The invention relates to a turbomachine comprising a device for ventilating and pressurising a turbine rotor of a turbomachine of axis (A), the device comprising at least one collection pipe suitable for collecting a fraction of the air circulating in a high-pressure compressor of the turbomachine and conveying it to a first inner chamber (39) inside the turbomachine that communicates with a second inner chamber (40) delimited by the turbine (24) rotor (23), the first and second chambers (39, 40) being at least partially separated by a stationary shroud (56) of axis (A), characterised in that it comprises at least one injector (58) passing through the stationary shroud (56) and having a cross-section that varies in response to a pressure difference between said first and second chambers (39, 40).

In accordance with at least one aspect of this disclosure, there is provided a fuel system for a gas turbine engine of an aircraft, including a main inlet feed conduit fluidly connected to a primary manifold feed conduit and a secondary manifold feed conduit. A primary manifold fluidly connects the primary manifold feed conduit to a plurality of primary fuel injectors, and a secondary manifold fluidly connects the secondary manifold feed conduit to a plurality of secondary fuel injectors.

A method of designing a turbofan engine according to an exemplary aspect of the present disclosure includes, among other things, providing a fan section including a plurality of fan blades, providing a low pressure turbine driving the plurality of fan blades through a gear train, providing a fan nacelle and a core nacelle, the fan nacelle at least partially surrounding the core nacelle, providing a fan bypass flow path defined between the core nacelle and the fan nacelle, and providing a fan variable area nozzle in communication with the fan bypass flow path and defining a fan nozzle exit area between the fan nacelle and the core nacelle.

A method serves for operating an electronically controlled pump assembly (1), with which setting parameters of the pump (2) can be adjusted in an electronic control (6), for adaptation to the hydraulic demands of the location installation situation (4, 5). Operating data is registered during the operation of the pump assembly (1). After a predefined time and on the basis of the registered operating data, it is examined as to whether the pump assembly (1) has been set vis-à-vis the factory settings. If this is not the case a signal (11) is issued in order to point out the necessary setting.

A system and a method for configuring at least one variable geometry mechanism (VGM) of an aircraft engine are provided. Pass-off testing data for the aircraft engine is obtained, the pass-off testing data indicative of an actual value of at least one operating parameter of the aircraft engine. Based on the pass-off testing data, at least one trim value to be used to adjust a setting of the at least one VGM to bring the actual value of the at least one operating parameter towards a target value is determined, a running line of the aircraft engine being substantially constant when the actual value of the at least one operating parameter is at the target value. The setting of the at least one VGM is adjusted, during pass-off testing of the aircraft engine, using the at least one trim value.

A fuel control device includes a stem fuel valve opening degree determination unit, a branch line flow rate determination unit, and a correction value determination unit. The stem fuel valve opening degree determination unit is configured to determine an opening degree of a flow rate adjustment valve of a stem fuel supply line. The branch line flow rate determination unit is configured to determine an opening degree of a flow rate adjustment valve of at least one branch line. The correction value determination unit is configured to determine a correction value of the opening degree of the flow rate adjustment valve of the at least one branch line based on a value of a pressure difference between a fuel pressure upstream of a nozzle connected to the at least one branch line and a corrected fuel pressure for a fuel pressure at an outlet.

Methods and systems for supply of fuel for a turbine-driven fracturing pump system used in hydraulic fracturing may be configured to identify when the supply pressure of primary fuel to a plurality of gas turbine engines of a plurality of hydraulic fracturing units falls below a set point, identify a gas turbine engine of the fleet of hydraulic fracturing units operating on primary fuel with highest amount of secondary fuel available, and to selectively transfer the gas turbine engine operating on primary fuel with the highest amount of secondary fuel from primary fuel operation to secondary fuel operation. Some methods and systems may be configured to transfer all gas turbine engines to secondary fuel operation and individually and/or sequentially restore operation to primary fuel operation and/or to manage primary fuel operation and/or secondary fuel operation for portions of the plurality of gas turbine engines.

A heat exchange system for an aircraft engine includes a heat exchanger, a main conduit directing fuel to a combustion chamber of the aircraft engine, and a pump connected to the main conduit. A return conduit receives excess fuel outputted by the pump and exceeding a fuel requirement of the combustion chamber. The return conduit, which is connected to a fuel conduit of the heat exchanger, has an inlet connected to the main conduit downstream of the pump and an outlet connected to the main conduit upstream of the pump. An actuator has an inlet connected to the main conduit downstream of the pump and an outlet connected to the main conduit upstream of the pump while bypassing the heat exchanger, wherein a pressure differential between the actuator inlet and the actuator outlet remains substantially unchanged with variations of a fuel flow through the heat exchanger.

A method for determining a mass flow of a dynamic compressor that does not include a mass flow sensor while the compressor is operating to compress a working fluid includes determining, by a processor, a current operating point of the compressor. If the current operating point is the same as one in a map of a plurality of predetermined operating points stored in a memory, the mass flow of that predetermined operating point is retrieved as the mass flow of the current operating point. Otherwise, the processor calculates the mass flow at the current operating point from the mass flows of a subset of the predetermined operating points nearest the current operating point. The dynamic compressor continues to operate to compress the working fluid based at least in part on the calculated mass flow rate for the current operating point.

Methods and systems for controlling a bleed-off valve of a gas turbine engine are described. The method comprises maintaining a first bleed-off valve associated with a first compressor of the gas turbine engine at least partially open upon detection of an unintended engine disturbance causing a drop in pressure of a combustion chamber of the engine; monitoring a rotor acceleration of the first compressor; and controlling closure of the first bleed-off valve when the rotor acceleration of the first compressor reaches a first threshold for a first duration.