A method for checking the maximum available power of a turbine engine of an aircraft equipped with two turbine engines configured to operate in parallel and together to supply a necessary power to the aircraft during a flight phase includes: placing one of the turbine engines in a maximum take-off power regime, and adjusting a power supplied by the other turbine engine, such that the turbine engines continue to supply the necessary power to the aircraft during the flight phase; determining a power supplied by the turbine engine placed in the maximum take-off power regime, and processing the supplied power determined in this way, in order to deduce a piece of information relating to the maximum available power.

Flow multiplier systems for aircraft are described herein. A flow multiplier system includes a turbo-compressor having a compressor, a turbine, and a drive shaft coupled between the compressor and the turbine. A compressor outlet of the compressor is fluidly coupled to an ejector in a gas turbine engine. The system also includes a supply line fluidly coupling a compressed air tank and a turbine inlet and a valve coupled to the supply line. The system includes a controller configured to, based on an input signal requesting to increase output power of the gas turbine engine, send a command signal to open the valve to enable a flow of pressurized air from the compressed air tank to the turbine inlet. The turbine drives the compressor to create high pressure air at the compressor outlet, which is provided into the gas turbine engine to increase the output power.

An embodiment of an engine assembly includes a plurality of offtakes powered by a combustion turbine engine having a high spool and at least one lower spool, and a controller configured to operate the combustion turbine engine through a range between a first low-idle mode, a second high idle mode, and a maximum takeoff power rating mode. The controller operates the engine in the low-idle mode by directing at least a first portion of power from the at least one lower spool to the plurality of offtakes, and wherein the controller operates the engine in the high idle mode by increasing a speed of the high spool relative to a speed of the high spool in the low-idle mode, thereby increasing a compressor outlet (T.sub.3) temperature in the high idle mode relative to a T.sub.3 temperature in the low-idle mode.

An auxiliary power unit (APU) control system for an aircraft is disclosed. The APU control system includes an APU, one or more processors, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the APU control system to receive a one or more ambient signals indicative of an air density value and one or more power signals indicative of a specific amount of power generated by the APU. The APU control system is further caused to determine a variable rotational speed of the APU based on the air density value and instruct the APU to operate at the variable rotational speed. The APU continues to generate the specific amount of power when operating at the variable rotational speed.

An auxiliary power unit (APU) control system for an aircraft is disclosed, and includes an APU drivingly coupled to one or more generators, one or more processors, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the APU control system to receive one or more ambient signals indicative of an air density value and one or more power signals indicative of a specific amount of power generated by the APU. The system is further caused to determine a first variable rotational speed of the APU based on the air density value. The APU continues to generate the specific amount of power when operating at the first variable rotational speed. After instructing the APU to operate at the first variable rotational speed, the system receives an electrical load signal.

A method includes receiving a command to operate a power load of a power system at a command output power while operating the power load at a reference output power; operating a gas turbine engine of the power system in a maximum regulator mode to increase a power generation of the gas turbine engine when the command output power is greater than the reference output power or in a minimum regulator mode to decrease the power generation of the gas turbine engine when the command output power is less than the reference output power; and coordinating an electric machine power draw from the gas turbine engine with a change in power generation of the gas turbine engine to maintain a rotational speed parameter of the gas turbine engine substantially constant while operating the gas turbine engine in the maximum regulator mode or in the minimum regulator mode.

A gas turbine engine comprises a fan at an axially outer location, the fan rotating about an axis of rotation, delivering air into an outer bypass duct, a radially middle duct, and a radially inner core duct. Air from the inner core duct is directed into a compressor, and then flows axially in a direction back toward the fan through a combustor section, and across a core turbine section, and is then directed into the middle duct. A gear reduction drives the fan from a fan drive turbine section. A method of operating a gas turbine engine is also disclosed.

The disclosure includes a system that includes an adaptive control module for an engine. The adaptive control module is configured to receive a power input signal and receive, from an engine vibration sensor, a vibration signal indicative of an operating condition of the engine. The adaptive control module is further configured to determine, using a set of control laws, a power demand signal based on inputs including the power input signal and the vibration signal. The adaptive control module is further configured to output the power demand signal to at least one component of the engine.

Herein provided are methods and systems for controlling an engine having a variable geometry mechanism. A pressure ratio between a first pressure at an inlet of the engine and a predetermined reference pressure is determined. An output power for the engine is determined. The output power is adjusted based at least in part on the pressure ratio to obtain a corrected output power. A position control signal for a variable geometry mechanism of the engine is generated based on the corrected output power and the pressure ratio. The position control signal is output to a controller of the engine to control the variable geometry mechanism.

Hybrid electric propulsion systems are described. The systems include a gas turbine engine having low and high speed spools, each spool having a respective compressor and turbine. A mechanical power transmission is configured to at least one of extract power from and supply power to at least one of the low speed spool and the high speed spool, an electric machine is configured to augment rotational power of at least one of the spools, and a controller is operable to determine a rotational speed of the low speed spool, determine a rotational speed of the high speed spool, determine if a predetermined operational zone of operation based on the determined rotational speeds is present, and when a predetermined operational zone is determined, control a power augmentation of at least one spool to limit dwell operation of the gas turbine engine within the predetermined operational zone.