An auxiliary power unit (APU) control system for an aircraft is disclosed, and includes an APU drivingly coupled to one or more generators, one or more processors, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the APU control system to receive one or more ambient signals indicative of an air density value and one or more power signals indicative of a specific amount of power generated by the APU. The system is further caused to determine a first variable rotational speed of the APU based on the air density value. The APU continues to generate the specific amount of power when operating at the first variable rotational speed. After instructing the APU to operate at the first variable rotational speed, the system receives an electrical load signal.

In one embodiment, a turbine system includes a compressor, an intake section including a filter house and an inlet duct. The intake section is coupled to the compressor, and the filter house is upstream from the inlet duct. The turbine system also includes one or more sensors disposed in the intake section, and a processor configured to receive sensor data from the one or more sensors, one or more filter degradation rates for one or more filtration stages of the filter house, or some combination thereof, predict a compressor degradation rate for the compressor using a compressor degradation prediction model that provides a function of performance of the compressor based on the sensor data, the one or more filter degradation rates, or some combination thereof, and perform one or more preventative actions based on the compressor degradation rate prediction.

In an example, a method for on-board maintenance of an aircraft is described. The method includes measuring, by a pressure sensor, a pressure in a tube associated with an engine of an aircraft. The method also includes determining, by a control system and based on the pressure measured by the pressure sensor, that the tube is at least partially blocked by moisture. Additionally, the method includes, responsive to determining that the tube is at least partially blocked by the moisture, providing an alert signal from the control system to a flight deck of the aircraft. The method also includes, responsive to the alert signal, operating an actuation switch at the flight deck to actuate a valve to an open state. The method further includes, responsive to actuating the valve to the open state, supplying an inert gas from an inert gas supply to the tube to expel the moisture.

Systems and methods for condition-based validation of performance updates are provided. According to one embodiment of the disclosure, a method can include operating an asset under updated settings, ascertaining ambient conditions of the asset and matching the ambient conditions to a condition range, determining whether data completion criteria for the condition range are satisfied and, based at least in part on the determination, selectively switching between using the updated settings for operating the asset and using baseline settings for operating the asset while collecting data points for a predetermined period of time.

The present invention provides a deep learning regulation and control and assembly method and device for large-scale high-speed rotary equipment based on dynamic vibration response properties. The present invention starts from geometrical deviation of multiple stages of rotor/stator of an aircraft engine, amount of unbalance of rotor/stator, rigidity of rotor/stator and vibration amplitude of rotor/stator, considers the influence of the area of the assembly contact surface between two stages of rotors/stators, and sets the rotation speed of rotor/stator to be the climbing rotation speed to obtain vibration amplitude parameters. According to the calculation method of the coaxiality, amount of unbalance, rigidity and vibration amplitude of multiple stages of rotor/stator, an objective function taking assembly phases as variables is established, a Monte Carlo method is used to solve the objective function, and a probability density function is solved according to a drawn distribution function to obtain the probability relationship between the contact surface runout of the rotor/stator of the aircraft engine and the final coaxiality, amount of unbalance, rigidity and vibration amplitude of multiple stages of rotor/stator, thereby realizing assembly optimization and distribution of tolerances of multiple stages of rotor/stator.

A centrifugal compressor includes: a casing; a compression mechanism disposed inside the casing; a flow rate regulation valve disposed inside the casing and that regulates a flow rate of air sucked into the casing; a conversion mechanism disposed outside the casing and that changes a direction of the flow rate regulation valve based on an output of an actuator; and a cover that surrounds and houses the conversion mechanism, wherein dry air is supplied to an inside of the cover, and the cover forms an air reservoir that prevents dew condensation on the conversion mechanism.

A method for operating a gas turbine plant having a compressor and a turbine, where a limit value of a guide blade adjustment for the compressor of the gas turbine is identified depending on at least one drive shaft speed of the gas turbine plant. For the at least one drive shaft speed, a maximum allowable turbine entry temperature corresponding to the limit value of the guide vane adjustment for the compressor or a maximum allowable temperature for the turbine of the gas turbine, which is dependent on the turbine entry temperature, is identified. The gas turbine is operated in consideration of the identified maximum allowable turbine entry temperature or the identified maximum allowable temperature.

Systems and methods for mitigating flameout risk in an engine of an aircraft are provided. A humidity value is obtained from a humidity sensor associated with the engine. A flameout risk for the engine is determined based on the humidity value. The flameout risk is compared to a predetermined risk threshold. When the flameout risk is above the predetermined risk threshold, a rate of fuel flow to the engine is increased.

Herein provided are systems and methods for operating an engine of an aircraft. The engine is operated at a first fuel flow rate. An indication of a measured humidity level within the engine is obtained from a humidity sensor coupled to the engine. A determination is made regarding whether the measured humidity level within the engine is indicative that a flameout risk for the engine is below a predetermined risk level. Responsive to determining that the flameout risk is below the predetermined risk level, the engine is operated at a second fuel flow rate lower than the first fuel flow rate.

Methods and apparatus for controlling liquid flow to a turbine fogging array. Some implementations are generally directed toward adjusting the output of a variable output pump that supplies water to the turbine fogging array. In some of those implementations, the output is adjusted based on a determined target pump output value that is indicative of a pump output required to change the moisture content of intake air of a combustion turbine to meet a target humidity value. Some implementations are generally directed toward actuating at least one control valve of a plurality of control valves that control liquid throughput to one or more fogging nozzles of a fogging array.