Device and methods for guiding bleed air in a turbofan gas turbine engine are disclosed. The devices provided include louvers and baffles that guide bleed air toward a bypass duct of the turbofan engine. The louvers and baffles have a geometric configuration that promotes desirable flow conditions and reduced energy loss.

A multistage centrifugal pump for conveying a fluid includes a pump housing with an inlet to receive the fluid and an outlet to discharge the fluid, a first stage impeller and a last stage impeller to convey the fluid from the inlet to the outlet, a shaft to rotate the first stage impeller and the last stage impeller about an axial direction, a suction chamber arranged upstream of the first stage impeller and in fluid communication with the inlet, a recirculation path for the fluid including a return opening and extending from the return opening to the suction chamber, the return opening located at or in the flow path downstream of the first stage impeller and upstream of the last stage impeller, and a flow control rod disposed in the recirculation path, the flow control rod to adjust a recirculation flow through the recirculation path into the suction chamber.

An apparatus for diagnosing and controlling the aerodynamic stability of a compressor and method there of are provided. The apparatus includes a measurement device (100), a signal processing device (200) and a control and execution device (300), wherein the measurement device (100) is configured to measure the pressure or velocity fluctuations of air flows in different positions inside a compressor in real time, and to transmit real-time measurement signals obtained from different positions to the signal processing device (200); the signal processing device (200) is configured to determine, according to the real-time measurement signals, a type and spatial distribution of instability precursor in the compressor, and to output corresponding control strategy signals to the control and execution device (300); and the control and execution device (300) executes, according to the received control strategy signals, corresponding control actions to regulate the stability of the compressor (S3).

An illustrative example embodiment of a compressor includes an inlet defining an intake passage, a plurality of inlet guide vanes, an impeller, and a plurality of swirl nozzles. Fluid flow through the plurality of inlet guide vanes into the intake passage is selectively adjustable to control fluid flow through at least the portion of the intake passage downstream of the swirl nozzles. The impeller includes a plurality of blades and directs fluid from the intake passage toward an outlet. The swirl nozzles have outlets positioned downstream of the plurality of inlet guide vanes and upstream of the impeller. The swirl nozzles are configured to introduce fluid into the intake passage to cause swirl of fluid in the intake passage between the plurality of inlet guide vanes and the impeller.

A centrifugal compressor for a chiller system includes a casing having an inlet portion and an outlet portion, a recirculation structure including a recirculation path and a recirculation discharge cavity, an impeller disposed downstream of the recirculation discharge cavity, a plurality of recirculation discharge guide vanes disposed to surround the recirculation discharge cavity, and a diffuser disposed in the outlet portion downstream of the impeller. The recirculation structure is configured to impart a swirl to a flow of refrigerant into the inlet portion. The recirculation path supplies the refrigerant from the diffuser to the recirculation discharge cavity. The recirculation path includes a recirculation pipe that introduces the refrigerant toward the plurality of recirculation discharge guide vanes. An annular groove is disposed between the recirculation pipe and the plurality of recirculation discharge guide vanes. An annular plate is disposed between the annular groove and the recirculation discharge cavity.

Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a capacity control valve that has a curved surface facing a flow of refrigerant from the first stage to the second stage. The capacity control valve can allow or obstruct flow through the side stream injection port. The capacity control valve can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. The side stream injection port and the capacity control valve can be ring-shaped. The side stream injection port and the capacity control valve can allow at least some of the side stream to be introduced on a side of the capacity control valve opposite the curved surface.

Embodiments of a compressor stage, in particular for a turbocharging system and/or a turbocompound, and a process for operating a compressor stage are provided herein. The compressor stage comprises an impeller, and a vaned diffuser arranged downstream of the impeller. The vaned diffuser is in fluid connection with an outlet of the impeller and comprises an injection device configured to inject a secondary fluid into the vaned diffuser. The injection device comprises a displaceable port at least partially arranged between an adjacent pair of vanes of the diffuser.

A structural assembly for a fluid-flow machine includes: a main flow path boundary and at least one row of relatively rotating blades with a gap existing between blade ends of the at least one row of blades and the main flow path boundary. At least one secondary flow duct has in the main flow path boundary one opening each at ends spaced apart in the flow direction, such that the secondary flow duct is connected to the main flow path via the two openings. The structural assembly has at least two components connected to one another, i.e. at least one support component and at least one connecting component, where the support component at least partially forms the main flow path boundary and where the connecting component forms or surrounds at least one part-section of the secondary flow duct.

To solve the problems of compressor wheel blade flow separation causing surge type noises when an exhaust gas recirculation (EGR) duct introduces into the compressor exhaust gases to be returned to the engine, the exhaust gas is fed into an annular volume, defined between inner and outer walls or an annular transition cavity shaped as a radially expanded, axially flattened cylindrical space in the compressor inlet, so that the generally unidirectional radial flow from an EGR duct is re-directed and organized as it is turned from generally radial to generally axial, merging with the general inlet flow and presenting the compressor wheel with airflow of “circumferentially uniform” flow velocity.

Centrifugal compressors can incorporate a side stream flow of intermediate pressure vapor between stages of that compressor. The side stream flow can be controlled by a side stream injection port controlled by a capacity control valve that has a curved surface facing a flow of refrigerant from the first stage to the second stage. The capacity control valve can allow or obstruct flow through the side stream injection port. The capacity control valve can extend and retract in a direction substantially perpendicular to the direction of flow from the first stage impeller to the second stage impeller. The side stream injection port and the capacity control valve can be ring-shaped. The side stream injection port and the capacity control valve can allow at least some of the side stream to be introduced on a side of the capacity control valve opposite the curved surface.