Abstract: A method of modulating a cooling supply in a gas turbine engine includes providing the engine comprising a compressor section and a turbine section and including a cooling flow circuit, the cooling flow circuit supplying a cooling air flow from a compressor cavity in the compressor section to a blade ring cavity in the turbine section, wherein the cooling flow circuit includes a main line with a full capacity valve, measuring a first pressure in the blade ring cavity, measuring a second pressure in the compressor cavity, adjusting, by a control system, the opening of the full capacity valve to control the cooling air flow through the main line in order to maintain a target pressure ratio, wherein the pressure ratio defined as a ratio of the first pressure to the second pressure. The method is performed in an ambient temperature operating range of the engine.

Abstract: A combustor assembly for a gas turbine engine defining a radial direction and a circumferential direction includes a liner assembly at least partially defining a combustion chamber and including at least one liner extending between a downstream end and an upstream end, the downstream end of the at least one liner defining a radial opening and an interface surface extending along the circumferential direction and along the radial direction; and a seal member including a body, a flange, and a radial element, the body defining a body surface extending along the radial direction and positioned adjacent the interface surface of the at least one liner, the flange extending forward from the body, and the radial element coupled to the flange and extending into the radial opening defined by the at least one liner.

Abstract: An aircraft has first and second fuel sources containing fuels with different characteristics, and one or more gas turbine engines powered by the fuels and each having a staged combustion system having pilot and main fuel injectors and being operable in pilot-only and pilot-and-main ranges of operation. The gas turbine engines each have a fuel delivery regulator arranged to control fuel delivery to the pilot and main fuel injectors. The method includes: obtaining a proposed mission description; obtaining nvPM impact parameters for the gas turbine engines, the impact parameters being associated with each operating condition of the proposed mission; calculating an optimised set of one or more fuel characteristics for each flight condition of the proposed flight defined in the flight description based on the nvPM impact parameters; and determining a fuel allocation based on the optimised set of one or more fuel characteristics.

Abstract: In accordance with at least one aspect of this disclosure, there is provided a system for an aircraft engine. In embodiments, the system includes an accessory box and a fuel accessory located in an interior space within the accessory box, where a vent is defined through a wall of the accessory box. In embodiments, the vent includes a plurality of holes or slots in an outer wall of the accessory box for passage of gaseous fuel from the interior space. In embodiments, the vent is configured for passive ventilation of the interior space.

Abstract: A cartridge tip includes a main body having an outer annular wall and an inner core each extending between a respective upstream end and a respective downstream end. The inner core is radially spaced apart from the outer annular wall such that an annular air passage is defined at least partially between the outer annular wall and the inner core. A pilot fuel circuit extends between a pilot inlet defined in the upstream end of the inner core and a pilot outlet defined in a downstream end of the inner core. The pilot fuel circuit extends at least partially along an axial centerline of the cartridge tip. A main fuel circuit extends between a main inlet in the upstream end of the inner core and a plurality of main outlets circumferentially spaced apart from one another and disposed upstream from the from the pilot outlet.

Abstract: In some examples, propulsion, electrical generation, and cooling system. The system comprises a gas turbine engine including a compressor and a bleed air outlet from the compressor, wherein the compressor is configured to compress a first fluid, wherein a portion of the compressed first fluid is directed out of the bleed air outlet to define bleed air from the compressor. The system also includes a turbo-generator including a combustor, wherein the combustor is configured to receive the bleed air from the compressor and combust a fuel with the bleed air, wherein the turbo-generator is configured to generate electrical energy via the combustion of the fuel by the combustor. The system also includes an air cycle cooling system configured to remove heat via an air cycle cooling process, wherein the air cycle cooling process is charged via the bleed air from the compressor. A compressor of the air cycle cooling system may be driven by a turbine of the turbo-generator or a turbine of the gas turbine engine.

Abstract: A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold.

Abstract: An apparatus is provided for a turbine engine. This apparatus includes a fuel conduit and a fuel nozzle. The fuel conduit includes a supply passage. The fuel nozzle includes a nozzle passage, an end wall and a nozzle orifice. The nozzle passage has a longitudinal centerline and extends longitudinally through the fuel nozzle along the longitudinal centerline from the end wall to the nozzle orifice. The nozzle passage is configured with a convergent portion and a throat portion. The nozzle passage converges radially inward towards the longitudinal centerline as the convergent portion extends longitudinally along the longitudinal centerline away from the end wall and towards the throat portion. The supply passage is fluidly coupled to the nozzle passage by a fuel aperture in the end wall. A centerline of the fuel aperture is angularly and laterally offset from the longitudinal centerline.

Abstract: A fluid flow system includes a main valve having a spool, a first chamber, and a second chamber. A pressure difference between the first chamber and the second chamber is configured to move the spool to control fluid flow. An electromechanical meter interface device (EMID) is in fluid communication with at least one of the first and second chambers of the main valve. The EMID is configured to meter fluid from a first source and a second source to the at least one of the first chamber and the second chamber. The first source has a different pressure from the second source. A fixed orifice is arranged between the main valve and the EMID. A fuel system for a gas turbine engine is also disclosed.

Abstract: A cooling arrangement for a gas turbine engine according to an example of the present disclosure includes, among other things, an offtake duct that has an offtake inlet coupled to a cooling source, the offtake duct defining a throat, and a valve downstream of the throat. The valve couples the offtake duct and a first cooling flow path. The valve is operable to selectively modulate flow through the offtake duct. A bleed passage includes a bleed inlet coupling the offtake duct and a second cooling flow path. The bleed inlet is defined at a location between the offtake inlet and the throat, inclusive. A method of cooling a propulsion system is also disclosed.

Abstract: An Electronic Engine Controller (EEC) for a gas turbine engine. The EEC is configured to be connected to a solenoid valve, and configured to control the solenoid valve by providing a driving signal to either a first solenoid winding or a second solenoid winding of the solenoid valve, the first and second solenoid windings being magnetically coupled to one another by an armature of the solenoid valve. The armature is movable under the action of the driving signal to operate the solenoid valve. The solenoid winding of the first and second solenoid windings provided with the driving signal is a driving winding and the other solenoid winding of the first and second solenoid windings is a pick-up winding. When the EEC controls the solenoid valve via the driving winding by providing the driving signal thereto, it is further configured to sense a position of the solenoid valve via the pick-up winding by detecting a signal induced in the pick-up winding by the magnetic coupling.

Abstract: Methods and systems for operating an engine, the engine having an engine core, an exhaust nozzle, and variable geometry mechanisms, are provided. A request for an increase in thrust generated by the engine is received. In response to receipt of the request, it is determined that at least one operating condition for engine degradation thrust is met. In response to this determination, the variable geometry mechanisms are modulated to degrade an efficiency of the engine, thereby increasing a temperature of core air flowing through the engine core. The increase in thrust is generated from the increased temperature of the core air flowing through the engine core and into the exhaust nozzle.

Abstract: A method for operating a hybrid-electric gas turbine engine is provided. The method includes: receiving data indicative of an actual rotational speed of a shaft; calculating an error between the actual rotational speed of the shaft and a commanded rotational speed of the shaft; providing the calculated error to a fuel flow control circuit operable with a fuel delivery system of the hybrid-electric propulsion engine; providing the calculated error to an electric machine control circuit operable with an electric machine of the hybrid-electric propulsion engine, the electric machine drivingly coupled to the shaft; and modifying a torque on the shaft from the electric machine with the electric machine control circuit based on the calculated error.

Abstract: Disclosed herein is an apparatus. The apparatus comprises an injector coupled to a head portion of a combustion chamber, the injector comprising a plurality of injector elements distributed away from an inner annulus and in an outer annulus. A geometry of combustion chamber comprises a body portion, an optional shoulder portion, and a throat portion. An inner wall of combustion chamber converges radially inward towards the throat. The plurality of injector elements in combination with the geometry of the combustion chamber are configured to confine a predetermined percentage of mass flow associated with combustion to a predetermined outer annulus of the chamber.

Abstract: A gas turbine including a fuel gas supply system to supply fuel gas via a fuel piping to a gas turbine combustor, a pressure control valve installed halfway along the fuel piping, a flow control valve installed in the fuel piping at downstream of the pressure control valve, and a control device configured that in a case where a flow rate change occurs in the fuel gas flowing through the fuel gas supply system, along with a tendency of change in an opening degree of the pressure control valve or a pressure P1 at upstream of the pressure control valve, a command value of the flow rate of the fuel gas that is determined based on a demand value of a gas turbine load is adjusted so that the change is suppressed in the opening degree of the pressure control valve or the pressure P1.

Abstract: A cooling system for a plurality of conductive cables in a gas turbine engine includes a cooling source and an electric motor disposed in a tail cone. The cooling source may comprise an electric fan or an oil pump. The cooling source may be configured for active cooling of the plurality of conductive cables. The electric fan may be in fluid communication with ambient air during operation of the gas turbine engine.

Abstract: In a method for operating an engine, a request for an increase in thrust generated by the engine is received. In response to receipt of the request, a determination is made as to whether at least one operating condition for heat application-based thrust is met. If so, a heat source is applied to heat bypass air flowing through the bypass duct towards the exhaust nozzle and the increase in thrust is generated from an increased temperature of mixed bypass air and core air at the exhaust nozzle.

Abstract: A premixer for a combustor includes: a centerbody having a hollow interior cavity; a swirler assembly radially outward of the centerbody; a peripheral wall disposed radially outward of the centerbody and the swirler assembly such that a mixing duct is defined between the peripheral wall and the centerbody, downstream from the swirler assembly; an annular splitter radially inward of the swirler assembly and radially outward of the centerbody such that a radial gap is defined between the splitter and an outer surface of the centerbody, wherein the splitter includes a trailing edge which extends axially aft of the swirler assembly; a fuel gallery disposed inside the interior cavity of the centerbody; and at least one fuel injector extending outward from the fuel gallery and passing through an injector port communicating with the outer surface of the splitter.

Abstract: The present application discloses a method of determining one or more fuel characteristics of an aviation fuel used for powering a gas turbine engine of an aircraft. The method comprises: determining one or more performance parameters of the gas turbine engine during a first time period of operation of the gas turbine engine; and determining one or more fuel characteristics of the fuel based on the one or more performance parameters. A method of operating an aircraft, a fuel characteristic determination system, and an aircraft are also disclosed.

Abstract: A method of repairing a component of a gas turbine engine in situ, wherein the component includes a deposit, includes directing a flow of gas, which may be an oxygen-containing gas, to the deposit of the component; and heating the component including the deposit while the component is installed in the gas turbine engine and for a duration sufficient to substantially remove the deposit.