Abstract: A passive flow splitting system for use in a turbine engine control system to provide split fuel flow to two fuel manifolds to supply primary and secondary fuel injectors for the particular combustion zones thereof utilizing intentionally different split ratios dependent on ascending or descending combustion fuel flow is provided. The system includes a passive fuel divider valve (FDV) that includes a primary piston and a secondary piston. The primary piston is moveable independently from the secondary piston during a portion of its stroke, and is hydro-locked to the secondary piston during another portion of its stroke. An ecology valve is also provided to purge the fuel from the primary and/or secondary manifolds during different modes of operation. A transfer valve is included to control the position of ecology piston of the ecology valve.

Abstract: The subject matter of this specification can be embodied in, among other things, a turbofan engine assembly includes a engine, a nacelle defining a generally forward-to-aft bypass air flow path, a thrust reverser comprising a first movable element, movable to and from a reversing position where at least a portion of the bypass air flow is reversed, a hydraulic actuator coupled to the first movable element to move the first movable element into and out of the reversing position, and a second moveable element, configured to move in synchronicity with the first moveable element, a first hydraulic valve operable to control a flow of hydraulic fluid for actuation of the hydraulic actuator, a second hydraulic valve operably coupled to the second moveable element and moveable between a restricted condition wherein the flow of hydraulic fluid is restricted, and a permit condition wherein the flow of hydraulic fluid is permitted.

Abstract: The subject matter of this specification can be embodied in, among other things, a system includes a turbofan engine, a nacelle surrounding the engine and defining an annular bypass duct through the engine to define a generally forward-to-aft bypass air flow path, a thrust reverser movable to and from a reversing position where at least a portion of the bypass air flow path is reversed and comprising a first reverser portion having a first latch element, and a second reverser portion having a second latch element that is reversibly engageable with the first latch element to reversibly secure the second reverser portion to the first reverser portion, and an actuator comprising a catch element coupled to a portion of at least one of the first latch element and the second latch element to move the first reverser portion and the second reverser portion into and out of the reversing position.

Abstract: The subject matter of this specification can be embodied in, among other things, an engine system that includes an intake manifold configured to receive and convey air to a combustion chamber, an intake valve upstream of the intake manifold and configured to regulate an air flow into the intake manifold, an exhaust manifold configured to receive combustion products from the combustion chamber, a recirculation flow passage configured to convey exhaust gasses from the exhaust manifold to the intake manifold, a recirculation flow control valve configured to regulate gas flow through the recirculation flow passage, and a controller configured to determine that the engine system is in a motoring condition, open, during the motoring condition and based the determining, the recirculation flow control valve, and close, during the motoring condition and based the determining, the intake valve.

Abstract: A first pressure upstream of a throttle is received. A temperature upstream of the throttle is received. A throttle position is received. A second pressure at a convergent end of a convergent nozzle positioned downstream of the throttle is received. An air flow is estimated based on the received first pressure, the received temperature, the received throttle position, and the received second pressure, wherein estimating the air flow includes determining one or more models to use for calculating air flow based on the throttle position, the models including a throttle flow model, a convergent nozzle flow model, or both.

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

Abstract: The subject matter of this specification can be embodied in, among other things, a method of sensing that includes activating a first emitter to emit at least one incident wave, transmitting the incident wave along a buffer rod having a first axial end abutted to the first emitter and a second axial end opposite the first axial end, reflecting a first echo of the incident wave by a gap defined along a portion of the buffer rod, detecting the first echo, determining a first amplitude of the first echo, reflecting a second echo of the incident wave by the second axial end, detecting the second echo, determining a second amplitude of the second echo, and determining a reflection coefficient based on the first amplitude and the second amplitude.

Abstract: The method includes the following features. A first pressure upstream of a throttle is received. A temperature upstream of the throttle is received. A second pressure within an intake manifold is received. An engine speed is received. An air flow is estimated based on the received first pressure, the received temperature, the received second pressure, and the received engine speed. Estimating the air flow includes determining one or more models to use for calculating air flow based on the received first pressure and the received second pressure. The models include a throttle flow model, a port flow model, or both.

Abstract: The subject matter of this specification can be embodied in, among other things, an assembly that includes a piston having a piston inner surface defining a cylindrical cavity and includes a first axial portion, a piston face at a first end of the first axial portion, a second axial portion at a second end of the first axial portion, and a helical piston thread defined upon the piston inner surface, a bushing configured to contact the piston inner surface, and a lock nut configured to engage the piston and the bushing.

Abstract: A tip for a nozzle of a fuel injector and an associated method are provided. The tip includes a tip body and a swirler. The swirler includes a plurality of pre-swirl passages which fluidly communicate an internal cavity of the swirler with a feed annulus. The swirler also includes a plurality of swirl chamber passages which fluidly communicate a swirl chamber with the feed annulus. Methods include manufacturing at least a portion of the swirler by additive manufacturing.

Abstract: Methods and systems for synchronization of multiple processing cores of an electronic control system are disclosed. The electronic control system is configured to monitor and control operation of a multicore architecture employing one or more processing cores to generate a time reference signal and/or to synchronize with the time reference signal. In some examples, the system employs a single master processor to generate the reference synchronization signal (e.g., a master sync signal). In examples, a rising edge of the partition time reference signal is used as the marker of reference time zero (e.g., the start of a new partition frame). If a core is out of sync with the master sync signal, that core adjusts one or more timing characteristics to align the associated signal with the reference signal.

Abstract: Methods and systems for an epicyclic gear mechanism that includes a primary differential assembly to selectively drive the fore secondary differential assembly and the aft secondary differential assembly. The fore secondary differential assembly selectively drives one or more fore interfaces (e.g., output gears), whereas the aft secondary differential assembly selectively drives one or more aft interfaces (e.g., output gears). Each of the primary differential assembly, the fore and aft secondary differential assemblies, and the interfaces rotate about a common central axis. The primary differential assembly drives the fore secondary differential assembly via a first sun gear, and drives the aft secondary differential assembly via a second sun gear, both of which rotate about the common central axis. Further, one or more actuators are to activate or deactivate in order to drive or be driven by a selected interface.

Abstract: A method of controlling combustion in an internal combustion engine includes measuring parameters of combustion in a cylinder of the engine during a combustion phase of the cylinder, after igniting an air/fuel charge in the cylinder, and calculating the heat release of combustion in the cylinder based on the measured parameters. An auto-ignition event of the air/fuel charge is identified based on the calculated heat release, and, based at least in part on the identified auto-ignition event, at least one of ignition timing in the cylinder for the next combustion phase of the cylinder or an amount of exhaust gas supplied to the cylinder for the next combustion phase of the cylinder is controlled to cause an auto-ignition event of the air/fuel charge in the next combustion phase to shift toward a specified crank angle.

Abstract: The subject matter of this specification can be embodied in, among other things, a fluid flow measurement apparatus includes an inlet configured to flow a dynamic fluid flow, an outlet configured to flow the dynamic fluid flow, a first fluid conduit fluidically connected between the inlet and the outlet, configured with a first predetermined geometry, and configured to flow a first portion of the dynamic fluid flow, a second fluid conduit fluidically connected between the inlet and the outlet, configured with a second predetermined geometry, and configured to flow a second portion of the dynamic fluid flow, and a first flow meter configured to measure the second portion of the dynamic fluid flow.

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: Embodiments of a gaseous or dual fuel electronic pressure regulation system (EPRS) for a multipoint fuel injection engine are described herein. Additionally, embodiments of a method for controlling the EPRS are provided. In particular, the EPRS employs an electronic pressure regulator (EPR) capable of accurately determining and controlling the mass flow of gaseous fuel into a fuel rail so as to avoid pressure droop and over- and under-pressurization of the gas admission valves (GAVs). By using the EPRS described above, mass flow is able to be distributed to the downstream manifold or engine cylinders very accurately, and the GAVs are able to be driven simultaneously in a pressure/pulse duration that is optimal for accurate and repeatable operation.

Abstract: The subject matter of this specification can be embodied in, among other things, a controller apparatus that includes a digital controller configured to provide a digital position signal based on a setpoint and a differential analog feedback signal, and a converter circuit configured to provide a differential analog electrohydraulic servo valve position control signal based on the digital position signal, and provide the differential analog feedback signal based on the differential analog electrohydraulic servo valve position control signal.

Abstract: A stepper motor driven actuator system is provided. The system includes a stepper motor, a cam, and a gearbox system. The gearbox system operatively connects the stepper motor to the cam. The cam rotates in response to stepping of the stepper motor. The system also includes a valve having a control piston located therein. The control piston is configured to translate in response to rotation of the cam. The system further includes a rotary actuator. The rotary actuator is fluidly connected to the valve, and the rotary actuator is configured to rotate the cam in response to translation of the control piston.