A gas turbine system includes a turbine combustor, a turbine, an exhaust gas compressor, an exhaust gas recirculation (EGR) system, a carbon black recovery system, and a carbon black production controller. The carbon black production controller monitors data corresponding to a parameter of the carbon black. The carbon black production controller is also configured to adjust, based on the data, the fuel provided to the turbine combustor while maintaining a ratio of the fuel to the oxidant within a predetermined range to adjust the parameter of the carbon black.

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.

An assembly including a first turbocharger, the first turbocharger including a first turbine and a first compressor, the first turbine arranged in a turbine flowpath to be driven in rotation by an exhaust gas flowing at a variable flow rate through the turbine flowpath. The first compressor arranged in a compressor flowpath to be driven by the first turbine to urge an intake gas to flow through the compressor flowpath. The first turbine and first compressor being supported for rotation in bearings supplied via an oil flowpath at an oil pressure. The assembly further including a seal arranged between the oil flowpath and the compressor flowpath to resist leakage of the oil into the compressor flowpath and a flow control means configured to control a rotational speed of the first turbine and first compressor by controlling the flow of exhaust gas in the turbine flowpath.

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.

This invention concerns an aircraft propulsion system in which an engine has an engine core comprising a compressor, a combustor and a turbine driven by a flow of combustion products of the combustor. At least one propulsive fan generates a mass flow of air to propel the aircraft. An electrical energy store is provided on board the aircraft. At least one electric motor is arranged to drive the propulsive fan and the engine core compressor. A controller controls the at least one electric motor to mitigate the creation of a contrail caused by the engine combustion products by altering the ratio of the mass flow of air by the propulsive fan to the flow of combustion products of the combustor. The at least one electric motor is controlled so as to selectively drive both the propulsive fan and engine core compressor.

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.

A method, system and apparatus are provided for reducing or eliminating contrails formed by an aircraft as it travels through the sky, and more particularly, to disrupting formation of contrails and altering the electromagnetic properties of already-formed contrails through use of one or more lasers. Methods include: positioning at least one laser such that at least one beam from the at least one laser is directed to a position at which contrails form aft of a wing of the aircraft; detecting contrail formation in the position at which contrails form aft of the wing of the aircraft; activating the at least one laser source in response to detecting contrail formation; and reducing or eliminating the contrail in response to activating the at least one laser source.

A gas turbine engine for an aircraft includes a staged combustion system having pilot fuel injectors and main fuel injectors. The gas turbine engine further includes a fuel delivery regulator arranged to control delivery of fuel to the pilot and main fuel injectors, and a fuel characteristic determination module configured to determine one or more fuel characteristics of the fuel being supplied to the staged combustion system. A controller is configured to determine a staging point defining the point at which the staged combustion system is switched between pilot-only operation and pilot-and-main operation, the staging point being determined based on the determined one or more fuel characteristics, the controller being configured to control the staged combustion system according to the determined staging point.

This invention concerns a fuel delivery system for an aircraft engine, including a fuel delivery regulator arranged to receive fuel from a plurality of fuel sources for supply to the engine. An engine operating condition sensor reading is received by a control unit arranged to control operation of the regulator. The control unit actuates the regulator based on a received signal from the engine operating condition sensor in order to vary the volume of fuels from the plurality of fuel sources supplied to the engine during at least a portion of the landing/take-off (LTO) cycle relative to a further portion of the aircraft flight. The different fuels may include kerosene and an alternative fuel, such as a biofuel.