A gas turbine is equipped with: a low-pressure bleed passage, a medium-pressure bleed passage, and a high-pressure bleed-passage for supplying compressed air bled from respective bleed chambers to a turbine; a low-pressure exhaust passage, a medium-pressure exhaust passage, and a high-pressure exhaust passage for exhausting the compressed air in the respective bleed passages to an exhaust chamber; a low-pressure exhaust valve, a medium-pressure exhaust valve, and a high-pressure exhaust valve provided respectively in the exhaust passages; a low-pressure ejector and a medium-pressure ejector provided in the respective exhaust passages; a driving air supply passage for supplying the compressed air to the ejectors; and a control device configured to open the exhaust valves and supply compressed air from the driving air supply passage to the ejectors when an operating state of a gas turbine is in a region in which rotation stall is generated.

A bleed valve system comprises a duct, featuring a central longitudinal axis and allowing a main flow of fluid to pass from a first environment at a first static pressure to a second environment at a second static pressure along a bleed direction, a valve comprising a valve member arranged within the duct between the first and second environments and movable to partially obstruct the duct and deviate the main flow of fluid to direct at least a part of it towards a portion of an internal wall of the duct; and an ejector, arranged within the duct, downstream of the valve member and offset from the central longitudinal axis in correspondence of said portion of the internal wall, adapted to supply an additional flow of fluid within the duct to accelerate the main flow of fluid and reduce the second static pressure.

An assembly is provided for a turbine engine with an axial centerline. This assembly includes a turbine engine structure and a valve assembly. The turbine engine structure includes an outer duct wall, an inner duct wall, a first flow path and a second flow path. The inner duct wall is radially inward of the outer duct wall. The first flow path is radially inward of the inner duct wall. The second flow path is radially outward of the inner duct wall and is radially inward of the outer duct wall. The valve assembly includes a valve element and a valve actuator. The valve element is configured to regulate flow of fluid between the first flow path and the second flow path. The valve actuator is configured to move the valve element. The valve actuator is positioned entirely radially outward of the outer duct wall.

Controller for controlling a bleed valve including a first body with an internal cavity connected to an air inlet port and an air outlet port, a second body including a chamber, a mobile member in the cavity and in the chamber, connecting the two bodies. The member is mobile between a position whereby the ports fluidly communicate and a position whereby the ports are isolated, the member further including two pistons housed in the chamber and defining in this chamber at least two spaces. The controller also includes a fluid supply for at least one of the spaces for the purpose of moving the pistons in the chamber.

A system for delivering a flow stream of a gas to a compressor. A shroud extends from an inlet to the compressor and defines a main inlet passage configured to direct the flow stream from the inlet to the compressor. A communication plenum is separated from the main inlet passage. A port system includes first and second port subsystems that each provide an opening between the main inlet passage and the communication plenum. The first port subsystem is disposed further from the compressor than the second port subsystem. The port system is configured so that a portion of the gas enters or exits the compressor through the second port subsystem, depending on operating conditions of the compressor.

A bleed valve for a gas turbine engine includes a housing that defines an inlet upstream from an outlet. The bleed valve includes a poppet movable relative to the housing between a first position, in which the poppet closes the inlet, and a second position, in which the inlet is open and configured to receive a fluid flow. The housing defines a tortuous path for the fluid flow from the inlet to the outlet configured to reduce a pressure of the fluid flow from the inlet to the outlet within the housing. The tortuous path is defined by a plurality of rings positioned about the poppet, with each ring of the plurality of rings spaced apart from an adjacent ring of the plurality of rings between the inlet and the outlet to define the tortuous path.

A centrifugal compressor and a method of operating a centrifugal compressor. The centrifugal compressor includes: an impeller configured to suction a gas to be compressed; a diffuser disposed downstream of the impeller to pressurize the gas, the diffuser comprising a movable ring, a main passage in which the gas flows past the ring, and an openable branch passage; and a circulation loop comprising an inlet and an outlet, the outlet being in communication with an inlet of the impeller; the branch passage is disposed to be in communication with the main passage and the circulation loop when the ring moves into the main passage so that a portion of the gas in the main passage passes through the circulation loop and returns to the impeller so as to be suctioned, and to be closed when the ring is withdrawn from the main passage.

A bleed valve for use in a gas turbine engine of an aircraft includes a high-pressure cavity coupled to a valve terminal, which is itself coupled to a cap, which cap includes a valve seat configured to be sealed by a tube that serves as the valve gate. The tube is operably coupled to a movable end of a bellows, which is positioned within the high-pressure cavity. The opening and closing of the valve is controlled by the movement of the bellows within the high-pressure cavity, and, in turn, the movement of the tube towards the valve seat, with the valve closing as the bellows compresses.

A centrifugal compressor includes: an impeller; a compressor inlet tube configured to guide air to the impeller; a scroll flow passage disposed on a radially outer side of the impeller; a bypass flow passage branching from the scroll flow passage via a branch port, the bypass flow passage connecting to the compressor inlet tube not via the impeller; and a bypass valve capable of opening and closing a valve port disposed in the bypass flow passage. The branch port has a non-circular shape when viewed along a normal N1 of the branch port passing through a center of the branch port.

A method of operating a gas turbine engine having a high pressure compressor and a secondary air system includes, when the gas turbine engine is operating in a first power range, providing a first bleed source for the secondary air system by bleeding air from a first bleed location, providing bleed air at a first pressure, proximate to an outlet of the high pressure compressor. When the gas turbine engine is operating in a second power range, higher than the first power range, the method includes providing a second bleed source by bleeding air from both a second bleed location and a third bleed location. The second and third bleed locations, respectively providing bleed air at second and third pressures, are both disposed upstream of the first bleed location within the gas turbine engine. The second and third pressures are different from the first pressure.