Abstract: An aircraft including lean-burn gas turbine engines operating in pilot-plus-mains mode with a given initial fuel flow W0, a method of controlling the optical depth of contrails produced by a first group of engines includes the steps of (i) reducing fuel flow to each engine in the first group to change the operation of each engine from pilot-plus-mains mode to pilot-only mode, and (ii) adjusting fuel flow to one or more engines in a second group of engines such that the total fuel flow to engines of the second group is increased, all engines of the second group remaining in pilot-plus-mains mode, and wherein the set of lean-burn engines consists of the first and second groups. Depending on atmospheric conditions, the average optical depth of contrails produced by the engines may be enhanced or reduced compared to when all engines operate in pilot-plus-mains mode with a fuel flow W0.

Abstract: A method of determining a calorific value of fuel supplied to a gas turbine engine of an aircraft comprises sensing at least one engine parameter during a first time period of aircraft operation during which the gas turbine engine uses the fuel; and, based on the at least one sensed engine parameter, determining a calorific value of the fuel. The sensing may be repeated such that the at least one engine parameter is monitored over time. The gas turbine engine may be a propulsive gas turbine engine of the aircraft or a gas turbine engine of an auxiliary power unit of the aircraft.

Abstract: A fuel injector is provided for a turbine engine. This fuel injector includes a fuel nozzle, and the fuel nozzle includes a gallery, one or more feed passages and a plurality of exit passages. The gallery extends within the fuel nozzle circumferentially around an axis between a first end of the gallery and a second end of the gallery. A size of the gallery changes as the gallery extends circumferentially around the axis between the first end of the gallery and the second end of the gallery. The one or more feed passages extend within the fuel nozzle to the gallery. The one or more feed passages are configured to supply fuel to the gallery. The exit passages extend within the fuel nozzle from the gallery. The exit passages are configured to receive the fuel from the gallery.

Abstract: A method of purging fuel injectors of a gas turbine engine, the fuel injectors fluidly connected to a fuel manifold and having primary and secondary fuel passages fluidly connectable to the fuel manifold, the method includes: selectively fluidly disconnecting one or more of the primary and secondary fuel passages from the fuel manifold; and purging the one or more of the primary and secondary fuel passages by injecting a purging fluid into the one or more of the primary and secondary fuel passages while bypassing the fuel manifold. A fuel injector having two fuel passages, a flow divider valve, and a purging valve is disclosed.

Abstract: A heat shielded assembly includes a fuel structure of a combustor of a gas turbine engine and a woven heat shield at least partially conformally surrounding the fuel structure and spaced from an exterior of the fuel structure by a distance where it surrounds the fuel structure. The fuel structure is configured to deliver fuel to the combustor. The woven heat shield comprises a first set of strands, a second set of strands interwoven with the first set of strands, and a weave pattern comprising the first set of strands and the second set of strands. Each strand of the first set of strands extends in a first direction, each strand of the second set of strands extends in a second direction transverse to the first direction, and the first set of strands and the second set of strands are not attached where they intersect in the weave pattern.

Abstract: A torch igniter system for a combustor of a gas turbine engine includes a housing defining a combustion chamber, an ignition source disposed at least partially in the combustion chamber, a fuel injector, a first fluid path connecting a first fuel source to the fuel injector, a second fluid path connecting an air source to the fuel injector, and a third fluid path connecting a second fuel source to the combustion chamber. The fuel injector is configured to inject fuel, air, or a mixture of fuel and air into the combustion chamber and to impinge on the ignition source.

Abstract: An airflow profile structure having a leading and/or trailing edge profiled with a serrated profile. The serrated profile has a succession of teeth and depressions, characterized in that, along the leading and/or trailing edge, from a first location to a second location, the teeth of the serrated profile are individually inclined towards the second location.

Abstract: Supercritical fluid systems and aircraft power systems are described. The systems include a compressor, a turbine, and a generator. A primary working fluid flow path has a primary working fluid that passes through the compressor, a separator, the turbine, and back to the compressor. A secondary working fluid flow path having a secondary working fluid that passes through the generator, the compressor, the separator, and back to the generator. The primary working fluid and the secondary working fluid are compressed and mixed within the compressor to form a mixture of the two fluids and the separator separates the mixture of the two fluids to direct the primary working fluid back to the turbine and the secondary working fluid to the generator.

Abstract: A gas turbine includes a compressor configured to compress air; a combustor configured to mix and combust fuel and compressed air compressed by the compressor; a turbine configured to obtain rotational power using combustion gas generated by the combustor; an inlet guide vane disposed at an intake of the compressor to adjust a flow rate of air flowing into the compressor; a bleed line configured to return a part of the compressed air pressurized in the compressor to the intake of the compressor; and an on-off valve disposed in the bleed line. When the output of the gas turbine increases, a preset maximum value limit of the inlet guide vane is corrected based on a valve opening degree command value of the on-off valve and a compressor intake temperature such that the gas turbine achieves a predetermined performance.

Abstract: A method and system for bleed flow power generation is provided. The engine includes a core flowpath formed by a compressor section, a heat addition system, and an expansion section in serial flow arrangement. A bleed circuit is extended from the core flowpath to extract a portion of compressed fluid from the core flowpath. The method and system include bleeding compressed fluid through a bleed circuit extended in fluid communication from the core flowpath of the engine; flowing the compressed fluid through the bleed circuit to a turbine rotor positioned at the bleed circuit; extracting, via the turbine rotor, energy from the flow of compressed fluid across the turbine rotor; and receiving energy at an electric machine operably coupled to the turbine rotor.

Abstract: A liner cooling device for cooling a liner of a gas turbine is provided. The liner cooling device may include a support portion disposed between a liner and a transition piece of a gas turbine and configured to include a cooling flow passage through which cooling air moves to the transition piece. The support portion includes a support member disposed between the liner and the transition piece and an auxiliary support member disposed in the cooling flow passage and having a hole through which the cooling air passes.

Abstract: A aircraft gas turbine engine and operation method, the engine including: a staged combustion system having pilot and main fuel injectors, and operates in a pilot-only range wherein fuel delivers to pilot fuel injectors, and a pilot-and-main operation range wherein fuel is delivered to at least the main fuel injectors. The engine further includes a fuel delivery regulator to pilot and main fuel injectors, which receives fuel from a first and second source containing fuels each with different characteristics. The staged combustion system switches between pilot-only and pilot-and-main range operation when in steady cruise mode, the mode defining a boundary between first and second engine cruise operation range. The fuel delivery regulator delivers fuel to pilot fuel injectors during at least part of the first engine cruise operation with different fuel characteristics from fuel delivered to one or both pilot and main fuel injectors the second engine cruise operation range.

Abstract: A gas turbine combustion chamber, having a combustion chamber housing, a burner positioned at least partially in the combustion chamber housing and a flame tube positioned in the combustion chamber housing. An upstream end of the flame tube has a flame tube cover. In the region of the flame tube cover radially inside the flame tube cover a mixing tube of the burner extends, which defines a pre-primary combustion zone. Between the mixing tube of the burner and the flame tube cover an axial air flow passage is formed, via which air can be conducted in the axial direction outside along the mixing tube, and into the flame tube cover radial air flow passages are introduced via which the air following the axial air flow passage can be conducted in the radial direction of the flame tube cover for cooling the flame tube cover.

Abstract: A mixing assembly for a combustor includes: a pilot mixer including a pilot housing extending along a mixer centerline and a pilot fuel nozzle; a main mixer surrounding the pilot mixer; a fuel manifold between the pilot and main mixers; a mixer foot extending from a main housing of the main mixer; a main swirler body surrounding the main housing defining a mixing channel between the main housing and the main swirler body; and a main fuel ring in the mixing channel connected to the main housing by main fuel vanes, at least one of the main fuel ring and main fuel vanes including fuel injection ports for discharging fuel into the mixing channel, wherein the fuel injection ports are disposed non-uniformly relative to the mixer centerline, so as to produce a static pressure difference therebetween in response to mixer air flow passing around the main fuel ring.

Abstract: The aircraft can have a first engine secured to a first wing on a first side of a fuselage, and a second engine secured to a second wing on a second side of the fuselage, the second wing having a proximal end secured to the fuselage, and a distal end extending away from the fuselage. While operating the first engine, compressed gas can be conveyed from the first engine to a thrust generating device located at the distal end of the second wing.

Abstract: A control device includes a load fuel quantity calculation unit, an allowable fuel quantity calculation unit, a flow rate low value selection unit, a basic drive quantity calculation unit, a fuel deviation calculation unit, and a correction unit. The load fuel quantity calculation unit determines a load fuel quantity based on a required output. The allowable fuel quantity calculation unit determines an allowable fuel quantity to protect a gas turbine. The flow rate low value selection unit selects a minimum fuel quantity from among the determined fuel quantities. The basic drive quantity calculation unit determines a basic drive quantity of an air intake quantity regulator. The fuel deviation calculation unit determines a fuel deviation between the allowable fuel quantity and the minimum fuel quantity. The correction value calculation unit determines a correction value corresponding to the fuel deviation which is then used to correct the basic drive quantity.

Abstract: A gas turbine engine includes a compressor section, a combustor, and a turbine section. The turbine section includes a high pressure turbine comprising a plurality of turbine blades. The gas turbine engine includes a tap for tapping air that is compressed by the compressor, to be passed through a heat exchanger to cool the air, the cooled air to be passed to the plurality of turbine blades. A sensor is located downstream of a leading edge of the combustor, and is configured to measure a characteristic of the cooled air. A controller is configured to compare the measured characteristic to a threshold and control an operating condition of the gas turbine engine based on the comparison.

Abstract: One or more cooling systems for ventilating a turbine and rotary shaft of a gas turbine system is provided. The gas turbine system includes a gas turbine engine and a turbine exhaust collector in separate enclosures. A first cooling system includes an educator that sucks exhaust gas through a diffuser and directs it out of the turbine exhaust collector enclosure based on suction pressure created from the high velocity of exhaust gas. A second cooling system include struts that enable the exhaust gas to flow from the diffusers to a ventilation flow stack. A third cooling system includes exhaust gas sucked from an opening to a top duct based on suction pressure created from the rotation of the rotary shaft disposed about a coupling. A guideway associated with the third cooling system also directs the exhaust gas to flow to the top duct.

Abstract: A gas turbine engine, has: a compressor; a turbine having a rotor; and an inertial particle separator located upstream of the turbine downstream of the compressor, the inertial particle separator having: an intake conduit in fluid flow communication with the compressor and defining an elbow, a splitter, a leading edge of the splitter located downstream of the elbow, the splitter located to divide a flow into a particle flow and an air flow, and an inlet conduit and a bypass conduit located on respective opposite sides of the splitter, the inlet conduit receiving the air flow, the inlet conduit in fluid flow communication with a cavity containing the rotor for cooling the rotor of the turbine section, the bypass conduit receiving the particle flow, the bypass conduit in fluid flow communication with an environment outside the gas turbine engine while bypassing the cavity containing the rotor.

Abstract: A method of operating a fuel delivery system of an aircraft engine of an aircraft includes operating the aircraft engine in a standby mode by maintaining combustion in a combustor of the aircraft engine by supplying fuel to the combustor via a first set of fuel nozzles of a first fuel manifold while providing a trickle flow of fuel via a second set of fuel nozzles of a second fuel manifold into the combustor during engine operation, the trickle flow being defined as a fuel flow rate selected to prevent flame-out of the combustion while providing one of: substantially no motive power to the aircraft, and no motive power to the aircraft, via the combustion of the trickle flow of fuel. An aircraft gas turbine engine is also described.