A method for detecting blowout precursors in at least one gas turbine combustor comprising: receiving combustion dynamics acoustic data measured by an acoustic measuring device associated with the combustor in real time; performing wavelet analysis on the acoustic data using simplified Mexican Hat wavelet transform analysis; and determining the existence of a blowout precursor based at least in part on the wavelet analysis. Provided also is a system and a non-transitory computer readable medium configured to perform the method.

A method of controlling at least part of a start-up or re-light process of a gas turbine engine, the method comprising: determining when a flame in a combustion chamber of a gas turbine engine is extinguished, during a start-up process or re-light process or during operation; purging the combustion chamber by controlling rotation of a low pressure compressor using a first electrical machine, and controlling rotation of a high pressure compressor using a second electrical machine, the combustion chamber downstream of the low pressure compressor and high pressure compressor; and controlling rotation of the low pressure compressor using the first electrical machine, and controlling rotation of the high pressure compressor using the second electrical machine to restart the start-up process or perform the re-light process.

A gas turbine engine for an aircraft comprises a high-pressure (HP) spool comprising an HP compressor and a first electric machine driven by an HP turbine; a low-pressure (LP) spool comprising an LP compressor and a second electric machine driven by an LP turbine; a combustion system comprising a fuel metering unit; and an engine controller configured to, in response to a change of a power lever angle setting indicative of a deceleration event, reduce fuel flow to the combustion system by the fuel metering unit, and to operate the first electric machine in a generator mode to reduce the HP spool rotational speed and engine core mass flow.

In a method for operating a combustor of an embodiment, before ignition in the combustor, a mixed gas containing oxygen is circulated through the combustor as a circulating gas. Then, in an operating time from the time of ignition in the combustor to the time of a rated load of a turbine, from the time of ignition until reaching stable combustion conditions allowing stable combustion, a combustion gas in which a controller controls a flow rate of a fuel supplied from a fuel supply part and a flow rate of an oxidant supplied from an oxidant supply part to maintain the same oxygen concentration as an oxygen concentration in the mixed gas is circulated as the circulating gas.

A controller for a gas turbine, wherein the gas turbine includes the compressor arranged to operate at a rotational speed n, the combustor and the fuel supply including the first fuel supply and the second fuel supply, wherein the compressor is arranged to provide air to the combustor at a steady state air mass flow rate m.sub.ss and wherein the fuel supply is arranged to supply fuel at a fuel mass flow rate m.sub.total to the combustor. The controller is arranged to, responsive to a load change ΔL to the load L, control the compressor to provide air to the combustor at a new air mass flow rate m.sub.TR, wherein the new air mass flow rate m.sub.TR is within a range between a first threshold m.sub.LBO and a second threshold m.sub.SUR.

A method for detecting blowout precursors in at least one gas turbine combustor comprising: receiving combustion dynamics acoustic data measured by an acoustic measuring device associated with the combustor in real time; performing wavelet analysis on the acoustic data using simplified Mexican Hat wavelet transform analysis; and determining the existence of a blowout precursor based at least in part on the wavelet analysis. Provided also is a system and a non-transitory computer readable medium configured to perform the method.

Methods and systems for detecting and responding to an engine disturbance are described. The method comprises monitoring a rate of change of a combustor pressure of an engine, detecting an engine disturbance when the rate of change of the combustor pressure falls below an event detection threshold, initiating an engine recovery sequence in response to detecting the engine disturbance, confirming a surge event when the rate of change of the combustor pressure increases above a surge confirmation threshold within a flameout confirmation time period after having crossed the event detection threshold, applying a surge recovery sequence in response to confirming the surge event, confirming a flameout event when the flameout confirmation time period expires and the rate of change of the combustor pressure remains below the surge confirmation threshold after having crossed the event detection threshold, and applying a flameout recovery sequence in response to confirming the flameout event.

A system and method for adaptively controlling a cooldown cycle of an auxiliary power unit (APU) that is operating and rotating at a rotational speed includes reducing the rotational speed of the APU to a predetermined cooldown speed magnitude that ensures combustor inlet temperature has reached a predetermined temperature value, determining, based on one or more of operational parameters of the APU, when a lean blowout of the APU is either imminent or has occurred, and when a lean blowout is imminent or has occurred, varying one or more parameters associated with the shutdown/cooldown cycle.

Methods and systems are provided for presenting an energy state associated with an aircraft with respect to an operating envelope region for a procedure to restart an engine of the aircraft. One method involves providing a graphical user interface display having a first reference axis corresponding to a first energy state parameter and a second reference axis corresponding to a second energy state parameter different from the first energy state parameter, providing a graphical representation of an operating envelope region associated with a procedure for starting an engine of the aircraft with respect to the first and second reference axes, obtaining current values for the first and second energy state parameters for the aircraft, and providing a graphical representation of the aircraft positioned with respect to the first and second reference axes based on the current values for the first and second energy state parameters.

An aircraft includes an aircraft engine, a starter motor, an engine fuel delivery system, an engine ignition system, and a controller communicatively coupled to the starter motor, engine fuel delivery system, and engine ignition system. The controller is configured to automatically initiate operation of the starter motor as needed to start the aircraft engine while the aircraft engine is not running. Optionally, the controller may be configured to execute operations in accordance with either or both of two modes of operation. In the first mode, the controller automatically initiates operation of the starter motor for an aircraft engine that is not running while the aircraft is in flight. In the second mode, the controller automatically initiates operation of the starter motor for an aircraft engine that is not running while the aircraft is on ground. These operations can be done by a single, multi-position control.