Methods are provided for identifying degradation in components of a compressor recirculation valve (CRV). One method may include inferring degradation of the CRV based on adaptation of a compressor surge line outside an expected range.

A solenoid for a bleed valve includes a solenoid body with an actuation fluid passage, a bleed valve passage, and a drive fluid chamber. A main armature is disposed within the solenoid body and is movable between open and closed positions, the actuation fluid passage being in fluid communication with the control outlet in the open position, the actuation fluid passage being fluidly isolated from the bleed valve passage in the second position. A pilot armature is disposed within the solenoid body, is movable relative to the main armature, and is operably coupled to the main armature by the drive fluid chamber to move the main armature between the open and closed positions by controlling issue of a drive fluid into and out of the drive fluid chamber.

A bleed valve assembly includes a flow duct with an inlet and an outlet disposed downstream from the inlet. The outlet is smaller in cross-sectional area than a region of the flow duct disposed between the inlet and the outlet. A piston housing is disposed inside the flow duct between the inlet and the outlet so as to form an annular flow passage between the flow duct and the piston housing. The piston housing is axially aligned with a center axis of the flow duct. At least one rib extends between the flow duct and the piston housing. A sleeve piston is disposed inside the piston housing and is configured to extend downstream of the piston housing in a closed position. The sleeve piston comprises an outer wall that is at least the same in cross-sectional area as the outlet of the flow duct.

A bleed system of a gas turbine engine includes a bleed duct having a duct inlet located at a flowpath of a gas turbine engine, and a bleed outlet located outside of the flowpath, and extending circumferentially around a central longitudinal axis. A plurality of bleed doors are located at the bleed outlet and are arrayed along a circumferential length on the bleed duct. Each bleed door includes a first circumferential end, and a second circumferential end. The bleed doors are arrayed such that when the bleed doors are in a closed position the first circumferential end is located at the second circumferential end of an adjacent bleed door of the bleed doors. Each bleed door includes a pivot, such that each bleed door rotates about the pivot from the closed position covering the duct outlet to an opened position allowing a bleed airflow to pass through the duct outlet.

A compressor for a gas turbine engine having a bleed air recirculation system includes a plurality of bleed holes extending through the shroud at a first axial location thereon substantially adjacent the blade tips. The bleed holes have a closed outer perimeter along their complete length. An annular bleed cavity surrounds the shroud and is in communication with outlet openings of the bleed holes. The bleed holes provide communication between the main gas flow passage and the bleed cavity. The bleed cavity includes exit passages having outlets disposed in the shroud at a second axial location which is upstream of both the first axial location and the leading edge of the blades of the rotor. Bleed air is passively bled from the main gas flow passage via the bleed holes, recirculated through the bleed cavity and re-injected back into the main gas flow passage at the second axial location.

A system for bleeding air from a core flow path of a gas turbine engine is disclosed. In various embodiments, the system includes a bleed valve having a bleed valve inlet configured to receive a bleed air from a first access point to the core flow path and a bleed valve outlet; and an air motor having a first air motor inlet configured to receive the bleed air from the bleed valve outlet and a first air motor outlet configured to exhaust the bleed air, the air motor configured to pump the bleed air from the core flow path of the gas turbine engine.

A gas turbine engine comprising: a compressor; a first turbine; and a first compressor bleed valve in fluid communication with the compressor and configured to release bleed air from the compressor; wherein the first compressor bleed valve is configured to release bleed air to a downstream location in the engine, the downstream location being downstream of the first turbine; wherein the first compressor bleed valve is configured to open wherein the first compressor bleed valve is configured to open to at least two positions, to thereby release a variable amount of bleed air from the compressor.

An apparatus and method of controlling a multi-stage compressor of a gas turbine engine having a front-block of stages with variable stator vanes (VSVs), a rear block of stages downstream of the front-block, and a bleed air off-take from at least one of the stages. The method includes sensing the pressure of the bleed air from the bleed air off-take and adjusting the position of the VSV for the front-block.

A system for actuating components of a gas turbine engine may generally include a turbine component incorporating a jamming device. The jamming device may include a bladder and a jammable media contained within the bladder. The jammable media may be jammable within the bladder from an unjammed state, wherein a fluid is contained within the bladder, to a jammed state, wherein the fluid is at least partially evacuated from the bladder. The system may also include a fluid coupling in fluid communication with the bladder. A portion of the turbine component may be located at a first position when the jammable media is in the unjammed state. Additionally, such portion of the turbine component may be located at a second position when the jammable media is in the jammed state.

A gas turbine engine compressor includes a rotor defining a central axis of rotation and a plurality of blades which project into an annular compressor gas flow passage, and a shroud circumferentially surrounding the rotor and having a radially inner surface adjacent to the blade tips. Bleed holes extend through the shroud adjacent the blade tips, each of the bleed holes having an inlet end disposed in the shroud radially inner surface and an outlet end disposed in a shroud radially outer surface. Bleed air removed from the annular gas flow passage flows through the bleed holes from the inlet to the outlet ends. The outlet end of each bleed hole is located circumferentially upstream of the inlet end relative to a direction of rotational flow in the annular gas flow passage driven by a direction of rotation of the rotor.