In accordance with at least one aspect of this disclosure, there is provided a fuel control system for gaseous fuel in an aircraft. The system includes a control module operatively connected to a metering device in a fuel flow conduit, the control module operable to control the flow of fuel through the fuel flow conduit. The control module includes an input line operable to receive a command input indicative of a requested engine state. In embodiments, the control module includes a compressibility logic and machine readable instructions. The machine readable instruction can be configured to cause the control module to control the metering device to achieve the requested engine state based on a compressibility factor input from the compressibility logic.

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 to contact, scrub, carry, and remove fouling away from equipment to restore performance.

Systems and methods for optimizing clearances within an engine include an adjustable coupling configured to couple a thrust link to the aircraft engine, an actuator coupled to the adjustable coupling, where motion produced by the actuator adjusts a hinge point of the adjustable coupling, sensors configured to capture real time flight data, and an electronic control unit. The electronic control unit receives flight data from the sensors, implements a machine learning model trained to predict clearance values within the engine based on the received flight data, predicts, with the machine learning model, the clearance values within the engine based on the received flight data, determines an actuator position based on the clearance values, and causes the actuator to adjust to the determined actuator position.

There are describes methods and systems for operating an engine coupled to a fuel system having a fuel manifold configured to supply fuel to a combustor of the engine. The method comprises receiving a gaseous fuel flow request indicative of a change in demand for gaseous fuel to the engine; applying a fuel loss bias to the gaseous fuel flow request to obtain a biased fuel flow request, the fuel loss bias associated with a change in mass flow rate of the gaseous fuel from the fuel manifold to the combustor in response to the change in demand; and causing the gaseous fuel to flow into the combustor in accordance with the biased fuel flow request.

A method of monitoring turbine blade creep in a gas turbine engine is provided. The method includes: receiving stereo images of a turbine blade of a row of turbine blades, the images having been obtained using a stereo borescope located in the engine adjacent the row of turbine blades; identifying same features of the blade in each of the stereo images; mapping each of the identified features by triangulation onto a 3D space to produce a 3D depth map of at least part of the blade; providing a 3D reference model of the blade; and comparing the 3D reference model with the 3D depth map to measure one or more deviations in shape of the blade to determine an amount of creep-induced distortion of the blade.

A control parameter optimization device is provided with: a plant model configured to calculate a control command value by a control device and a process quantity of a plant; a control parameter updating unit configured to update a control parameter used for calculating the control command value in the plant model, on the basis of an objective function calculated based on a calculation result of the process quantity in the plant model; and a structural model configured to calculate a clearance between a stationary member and a rotating member in the rotating machine, on the basis of the process quantity from the plant model. The control parameter updating unit is configured to search for an optimal control parameter within a range where the clearance calculated by the structural model satisfies a constraint condition.

A turbine device includes a fluid compressing device compressing a fluid, a combustion device, a fuel supply device supplying a fuel to the combustion device, the combustion device combusting a mixture of the fluid and the fuel, a sensing device, and a control device. The sensing device senses a humidity of the fluid compressed in the fluid compressing device. The control device controls the supply of the fuel by the fuel supply device based on the humidity sensed by the sensing device.

Various embodiments herein pertain to apparatus and methods that utilize the water and existing 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, to contact, scrub, carry, and remove fouling away from equipment to restore performance. Various embodiments include operating a gas turbine engine; measuring the performance of the engine during operation; determining that the engine should be foam washed based on the measurements; mixing pressurized gas with pressurized liquid and creating a supply of foam; and streaming the supply of foam into the engine.

A method of determining a calorific value of fuel supplied to a gas turbine engine of an aircraft comprises sensing at least one engine parameter during a first time period of aircraft operation during which the gas turbine engine uses the fuel; and, based on the at least one sensed engine parameter, determining a calorific value of the fuel. The sensing may be repeated such that the at least one engine parameter is monitored over time. The gas turbine engine may be a propulsive gas turbine engine of the aircraft or a gas turbine engine of an auxiliary power unit of the aircraft.

A system for a gas turbine engine includes an igniter event conductor. The igniter event conductor has a first portion adjacent an igniter of the engine and in a combustion chamber of the engine and a second portion apart from the igniter and apart from the combustion chamber. The conductor is adapted to conduct an aspect of an igniter event at the igniter from the first portion to the second portion. A sensor is coupled to the second portion of the conductor to sense the aspect of the igniter event.