Abstract: The subject matter of this specification can be embodied in, among other things, a hydrogen fuel cell anode control system including a hydrogen inlet configured to receive pressurized hydrogen, a hydrogen outlet configured to be fluidically coupled to an anode manifold of a hydrogen fuel cell, a recirculation inlet configured to receive overflow hydrogen from the anode manifold, a hydrogen pressure regulator configured to receive pressurized hydrogen from the hydrogen inlet, a hydrogen recirculation module configured to mix hydrogen received from the hydrogen pressure regulator and the recirculation inlet, and provide a hydrogen mixture to the hydrogen outlet, a differential pressure measurement module configured to measure a differential pressure between the anode manifold and a cathode manifold of the hydrogen fuel cell, and a controller configured to control at least one of the hydrogen pressure regulator or the hydrogen recirculation module based on the measured differential pressure.

Abstract: The subject matter of this specification can be embodied in, among other things, a fuel delivery component, including a substantially rigid, unitary structure formed as a single piece of material, and at least a first seamless lumen defined by the unitary structure.

Abstract: A fuel nozzle metering valve that includes a spool having an inlet port and an outlet flow port, and a retainer assembled to one end of the spool. A valve liner houses a portion of the spool. The spool is configured to move back and forth within the valve liner. The metering valve is biased in a closed position in which the outlet flow port is disposed entirely within the valve liner. The valve is opened when the spool slides within the valve liner such that some portion of the outlet flow port extends beyond an end of the valve liner. The retainer has a stepped portion configured to abut an end of the retainer at a fuel flow pressure below the expected maximum fuel flow pressure to be used in the fuel nozzle metering valve.

Abstract: The subject matter of this specification can be embodied in, among other things, a thrust reverser tertiary lock apparatus that includes a probe affixed to an aircraft engine frame and having a shaft having a barb at a first end and configurable to a first configuration and a second configuration, and a receiver affixed to a thrust reverser transcowl slider configured to accommodate the barb and having an end wall with an aperture defined therein, the aperture shaped to permit escapement of the barb in the first configuration and prevent escapement of the barb in the second configuration.

Abstract: Embodiments of the disclosure include a redundant control system for a vehicle. The redundant control system includes first and second actuator pistons mechanically coupled to one another and disposed in respective first and second fluid chambers. The first and second actuator pistons are movable by first and second primary stages. One of the primary stages includes a bypass valve with a pilot valve actuatable in response to movement of the first actuator piston.

Abstract: A multiphase fuel injector has an injector body with a fuel inlet at a first end and a fuel outlet at a second end opposite the first end. A primary circuit disposed proximate the fuel inlet extends into a central portion of the injector body. The primary circuit is configured to receive a first flow of pressurized fuel from the fuel inlet that discharges into a spin chamber in the injector body downstream from the fuel inlet. The primary circuit is configured to impart a swirling action to the first flow of pressurized fuel. A secondary circuit is located in the injector body radially outward from the primary circuit. The secondary circuit is configured to receive a second flow of pressurized fuel from the fuel inlet that discharges into the fuel outlet. The secondary circuit is configured to impart a swirling action to the second flow of pressurized fuel.

Abstract: The subject matter of this specification can be embodied in, among other things, a linear-to-rotary apparatus that includes a linear actuator having an actuator housing including a piston chamber, a piston shaft disposed in the piston chamber, and a rotor apparatus. The rotor apparatus includes a rotary joint defining a rotational axis, a rotor arm extending radially from the rotary joint and configured to at least partially pivot about the rotary joint, and a torque linkage pivotably connected to the rotor arm. The torque linkage is also attached to an end of the piston shaft of the piston at a pivot connection joint, where the pivot connection joint defines a pivot axis that is substantially perpendicular to the translation axis of the piston shaft.

Abstract: Embodiments of a flow system are provided. The flow system includes a flow source device configured to receive fluid from a first flow line and output fluid on a second flow line. An output is in fluid communication with the flow source device on the second flow line. An actuation system is in fluid communication with the second flow line through a third flow line. A flow meter measures a flow rate in the second flow line without bypassing any fluid to the first flow line. A controller is in communication with the flow source device and the flow meter. The controller adjusts the flow source device to achieve a desired flow rate at the output based on a condition of the flow source device and the flow rate measured by the flow meter.

Abstract: An airplane rudder and brake pedal assembly includes a rudder arm assembly having one rudder arm with first upper and lower arm portions, and another rudder arm with second upper and lower arm portions. The rudder arm assembly is assembled to a beam at an intersection of the first upper and lower arm portions, and an intersection of the second upper and lower arm portions. The first and second rudder arms are configured to rotate about the beam at the intersection. The rotation of the first and second rudder arms is configured to adjust control surfaces that control a yaw axis of the airplane. A brake pedal is attached to the first and second lower arm portions. Rotation of the brake pedal brakes the airplane. A rotary sensor is assembled to the brake pedal and the lower arm portion, and configured to determine an extent of the brake pedal rotation.

Abstract: The subject matter of this specification can be embodied in, among other things, a control apparatus includes a first mounting member, a pivot member defining an axis, an elongate member configured to pivot about the axis and having a first elongate portion configured as a first lever arm extending away from the pivot member in a first direction, a second elongate portion extending away from the pivot member in a second direction opposite the first direction, a retainer bracket affixed to the second elongate portion, a gimbal moveably affixed to the first mounting member between the pivot member and the retainer bracket, a force bracket moveably affixed to the second elongate portion by the retainer bracket, and a bias member configured to urge movement of the force bracket in the second direction.

Abstract: A cold gas thruster having a two-stage solenoid is provided. Pressurized gas from the inlet flows to the back side of the piston to hold the piston closed. The pressure is maintained by a check ball held by the solenoid armature. When the solenoid is energized, the armature allows the check ball to move to bleed off the pressure holding the piston closed. The piston moves away from its seat and allows the pressurized gas to flow to the outlet creating thrust. When the solenoid coil is de-energized, the check ball is forced against its seat, which blocks the escape of pressure on the back side of the piston, so that it can re-pressurize back up to the inlet pressure. This creates a force imbalance and moves the piston to close the valve and stop the thrust. Different nozzles can be used for different thrust profiles without changing the solenoid.

Abstract: An enhanced safety coil that prevents crack formation and propagation to the coil windings from external sources and prevents exposure to fuel is provided. The enhanced safety coil may be used in a solenoid operated gas admission valve (SOGAV), and includes a plastic encapsulation body having at least one body de-stress feature, a coil wound on the plastic encapsulation body, a sleeve forming an outermost side protective wall configured to accommodate the plastic encapsulation body and coil therewithin, and potting provided between the plastic encapsulation body and the sleeve to seal the coil therein. The body de-stress feature is configured to reduce at least one of a formation or a propagation of a crack through the potting to the coil. The plastic encapsulation body forms retention latches configured to mate with a stator.

Abstract: The subject matter of this specification can be embodied in, among other things, a fluid flow conditioning apparatus that includes a linear fluid conduit having a first tubular body defining a major axis and extending from a conduit inlet to a conduit outlet arranged opposite the conduit inlet, and configured with a predetermined flow geometry to define a linear fluid flow path along the major axis, a fluid inlet non-parallel to the linear fluid flow path, a first fluid flow conditioner configured to receive fluid flow, condition fluid flow, and redirect conditioned fluid flow along the linear fluid flow path along the major axis, a second fluid flow conditioner configured to receive fluid flow from the linear fluid flow path along the major axis, redirect fluid flow away from the linear fluid flow path, and condition fluid flow.

Abstract: The subject matter of this specification can be embodied in, among other things, a fluid actuator system including a fluid actuator having a housing having an inner wall defining an interior cavity, a piston having a piston head configured for reciprocal movement within the interior cavity, the piston head contacting the inner wall and dividing the interior cavity into a first fluid chamber and a second fluid chamber, a first valve configured to control fluid flow between the first fluid chamber and a bypass conduit, and a second valve configured to control fluid flow between the bypass conduit and the second fluid chamber.

Abstract: A redundant fuel metering system and method for a multi-stage combustor that utilizes a fuel metering valve EHSV from a less critical combustor stage fuel metering system as a redundant backup to the main metering valve EHSV. In the event of a failure of the main FMV EHSV, a control module signals a transfer system to switch control of the main FMV to the less critical combustor stage fuel metering system EHSV, thus maintaining control of the FMV for the main combustor. In doing this, the transfer valve then drives the less critical combustor stage fuel metering system FMV to its failsafe position while maintaining control of the main system.

Abstract: The subject matter of this specification can be embodied in, among other things, a fuel injector for a gas turbine engine includes a fuel injector housing, and an elongated fuel tube held in position in said housing by spaced apart joints and including an undulating tube surface along at least a portion of its length between said joints, said undulating tube surface being in contact with another surface disposed in said housing at one or more locations of said undulating tube surface.

Abstract: The subject matter of this specification can be embodied in, among other things, an actuator that includes a piston configured to actuate relative to a housing, a sensor rod configured to be actuated by the piston, a sensor affixed to the housing and configured to detect a piston position of the piston relative to the housing based on a sensor rod position of the sensor rod relative to the sensor, and a linkage configured to couple the sensor rod to the piston, and to offset a change to the sensor rod position due to a temperature-induced dimensional change to at least one of the housing, piston, the sensor rod, and the sensor.

Abstract: The subject matter of this specification can be embodied in, among other things, a sensor that includes a first axial sensor housing portion having a first cross-sectional area, a second axial sensor housing portion arranged adjacent to the first axial sensor housing portion along the sensor axis and having a second cross-sectional area larger than the first cross-sectional area, and a face extending from the interior surface of the first axial sensor housing portion to the interior surface of the second axial sensor housing portion, a first buffer rod within the first axial sensor housing portion and having a first axial end and a second axial end, a second buffer rod within the second axial sensor housing portion and abutting the face, and having a third axial end and a fourth axial end, and an acoustic transceiver element acoustically mated to the second axial end and the third axial end.

Abstract: Embodiments of a metering valve for a fuel nozzle are disclosed. The metering valve includes a fitting having an interior cavity and an inlet, a liner disposed within the interior cavity, and a spool having an orifice. The liner includes inlet ports, and the spool is disposed within the liner. The spool is configured to slide within the liner to control flow between the inlet and the orifice. The spool has an open position in which the spool uncovers the inlet ports, a closed position in which the spool is seated against the fitting, and a lifted off position in which the spool is not seated against the fitting and covers the inlet ports. A dribble flow path through at least one of the spool or the liner provides fluid communication between the inlet and the orifice when the spool is in the lifted off position.

Abstract: Embodiments of the disclosure relate to a system designed to compensate for flow disturbances when changing a flow rate in the system. The system includes a flow source device having an inlet and an outlet. The inlet is configured to receive fluid at a first pressure, and the outlet is configured to output the fluid at a second pressure that is higher than the first pressure. The system also includes a fluid control device having an inlet port and a drain port. The inlet port of the fluid control device is configured to receive flow from the outlet of the flow source device. Further, the system includes a constant flow regulator configured to provide a leakage flow to a drain output. The constant flow regulator is configured to decrease the leakage flow in response to the drain port of the fluid control device.