Methods and systems for measuring an axial position of a rotating component of an engine are described herein. The method comprises obtaining a signal from a sensor coupled to the rotating component, the rotating component having a plurality of position markers distributed about a surface thereof, the position markers having an axially varying characteristic configured to cause a change in a varying parameter of the signal as a function of the axial position of the rotating component. Based on the signal, the method comprises determining a rotational speed of the rotating component from the signal, determining the varying parameter of the signal, and finding the axial position of the rotating component based on a known relationship between the axial position, the rotational speed, and the varying parameter of the signal.

A method of controlling a combustion system of a gas turbine engine which has a combustor with a primary combustion zone, of which a condition in the primary combustion zone is defined by a primary zone control parameter. The method includes controlling the primary zone control parameter to be substantially constant value over a range of values of compressor inlet air temperature.

Methods and system for operating a gas turbine engine are described. The method comprises determining an actual engine output power based on a torque of the gas turbine engine, comparing the actual engine output power to an estimated engine output power to obtain an error, obtaining an actual engine speed and biasing the actual engine speed using the error to produce a biased engine speed, determining the estimated engine output power using a model-based estimator having the biased engine speed as input, detecting a torque-related fault based on the error and a first threshold, and accommodating the torque-related fault in response to detecting the torque-related fault.

A steam turbine includes: a rotor; a casing; a thrust bearing; a steam inlet; a first pipe; a first regulation valve; a second pipe; a second regulation valve; and a control device. The control device estimates an exhaust flow rate of the steam turbine based on an operating point map which derives the exhaust flow rate of the steam turbine from an operating point of the steam turbine and estimates the thrust force applied to the thrust bearing based on the exhaust flow rate.

A gas turbine engine system includes an engine component comprising ceramic matrix composite materials, at least one control system configured to control at least a temperature of the engine component, and a controller. The controller includes a degradation map stored therein. The degradation map includes degradation fields, each field defined by a unique range of temperatures and stresses of the component and correlated to different types of degradation of the component. The controller is configured to determine a first temperature and stress of the component and a first field based on the first temperature and stress, determine a second field different from the first and a second temperature and stress that would locate the component in the second field, and instruct the control system to change the temperature of the component from the first to the second temperature to locate the component in the second field.

There is provided a rotor bow mitigation system and method for an aircraft engine. At least one value of at least one engine parameter prior to a shutdown of the engine is obtained, the at least one engine parameter comprising a first temperature internal to the engine. A second temperature external to the engine is measured and a motoring duration and a motoring interval for the engine are determined based on at least the first temperature and on the second temperature. Upon detecting a start indication for the engine, the engine is motored for the motoring duration and at the motoring interval.

There is provided a dynamic motoring system and method for an aircraft engine. Motoring of the engine is initiated for an initial motoring duration and at an initial motoring interval. At least one engine parameter is measured in real-time during the motoring, the at least one engine parameter comprising a temperature of the engine. The initial motoring duration and the initial motoring interval are modified in real-time, based on a value of the at least one engine parameter during the motoring, to obtain a modified motoring duration and a modified motoring interval. The motoring continues for the modified motoring duration and at the modified motoring interval, with a speed of rotation of the engine being controlled using the modified motoring interval.

Systems and methods for controlling a gas turbine engine are provided. The system comprises an interface to a fuel flow metering valve for controlling a fuel flow to the engine in response to a fuel flow command and a controller connected to the interface and configured for outputting the fuel flow command to the fuel flow metering valve in accordance with a required fuel flow. The controller comprises a feedforward controller configured for receiving a requested engine speed and acceleration, obtaining a steady-state fuel flow for the requested engine speed and a relationship between fuel flow and gas generator speed, and determining the required fuel flow to obtain the requested engine acceleration as a function of the requested engine speed, the steady-state fuel flow, and the relationship between fuel flow and gas generator speed.

A method, apparatus, system, and computer program product for managing pumps in an aircraft. Flight information about an operation of the pumps in a pump package in the aircraft is received by a computer system. The flight information is received from the aircraft. A number of times that an abnormal switching occurred for the pumps within a window of consecutive flights is determined by the computer system when the abnormal switching is identified from the flight information. A set of actions is performed by the compute system when the abnormal switching occurred a number of times for the pumps within the window of consecutive flights that exceeds a set of thresholds for the abnormal switching that is considered healthy for the pumps.

A fuel assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a fuel valve that meters flow of fluid between a combustor and a fuel supply, and a controller in communication with the fuel assembly. The controller is programmed to receive data corresponding to a present rotational speed of a gas turbine engine component and data corresponding to at least one present flight condition, and is programmed to cause a flow rate from the fuel valve to change in response to determining that a rate of change in an acceleration rate relating to the present rotational speed meets at least one predetermined threshold. At least one predetermined threshold relates to an engine light-off event of the combustor and is based upon the at least one present flight condition.