A method for controlling a combustion process in a gas turbine wherein a combustion chamber, a control device storing a calculation model of the combustion process, and an exhaust air measurement device are used. A permissible limit value for nitrogen oxides and for carbon monoxide as pollutants is set. The actual value of at least one of the two pollutants is measured continuously in the exhaust air. When a signal to reduce the power of the gas turbine to a lowest possible value is given, then a minimum fuel supply at which the limit values are complied with is calculated. The fuel supply is then reduced either until the calculated minimum fuel supply is reached or until the continuously measured proportion of the pollutant reaches the permissible limit value.

An assembly is provided for an engine. This engine assembly includes a fuel system, a sensor and a processing system. The fuel system includes a fuel source, an engine component and a fuel circuit configured to direct fuel from the fuel source to the engine component. The sensor is configured to provide sensor data indicative of a measured parameter of the fuel directed through the fuel circuit from the fuel source to the engine component. The processing system is configured to identify a fuel leak in the fuel system based on the sensor data. The fuel leak is identified when a measured value corresponding to the measured parameter of the fuel is less than an expected value corresponding to an expected parameter for the fuel directed through the fuel circuit from the fuel source to the engine component.

The invention relates to a method for controlling a pitch angle of the vanes or blades of a propellant body of a turbine engine, comprising generating a pitch command (i.sub.final) according to a rotational speed of the propeller (XN.sub.mes) and a speed setpoint (XN.sub.cons), the method comprises a nominal regulating chain (13), wherein the pitch command is further generated according to a value of a pitch angle (βmes) of the vanes or blades of the propellant body, and an off-nominal regulating chain (16), wherein the pitch command is generated independently of a value of a pitch angle of the vanes or blades of the propellant body.

A method of evaluating compliance of a component of an aircraft engine with flow requirements has: obtaining experimental data from experimental testing on a prototype of the component; obtaining a digitized model of a production model of the component, the digitized model including digitized apertures having geometrical data corresponding to that of apertures defined in the production model; computing a nominal mass flow rate through the digitized apertures using the geometrical data and flow parameters from the experimental data; correcting the nominal mass flow rate of the digitized model to obtain a computed mass flow rate of the production model; and assigning at least one parameter to the production model, the at least one parameter indicative of installation approval of the production model of the component for installation on the aircraft engine when the computed mass flow rate is determined to be within a prescribed range of the flow requirements.

A position deviation calculated by a subtractor of a vacuum pump is input to the PIDs of three modes. The first PID is a PID controller for a high-bias mode, the second PID is a PID controller for a high-rigidity mode, and the third PID is a PID controller for a low-rigidity mode. The output signal of the third PID is extracted as a change of an indicator current for each clock of a PWM frequency and then the mean value of a change of an indicator current for several clocks is determined in a calculating unit. At this point, a switching control unit performs an operation on whether the mean value of the averaged change of the indicator current is larger than a preset redetermined value and then according to the result, an α value is outputted in the range of 0 to 1 from the switching control unit.

A system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of a segregated impeller shroud in a turbine engine. The system comprises a driving mechanism coupled to a portion of a segregated impeller shroud. The driving mechanism comprises a driving arm and threaded axial member configured to translate motion of an actuator ring into axially forward and aft motion of the portion of the segregated impeller shroud.

Aspects of the disclosure are directed to systems and methods for receiving operating state parameters associated with an operative state of an aircraft, determining a clearance value between a first structure of the engine and a second structure of the engine, where the clearance value is determined based on the operating state parameters and a passive clearance model that includes a specification of an uncertainty in the clearance value, determining that the clearance value deviates from a clearance target in an amount that is greater than a threshold, and engaging an active clearance control (ACC) mechanism based on the deviation.

Systems and methods for measuring a clearance between a rotating machine component and a sensor unit are disclosed. In some aspects, a system includes a sensor unit oriented to detect the rotating machine component as the rotating machine component rotates past the sensor unit, the sensor unit including at least a first sensing element and a second sensing element spaced apart from the first sensing element. The system includes a sensor processing unit in electrical communication with the sensor unit. The sensor processing unit is configured for receiving a first waveform from the first sensing element; receiving a second waveform from the second sensing element; and determining, based on a comparison between the first waveform and the second waveform, a distance between the blade tip and the sensor unit.

A system and method for inspecting fan blade clearances in a fan stator module are presented. The method includes rotating a fan rotor assembly that includes an attached bracket situated between adjacent fan blades connected to the fan rotor assembly. The bracket includes a laser module and an inclinometer configured to measure a circumferential position of the laser module. The method further includes projecting a laser beam from the laser module to the fan case to determine a distance measurement between the laser module and the fan case at multiple circumferential points around the fan case. The distance measurement and circumferential position data is processed by a computing device to determine a clearance distance between a fan blade and the fan case.

The invention relates to a device (9) for cooling a turbine casing (7) for a turbomachine, such as for example an aircraft turbojet engine, extending around an axis (X) and comprising air-distribution means configured to take in air and convey it to the casing, characterized in that the air-distribution means comprising at least a first ramp (20a, 20b) and a second ramp (20a, 20b) extending circumferentially about the axis (X) respectively on a first circumferential portion and on a second circumferential portion which are different from each other, each ramp (20a, 20b) comprising air ejection orifices intended to be directed towards the casing in order to cool it, characterized in that it comprises adjustment means (23) capable of adjusting the flow rate of air ejected at the level of the first ramp (20a, 20b) with respect to the flow rate of air ejected at the level of the second ramp (20a, 20b).