The present disclosure provides a method of multi-objective and multi-dimensional online joint monitoring for a nuclear turbine. The method includes: obtaining first temperature monitoring data of the nuclear turbine by performing online thermal monitoring on a rotor, a valve cage and a cylinder of the nuclear turbine under quick starting-up; obtaining second temperature monitoring data of tightness of a flange association plane of the cylinder of the nuclear turbine by performing online thermal monitoring on the tightness of the flange association plane; obtaining operation monitoring data of a shafting vibration of a rotor and bearing system of the nuclear turbine by performing online safety monitoring on the shafting vibration of the rotor and bearing system; and optimizing operation and maintenance control of the nuclear turbine according to at least one type of monitoring data among the first temperature monitoring data, the second temperature monitoring data and the operation monitoring data.

A gas turbine engine starting system including an electric start generator (ESG) free of temperature sensors and configured to provide torque to a gas turbine engine. A fuel metering module is configured to provide a quantity of fuel to the gas turbine engine, and an electronic control system (ECS). The ESG includes a plurality of subcomponents. The ECS is configured to predict a future temperature of the ESG, predict that at an ongoing start or an uninitiated start will be unsuccessful, and provide the prediction that at an ongoing start or an uninitiated start will be unsuccessful to an operator. The prediction of the future temperature of the ESG is based on a plurality of historical ESG thermal trending information and an input ambient temperature. The prediction that at an ongoing start or an uninitiated start will be unsuccessful is based on the future temperature of the ESG.

A gas turbine engine starting system including an electric start generator (ESG) free of temperature sensors and configured to provide torque to a gas turbine engine. A fuel metering module is configured to provide a quantity of fuel to the gas turbine engine, and an electronic control system (ECS). The ESG includes a plurality of subcomponents. The ECS is configured to predict a future temperature of the ESG, predict that at an ongoing start or an uninitiated start will be unsuccessful, and provide the prediction that at an ongoing start or an uninitiated start will be unsuccessful to an operator. The prediction of the future temperature of the ESG is based on a plurality of historical ESG thermal trending information and an input ambient temperature. The prediction that at an ongoing start or an uninitiated start will be unsuccessful is based on the future temperature of the ESG.

According to an aspect, a method includes predicting, by a processor, a projected oil-wetted metal temperature in a lubrication system of a gas turbine engine at shutdown based on one or more thermal models prior to shutdown of the gas turbine engine. The processor determines a coking index based on the projected oil-wetted metal temperature and a coking limit threshold associated with one or more engine components. An oil coking mitigation action is triggered as a shutdown management event of the gas turbine engine based on the coking index.

A method of monitoring for combustion anomalies in a gas turbomachine includes sensing an exhaust gas temperature at each of a plurality of temperature sensors arranged in an exhaust system of the gas turbomachine, comparing the exhaust gas temperature at each of the plurality of temperature sensors with a mean exhaust gas temperature, determining whether the exhaust gas temperature at one or more of the plurality of temperature sensors deviates from the mean exhaust temperature by a predetermined threshold value, and identifying an instantaneous combustion anomaly at one or more of the temperature sensors sensing a temperature deviating from the mean exhaust temperature by more than the predetermined threshold value.

A method of monitoring for combustion anomalies in a gas turbomachine includes sensing an exhaust gas temperature at each of a plurality of temperature sensors arranged in an exhaust system of the gas turbomachine, comparing the exhaust gas temperature at each of the plurality of temperature sensors with a mean exhaust gas temperature, determining whether the exhaust gas temperature at one or more of the plurality of temperature sensors deviates from the mean exhaust temperature by a predetermined threshold value, and identifying an instantaneous combustion anomaly at one or more of the temperature sensors sensing a temperature deviating from the mean exhaust temperature by more than the predetermined threshold value.

A method includes obtaining a first test matrix for a first aircraft system and a second test matrix for a second aircraft system. The method also includes, during a first operational test of the first test matrix, obtaining sensor data that includes second sensor data that is not specified by the first test matrix. The method includes evaluating a second operational test of the second test matrix by processing the second sensor data using a second analytic model of the second aircraft system. The method also includes generating second predicted sensor data based on the evaluation of the second operational test. The method includes generating a second error measure by comparing a second subset of the sensor data to the second predicted sensor data. The method includes determining, based at least in part on a range of the second sensor data, a test coverage metric of the second test matrix.

Methods of determining a desired sensor probe location in a closed loop emissions control (CLEC) system of a gas turbine engine are provided. One method includes determining, at different locations, a plurality of temperature contour profiles for exhaust flowing through an exhaust duct, selecting an emissions component entrained in the exhaust to be measured, and determining a desired sensor probe installation location based on the emissions component to be measured and based on the plurality of temperature contour profiles.

Methods of determining a desired sensor probe location in a closed loop emissions control (CLEC) system of a gas turbine engine are provided. One method includes determining, at different locations, a plurality of temperature contour profiles for exhaust flowing through an exhaust duct, selecting an emissions component entrained in the exhaust to be measured, and determining a desired sensor probe installation location based on the emissions component to be measured and based on the plurality of temperature contour profiles.

An electric machine and a turning gear system for aircraft gas turbine engines are provided. The system has an electric machine designed for dual mode operation and a controller. The stator winding arrangement in the electric machine enables operation in either generating mode, during normal flight or motoring mode, during active engine turning. The controller is configured to reconfiguration connections of the windings external to the electric machine.