Abstract: The disclosure describes an apparatus for sealing a rotating machine, such as an electric machine or gas turbine engine. The apparatus includes a brush seal. The brush seal includes a plurality of first filaments and a plurality of electrically conductive filaments. The first filaments are configured to seal a lubricant within a bearing chamber or sump of the rotating machine. The plurality of electrically conductive filaments is configured to contact a shaft of the rotating machine and discharge a shaft voltage-induced current from the shaft to an external ground of the rotating machine.

Abstract: In some examples, a system including a gas turbine engine, the engine including a high-pressure (HP) shaft; HP compressor; HP turbine, second shaft; second compressor; second turbine, the second turbine being coupled to the second compressor via the second shaft (e.g., LP shaft); and a generator coupled to the LP shaft. The generator is configured to generate electrical power from rotation of the LP shaft, and increase electrical power generated by the generator to increase a torque applied to the LP shaft by the generator, e.g., in combination with reduction in engine thrust, or in response to the detection of a stall and/or surge of the engine. The increase in torque applied to the second shaft is configured to increase a rate at which a rotational speed of the second shaft decreases, e.g., in combination with the reduction in engine thrust or during the stall/surge of the engine.

Abstract: In some examples, a system including a gas turbine engine, the engine including a high-pressure (HP) shaft; HP compressor; HP turbine, second shaft; second compressor; second turbine, the second turbine being coupled to the second compressor via the second shaft (e.g., LP shaft); and a generator coupled to the LP shaft. The generator is configured to generate electrical power from rotation of the LP shaft, and increase electrical power generated by the generator to increase a torque applied to the LP shaft by the generator, e.g., in combination with reduction in engine thrust, or in response to the detection of a stall and/or surge of the engine. The increase in torque applied to the second shaft is configured to increase a rate at which a rotational speed of the second shaft decreases, e.g., in combination with the reduction in engine thrust or during the stall/surge of the engine.

Abstract: In some examples, a gas turbine engine including a high-pressure (HP) spool assembly including a HP shaft, a HP compressor and HP turbine; a lower pressure (LP) spool assembly including a LP shaft and LP turbine; a motor-generator coupled to the LP shaft; and a controller. The controller is configured to control the motor-generator to operate in a motor mode to apply torque the LP shaft during a starting of the HP spool assembly, and control the motor-generator to operate in a generator mode for a least a period of time following the starting of the HP spool assembly.

Abstract: A member may have a primary major surface and a secondary major surface. The member may form an array of apertures extending from the primary major surface to the secondary major surface. The array of apertures includes at least one aperture comprising two or more conduits. The axis of each conduit intersects the axis of each other conduit in the aperture. The cross-section of at least one of the conduits perpendicular to its axis may be circular. In some embodiments, an aperture may comprise two or three conduits.

Abstract: The disclosure describes an apparatus for sealing a rotating machine, such as an electric machine or gas turbine engine. The apparatus includes a brush seal. The brush seal includes a plurality of first filaments and a plurality of electrically conductive filaments. The first filaments are configured to seal a lubricant within a bearing chamber or sump of the rotating machine. The plurality of electrically conductive filaments is configured to contact a shaft of the rotating machine and discharge a shaft voltage-induced current from the shaft to an external ground of the rotating machine.

Abstract: A member may have a primary major surface and a secondary major surface. The member may form an array of apertures extending from the primary major surface to the secondary major surface. The array of apertures includes at least one aperture comprising two or more conduits. The axis of each conduit intersects the axis of each other conduit in the aperture. The cross-section of at least one of the conduits perpendicular to its axis may be circular. In some embodiments, an aperture may comprise two or three conduits.

Abstract: A unique compressor includes a rotating compressor blade having a blade tip; a compressor case having a blade track disposed opposite the blade tip; and a tip clearance control system including a fluid impingement structure. This structure has a plurality of openings to impinge a fluid received from a diffuser onto the compressor case. The tip clearance control system is configured to control a clearance between the blade tip and the blade track by impinging the fluid onto the compressor case and modulating the same with a valve in fluid communication with the diffuser. A further form includes a unique gas turbine engine having a compressor with a compressor blade tip, a compressor case disposed opposite the blade tip, and a fluid impingement structure having openings to impinge a fluid onto the case. Also included are other apparatuses, systems, devices, hardware, methods, and combinations for compressor blade tip clearance control.

Abstract: One embodiment of the present invention is a unique compressor. Another embodiment of the present invention is a unique gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for blade tip clearance control for compressors and gas turbine engine compressors. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.