Abstract: A blade outer air seal assembly includes a plurality of seal segments circumferentially disposed about an array of blades rotatable about an axis, each of the plurality of seal segments having a radially inner surface facing a tip of each blade of the array of blades, the radially inner surface having an arrangement of trenches formed therein, and a radially outer surface opposite the radially inner surface. The arrangement of trenches is disposed between 30% and 80% of a chord of a blade of the array of blades as taken at the respective tip, and the arrangement of trenches is aperiodic in the axial direction.

Abstract: A seal system has: a first member; a seal carried by the first member and having a seal face; and a second member rotatable relative to the first member about an axis. The second member has: a seat on a first piece of the second member, the seat having a seat face in sliding sealing engagement with the seal face; and a radially outwardly closed collection channel for collecting centrifuged oil; a second piece encircling and attached to the first piece and having a circumferential array of apertures; and cooperating with the first piece to define a plenum; and a flowpath from the collection channel passing radially outward axially spaced from the seat face to cool the seat face and passing axially away from the seat face in the plenum.

Abstract: An additively manufactured vane cluster has a platform, a shroud, and airfoils joining the platform to the shroud. The platform has openings, each opening between a respective two of the airfoils and forming accommodating differential thermal expansion of a leading end of the platform relative to a trailing end of the platform.

Abstract: An assembly for an aircraft propulsion system includes a propulsor section, an imaging device, a plurality of light sources, and a controller. The propulsor section includes a propulsor. The propulsor includes a plurality of propulsor blades. The imaging device is disposed in the propulsor section. The imaging device includes a camera. The plurality of light sources are disposed in the propulsor section. The controller includes a processor in communication with a non-transitory memory storing instructions, which instructions when executed by the processor, cause the processor to: control the plurality of light sources to direct light to the plurality of propulsor blades, control the camera to capture image data of each propulsor blade of the plurality of propulsor blades, and identify a presence or an absence of damage for each propulsor blade of the plurality of propulsor blades using the image data.

Abstract: A gas turbine engine has a fan drive turbine driving a gear reduction, the gear reduction, in turn, driving a fan rotor, the fan rotor delivering air into a bypass duct as bypass air and into a compressor section as core flow. A forward bearing is positioned between the gear reduction and the fan rotor and supports the gear reduction. A second bearing is positioned aft of the gear reduction and supports the gear reduction. The second bearing is a thrust bearing. A fan drive turbine drive shaft drives the gear reduction. The fan drive turbine drive shaft has a weakened link which is aft of the second bearing such that the fan drive turbine drive shaft will tend to fail at the weakened link, and at a location aft of the second bearing.

Abstract: An aircraft system is provided that includes a first gas turbine engine, a propulsor rotor, a second gas turbine engine, an electric generator and an electric component. The first gas turbine engine includes a first compressor section, a first combustor section, a first turbine section and a first flowpath. The propulsor rotor is rotatably driven by the first gas turbine engine. The second gas turbine engine includes a second compressor section, a second combustor section, a second turbine section and a second flowpath between a second inlet and a second exhaust. The second inlet and the second exhaust are each fluidly coupled with the first flowpath upstream of a combustor of the first combustor section. The electric generator is rotatably driven by the second gas turbine engine. The electric component receives electricity generated by the electric generator. The electric component is discrete from the first gas turbine engine.

Abstract: A bearing scavenge pump incorporated into a disk cover plate including a rotor disk having a rear surface and an axis; the disk cover plate attached to the rotor disk, the disk cover plate including fins extending into a gap formed between a rear surface of the rotor disk and the disk cover plate, the disk cover plate including anti-vortex features located axially distal from the fins relative to the axis; an inverted bearing located in a bearing compartment proximate the disk cover plate and disk; and a liquid fuel lubricant contacting the inverted bearing.

Abstract: A lubrication system including a bearing compartment housing defining a bearing compartment housing interior having a bearing compartment housing interior surface and a bearing compartment housing exterior having a bearing compartment housing exterior surface; a shaft supported by bearings located within the bearing compartment housing; and a lubricant dispenser in operative communication with the bearing compartment housing interior, the lubricant dispenser configured to contain at least one lubricant, the at least one lubricant configured to be released onto the bearings; and a pitot tube fluidly coupled to the lubricant dispenser.

Abstract: A method for coating a metallic substrate includes applying an MCrAlY coating. Machining removes the MCrAlY coating from one or more regions of the substrate. A simultaneous aluminizing and chromizing: aluminizes an interior surface region of the substrate lacking the MCrAlY and at least a portion of a region where the MCrAlY remains; and chromizes an exterior surface region of the substrate lacking the MCrAlY and at least a different portion of the region where the first MCrAlY remains.

Abstract: A lubrication system including a bearing compartment housing defining a bearing compartment housing interior having a bearing compartment housing interior surface and a bearing compartment housing exterior having a bearing compartment housing exterior surface; a shaft supported by bearings located within the bearing compartment housing; and a lubricant dispenser in operative communication with the bearing compartment housing interior, the lubricant dispenser configured to contain at least one lubricant, the at least one lubricant configured to be released onto the bearings.

Abstract: A lubrication system including a bearing compartment housing; a shaft supported by bearings located within the bearing compartment housing; and a persuader in operative communication with the shaft, the persuader configured to propel at least one of a lubricant, air and a mist of lubricant entrained in the air onto the bearing.

Abstract: A lubrication system including a bearing compartment housing defining a bearing compartment housing interior having a bearing compartment housing interior surface and a bearing compartment housing exterior having a bearing compartment housing exterior surface; a shaft supported by bearings located within the bearing compartment housing; and a lubricant trap formed on the bearing compartment housing interior surface, the lubricant trap configured to contain at least one lubricant, the at least one lubricant configured to be released onto the bearing.

Abstract: A lubrication system including a bearing compartment housing; a shaft supported by bearings located within the bearing compartment housing; and a flinger in operative communication with the shaft, the flinger configured to propel at least one of a lubricant, air and a mist of lubricant entrained in the air onto the bearing.

Abstract: A buffer air assembly for an aircraft engine includes a low-pressure header, a high-pressure header, a low-pressure bleed air source, a high-pressure bleed air source, and an electric buffer compressor. The low-pressure header is connected to at least one low-pressure bearing compartment. The high-pressure header is connected to at least one high-pressure bearing compartment. The low-pressure bleed air source is connected to the low-pressure header. The low-pressure bleed air source is configured to direct a low-pressure buffering air to the at least one low-pressure bearing compartment through the low-pressure header. The high-pressure bleed air source is configured to direct a high-pressure buffering air to the at least one high-pressure bearing compartment through the high-pressure header. The electric buffer compressor is connected to the low-pressure header and the high-pressure header.

Abstract: A fluid system is provided for an aircraft engine. This fluid system includes a lubricant reservoir and a pressure relief system. The lubricant reservoir includes an internal volume. The pressure relief system includes a sensor system, a pressure relieve valve and a controller. The sensor system is configured to provide sensor data indicative of an air pressure within the internal volume. The pressure relief valve is fluidly coupled with the internal volume. The controller is configured to control operation of the pressure relieve valve based on the sensor data.

Abstract: An assembly for an aircraft propulsion system includes a propulsor section and an imaging device. The propulsor section includes a propulsor and a structural body. The propulsor includes a plurality of propulsor blades. The structural body forms an outer air flow surface forming a portion of an air flow path through the propulsor section. The imaging device includes a housing and a camera. The housing includes a housing body and a cover. The housing body is mounted in the structural body. The housing body forms a cavity and an opening of the cavity. The cover is pivotable between a stowed position and a deployed position. The camera is disposed in the cavity with the cover positioned in the stowed position. The camera is configured to capture image data of each propulsor blade of the plurality of propulsor blades with the cover positioned in the deployed position.

Abstract: A gas turbine engine component includes an airfoil extending between a leading edge and a trailing edge. The airfoil has hollow cells with walls separating the plurality of hollow cells. A perforated surface has a plurality of perforations and closes off the hollow cells. The hollow cells have a diverter plate which extends away from the face surface at a first angle for a first portion. A gas turbine engine and a method are also disclosed.

Abstract: A hollow airfoil body includes a baffle that is arranged in the airfoil body that extends in a radial direction and provides a fluid flow direction. The baffle has multiple holes that include first and second holes that are configured to conduct the cooling airflow in a chordwise direction toward the trailing edge of the airfoil body. The airfoil has a first standoff that extends from the airfoil body to support the baffle. The first axial standoff has a first length that defines an axial passage including the multiple holes. The airfoil includes a second standoff that has a second length less than the first length. The second standoff is arranged radially between the first and second holes. The first hole is smaller than the second hole. The second hole is downstream from the first hole relative to the fluid flow direction.

Abstract: A heat exchanger including an internal passage extending from a first inlet end to a first outlet end; a first longitudinal length extending from the first inlet end to the first outlet end; an inner surface of the passage including a first augmentation feature disposed along the first longitudinal length across the inner surface; an outer surface extending from a second inlet end to a second outlet end, the outer surface being in heat transfer communication with the inner surface; and a first region including portions of both the inner surface and the outer surface adjacent at least a portion of the first inlet end, wherein the first augmentation feature varies a cross-sectional area in a direction along the first longitudinal length and within the first region.

Abstract: A method for forming a hollow component includes injecting a fluid into an internal cavity of the hollow component to achieve a pressure of the fluid within the internal cavity that is greater than an ambient pressure. The method further includes drilling at least one hole through the hollow component from an external surface of the hollow component to the internal cavity by applying a laser beam to the hollow component with a laser generator. The method further includes directing the fluid from the internal cavity and through the at least one hole so as to exit the hollow component via the at least one hole.