A system has first and second fuel stores for first and second fuels, an engine, a fuel distribution system, first and second flow rates of the fuel contributing to a total flow rate of fuel; and a controller for controlling the relative fractions of the total flow rate of fuel to the engine according to the required power output of the engine such that the relative fraction of the total flow rate of fuel to the engine represented by the second flow rate increases with increasing required power output of the engine. The fuels are selected such that using only the second fuel results in a lower engine temperature than using only the first fuel, for the same mechanical power and/or the second fuel has a lower specific energy than the first and/or the second fuel produces more water during combustion than the first fuel per unit of fuel energy.

A system comprises first and second first fuel stores, an engine arranged to produce mechanical power, a fuel distribution system arranged to deliver fuel from the first and second fuel stores to the engine, the first fuel delivered at a first mass flow rate, the second fuel delivered at a second mass flow rate, the first and second mass flow rates contributing to a total mass flow rate of fuel to the engine, and a control system arranged to increase the relative fraction of the total mass flow rate of fuel represented by the second mass flow rate during a period of acceleration of the engine, in order to control a surge margin of the engine. The second fuel is selected to have a higher specific energy than the first fuel and to release a greater mass of water per unit mass of fuel than the first fuel.

An engine system comprises a first fuel store, a second fuel store, an engine arranged to produce mechanical power by combustion or oxidation of a fuel in an engine, a fuel distribution system arranged to deliver fuel from the first and second fuel stores to the engine, the first fuel delivered at a first mass flow rate, the second fuel delivered at a second mass flow rate, the first and second mass flow rates contributing to a total mass flow rate of fuel to the engine; and a control system arranged to control the relative fractions of the total mass flow rate of fuel to the engine represented by the first mass flow rate and the second mass flow rate, based on an engine temperature.

An apparatus measuring thrust of an aircraft gas turbine engine includes a core shaft connecting a turbine and compressor, a fan and gearbox with a sun gear driven by the core shaft, a plurality of planet gears, an annulus gear mounted in a static structure, and a planet carrier driven by the fan via fan shaft. The apparatus includes a sensor to measure force applied by the annulus gear on the static structure and first and second sensors to measure rotational speed of the core and fan shafts. A processor determines restoring torque on the annulus gear from measurement of force applied by the gear on the static structure, torque applied to the fan by the planet carrier using rotational speeds of core and fan shafts and restoring torque on the annulus gear, and thrust of the fan from torque applied to the fan and the fan's rotational speed.

An aspect of the present disclosure provides a diagnosis device for an internal combustion engine. The internal combustion engine 1 includes a variable geometry type turbocharger 14, and the turbocharger includes a variable vane 28, a link mechanism configured to operate the variable vane, and an actuator 29 configured to drive the link mechanism. The diagnosis device includes a control unit 100 configured to control an opening degree of the variable vane by controlling the actuator. The control unit determines that an abnormality has occurred in the link mechanism of the turbocharger when an operating time of the internal combustion engine in a predetermined operating region exceeds a predetermined upper limit value and a differential pressure between a target boost pressure determined according to an operating state of the internal combustion engine and an actual boost pressure exceeds a predetermined upper limit value.

The present application relates to a system for quality management of a filter unit disposed in an intake passage. The system includes a plurality of evaluation parameter detection units configured to detect an evaluation parameter relating to of each filter constituting a filter layer of the filter unit. By determining a distribution of the evaluation parameter based on the detection values, the quality evaluation is performed.

A controller for a gas turbine arranged to supply a load is described. The gas turbine includes a fuel supply arranged to supply fuel at a fuel flow rate to a combustor. The fuel supply includes a first fuel supply and a second fuel supply. The controller is arranged to control a proportion of the fuel flow rate supplied via the first fuel supply based, at least in part, on the fuel flow rate. A gas turbine includes such a controller and a method controls such a gas turbine.

A gas turbine engine for an aircraft. The gas turbine comprises a staged combustion system having pilot injectors and main injectors, a fuel metering system configured to control fuel flow to the pilot injectors and the main injectors, and a fuel system controller. The controller is configured to identify an atmospheric condition, determine a ratio of pilot fuel flow rate for the pilot injectors to main fuel flow rate for the main injectors in response to the atmospheric condition, and inject fuel by the pilot injectors and the main injectors in accordance with said ratio to control an index of soot emissions caused by combustion of fuel therein.

A method for operating a power plant, having at least one gas turbine engine and at least one fuel gas compressor, includes supplying fuel gas through a utility supply line, compressing the fuel gas to a plant supply pressure in the operating fuel gas compressor, and supplying the compressed fuel gas to a plant supply line. The gas turbine engine is operated at a set power output according to a power demand signal. If a failure of an operating fuel gas compressor is detected, the power output of the gas turbine engine is reduced to an emergency power output (which is lower than the set power output), and the power output of the gas turbine engine is restricted to the emergency power output. The reduction of the power output is performed in one single step and is controlled by at least one feedforward control signal.

A method for controlling the bending deformation of a turbomachine shaft at rest subjected to the residual heat of operation of the turbomachine, wherein the shaft is rotated at a rotation speed between 0.1 and 50 revolutions per minute depending on the bending deformation deflection of the shaft when the turbomachine is at rest.