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 of controlling a combustor of a gas turbine engine, the method comprising the steps supplying a total fuel quantity to the combustor dependent on a load of the gas turbine engine, the total fuel quantity is split into a pilot fuel quantity and a main fuel quantity via a scheduled pilot fuel split, the pilot fuel split is the percentage of the pilot fuel quantity of the total fuel quantity, monitoring combustion instability, applying a steady state active pilot split offset to the scheduled pilot fuel split when a predetermined temperature of the combustor is exceeded and/or a predetermined value of combustion instability is exceeded to create a steady state pilot fuel split, monitoring a condition of the gas turbine engine that influences an air/fuel ratio in the combustor, disabling the steady state active pilot split offset when the condition of the gas turbine engine is indicative of a transient condition and when a threshold value of combustion instability is exceeded, and applying a transient active pilot split offset to the steady state pilot fuel split while maintaining the total fuel quantity being supplied at any point in time, the transient active pilot split offset and the steady state active pilot split offset result in a total split offset, the total split offset being greater than the steady state active pilot split offset and the rate of change of the transient active pilot split offset is faster than the rate of change of the steady state active pilot split offset.

A non-transitory computer readable storage medium storing one or more processor-executable instructions wherein the one or more instructions when executed by a processor of a controller, cause acts to be performed is provided. The acts to be performed include controlling a fuel split to a combustor of a gas turbine utilizing automatic tuning and switching control of the fuel split to the combustor of the gas turbine to utilizing an adjusted fixed fuel split schedule instead of automatic tuning. The adjusted fixed fuel split schedule includes a fixed fuel split schedule adjusted via a biasing value, and the biasing value is based on both the fixed fuel split schedule and an automatic tuning based fuel split.

Methods and systems for processing a signal indicative of at least one operating condition of a gas turbine engine to remove noise associated therewith are provided. The method and systems receive a signal from one or more sensors operably coupled to a gas turbine engine, retrieves one or more known system parameters and a previously determined average signal, and processes the signal using the system parameter and the previously determined average signal to remove noise therefrom. In some of the described methods and systems, the processed signal is then compared to predetermined upper and lower limits, and, if the processed signal exceeds the limits, at least one component of the gas turbine engine, such as a fuel-flow split, is adjusted in an effort to bring the signal back within the limits.

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.

A method for operating a supply assembly configured for supplying fuel gas and an inert purge media to a gas turbine combustor, the method including supplying fuel gas in a fuel gas circuit with an upper flow rate; reducing the fuel gas flow rate in the fuel gas circuit from the upper flow rate to a lower flow rate; stopping the supply of the fuel gas in the fuel gas circuit; and starting the supply of the inert purge media in the inert purge media circuit, wherein the starting is performed before the stopping to have a temporary parallel supply of fuel gas and of inert purge media to a fuel distribution system.

A fuel distribution manifold for a gas turbine engine is disclosed herein. The fuel distribution manifold includes a manifold body, a stage divider, and a plurality of manifold outlet ports. The stage divider subdivides an internal volume of the manifold body into a primary stage volume and a secondary stage volume. A majority of the plurality of manifold outlet ports extends from the manifold body between the primary inlet port and the stage divider, each being fluidly connected to the primary stage volume. A remainder of the plurality of manifold outlet ports extends from the manifold body between the secondary inlet port and the stage divider, each being fluidly connected to the secondary stage volume.

A method for operating a gas turbine engine is disclosed. The method includes detecting an off-load transient of the gas turbine engine. The method includes reducing a total flow of fuel to a combustor section of the gas turbine engine to a first reduced flow in response to detecting the off-load transient. The method includes adjusting a position of an inlet guide vane in response to detecting the off-load transient until either an on-load transient is detected or until an amount of time elapsed since detection of the off-load transient exceeds a maximum override time.

A turbomachine including: a combustion chamber, with a fuel injection device in the combustion chamber; a supply mechanism supplying fuel to the fuel injection device; a mechanism determining instantaneous variation of fuel flow rate of the supply mechanism; and a regulation mechanism regulating the fuel flow rate of the injection device according to the instantaneous variation of the fuel flow rate of the supply mechanism determined by the determination mechanism.

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.