Examples described herein provide a computer-implemented method that includes receiving training data indicative of incipient compressor surge for cabin air compressors. The method further includes generating, using the training data, a training spectrogram. The method further includes training, by a processing system, a machine learning model to detect incipient compressor surge events for the cabin air compressors using the spectrogram. The method further includes receiving, at a microcontroller associated with a cabin air compressor, operating data associated with the cabin air compressor. The method further includes generating, at the microcontroller and using the operating data, an operating spectrogram. The method further includes detecting, by the microcontroller associated with the cabin air compressor, an incipient compressor surge event by applying the machine learning model to the operating spectrogram. The method further includes implementing a corrective action to correct the incipient compressor surge event.

A compressor is provided with: an impeller a housing configured to rotatably house the impeller and having an intake passage for introducing a gas to the impeller from outside the housing, a scroll passage for guiding the gas having passed through the impeller to the outside, and a bypass passage connecting the intake passage and the scroll passage so as to bypass the impeller; and a bypass valve having a valve body disposed in the bypass passage and capable of opening and closing the bypass passage. The valve body is configured to, in a fully closed state, separate the bypass passage into an inlet-side passage having a communication port communicating with the scroll passage and an outlet-side passage communicating with the intake passage. An inlet-side passage wall surface which defines the inlet-side passage includes at least an upstream passage wall surface portion connected to an upstream end of the communication port in a cross-sectional view of the housing taken along an axis of the impeller. The upstream passage wall surface portion is configured such that an angle between the upstream passage wall surface portion and an upstream scroll wall surface of a scroll passage wall surface which defines the scroll passage connected to the upstream end is less than 90 degrees.

A system includes a dynamic compressor and a controller having a processor and a memory. The compressor includes a first compressor stage having a first variable inlet guide vane (VIGV) and a second compressor stage having a second VIGV. The memory stores instructions that program the processor to operate the compressor at a current speed, a first position of the first VIGV, and a second position of the second VIGV to compress the working fluid, and to determine if a condition is satisfied. If the condition is not satisfied, the processor is programmed to continue to operate the compressor at the current speed, the first position of the first VIGV, and the second position of the second VIGV. If the condition is satisfied, the processor is programmed to change the second position of the second VIGV to a third position and maintain the first position of the first VIGV.

Aero-acoustically damped bleed valves are disclosed. An example variable bleed valve apparatus comprises a variable bleed valve door to actuate the variable bleed valve apparatus, and a variable bleed valve port including an upstream edge and a downstream edge, the VBV port to define a secondary flowpath, the VBV door to cover the VBV port in a closed position, and a vortex device at the upstream edge of the variable bleed valve port, the vortex device including a vorticity generating feature along the upstream edge of the variable bleed valve port.

A casing treatment for a compressor includes one or more cavities in a casing disposed radially outwardly of tips of the compressor rotor blades. A liner is moveable relative to the casing between a first position and a second position. The liner is shaped to add a volume to the tip clearance gap when moving from the second position toward the first position. The liner is displaceable between the first and second positions in coordination with at least the rotation of inlet guide vanes (IGVs) between IGV positions.

A sleeve valve includes an inlet port and an outlet port. A sleeve is movable to close flow from the inlet port to the outlet port. The sleeve valve has a sleeve biased to an open position at which it allows flow from the inlet port to the outlet port by a spring. Pressure in a pressure chamber urges the sleeve to a closed position at which it blocks flow from the inlet port to the outlet port. A line pressure conduit communicates the fluid chamber into the pressure chamber. Pressurized air is supplied to the pressure chamber through a selectively closed valve. The selectively closed valve is opened to allow the flow of high pressure air from a pressure source into the pressure chamber to move the sleeve to a closed position. A bleed air system for a gas turbine engine is also disclosed.

An illustrative example embodiment of a compressor includes an inlet defining an intake passage, a plurality of lateral inlet guide vanes in the intake passage, and a plurality of medial inlet guide vanes in the intake passage. The lateral guide vanes are selectively oriented to alter an amount of fluid flow through a first, lateral portion of the intake passage. The medial inlet guide vanes are selectively oriented to alter an amount of fluid flow through a second, medial portion of the intake passage.

A throttle assembly for a pressure control system in a vehicle includes at least one throttle valve. The at least one throttle valve defines an assembly cross-section of the throttle assembly, the assembly cross-section specifies a flow resistance acting on a pressure medium entering the throttle assembly, and the at least one throttle valve includes at least one controllable throttle valve configured to be controlled in accordance with an upstream pressure. The assembly cross-section of the throttle assembly is configured to be set, by control of the at least one controllable throttle valve, in such a way that an inlet volume flow of the pressure medium entering the throttle assembly can be limited to a limit volume flow in accordance with the upstream pressure, in order to set, in accordance with the upstream pressure, a power consumption of a pneumatic load in the pressure control system.

A heat transfer circuit includes a compressor, a condenser, an expander, and an evaporator that are fluidly connected together. The compressor includes a housing and a shaft rotatable relative to the housing to compress a working fluid received at a suction inlet, in which the shaft is supported by a gas bearing, and the gas bearing including a bearing housing having a fluid inlet and an outlet. A high pressure gas source is fluidly connected to the fluid inlet of the bearing housing for supplying high pressure fluid to the fluid inlet of the gas bearing such that the gas bearing supports the shaft when the shaft is rotating. A pressure reducer is connected to the outlet of the gas bearing is provided for reducing a vent pressure of the gas bearing.

Provided is a centrifugal compressor, including: a movable member which is movable between a first position and a second position, the first position being a position at which an opening degree of an auxiliary flow passage arranged more on an outer diameter side than a main flow passage becomes a first opening degree, the second position being a position at which an opening degree of the auxiliary flow passage becomes a second opening degree smaller than the first opening degree; and a linear actuator configured to drive the movable member in a rotation axis direction of the impeller.