An aircraft engine, has: a low-pressure compressor and a high-pressure compressor located downstream of the low-pressure compressor; a gaspath valve upstream of the high-pressure compressor, the gaspath valve movable between an open configuration and a closed configuration; and a bypass flow path having in flow series a bypass inlet, a bypass valve, and a bypass outlet, the bypass inlet fluidly communicating with the gaspath upstream of at least one stage of the low-pressure compressor, the bypass valve having an open configuration in which the bypass valve allows a bypass flow and a closed configuration in which the bypass valve blocks the bypass flow, the bypass outlet fluidly communicating with the bypass inlet via the bypass valve and with the gaspath at a location in the gaspath fluidly downstream of the gaspath valve, downstream of the low-pressure compressor, and upstream of the high-pressure compressor.

A gas turbine engine includes a first spool associated with a primary combustor, a second spool associated with a secondary combustor, and a third spool, each spool including a compressor and a turbine mounted to a shaft. A transmission and accessory gearing are enclosed within an housing of an accessory gearbox. The transmission rotationally couples the third spool to the second spool and accessory gearing. A method of operating the gas turbine engine includes supplying a first fuel flow rate to the primary combustor and supplying a second fuel flow rate to the secondary combustor within an intermediate speed range of the gas turbine engine.

A gas turbine power plant comprises a gas turbine, a power turbine, a clutch, an electrical generator and a controller. The power turbine is fluidly connected to the gas turbine without any mechanical connection. The clutch comprises an input mechanically connected to the power turbine and an output mechanically connected to the electric generator. The controller can identify that a speed of the electric generator is greater than a speed of the power turbine, determine a difference between the speed of the electric generator and the power turbine, in response to the difference being greater than a threshold, control the gas turbine to a first maximum acceleration of the power turbine, and in response to the difference being equal or less than to the threshold, control the gas turbine to a second maximum acceleration of the power turbine that is less than the first maximum acceleration.

A gas turbine power plant comprises a gas turbine, a power turbine, a clutch, an electrical generator and a controller. The power turbine is fluidly connected to the gas turbine without any mechanical connection. The clutch comprises an input mechanically connected to the power turbine and an output mechanically connected to the electric generator. The controller can identify that a speed of the electric generator is greater than a speed of the power turbine, determine a difference between the speed of the electric generator and the power turbine, in response to the difference being greater than a threshold, control the gas turbine to a first maximum acceleration of the power turbine, and in response to the difference being equal or less than to the threshold, control the gas turbine to a second maximum acceleration of the power turbine that is less than the first maximum acceleration.

A pumping system includes a pump array of multiple pump-engine assemblies. Each pump-engine assembly comprises a pump and a gas turbine engine driving the pump. A manifold is coupled to the pumps. A master controller is coupled to each of the pump-engine assemblies either directly or via one or more intermediate controllers. The master controller and any intermediate controllers are collectively programmed to respond to user input including a desired hydraulic output at the manifold by automatically calculating and applying inputs to the individual pump-engine assemblies to provide the desired hydraulic output.

A device for temporarily increasing power in order to increase the power from at least one first turbine engine and from at least one second turbine engine, the device including a tank of coolant liquid, a first injection circuit connected to the tank and leading to at least one injection nozzle configured to be installed upstream from the first turbine engine, a second injection circuit connected to the tank and leading to at least one injection nozzle configured to be installed upstream from the second turbine engine, each of the first and second injection circuits including at least one first valve and at least one second valve arranged upstream from said at least one first valve, and a bridge pipe connecting together the first injection circuit and the second injection circuit upstream from their respective first valves and downstream from their respective second valves.

A device for temporarily increasing power in order to increase the power from at least one first turbine engine and from at least one second turbine engine, the device including a tank of coolant liquid, a first injection circuit connected to the tank and leading to at least one injection nozzle configured to be installed upstream from the first turbine engine, a second injection circuit connected to the tank and leading to at least one injection nozzle configured to be installed upstream from the second turbine engine, each of the first and second injection circuits including at least one first valve and at least one second valve arranged upstream from said at least one first valve, and a bridge pipe connecting together the first injection circuit and the second injection circuit upstream from their respective first valves and downstream from their respective second valves.

The invention relates to an aircraft propulsion system, comprising a main transmission unit (12) and at least two turbojet engines connected to the main transmission unit (12), respectively a first turbojet engine (14a) and a second turbojet engine (14b), each turbojet engine comprising a free turbine (24a, 24b), characterized in that the first turbojet engine (14a) comprises a heat exchanger (30) configured to recover some of the thermal energy from the exhaust gas at the outlet of the free turbine, and in that the propulsion system comprises at least one computer (28a, 28b) configured to control the two turbojet engines and to limit the acceleration and the deceleration of the first turbojet engine (14a) when neither of the turbojet engines is broken down, in order to limit the reactor power transients at the heat exchanger (30).

The invention relates to an aircraft propulsion system, comprising a main transmission unit (12) and at least two turbojet engines connected to the main transmission unit (12), respectively a first turbojet engine (14a) and a second turbojet engine (14b), each turbojet engine comprising a free turbine (24a, 24b), characterized in that the first turbojet engine (14a) comprises a heat exchanger (30) configured to recover some of the thermal energy from the exhaust gas at the outlet of the free turbine, and in that the propulsion system comprises at least one computer (28a, 28b) configured to control the two turbojet engines and to limit the acceleration and the deceleration of the first turbojet engine (14a) when neither of the turbojet engines is broken down, in order to limit the reactor power transients at the heat exchanger (30).

A multi-engine aircraft includes a first engine drivingly engaged to a common rotatable load and a second engine drivingly engaged to the common rotatable load, the second engine having a bleed air system and a control system in communication with a compressed air switching system. The control system controls operation of the second engine and/or the compressed air switching system. The compressed air switching system includes a switching valve that is displaceable between at least a first position and a second position, the first position interconnecting a lower pressure inlet and a switch outlet, and the second position interconnecting a high pressure inlet and the switch outlet. The switch outlet is in communication with the bleed air system of the second engine. The control system actuates the switching valve to switch between the first and second positions.