A system can include a gas turbine and a processing system. The gas turbine can include a compressor coupled to a turbine through a shaft. The processing system can be configured to: automatically transition an operating condition of the system through a plurality of operating states; determine an efficiency of the system at each of a plurality of the operating states; for each of the plurality of operating states: select a future operating state of the system based on the determined efficiency of the current operating state.

A method of controlling a gas turbine engine. The gas turbine engine has a compressor, a combustor, and a motor configured to drive the compressor. The method has in a first idle mode, controlling combustor fuel flow to maintain compressor rotational speed at or above a predetermined value; and in a second idle mode, controlling the combustor and the motor to drive the compressor to maintain the compressor rotational speed at or above a second predetermined value, lower than the first predetermined value.

The present disclosure provides methods for controlling volumetric flows of streams into a combustor, and particularly in a combustor utilized in a power production method. A controller can be used to receive a variety of inputs, carry out calculations, and output one or more signals that adjust one or more parameters of one or more of the streams entering the combustor. Such adjustments can be effective to normalize a volumetric flow rate between the combustor and a turbine immediately downstream from the combustor without requiring direct measurement of the volumetric flow rate between the combustor and the turbine immediately downstream from the combustor.

A system and a method for configuring at least one variable geometry mechanism (VGM) of an aircraft engine are provided. Pass-off testing data for the aircraft engine is obtained, the pass-off testing data indicative of an actual value of at least one operating parameter of the aircraft engine. Based on the pass-off testing data, at least one trim value to be used to adjust a setting of the at least one VGM to bring the actual value of the at least one operating parameter towards a target value is determined, a running line of the aircraft engine being substantially constant when the actual value of the at least one operating parameter is at the target value. The setting of the at least one VGM is adjusted, during pass-off testing of the aircraft engine, using the at least one trim value.

A method of maintaining at least one gas turbine engine includes monitoring a compressor of the gas turbine engine. The compressor includes a compressor case at least partially defining a flow path, a plurality of stages and a vane actuator system configured to move at least one of the stages. The vane actuator system includes a vane mover having one or more slots formed therein and configured to actuate the at least one stage. The vane mover may be replaced after the gas turbine engine has experienced engine degradation.

An aircraft includes a gas turbine engine and an optically-based measurement system. The gas turbine engine is configured to ingest a first mass flow and to exhaust a second mass flow. The optically-based measurement system is configured to determine the first and second mass flows in response to performing an imaging process on the gas turbine engine.

Methods and systems for determining an engine temperature for a gas turbine engine are provided. An estimated combustor temperature is determined based on at least one operating condition of the gas turbine engine and an estimated vane mass flow. A corrected vane mass flow is determined based on the estimated combustor temperature, the estimated vane mass flow, and a combustor pressure. The corrected vane mass flow is compared to a reference vane mass flow to obtain the mass flow correction factor. When a condition associated with the mass flow correction factor is not satisfied, the estimated combustor temperature is adjusted based on the mass flow correction factor to produce an adjusted combustor temperature; and the mass flow correction factor is updated based on the adjusted combustor temperature. When the condition associated with the mass flow correction factor is satisfied, the estimated combustor temperature is assigned as the engine temperature.

Methods and systems for operating an aircraft engine having a compressor are described. The method comprises determining, based on actual operating parameters of the aircraft engine, a compressor mass flow limit for an aerodynamic stability of the aircraft engine; determining an actual compressor mass flow of the compressor of the aircraft engine, wherein the actual compressor mass flow is based on measured values of the aircraft engine; comparing the actual compressor mass flow to the compressor mass flow limit; and governing operation of the aircraft engine to cause an alternative compressor mass flow when the actual compressor mass flow reaches or is anticipated to reach the compressor mass flow limit.

An acquisition unit is configured to acquire measurement values of a target device. The measurement values that are acquired include at least a temperature and a flow rate of an input fluid to be input to the target device, and a temperature and a flow rate of an output fluid to be output from the target device. A correction unit is configured to obtain a correction measurement value by which the measurement values are corrected through thermal equilibrium calculations based on the measurement values. A distance calculation unit is configured to calculate a Mahalanobis distance with a factor of the correction measurement value.

A method for determining a mass flow of a dynamic compressor that does not include a mass flow sensor while the compressor is operating to compress a working fluid includes determining, by a processor, a current operating point of the compressor. If the current operating point is the same as one in a map of a plurality of predetermined operating points stored in a memory, the mass flow of that predetermined operating point is retrieved as the mass flow of the current operating point. Otherwise, the processor calculates the mass flow at the current operating point from the mass flows of a subset of the predetermined operating points nearest the current operating point. The dynamic compressor continues to operate to compress the working fluid based at least in part on the calculated mass flow rate for the current operating point.