structure includes a thermally expandable material and a rigid shell. The thermally expandable material is positioned between the first tool portion and the rigid shell. During compaction, the thermally expandable material is subjected to elevated temperatures and pressures, e.g., within an autoclave. When subjected to elevated temperatures and pressures, the thermally expandable material applies a force on the rigid shell, which in turn applies a force on the component so as to compact the component between the rigid shell and the second tool portion.

Abstract: An air turbine starter that includes a housing. The housing can circumscribe a turbine coupled that is coupled to a gear train in a gear box via a drive shaft. The gear train can couple to an output shaft via at least a carrier. The air turbine starter can include at least a first bearing assembly and a second bearing assembly to rotatably support the drive shaft and the output shaft.

Abstract: A reclamation system for an additive manufacturing apparatus can include a collection structure configured to remove at least a portion of the resin from a foil. A containment vessel can be configured to retain the resin removed from the foil. A drain can direct the resin from the containment vessel to a reservoir.

Abstract: An additive manufacturing apparatus can include a stage configured to hold one or more cured layers of resin that form a component. A radiant energy device can be operable to generate and project radiant energy in a patterned image. An actuator can be configured to change a relative position of the stage relative to the radiant energy device. A reclamation system can be downstream of the stage and can be configured to remove at least a portion of the resin from a resin support. The reclamation system can include a first collection structure configured to accept a resin support therethrough along a resin support movement direction. A first scraper is positioned within the first collection structure. The first scraper has an elongation axis that is offset from the resin support movement direction by an offset angle that is less than 90 degrees.

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 an intermediate member disposed at least partially between the forward and aft liner segments and extending in the circumferential direction.

Abstract: A fuel supply system for a turbine engine that provides a modulated thrust control malfunction accommodation (TCMA) is disclosed. An example fuel supply system includes a fuel supply line to supply fuel to a combustion engine, a fuel metering valve coupled to the fuel supply line, the fuel metering valve to control a flow of fuel through the fuel supply line to the combustion engine, a throttle valve coupled to the fuel supply line downstream of the fuel metering valve, the throttle valve to bleed off fuel supplied to the combustion engine based on a pressure difference across the fuel metering valve, and a controllable servo coupled to the throttle valve, the controllable servo to control the throttle valve based on a sensor output indicative of the pressure difference.

Abstract: A Brayton cycle engine including a longitudinal wall extended along a lengthwise direction. The longitudinal wall defines a gas flowpath of the engine. An inner wall assembly is extended from the longitudinal wall into the gas flowpath. The inner wall assembly defines a detonation combustion region in the gas flowpath upstream of the inner wall assembly.