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 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: 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 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 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 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: 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: A magnetic-core assembling tool may include first and second compression plate alignment guides configured to be respectively fitted to first and second compression plates of a magnetic-core assembly, a plurality of semiannular tension bars, and a clamping plate. The semiannular tension bars may be attached at a first end to the first compression plate alignment guide and at a second end to the clamping plate. The clamping plate may include a plurality of compression shoes configured to apply a variable amount of compression to the magnetic-core assembly. A method of assembling a magnetic-core assembly includes assembling a plurality of lamination stacks, staging the plurality of lamination stacks to provide a magnetic-core assembly, assembling a magnetic-core assembling-tool around the magnetic-core assembly, and injecting magnet retention adhesive into a plurality of magnet retention slots in the magnetic-core assembly housed in the magnetic-core assembling tool.

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: 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: An airfoil assembly for a turbine engine comprising an outer band, an inner band radially spaced inwardly from the outer band to define an annular region, and multiple airfoils circumferentially spaced within the annular region. Each corresponding airfoil of the multiple airfoils can project from a surface at a root and can further include an outer wall defining a pressure side and a suction side. A projection can extend upwardly from the surface on the pressure side and a valley can extend into the surface on the suction side to define a contour in the surface.

Abstract: A component and a system for mitigating coke formation during delivery of a hydrocarbon fluid. The component includes a contact surface configured to be in contact with the hydrocarbon fluid. Tuning the zeta potential of the contact surface allows selective attraction and/or repulsion of coke-catalyzing materials, metal ions, heteroatomic hydrocarbons, and/or coke precursors present in the hydrocarbon fluid. A method of mitigating coke formation during delivery of a hydrocarbon fluid includes tuning a zeta potential of the contact surface of the component and injecting or circulating the hydrocarbon fluid through the system such that the contact surface selectively attracts and/or repels coke-catalyzing materials, metal ions, heteroatomic hydrocarbons, and/or coke precursors present in the hydrocarbon fluid.

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: 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 electric machine is provided herein that includes a stator assembly. The stator assembly includes a stator core having one or more lamination packages. The stator core can define an outer ring and a plurality of teeth extending from the outer ring. A cooling plate may be positioned adjacent to at least one of the one or more lamination packages. The cooling plate can define one or more channels therethrough. One or more windings can be arranged around one or more of the plurality of teeth of the stator core. A rotor can be operably coupled with the stator assembly. A cooling system can be fluidly coupled with the one or more channels of the cooling plate. The cooling system provides a cryogenic fluid through the one or more channels to cool the electric machine.

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 rotor blade system. The rotor blade system includes a rotor and a plurality of blades coupled to the rotor. The plurality of blades are arranged in an airfoil distribution pattern. The airfoil distribution pattern includes one or more baseline blades and one or more intentionally mistuned blades including an intentional mistuning feature.

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.