Abstract: A control system for limiting power turbine torque (QPT) of a gas turbine engine includes a controller including a processor and memory configured to control the gas turbine engine, the controller including an engine control module that provides an effector command signal to a gas generator of the gas turbine engine; a power turbine governor module that outputs a preliminary torque request (QPT_req_pre); and a power turbine torque (QPT) optimal limiter module that outputs a maximum torque topper (QPT_max) to limit a power turbine speed overshoot of the gas turbine engine; wherein the controller outputs a minimum value between the preliminary torque request (QPT_req_pre) and the maximum torque topper (QPT_max) to the engine control module.

Abstract: A gas turbine engine includes a first spool associated with a primary combustor, a second spool associated with a secondary combustor, and a third spool, each spool including a compressor and a turbine mounted to a shaft. A transmission and accessory gearing are enclosed within an housing of an accessory gearbox. The transmission rotationally couples the third spool to the second spool and accessory gearing. A method of operating the gas turbine engine includes supplying a first fuel flow rate to the primary combustor and supplying a second fuel flow rate to the secondary combustor within an intermediate speed range of the gas turbine engine.

Abstract: A blade outer air seal segment including a radially outward surface, a radially inward surface oriented away from the radially outward surface, and a cooling channel located between the radially outward surface and the radially inward surface. The blade outer air seal segment also including a stress-relief boss extending into the cooling channel and an inlet orifice fluidly coupled to the cooling channel through the stress-relief boss. The blade outer air seal segment further including a stress-relief recess. The stress-relief boss being located within the stress relief recess.

Abstract: An engine system for an aircraft includes a first gas turbine engine, a second gas turbine engine, and a control system. The control system is configured to operate the first gas turbine engine with a sub-idle fuel burn schedule based on detecting landing of the aircraft, where the sub-idle fuel burn schedule includes a reduction of an idle fuel burn schedule. The control system is configured to operate the second gas turbine engine with the idle fuel burn schedule based on detecting landing of the aircraft.

Abstract: A section of a gas turbine engine includes a ceramic component and a metallic component situated adjacent the ceramic component. The ceramic component and the metallic component are situated outside of a core flow path of the gas turbine engine. The section of a gas turbine engine also includes an interface between the ceramic component and a metallic component and a mullite-based coating disposed at the interface. The coating provides thermal protection to the ceramic component and the metallic component, and provides thermochemical protection against interaction between the ceramic component and the metallic component. A gas turbine engine and a method of protecting components in a gas turbine engine are also disclosed.

Abstract: Fuel injectors for gas turbine engines include a housing and a tube defining a portion of a first fluid passage therein and a second fluid passage is defined between an exterior surface of the tube and an interior surface of the housing. An inner airflow tube is arranged having an inflow vane assembly and a central air passage. A portion of the first fluid passage extends axially at a position radially outward from the inner airflow tube, and the third fluid passage extends axially at a position radially outward from the first fluid passage. A nozzle outlet is configured to receive first, second, and thirds fluids from the respective fluid passages to cause mixing thereof. The inflow vane assembly comprises a number of vanes, with each vane angled relative to a nozzle axis at an angle between 20° and 40°.

Abstract: A piston seal assembly for a gas turbine engine includes a seal composed of a nickel-based superalloy; a component in contact with the seal and defining a seal-counterface; and a coating on the seal at the seal-counterface, wherein the coating is a metal alloy binder phase and a hard particle phase distributed through the binder phase.

Abstract: A gas turbine engine has a compressor section, a combustor, and a turbine section. An associated fluid is to be cooled and an associated fluid is to be heated. A transcritical vapor cycle heats the fluid to be heated, and cools the fluid to be cooled. The transcritical vapor cycle includes a gas cooler in which the fluid to be heated is heated by a refrigerant in the transcritical vapor cycle. An evaporator heat exchanger at which the fluid to be cooled is cooled by the refrigerant in the transcritical vapor cycle. A compressor upstream of the gas cooler compresses the refrigerant to a pressure above a critical point for the refrigerant. An expansion device expands the refrigerant downstream of the gas cooler, with the evaporator heat exchanger being downstream of the expansion device, and such that the refrigerant passing through the gas cooler to heat the fluid to be heated is generally above the critical point.

Abstract: Disclosed is a ceramic matrix component having a fibrous core and a ceramic matrix composite shell surrounding at least a portion of the fibrous core. The ceramic matrix composite shell comprises a fibrous preform. The fibrous core has a greater porosity than the fibrous preform. A method of making the ceramic matrix component is also disclosed.

Abstract: Examples described herein provide a method that includes receiving engine data from a sensor associated with the engine. The method further includes associating a header with the engine data to generate packaged engine data. The method further includes transmitting the packaged engine data to an aircraft communication unit, wherein the header provides for the aircraft communication unit to transmit the packaged engine data to a ground station communication unit via a communication protocol.

Abstract: A gas turbine engine and engine mount structure includes a core engine including a compressor section, a combustor section and a turbine section mounted within a core engine housing. The fan, the compressor section and the turbine section rotate about an axis of rotation. An outer nacelle surrounds the fan, and is spaced from the core engine housing to define a bypass duct. The fan delivers air into the bypass duct and into the core engine housing. The nacelle is formed with camber so as to be curved in a first plane away from the axis of rotation in a first lateral direction. An engine mount structure extends from the nacelle at an angle that is non-parallel and non-perpendicular to the first plane, and has a component in a lateral direction that is opposed to the first lateral direction. An aircraft is also disclosed.

Abstract: A gas turbine engine according to an aspect of the present disclosure includes, among other things, propulsor means, first compression means, second compression means, reduction means for reducing a rotational speed of an output that drives the propulsor means relative to an input, first expansion means for driving the second compression means, and second expansion means for driving the input of the reduction means. The first compression means includes a plurality of arrays of rotor blades and a plurality of arrays of stator vanes arranged in a plurality of compression stages. A factor (F) is defined as a total number of the rotor blades in an array of the plurality of arrays divided by a total number of the stator vanes in an adjacent array of the plurality of arrays. The factor (F) is between 1.19 and 1.55 for at least two of the arrays of the rotor blades.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a propulsor section including a propulsor that delivers flow to a core flowpath and a compressor section including first and second compressors. The core flowpath passes through the first compressor. The core flowpath in the first compressor has an outer diameter relative to the engine longitudinal axis. The outer diameter has a slope angle relative to the axis.

Abstract: A propulsion system for an aircraft includes a core flow path in communication with a compressor section, combustor section and a turbine section. A first bottoming cycle system includes a bottoming working fluid flow in thermal communication with a high energy exhaust gas flow that is generated by the core engine. The first bottoming cycle is configured to recover power from the high energy exhaust gas flow in a first engine operating condition and in a second engine operating condition. A second bottoming cycle system is configured to recover power from the high energy exhaust gas flow in the first engine operating condition and not to recover power in a second engine operating condition.

Abstract: A component includes a diffusion coating comprising an inter-diffusion zone between the diffusion coating and a substrate and a non-metallic inclusions zone adjacent to an outer surface of the diffusion coating. A method of coating a component includes applying an aluminizing slurry to a localized area of a component and applying a chromizing slurry to the localized area of the component subsequent to heat treating the aluminizing slurry.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a propulsor section including a propulsor, a gear reduction, a first spool including a first compressor, a first turbine and a first shaft, and a second spool including a second compressor, a second turbine and a second shaft. The gear reduction includes a carrier and a plurality of gears. The plurality of gears include a sun gear, a ring gear, and a plurality of intermediate gears that engage the sun gear and the ring gear. At least two of the plurality of gears are double helical gears in meshed engagement.

Abstract: A fluid filtration assembly (FFA) includes a housing having a thickness defined between an internal surface and an external surface, the housing receiving a filter and defining an outer annular flow passage between an outer surface of the filter and the internal surface of the housing; an inlet pipe communicates with the FFA and injects a fluid into the housing to impart a centrifugal force; an outlet pipe communicates with the FFA and discharges the fluid from the housing; and a collection area disposed towards an end of the outer annular flow passage collects particulate matter from the fluid; wherein a width of the outer annular flow passage increases towards the collection area.

Abstract: A scupper suitable for a bearing compartment of a gas turbine engine includes a windage blocker in a gutter section upstream of a drain hole, the windage blocker extends from a wall of the gutter section. A method for capturing wept oil in a bearing compartment of a gas turbine engine includes positioning a windage blocker adjacent to a drain hole forming a passage space and increasing a pressure upstream of the windage blocker to generate a vortex downstream of the windage blocker creating an oil re-circulation zone promoting oil drainage into the drain hole.

Abstract: A gas turbine engine includes a propulsor section including a propulsor, a compressor section including a first compressor and a second compressor, a geared architecture, a turbine section including a first turbine and a drive turbine, and a power density of greater than or equal to 4.75 and less than or equal to 5.5 lbf/in3, wherein the power density is a ratio of a thrust provided by the engine to a volume of the turbine section.

Abstract: An airfoil includes an airfoil wall that defines a leading end, a trailing end, and first and second sides that join the leading end and the trailing end. A rib connects the first and second sides of the airfoil wall. The rib defines a tube portion that circumscribes a rib passage, and first and second connector arms that solely join the tube portion to, respectively, the first and second sides of the airfoil wall.