Methods and systems for governing an aircraft propeller of an engine are described. The method comprises obtaining a fluid flow command for speed control of the propeller, determining pulse parameters of a pulse width modulated valve control signal for actuating a two-position solenoid valve in accordance with the fluid flow command based on an average fluid flow through the solenoid valve and an opening and closing time of the solenoid valve, generating the valve control signal with the pulse parameters as determined, and transmitting the valve control signal to the solenoid valve for actuating the solenoid valve, thereby controlling the speed of the propeller.

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.

Methods and systems for calibrating an engine having a rotating shaft are provided. Readings from a plurality of speed sensors provided in one of a plurality of configurations about the shaft are obtained over a plurality of rotations of the shaft, the readings indicative of the passage of position markers and associated with a first precision level. A parameter indicative of relative spacing between the plurality of speed sensors is determined by applying a statistical algorithm to the readings, the parameter being associated with a second precision level higher than the first precision level. The parameter is compared to reference parameters associated with the plurality of configurations to identify an actual speed sensor configuration from amongst the plurality of configurations. The engine is calibrated based on the actual speed sensor configuration.

The subject matter of this specification can be embodied in, among other things, a method for controlling a turbine engine that includes receiving a predetermined arming threshold signal, receiving a predetermined triggering threshold signal, receiving a periodic signal from a speed sensor, determining a frequency signal based on the periodic signal, the predetermined arming threshold signal, and the predetermined triggering threshold signal, determining a speed value based on the determined frequency signal, and controlling a speed of a turbine based on the determined speed value.

A fuel supply system for a turbomachine, comprising a fuel circuit comprising pressurizer at the output of the circuit, a pump arranged to send into the circuit a fuel flow rate which is an increasing function of the rotational speed of a shaft of the pump, and a control circuit arranged to control the device to comply with a flow rate setpoint at the output of the fuel circuit. The system further comprises a feedforward corrector circuit configured to calculate an increment of the flow rate setpoint as a function of the engine speed of the turbomachine and of a variation in the engine speed of the turbomachine, and to add this increment to the flow rate setpoint. A method of regulating the pump is also described.

A turbine fracturing system and a controlling method thereof, a controlling apparatus and a storage medium are provided. The turbine fracturing system includes: N turbine fracturing apparatuses, wherein each of the N turbine fracturing apparatuses comprises a turbine engine, and N is an integer greater than or equal to 2; a fuel gas supply apparatus connected to the N turbine engines, wherein the fuel gas supply apparatus is configured to supply fuel gas and distribute the fuel gas to the N turbine engines as gaseous fuel; and a fuel liquid supply apparatus connected to at least one of the N turbine engines and configured to supply liquid fuel to at least one of the N turbine engines in a case that at least one of a flow rate and a pressure of the fuel gas decreases.

A system including: a journal bearing having a carrier, a rotor arranged rotatable about a rotational axis relative to the carrier, and a fluid in a clearance between the rotor and the carrier. A sensor measures a vibration signal of the rotor. A control system is adapted to determine a pressure set point for the fluid in the clearance based on the vibration signal, and to provide control signals generated based on the pressure set point. An active device is adapted to modify the pressure of the fluid in the clearance based on the control signals.

An aircraft power system includes an auxiliary power unit (APU), a generator, and a constant speed drive (CSD). The APU drives an APU drive shaft at a first rotational speed during a first condition and a second rotational speed during a second condition. The generator is rotatably coupled to a generator shaft and produces an AC voltage having a target frequency in response to rotation of the generator shaft at a target rotational speed. The CSD unit receives the first rotational speed from the APU drive shaft and rotates the generator shaft at the target rotational speed based on the first rotational speed. The CSD further receives the second rotational speed from the APU drive shaft and rotates the generator shaft at the target rotational speed based on the second rotational speed.

A system and method for adaptively controlling a cooldown cycle of an auxiliary power unit (APU) that is operating and rotating at a rotational speed includes reducing the rotational speed of the APU to a predetermined cooldown speed magnitude that ensures combustor inlet temperature has reached a predetermined temperature value, determining, based on one or more of operational parameters of the APU, when a lean blowout of the APU is either imminent or has occurred, and when a lean blowout is imminent or has occurred, varying one or more parameters associated with the shutdown/cooldown cycle.

The invention relates to a method for controlling the speed and the power of a turbine engine propeller, wherein at least two operating modes are implemented: —one operating mode, called “speed mode”, in which the pitch (β) of the propeller is controlled as a function of the desired propeller speed, while the fuel flow is controlled as a function of the desired torque; the other operating mode, called “β mode”, in which the fuel flow is controlled as a function of the desired propeller speed, the pitch (β) of the propeller being set to a limit angle (βmin) that limits the pitch of the propeller in the two operating modes, the pitch angle (βmin(t)) being continuously computed and updated during a flight on the basis of parameters relating to the flight conditions estimated in real time.