A shaft event is detected, such as a shaft shear, a shaft decoupling, and/or a shaft failure in a gas turbine engine comprising a first spool and a second spool different from the first spool. First and second parameters indicative of the power of the first spool and a load transfer through a shaft of the second spool are obtained. A detection threshold is determined as a function of the first parameter. The second parameter is compared to the detection threshold. The shaft event is detected when the second parameter is beyond the detection threshold and then a signal indicative of the shaft event is transmitted.

A method of health monitoring of a gas turbine engine includes mounting a detection system configured to detect an aeromechanical damping characteristic of a row of airfoils of a gas turbine. An actual aeromechanical damping characteristic of the row of airfoils is measured with the detection system. An output signal is generated indicative of the actual aeromechanical damping characteristic of the row of airfoils. A current flutter characteristic is determined based on the output signal indicative of the actual aeromechanical damping characteristic of the row of airfoils. An airfoil health monitoring system for gas turbine engine and a gas turbine engine are also disclosed.

An apparatus measuring thrust of an aircraft gas turbine engine includes a core shaft connecting a turbine and compressor, a fan and gearbox with a sun gear driven by the core shaft, a plurality of planet gears, an annulus gear mounted in a static structure, and a planet carrier driven by the fan via fan shaft. The apparatus includes a sensor to measure force applied by the annulus gear on the static structure and first and second sensors to measure rotational speed of the core and fan shafts. A processor determines restoring torque on the annulus gear from measurement of force applied by the gear on the static structure, torque applied to the fan by the planet carrier using rotational speeds of core and fan shafts and restoring torque on the annulus gear, and thrust of the fan from torque applied to the fan and the fan's rotational speed.

The invention relates to a drive system for an, in particular electrically driven, aircraft. The drive system is provided with thrust measuring means which measure a currently effective thrust of the thrust generator of the aircraft. The measurement values obtained in this way are supplied to a controller of the drive system, which uses the measured thrust, along with other parameters, to control the drive system such that a selectable parameter, e.g. the thrust or an efficiency of the drive system, can be is optimised.

Methods and apparatus are disclosed to determine material parameters of a turbine rotor. An example apparatus includes a rotor geometry determiner to determine a geometry of the rotor, a node radius calculator to calculate radial node locations of radial nodes including a first radial node, a thermocouple interface to record first temperature values over an interval, a first thermal stress calculator to calculate first thermal stress values at one or more of the radial nodes over the interval, a node temperature calculator to calculate second temperature values at respective internal nodes of the first radial node, a reference value lookup to lookup first material parameter information, a second thermal stress calculator to determine second thermal stress values, a thermal stress comparator to calculate a difference between the thermal stress values, and, in response to the difference not satisfying a threshold, a material parameter adjuster to determine material parameters.

The present invention discloses a dynamic strain field measuring method and system for a rotor blade based on blade tip timing. The method includes the following steps: establishing a three-dimensional finite element model of a to-be-measured rotor blade, and extracting modal parameters of the three-dimensional finite element model; determining the number and circumferential mounting positions of blade tip timing sensors; establishing a mapping relationship between single-point displacement and full-field dynamic strains of the blade; acquiring blade tip single-point displacement of the rotor blade based on the blade tip timing sensors; and realizing, by the single-point displacement, dynamic strain measurement in any position and direction of the rotor blade based on the mapping relationship.

[Object] To observe the sign or occurrence of an unstable operation of a turbo-machine. [Solving Means] An observation apparatus 1 includes: a detection unit 10 including one or two or more sensors 11, 12 that are disposed in a turbo-machine 2, are highly time responsive, and observe unsteady fluctuations of the turbo-machine 2; a computation unit 20 that output signals from the one or two or more sensors 11, 12 every moment, stores time series data for a predetermined period, and calculates in real time a parameter for detecting an unstable operation of the turbo-machine; and a determination unit 30 that compares the parameter for detecting the unstable operation with a predetermined threshold and outputs in real time a determination result of a sign or occurrence of the unstable operation.

A sensor system includes a rotor antenna, a radio frequency (RF) sensor, a stator antenna, and one or more processors. The rotor antenna and the RF sensor are configured to be disposed on a shaft of a rotor assembly and are conductively connected to each other. The RF sensor generates measurement signals. The stator antenna is mounted to a stator member of the rotor assembly and positioned radially outward from the rotor antenna. The stator antenna is wirelessly connected to the rotor antenna across an air gap. The one or more processors are communicatively connected to the stator antenna and are configured to monitor one or more electrical characteristics of the measurement signals that are received by the stator antenna from the rotor antenna over time as the shaft rotates and to determine rotational speed of the shaft based on recurrent variations in the one or more electrical characteristics.

There is described herein methods and systems for detecting a shaft event, such as a shaft shear, a shaft decoupling, and/or a shaft failure in a gas turbine engine comprising a first spool and a second spool different from the first spool. A first parameter indicative of one of power of the first spool and a load transfer through a shaft of the second spool is obtained and a second parameter indicative of the other one of power of the first spool and the load transfer through the shaft of the second spool is obtained. A detection threshold is determined as a function of the first parameter. The second parameter is compared to the detection threshold. The shaft event is detected when the second parameter is beyond the detection threshold and then a signal indicative of the shaft event is transmitted.

A method for creating a three-dimensional (3D) mark in a protective coating including at least one of a TBC and a bond coating over a metal part, is provided. The method may include positioning a mask over the protective coating, the mask including an opening pattern therein; and performing an abrasive waterjet process on the protective coating using the mask. The abrasive waterjet erodes a first portion of the protective coating exposed through the first opening pattern to create the 3D mark. The mask is removed, leaving the 3D mark in the protective coating. The 3D mark only partially penetrates through the protective coating. A metal part may include a metal body, a protective coating over the metal body, and the 3D mark in the protective coating, is also provided. The 3D mark in the protective coating may include an opening having a width of between 30 and 300 micrometers.