A starter air valve (SAV) system can include a pressure actuated SAV actuator configured to be operatively connected to a SAV and a first pressure valve configured to selectively allow pressure from a pressure source to the SAV actuator when in fluid communication with the SAV actuator. The first pressure valve can be a pulse-width modulation solenoid valve configured to provide a duty cycle of pressure from the pressure source to the SAV actuator.

A method of controlling a rotor tip clearance in a gas turbine engine (10). The method comprises determining an engine or component remaining useful life T.sub.r, and controlling a tip clearance control arrangement (38) to maintain a rotor tip clearance (36) at a target tip clearance D.sub.target. The target tip clearance D.sub.target is determined in accordance with a function of remaining engine life T.sub.r.

A starter air valve (SAV) system includes a pressure actuated SAV actuator configured to be operatively connected to a SAV, a first pressure valve configured to selectively allow pressure from a pressure source to the SAV actuator when in fluid communication with the SAV actuator, and a second pressure valve configured to selectively allow pressure from the pressure source to the SAV actuator when in fluid communication with the SAV actuator. A manual override (MOR) valve selector is disposed between the first pressure valve, the second pressure valve, and the SAV actuator, the MOR valve selector configured to selectively fluidly connect the first pressure valve and the SAV actuator in a first position and to fluidly connect the second pressure valve and the SAV actuator in a second position.

A method of controlling a complex system and a gas turbine being controlled by the method are provided. The method comprises providing training data, which training data represents at least a portion of a state space of the system; setting a generic control objective for the system and a corresponding set point; and exploring the state space, using Reinforcement Learning, for a control policy for the system which maximizes an expected total reward. The expected total reward depends on a randomized deviation of the generic control objective from the corresponding set point.

A gas turbine system includes a turbine combustor, a turbine, an exhaust gas compressor, an exhaust gas recirculation (EGR) system, a carbon black recovery system, and a carbon black production controller. The carbon black production controller monitors data corresponding to a parameter of the carbon black. The carbon black production controller is also configured to adjust, based on the data, the fuel provided to the turbine combustor while maintaining a ratio of the fuel to the oxidant within a predetermined range to adjust the parameter of the carbon black.

There is disclosed an aero gas turbine engine comprising a compressor and an array of variable inlet guide vanes for the compressor. The angle of the variable inlet guide vanes is controlled by scheduling, the scheduling comprising a first component invoked for engine ground start and a second component invoked for engine in-flight windmill start at least under particular flight conditions. The angle of the variable inlet guide vanes required by at least a portion of the second component is greater than the angle of the variable inlet guide vanes required by at least a portion of the first component.

A method for performing maintenance on an engine includes: providing an engine maintenance system including a database system having a database and a database management device: providing a first performance parameter stored in the database and characterizes an engine performance before an engine maintenance procedure; providing a maintenance parameter stored in the database and characterizes a scope of a maintenance measure performed on an engine during an engine maintenance procedure; providing a second performance parameter stored in the database and characterizes the engine performance after the engine maintenance procedure; determining, using the database management device, a functional relationship between the maintenance parameter and the contribution of the maintenance parameter to a difference between the first performance parameter and the second performance parameter; outputting the functional relationship via the engine maintenance system; and performing maintenance on the engine taking the functional relationship into account.

Turbines and associated equipment are normally cleaned via water or chemical pressure washing via a mist, spray systems. However, these systems fail to reach deep across the gas path to remove fouling materials. Various embodiments herein pertain to apparatus and methods that utilize the water and exiting chemicals to generate a foam. The foam can be introduced at that gas-path entrance of the equipment, where it contacts the stages and internal surfaces. In one embodiment, the method can include: forming a first foam with a liquid cleaning agent and pressurized gas; flowing the first foam over a member or matrix and increasing the size of the cells of the first foam to form a second foam; and flowing the second foam through a structure such as a mesh or one or more apertured plates and decreasing the size of the cells of the second foam to form a third foam.

An aircraft can comprise an engine, an environmental control system, an engine controller, and a plurality of sensors detecting engine or aircraft parameters. Engine or aircraft operation can be updated in real time based on input from the sensors, including airflow management or operation parameters.

A bleed air cooling system for a gas turbine engine includes one or more bleed ports located at one or more axial locations of the gas turbine engine to divert a bleed airflow from a gas turbine engine flowpath, a bleed outlet located at a cooling location of the gas turbine engine and a bleed duct in fluid communication with the bleed port and the configured to convey the bleed airflow from the bleed port to the bleed outlet. One or more safety sensors are configured to sense operational characteristics of the gas turbine engine, and a controller is operably connected to the one or more safety sensors and configured to evaluate the sensed operational characteristics for anomalies in operation of the bleed air cooling system.