Abstract: A method of DC-DC power conversion includes converting a DC link voltage to a DC output voltage for a load that is lower than the DC link voltage using a buck converter. The method includes controlling the buck converter in a normal switching mode in response to the DC link voltage being below a predetermined high threshold. The method also includes controlling the buck converter in a soft start switching mode in response to the DC link voltage being at or above the predetermined high threshold.

Abstract: A heat exchanger layer having an inlet side, IN, where a medium enters the layer and an outlet side, OUT, where the medium exits the layer, and a plurality of fins defining a plurality of flow channels for the medium from the inlet side to the outlet side. Each fin has a leading edge adjacent the inlet side and a trailing edge adjacent the outlet side, and wherein the leading edge of a subset of the fins is thicker than the rest of the fin, and the leading edge of the fins intermediate the fins of the subset of fins is recessed with respect to the inlet side compared to the leading edge of the fins of the subset of fins.

Abstract: A lattice filter for use in an inlet housing of a pump assembly including a lattice filter body extending from a filter inlet end to a filter outlet end. The lattice filter having a lattice structure. The lattice filter also includes one or more passageways within the lattice filter body. Each of the one or more passageways includes a passageway inlet located at the filter inlet end and a passageway outlet located at the filter outlet end. Each of the one or more passageways extend from the passageway inlet to the passageway outlet.

Abstract: A method of manufacturing a heat exchanger core from glass ceramic matrix composite includes placing one or more reinforcing fibers around one or more mandrels into a mold cavity. A glass matrix material infiltrates the one or more reinforcing fibers to produce an infiltrated core and the one or more mandrels is removed to create one or more passages passing through the infiltrated core.

Abstract: Aircraft electric motors include a rotor having magnet segments arranged on a frame of the rotor, the rotor defining an internal cavity radially inward from the magnet segments. An output shaft is operably coupled to the rotor and a stator, having a yoke and at least one winding wrapped about stator teeth, is arranged within the internal cavity of the rotor. The stator defines a radial span as a distance from the yoke to a radial outward edge of the at least one winding. The plurality of stator teeth have at least one tooth formed from a magnetic material with the tooth having an engagement end configured to engaged with the yoke, a distal end opposite the engagement end, and a shaped end at the distal end of the tooth, with a portion of the tooth at the shaped end being closer to the yoke than the radial span.

Abstract: Methods performed by a host platform operable in a Mobile User Objective System (MUOS) network are provided herein. A method according to some examples may include monitoring for outgoing data from a client, parsing the outgoing data to determine a priority level associated with the outgoing data, and queuing the outgoing data based on the priority level. Some methods may include monitoring for Secure Network Management Protocol (SNMP) traps to determine a floor status associated with an over-the-air interface. In some methods, if an SNMP trap is received indicating that the floor status associated with the over-the air interface is available, the queued outgoing data may be forwarded to a terminal for transmission via the over-the-air interface.

Abstract: A method of detecting electrical arc damage includes receiving input indicative of electrical power as a function of time in an electrical arc. The method includes using the input to model an amount of damage caused by the electrical arc, and comparing the amount of damage to a predetermined threshold. The method includes flagging a warning in response to the amount of damage exceeding a predetermined threshold. The method can include breaking a circuit to stop the electrical arc. Flagging the warning can include signaling to an operator to inspect a unit potentially damaged by the electrical arc. The method can include inspecting the unit potentially damaged by the electrical arc.

Abstract: A system includes a variable displacement pump (VDP) in fluid communication with an inlet line and with an outlet line. The VDP includes a variable displacement mechanism configured to vary pressure to the outlet line. A bypass valve (BPV) includes a BPV inlet in fluid communication with the outlet line, and a BPV outlet in fluid communication with a bypass line that feeds into the inlet line upstream of the VDP. An actuator is operatively connected to control the BPV to vary flow from the BPV inlet to the bypass line. A controller is operatively connected to the actuator to control recirculation flow passed through the BPV based on requested flow from a downstream system supplied by the outlet line and based on a predetermined low threshold of flow through the VDP.

Abstract: A terminal assembly of an electric machine includes an electric machine housing including a terminal opening defined in the electric machine housing. A conductive terminal extends through the terminal opening, from an inside of the electric machine housing to an outside of the electric machine housing. An insulator is located at the terminal. The insulator is positioned between the terminal and a housing wall of the terminal opening. The insulator is sized and configured for installation into the terminal opening after installation of the terminal in the terminal opening.

Abstract: A system includes a first electrohydraulic servo valve (EHSV) configured to be in fluid communication with a pressure supply and with a pressure return. The first EHSV includes a first actuator extend line and a first actuator retract line. A second EHSV is configured to be in fluid communication with the pressure supply and with the pressure return. The second EHSV includes a second actuator extend line and a second actuator retract line. An actuator includes an extend chamber in fluid communication with both of the first and second extend actuator lines, and a retract chamber in fluid communication with both of the first and second retract actuator lines for extending an end effector when the first and second EHSVs pressurize the extend chamber, and for retracting the end effector when the first and second EHSVs pressurize the retract chamber.

Abstract: A system and method for monitoring the health of a Litz wire. This can be done by representing the wire as a transmission line that is terminated at each end. A pulse can be induced in the transmission line and monitored with and using time domain reflectometry (TDR) to monitor the state of strands of the Litz wire.

Abstract: A heat exchanger includes a plurality of longitudinally-extending first channels and a plurality of second channels fluidly isolated from the plurality of first channels. Each first channels includes a plurality of spiraling internal fins and a plurality of external fins. The internal fins extend from and are integrally formed with the internal walls of the first channel. The external fins connect extend from and are integrally formed with the external walls of the first channels, connecting channels together. The plurality of second channels is defined in part by external walls of the plurality of first channels and the plurality of external fins.

Abstract: Described is a directed energy system that has a compact and modular configuration and that enables movement/assembly by a two-user team. The directed energy system includes one or more high-power laser sources that house one or more high-power fiber amplifiers, a beam combiner optically coupled to the one or more high-power laser sources, a beam director coupled to the beam combiner, a command and control module configurable to control operation of the one or more high-power fiber amplifiers. The directed energy system also includes a handheld controller with an integrated monitor, the handheld controller configurable to send control signals to the handheld controller module to control operation of the handheld controller module and a power module that includes batteries and power converters that provide electrical power required to run the directed energy system.

Abstract: A powder recoater for an additive manufacturing machine can include a body, a recoater blade extending downwardly from the body, and at least two distance probes attached to the body and configured to determine a distance to a build plate to determine if a recoater blade is parallel to the build plate and/or if a build plate is level. The at least two distance probes can be touch probes configured to determine if a build plate is contacting one or more of the probes. Any other suitable probe type is contemplated herein.

Abstract: Life support systems include a pressure garment, a helmet, and a life support system enclosure that define an enclosed environment. The life support system includes one or more life support components to generate breathable gas within the enclosed environment. The gas is directed along a closed-loop flow path through the system. The life support components includes a fan for driving a flow of the gas through the closed-loop flow path and an acoustic damper arranged along the flow path and to reduce noise generated by the fan. The acoustic damper includes a housing defining an annular cavity arranged about a portion of the flow path, with the housing having a solid exterior surface and an inner diameter surface with openings to fluidly connect the flow path with the annular cavity and at least one acoustic damping element arranged within the annular cavity.

Abstract: A multi-three-phase motor drive system includes a power distribution network, a motor drive unit, and a motor network. The power distribution network includes a partitioned direct current (DC) link connected between a positive voltage rail and a negative voltage rail. A connection between the positive voltage rail and a mid-point node defines an upper portion of the partitioned DC link and a connection between negative voltage rail and the mid-point node defines a lower portion of the partitioned DC link. The motor drive unit includes a plurality of inverter units, and the motor network includes a plurality of motor windings which are each connected to a respective inverter unit. A first group of the inverter units is connected in parallel with the upper portion of the portioned DC link, and a second group of the inverter units is connected in parallel with the lower portion of the partitioned DC link.

Abstract: A system includes an actuation pump sub-system (APS) with an inlet configured to feed fuel from a fuel source into the APS, a first outlet configured for connecting the APS in fluid communication with an actuation system to supply fuel flow for actuation, a second outlet feeding into a supply line, and a third outlet feeding into the supply line. A fuel oil cooler (FOC) is included in a first branch of the supply line. The FOC is in fluid communication to receive flow from the second outlet. The APS includes a bypass valve (BPV) in a second branch of the supply line, in parallel with the FOC and in fluid communication to allow flow from the third outlet into the supply line bypassing the FOC. A main pump and control sub-system has a main inlet connected in fluid communication with the supply line downstream of the BPV and FOC.

Abstract: In accordance with at least one aspect of this disclosure, a system includes a first wire configured to electrically connect a valve stop to a voltage source, a second wire configured to connect a valve pin to a negative terminal of the voltage source, such that the valve stop, and a valve flap operatively connected to the valve pin are configured to create a closed valve circuit when the valve flap is in a fully open position with the valve flap contacting the valve stop, and an open valve circuit when the valve flap is not in the fully open position. A meter is operatively connected to measure an electrical characteristic of the valve circuit to determine when the valve flap is in the fully open position based on an open/closed status of the valve circuit.