A method for controlling compressed air sent to pneumatic systems. The method includes acquiring a set of performance demands for each of a plurality of pneumatic systems in a platform, where the performance demands indicate needs for the compressed air supplied to each of the pneumatic systems, identifying a maximum allowable air discharge temperature limit of a variable speed air compressor configured to supply compressed air to the pneumatic systems, and controlling an operation of the compressor to supply the compressed air to the pneumatic systems to meet the acquired performance demands for at least one of the pneumatic systems while operating the compressor below the maximum allowable air discharge temperature limit.

A gas turbine engine includes a main compressor section with a downstream most location. A turbine section has a high pressure turbine. A tap line is connected to tap air from a location upstream of the downstream most location in the main compressor section. The tapped air is connected to a heat exchanger and then to a cooling compressor. The cooling compressor compresses air downstream of the heat exchanger, and is connected to deliver air into the high pressure turbine. A bypass valve is positioned downstream of the main compressor section, and upstream of the heat exchanger. The bypass valve selectively delivers air directly to the cooling compressor without passing through the heat exchanger under certain conditions.

A gas turbine engine includes a main compressor section with a downstream most location. A turbine section has a high pressure turbine. A tap line is connected to tap air from a location upstream of the downstream most location in the main compressor section. The tapped air is connected to a heat exchanger and then to a cooling compressor. The cooling compressor compresses air downstream of the heat exchanger, and is connected to deliver air into the high pressure turbine. A bypass valve is positioned downstream of the main compressor section, and upstream of the heat exchanger. The bypass valve selectively delivers air directly to the cooling compressor without passing through the heat exchanger under certain conditions.

An aircraft turbomachine (100) comprising a first channel (200) putting into communication the high-pressure compressor (30) and a high-pressure turbine (50), a second channel (400) putting into communication the high-pressure compressor and a low-pressure turbine (60), the first channel being equipped with a valve (600), a third channel (700) being in selective communication with the first channel via the valve, the third channel being in communication with the low-pressure turbine, the valve having a first configuration in which air circulation in the first channel is allowed and prohibited in the third channel, and a second configuration in which air circulation of the first channel is diverted to the third channel, a control device (800) being configured to determine an air pressure of the low-pressure turbine and command the valve to cause it to transition from the first configuration to the second configuration depending on the determined pressure.

A hybrid propulsion system and methods for cooling the same are provided. The system may comprise a gas turbine and a secondary engine. The gas turbine engine may have a core passage and an engine compartment. The secondary engine may be a supersonic and/or hypersonic engine. The system may comprise a thermal barrier, an inlet and an exhaust. The thermal barrier may longitudinally envelope the gas turbine engine. The thermal barrier may comprise an inner envelope, an outer envelope, an upstream opening, and a downstream opening. The inlet may be in fluid communication with the ambient environment and the gas turbine engine via the upstream opening. The exhaust may be in fluid communication with the ambient environment and the gas turbine engine via the downstream opening. The engine compartment may be located between a boundary of the core passage and the inner envelope.

A turbine section for a gas turbine engine includes an independently controllable wheel downstream of the first static vane structure and a turbine rotor downstream of the independently controllable wheel. A method of generating thrust for a gas turbine engine, includes rotating a independently controllable wheel located downstream of a combustor and upstream of a turbine rotor to augment a swirl of a core flow combustion gases.

A fuel system for an engine can include a fuel circuit and a primary fuel pump in fluid communication with the fuel circuit and configured to pump fuel to the engine as a function of engine speed. The primary fuel pump is configured to pump insufficient fuel flow to the engine during at least one engine speed or speed range. The system also includes a supplemental fuel pump in fluid communication with the fuel circuit configured to selectively pump fuel to the engine at least during the at least one engine speed or speed range to supplement fuel flow from the primary fuel pump to provide sufficient total fuel flow to the engine during all engine speeds.

A flow regulating system for increasing a flow of cooling fluid supplied to a cooling system of a component of a gas turbine system is provided. The flow regulating system includes: a pneumatic circuit embedded within a section of the component, the pneumatic circuit including a set of interconnected pneumatic passages; and a pressure-actuated switch fluidly coupled to the pneumatic circuit. The pressure-actuated switch is activated in response to a formation of a breach in the section of the component and an exposure of at least one of the pneumatic passages of the pneumatic circuit embedded in the section of the component. The activation of the pressure-actuated switch increases the flow of cooling fluid supplied to the cooling system of the component.

A method of controlling turbine tip clearance includes measuring turbine speed; measuring turbine temperature; measuring parameters indicative of current operating conditions; determining limits for the turbine speed and turbine temperature; calculating target tip clearance from the turbine speed, turbine temperature and parameters, to optimise turbine efficiency within the turbine speed and turbine temperature limits; and controlling turbine tip clearance apparatus to the calculated target tip clearance.

A method for controlling the clearance between the blade tips of a high-pressure turbine of a gas turbine aircraft engine and a turbine shroud, including the controlling of a valve delivering a stream of air to the turbine shroud, this method further including the following steps: the detection of a transient acceleration phase of the engine; the receiving of an item of data representative of the gas temperature at the outlet of the combustion chamber of the engine; a valve opening command, to deliver the air stream to the turbine shroud or to increase the flow rate of the delivered air stream, if the transient acceleration phase is detected and if the gas temperature at the outlet of the combustion chamber is greater than a first temperature threshold corresponding to a degraded clearance characteristic of an aged engine, this threshold being less than an operating limit temperature of the engine.