Abstract: A method and system for frequency matching a resonant cavity is disclosed. Light is received in a resonant cavity having at least a first mirror and a second mirror defining a path along which light is reflected. At least the second mirror is actuatable to vary the length of the path of the resonant cavity. An intensity of the light exiting or reflecting from the resonant cavity is monitored, and an error correction is determined. The second mirror is actuated towards a pose relative to the first mirror at which a frequency of the light is in resonance with the length of the path. In this manner, the resonant cavity is frequency matched to the light to maintain the resonant cavity in resonance.

Abstract: An inertial particle separator (IPS) has: a main duct having an inlet fluidly connected to an environment outside of the aircraft engine, the main duct having a first segment and a second segment, the first segment extending longitudinally away from the inlet and vertically toward an elbow, the second segment extending vertically and longitudinally away from the elbow, the main duct having a concave side and a convex side; two inlet ducts extending from the concave side of the main duct, the two inlet ducts extending laterally away from one another and vertically away from the elbow; and a bypass duct communicating with the main duct, an intersection between the bypass duct and the main duct defining a splitter, the bypass duct extending along the longitudinal direction and laterally between the two inlet ducts, the two inlet ducts and the bypass duct extending vertically away from one another.

Abstract: A resonant cavity and a method for manufacturing the same are provided. The resonant cavity includes a first reflective surface and a second reflective surface, each of the first and second reflective surfaces providing a phase shift of a reflected electric field component of light waves oscillating along a first principal axis that differs by about ? relative to a phase shift of a reflected electric field component of light waves oscillating along a second principal axis that is normal to the first principal axis. At least one of the first and second reflective surfaces having diattenuation. The first principal axis of the first reflective surface is set rotated relative to the first principal axis of the second reflective surface by about an angle ?0 between an unbroken parity-time symmetric region and a broken parity-time symmetric region. As a result, spatial hole burning and dual mode operation can be eliminated.

Abstract: An inertial particle separator (IPS) has: a main duct having an inlet fluidly connected to an environment outside of the aircraft engine, the main duct having a first segment and a second segment, the first segment extending longitudinally away from the inlet and vertically toward an elbow, the second segment extending vertically and longitudinally away from the elbow, the main duct having a concave side and a convex side; two inlet ducts extending from the concave side of the main duct, the two inlet ducts extending laterally away from one another and vertically away from the elbow; and a bypass duct communicating with the main duct, an intersection between the bypass duct and the main duct defining a splitter, the bypass duct extending along the longitudinal direction and laterally between the two inlet ducts, the two inlet ducts and the bypass duct extending vertically away from one another.

Abstract: A method and system for frequency matching a resonant cavity is disclosed. Light is received in a resonant cavity having at least a first mirror and a second mirror defining a path along which light is reflected. At least the second mirror is actuatable to vary the length of the path of the resonant cavity. An intensity of the light exiting or reflecting from the resonant cavity is monitored, and an error correction is determined. The second mirror is actuated towards a pose relative to the first mirror at which a frequency of the light is in resonance with the length of the path. In this manner, the resonant cavity is frequency matched to the light to maintain the resonant cavity in resonance.

Abstract: A system for producing single-frequency or near-single-frequency operation of a laser beam includes a laser for emitting a laser beam at each one of a plurality of cavity lengths, A detector is configured to receive at least a portion of the laser beam emitted, and generate a signal. A computer system is configured to identify at least one beat note in the signal for each of at least one of the plurality of cavity lengths, the at least one beat note indicating the presence of one or more higher-order transverse modes, longitudinal modes, or both, in the received at least the portion of the laser beam emitted at the at least one of the plurality of cavity lengths. The cavity is adjusted to one of the plurality of cavity lengths for eliminating or minimizing the at least one beat note.

Abstract: There is disclosed an inertial particle separator communicating with an engine inlet. The inertial particle separator has: a main duct body; a bypass duct; and a splitter defined by an intersection of the main duct and the bypass duct. The main duct and the bypass duct having particular geometric characteristics. A method of separating particles via inertia in an aircraft engine inlet is also provided.

Abstract: A system for producing single-frequency or near-single-frequency operation of a laser beam includes a laser for emitting a laser beam at each one of a plurality of cavity lengths, A detector is configured to receive at least a portion of the laser beam emitted, and generate a signal. A computer system is configured to identify at least one beat note in the signal for each of at least one of the plurality of cavity lengths, the at least one beat note indicating the presence of one or more higher-order transverse modes, longitudinal modes, or both, in the received at least the portion of the laser beam emitted at the at least one of the plurality of cavity lengths. The cavity is adjusted to one of the plurality of cavity lengths for eliminating or minimizing the at least one beat note.

Abstract: A turbine wheel for a hydrokinetic torque converter. The turbine wheel is rotatable about a rotational axis and comprises a substantially annular turbine shell member coaxial with the rotational axis, and a plurality of turbine blade members axially extending from the turbine shell member. The turbine wheel is a single-piece component such that the turbine blade members are unitarily formed with the turbine shell member. The turbine wheel (22) is made by an additive manufacturing process from a polymeric material.

Abstract: At least a selected one of a first and second engine are connected to a drive train for driving an aircraft accessory. A gearbox is connected to a primer mover propulsor and an actuator operatively associated with the selected engine is moveable between a position in which the selected engine drivingly engages the gearbox for driving the propulsor and a position in which the selected engine disengages from the gearbox. A position signal, a status signal, and a request signal respectively indicative of a present position of the actuator, a governing state and present speed of each engine, and a request for movement of the actuator from the present position to the other position are received. If the selected engine's speed differs from a predetermined threshold, a control signal is output for causing the engine's speed to be adjusted towards the threshold. A control signal indicating that movement of the actuator is permitted is then output.

Abstract: A turbine wheel for a hydrokinetic torque converter. The turbine wheel is rotatable about a rotational axis and comprises a substantially annular turbine shell member coaxial with the rotational axis, and a plurality of turbine blade members axially extending from the turbine shell member. The turbine wheel is a single-piece component such that the turbine blade members are unitarily formed with the turbine shell member. The turbine wheel (22) is made by an additive manufacturing process from a polymeric material.

Abstract: An inertial particle separator for an aircraft engine inlet, including inlet, intermediate and bypass ducts. The intermediate duct extends generally transversally from the inlet duct to the engine inlet, and communicates with the inlet duct adjacent its downstream end. The bypass duct extends downstream from the inlet duct and intermediate duct, and defines an outlet communicating with the environment of the engine. A wall of the intermediate duct intersects a wall of the inlet duct on an engine side of the wall of the inlet duct. The engine side of the wall of the inlet duct defines an engine-side inlet air flow line of the inertial particle separator. A wall of the bypass duct intersects the wall of the intermediate duct closer to a central axis of the engine than an extension of the engine-side inlet air flow line into the bypass duct.

Abstract: A system for producing single-frequency or near-single-frequency operation of a laser beam includes a laser for emitting a laser beam at each one of a plurality of cavity lengths, A detector is configured to receive at least a portion of the laser beam emitted, and generate a signal. A computer system is configured to identify at least one beat note in the signal for each of at least one of the plurality of cavity lengths, the at least one beat note indicating the presence of one or more higher-order transverse modes, longitudinal modes, or both, in the received at least the portion of the laser beam emitted at the at least one of the plurality of cavity lengths. The cavity is adjusted to one of the plurality of cavity lengths for eliminating or minimizing the at least one beat note.

Abstract: A method and system for obtaining single-frequency operation of a laser system. A laser beam is emitted from a laser cavity, having an adjustable length, at a plurality of cavity lengths. At least a portion of the laser beam is received at a detector, which detects the presence of transverse and/or longitudinal modes in the laser beam, and generates a laser beam signal having a beat-note indicative thereof. The laser beam signal for each of the plurality of cavity lengths can be analyzed, and a cavity length of best mode purity, indicating single-frequency operation, can be selected. The laser beam system can emit a laser and have a laser beam splitter for directing at least a portion of the emitted laser beam to a laser beam detector for generating at least one laser beam signal therefrom, and an actuator for adjusting the length of the laser cavity.

Abstract: An image generating device comprises a light source producing a light beam and a screen (5) traversed by the light beam and designed to modify the light beam so as to form an image. The screen (5) comprises a transparent element (150) traversed by the light beam and designed to evacuate the heat generated at the level of the screen (5). Said transparent element (150) is made of sintered transparent ceramic. Also described are a head-up display comprising such a device, and a method for manufacturing an image generating device.

Abstract: There is disclosed an inertial particle separator communicating with an engine inlet. The inertial particle separator has: a main duct body; a bypass duct; and a splitter defined by an intersection of the main duct and the bypass duct. The main duct and the bypass duct having particular geometric characteristics. A method of separating particles via inertia in an aircraft engine inlet is also provided.

Abstract: An exhaust mixer for a gas turbine engine has a lobe cross-over offset. The proposed geometric feature leads to improved exhaust performance and potential weight reduction.

Abstract: A turbine wheel for a hydrokinetic torque converter. The turbine wheel is rotatable about a rotational axis and comprises a substantially annular turbine shell member coaxial with the rotational axis, and a plurality of turbine blade members axially extending from the turbine shell member. The turbine wheel is a single-piece component such that the turbine blade members are unitarily formed with the turbine shell member. The turbine wheel (22) is made by an additive manufacturing process from a polymeric material.

Abstract: An inertial particle separator for an aircraft engine inlet, including inlet, intermediate and bypass ducts. The intermediate duct extends generally transversally from the inlet duct to the engine inlet, and communicates with the inlet duct adjacent its downstream end. The bypass duct extends downstream from the inlet duct and intermediate duct, and defines an outlet communicating with the environment of the engine. A wall of the intermediate duct intersects a wall of the inlet duct on an engine side of the wall of the inlet duct. The engine side of the wall of the inlet duct defines an engine-side inlet air flow line of the inertial particle separator. A wall of the bypass duct intersects the wall of the intermediate duct closer to a central axis of the engine than an extension of the engine-side inlet air flow line into the bypass duct.

Abstract: An image generating device comprises a light source producing a light beam and a screen (5) traversed by the light beam and designed to modify the light beam so as to form an image. The screen (5) comprises a transparent element (150) traversed by the light beam and designed to evacuate the heat generated at the level of the screen (5). Said transparent element (150) is made of sintered transparent ceramic. Also described are a head-up display comprising such a device, and a method for manufacturing an image generating device.