Abstract: A variable nozzle device 20 for a variable geometry turbocharger includes: a nozzle mount 21; a nozzle plate 22 disposed so as to face the nozzle mount, the nozzle plate forming a nozzle flow passage 4 having an annular shape between the nozzle plate 22 and the nozzle mount 21; and a plurality of variable nozzle vanes 6 disposed at a predetermined interval in a circumferential direction of the nozzle flow passage 4 so as to be individually rotatable about a pivot axis O2. The nozzle plate 22 includes a first surface 33 facing the nozzle mount 21, a second surface 34 opposite to the first surface 33, and at least one through hole 36 formed through the first surface 33 and the second surface 35.

Abstract: A fan includes a housing, a rotation body, and an auxiliary inlet. The housing includes an accommodation chamber, an air inlet, and an air outlet. The rotation body is arranged in the accommodation chamber, forms a guide channel with an inner wall of the accommodation chamber, and is configured to drive air to enter from the air inlet and be guided out from the air outlet through the guide channel. The auxiliary inlet is arranged on the guide channel and configured to introduce the air into the guide channel.

Abstract: Refrigeration systems and control methods therefor are described. The refrigeration systems include a main circuit to connect, through a pipeline, a multi-stage compressor, a condenser, an economizer, a main throttling element, and an evaporator. An air supply branch is configured to connect to the air outlet of the economizer and the intermediate stage air inlet of the multi-stage compressor. A liquid injection branch is configured to connect to the intermediate stage air inlet of the multi-stage compressor from a section having a high-pressure liquid-phase refrigerant in the main circuit. Through the design of the liquid injection branch, the liquid-phase refrigerant can be introduced when vibration or noise of the unit exceeds a limit. The liquid-phase refrigerant, in the form of droplets, can effectively absorb the sound wave energy in the compressor pipeline to reduce an overall discharge pulsation of the compressor and reduce the noise and vibration of the condenser.

Abstract: A housing for a fan, in an embodiment for an axial or diagonal fan, with the fan including an impeller and at least one flow-through region, wherein immediately downstream of the impeller or the blades of the impeller in an outer region of the housing and thus in the flow-through region, multiple individual, free-standing guide elements are provided. A fan includes a corresponding housing.

Abstract: A liquid cooling multi-pumping unit comprising a main body and first and second pumps arranged in series is provided. During operation, cooling fluid is sucked via a cooling fluid inlet into a first fluid chamber and then into a first central chamber opening to a plurality of curved blades of a first impeller assembled in a first pump chamber. From there, the cooling fluid travels and is sucked through a fluid distribution channel into a second fluid chamber and then into a second central chamber opening to a plurality of curved blades of a second impeller assembled in a second pump chamber, before exiting through a fluid outlet. The series arrangement of the first and second pumps increases head pressure, and provides sufficient liquid flow in the case where one liquid cooling pump fails. Additionally, lower energy consumption is achieved due to the lower operating speeds required.

Abstract: A range hood, includes a fan system (2), the fan system (2) having a volute (21) and an impeller (22); the volute (21) includes a front cover (211), a rear cover (212) and an annular wall (213); the annular wall (213) has a volute tongue (214); the front cover (211) has an air inlet (215), the air inlet (215) faces downward to make the range hood to be a horizontal range hood; the volute tongue (214) is gradually inclined from the rear cover (212) to the front cover (211) in a direction opposite to the rotation direction of the impeller (22).

Abstract: A motor for driving a liquid end of a pump system. The motor having an inner housing having an outer surface, a mechanical actuator disposed in the inner housing, and a water jacket surrounding at least a portion of the outer surface of the inner housing to define a volume between the inner housing and the water jacket. The volume being sized to circulate water within the water jacket so as to transfer heat from the inner housing to the water.

Abstract: Various methods and systems are provided for a radial turbocharger. In one example, the turbocharger comprises a turbine case housing a turbine wheel and a compressor case housing a compressor wheel, the turbine case including a vaneless turbine nozzle integrated into the turbine case, a bearing case surrounding a shaft connecting the turbine wheel to the compressor wheel and arranged between the turbine case and compressor case, a plurality of long bolts arranged around a circumference of the turbine case, and a plurality of slots arranged around a circumference of the turbine case, a slot length of each slot extending in a radial direction and adapted to receive a dowel pin having a diameter smaller than the slot length, where each dowel pin, via a corresponding slot, couples the bearing case to the turbine case.

Abstract: A centrifugal fan noise-lowering structure includes a frame having an upper and a lower cover and a sidewall, which together internally define a receiving space communicable with an air inlet and an air outlet of the frame; a stator assembly located in the receiving space and fixedly mounted on the lower cover; and a rotor assembly correspondingly assembled to the stator assembly. The receiving space is internally defined a high pressure zone and a low pressure zone. The upper cover is provided with an airflow passage, which has an inlet located at a position corresponding to the high pressure zone, and an outlet located at a position corresponding to the low pressure zone. With the airflow passage, air in the high pressure zone can be guided to jet out to the low pressure zone to thereby reduce noise produced by the centrifugal fan during its operation.

Abstract: A multiport pump and adapter kit for use with a water circulation system for a body of water includes a centrifugal pump assembly having a plurality of outlet ports oriented in different directions and at least one adapter having a first open end configured and dimensioned to be removably connectable to one of said outlet ports, a second open end configured and dimensioned to be removably connectable to a water circulation system, and a hollow body connecting the first open end and the second open end.

Abstract: A liquid cooling multi-pumping unit comprising a main body and first and second pumps arranged in series is provided. During operation, cooling fluid is sucked via a cooling fluid inlet into a first fluid chamber and then into a first central chamber opening to a plurality of curved blades of a first impeller assembled in a first pump chamber. From there, the cooling fluid travels and is sucked through a fluid distribution channel into a second fluid chamber and then into a second central chamber opening to a plurality of curved blades of a second impeller assembled in a second pump chamber, before exiting through a fluid outlet. The series arrangement of the first and second pumps increases head pressure, and provides sufficient liquid flak in the case where one liquid cooling pump fails. Additionally, lower energy consumption is achieved die to the lower operating speeds required.

Abstract: A turbocharger according to an embodiment is a turbocharger including a turbine housing for housing a turbine wheel rotary driven by an exhaust gas, a bearing housing for housing a rotational shaft on which the turbine wheel is mounted, the bearing housing being adjacent to the turbine housing, and a wastegate portion including a bypass passage and a valve body, the bypass passage allowing the exhaust gas to bypass the turbine wheel, the valve body being able to adjust a flow rate of the exhaust gas flowing through the bypass passage. In the turbine housing, a scroll passage for supplying the exhaust gas to the turbine wheel is formed by casting, at least on a radially outer side of the turbine wheel. A fastening portion for fastening the turbine housing and the bearing housing is disposed on a radially outer side of the scroll passage.

Abstract: In a compressor, a scroll includes a winding end portion, a discharge potion connected to the winding end portion, a winding start portion connected to the discharge potion, and a flow passage inner surface and when a projection plane is assumed for the scroll in a case in which a viewing point is located on a rotation axis of a compressor impeller and on a fluid suction side, and the flow passage inner surface on the projection plane includes a curved protrusion portion protruding outward in relation to the reference line.

Abstract: A turbomachine (105) configured to compress supercritical carbon dioxide is shown. The turbomachine comprises, in fluid flow series, an inlet (201), an inducerless radial impeller (202) having a plurality of blades, and a fully vaneless diffuser (203). The radius of the inlet (r0) is from 25 to 50 percent of the radius of the impeller (r2).

Abstract: A turbomachine (105) configured to compress supercritical carbon dioxide is shown. The turbomachine comprises, in fluid flow series, an inlet (201), an inducerless radial impeller (202) having a plurality of backswept blades (211,212) each of which have a blade exit angle (?2) of from ?50 to ?70 degrees, and a fully vaneless diffuser (203).

Abstract: Systems, methods, and devices for improved cooling of an implantable blood pump are disclosed herein. The implantable blood pump can include: a pump housing defining an internal volume and including a wall defining a blood flow conduit extending through the pump housing; a rotor including a magnet and located within the blood flow conduit; a magnetic core located in the internal volume and extending circumferentially around the blood flow conduit and the rotor, which magnetic core terminates proximate to the wall; a controller located in the internal volume; and a thermal conductor contacting and preferentially thermally connecting the controller and the magnetic core, wherein the thermal conductor is electrically non-conductive.

Abstract: A centrifugal blower assembly includes a scroll wall and at least one sidewall. The scroll wall is coupled to the at least one sidewall such that the scroll wall and the at least one sidewall at least partially define a blower chamber. The centrifugal blower assembly also includes an air stream splitter coupled to the scroll wall. The air stream splitter includes a base member fixedly coupled to the scroll wall and positioned within the blower chamber and a spline member extending a varying distance from the scroll wall and perpendicularly from the base member. An outer surface of the airstream splitter contacts an inner surface of the scroll wall.

Abstract: A compressor includes a compressor impeller configured to rotate about an axis of rotation as intake gases flow along the compressor impeller. The compressor impeller includes an inducer and an exducer. The compressor impeller defines a first impeller end at the inducer and a second impeller end at the exducer. The second impeller end extends along a radial axis. The compressor further includes a compressor housing encasing the compressor impeller. The compressor housing defines a compressor volute. The compressor housing partially defines a diffuser in fluid communication with the compressor volute. The diffuser is elongated along a diffuser axis. The diffuser axis is obliquely angled relative to the axis of rotation. The diffuser axis is obliquely angled relative to the radial axis to minimize a turbulence of the intake gases flowing from the diffuser to the compressor volute.

Abstract: A volute pump for delivering a liquid containing fibrous substances. The volute pump includes an impeller (1) rotatable together with a rotational shaft (11), and an impeller casing (5) having a suction port (3) and a volute chamber (7). A groove (18), extending from the suction port (3) to the volute chamber (7), is formed in an inner surface of the impeller casing (5). The impeller (1) includes a hub (13) to which the rotational shaft (11) is fixed, and a sweep-back vane (2) extending helically from the hub (13). The sweep-back vane (2) includes a leading edge portion (2a) extending helically from the hub (13), and a trailing edge portion (2b) extending helically from the leading edge portion (2a). The leading edge portion (2a) has a front-side curved surface (2e) extending from an inner end (2c) to an outer end (2d) of the leading edge portion (2a).

Abstract: Processes and apparatus for recovering energy from a petroleum, petrochemical, or chemical process are disclosed. The process comprises providing a fluid process stream in a petroleum, petrochemical, or chemical process zone having a direct current power input; controlling a flow rate of the process stream by directing at least a portion of the process stream through a first power-recovery turbine to generate electric power as direct current therefrom; and providing the recovered direct current to the direct current power input of the process zone.

Abstract: A shallow angle rotor bearing-vane system includes a smooth angled non-rotating journal component and a mating angled bearing/vane component, incorporating a plurality of integrated bearing/vanes oriented in a generally radial direction, which provide axial and radial load carrying support between the rotating components, and pumping action to the blood. The load carrying bearing surface situated in very close running proximity to the mating bearing component to prevent entry of red blood cells between the mating bearing surfaces, thereby creating a bearing operating in an elasto-hydrodynamic regime of mixed-lubrication or boundary-lubrication.

Abstract: A bearing module for adjusting a rotor blade angle of attack in an underwater power plant includes a rotor-blade shaft, at least two bearings for supporting the rotor-blade shaft, the at least two bearings being axially spaced from each other on the rotor-blade shaft, a first attachment structure for producing a mechanical connection to a rotor-blade hub, a second attachment structure for producing a mechanical connection to the rotor blade, and a third attachment structure for producing a mechanical connection to a blade adjustment mechanism, wherein the bearing module is an installation unit such that it can be assembled at one location and transported to a second location where rotor blades may be attached.

Abstract: A turbine wheel for a turbine of an exhaust gas turbocharger includes at least one turbine blade against which exhaust gas can flow. The maximum ratio of the wheel outlet diameter of the turbine wheel to the thickness of the turbine blade is 111.75.

Abstract: A fan (1) for a smoke and/or vapor extraction system that includes an impeller (3) located within a diffuser or volute (2), the impeller (3) being driven by an electric motor (24); the impeller (3) having a body (20) having a flat part (21) from which a plurality of radially arranged blades (33) extend; these blades are separated from each other by a variable distance based on a periodic function. In addition to this, the diffuser (2) has an air delivery or discharge conduit (5) having a cross-section increasing from an inlet to its outlet (6).

Abstract: The present invention includes a blower sucking and blowing air; a plurality of cylindrical air discharging units, each having an air discharging flow path through which the air blown by the blower passes and discharges, the plurality of air discharging units respectively having rotational center axes parallel with each other; and an air discharging unit rotating mechanism rotating each of the plurality of air discharging units, with the respective rotational center axes of the air discharging units kept in position. The plurality of air discharging units arranged in parallel with each other may distributively discharge air in multiple directions.

Abstract: A pump arrangement, in particular a magnetic clutch pump arrangement, includes a pump housing containing an impeller shaft, a containment shell which seals an enclosed chamber within the inner chamber of the pump housing, an impeller mounted on one end of the impeller shaft, an inner rotor mounted on the other end of the impeller shaft, an outer rotor which is mounted on the drive shaft and co-operates with the inner rotor, and an auxiliary impeller mounted in the chamber adjacent to a domed base of the containment can. The auxiliary impeller is secured to the inner rotor and includes vanes and impeller channels for circulation of media.

Abstract: In a compressor for a supercharger of an internal combustion engine comprising a shroud, an impeller, a vaneless diffuser, and a scroll, a hub-side wall of the vaneless diffuser is formed to be inclined to the opposite side to a shroud-side wall with respect to a direction perpendicular to a rotational axis of the impeller in the longitudinal cross section including the rotational axis of the impeller. With such a configuration, the amount of deposit formed on the hub-side wall of the vaneless diffuser is reduced.

Abstract: The high performance mini-pump for liquids includes a motor assembly including a motor to supply power to the pump, and a housing assembly including a housing. The housing has a first housing portion and a second housing portion removably connected to the first housing portion defining an inner chamber therein. The housing assembly also includes an impeller provided in the inner chamber of the housing, and at least one fastening member to removably connect the first housing portion and the second housing portion. The pump further comprises a shaft assembly removably connected to the impeller and operatively connected to the motor, such that when the high performance pump is activated, the motor rotates the impeller, forcing fluid to flow through the housing.

Abstract: An object is to provide a fluid machine whereby it is possible to improve performance, for example, expand a flow-rate operation rage with a simplified shape of an intake pipe. A fluid machine includes an impeller mounted to a rotation shaft, a housing which houses the impeller rotatably, and an intake pipe for supplying a fluid to the housing. The intake pipe includes at least a first bend portion disposed on a first plane, and a second bend portion disposed at a downstream side of the first bend portion and on a second plane which is different from the first plane. The second bend portion includes an upstream section having a center axis oriented along a center axis of a downstream section of the first bend portion and a downstream section having a center axis oriented along an axial direction of the impeller at a front of the impeller. The intake pipe has a constant cross-sectional shape from an upstream end of the first bend portion to a downstream end of the second bend portion.

Abstract: In one aspect, a diffuser for expanding the cross-sectional area of an airstream comprises an inlet comprising an inlet cross-sectional area and an outlet comprising an outlet cross-sectional area. The outlet cross-sectional area is greater than the inlet cross-sectional area. A curved sidewall extends from the inlet to the outlet and at least partially defines an inner passageway. The curved sidewall comprises a convex portion and a concave portion. The convex portion is adjacent the inlet and the concave portion is adjacent the outlet.

Abstract: A housing for receiving an impeller is provided. The housing includes a transition duct that extends between a volute of the housing and an exhaust exit of the housing. Cross-sections of the transition duct continuously vary from an inlet cross-section of the transition duct to an outlet cross-section of the transition duct along a length of the transition duct. A related dryer appliance is also provided.

Abstract: A centrifugal compressor for processing a wet gas. The centrifugal compressor includes: a casing; and least one compressor stage comprising at least one impeller rotatingly arranged in the casing and provided with an impeller hub and a plurality of impeller blades, each impeller blade having a suction side and a pressure side. The at least one compressor stage comprises at least one droplet breaking arrangement configured for promoting breakup of liquid droplets flowing through the compressor stage.

Abstract: The present invention provides a ventilating fan. In the ventilating fan, first and second flangings are extended outwards from vertical side edges and horizontal side edges of the air inlet of the adapter respectively, outer edges of the first flangings are firstly bent to form both side surface, and then edges of the both side surfaces are bent to form edge surfaces, and the first flangings, the side surfaces, and the edge surfaces confine open grooves; protrusions are disposed on an outer periphery of the air inlet, and a slot is formed between the protrusion and the first or the second flanging; and first folded sheets are extended outwards from both vertical side edges of the air outlet of the casing; and an edge of the air outlet of the frame abuts against and is clamped in the slot.

Abstract: A turbocharger system may include a turbine housing and a tongue insert. The turbine housing may include an inlet, an outlet, and a gas pathway between the inlet and outlet. The gas pathway may include a volute portion and an inlet portion extending approximately tangent to the volute portion. The turbine housing may be formed from a first material. The tongue insert may be received in the turbine housing and may at least partially define the volute portion and the inlet portion. The tongue insert may be formed from a second material that is more heat resistant than the first material.

Abstract: A turbine housing for a turbocharger has a plurality of interconnected housing parts. A central, one-piece contoured component that is constructed as a cast component or a forged component is provided on that side of a spiral channel which faces away from a bearing housing attachment flange in the turbine housing. The contoured component has a wall region of the spiral channel, a boundary wall of an exhaust gas inlet gap and a sealing contour region. The contoured component is connected to its adjacent housing parts, which are at least partly constructed as sheet metal molded parts, so as to form the turbine housing.

Abstract: A fan device includes a bottom shell, a cover, and an impeller. The cover includes a main body, a support, and a spoiler. The main body has a through opening. A connection position between the support and the main body has a first folding line. The support is bended along the first folding line to form a portion of the through opening. The support is perpendicular to the main body, and is abutted against the bottom shell. A connection position between the spoiler and the main body has a second folding line. The spoiler is bended along the second folding line to locate in the through opening. An acute angle is formed between the spoiler and the surface of the main body facing away from the bottom shell. The impeller is located in an accommodating space between the cover and the bottom shell.

Abstract: An impeller of a centrifugal pump is provided. The impeller includes at least two blades (4) for conveying media containing solids. An impeller blade leading angle (?1) is smaller than 0°. The blade angle (?) increases in a first section (9) until a value of 0° is reached. In a second section (10), another increase occurs until a maximum value is reached. In a third section (11), the blade angle (?) decreases again.

Abstract: A semiconductor package is provided, including a substrate having a top surface, a bottom surface opposing the top surface, a via communicating the top surface with the bottom surface, and a stator set formed by circuits; an axial tube axially installed in the via of the substrate; a plurality of electronic components mounted on the top surface of the substrate and electrically connected to the substrate; an encapsulant formed on the top surface of the substrate for encapsulating the electronic components and the axial tube; and an impeller axially coupled to the axial tube via the bottom surface of the substrate. In the semiconductor package, the stator set is formed in the substrate by a patterning process. Therefore, the thickness of the semiconductor package is reduced significantly.

Abstract: An air diffuser device suitable for use in an air diffuser system for a centrifugal pump the pump including a pump casing with a pumping chamber therein, an impeller mounted within the pumping chamber for rotation about a rotation axis, the impeller including a front side and a rear side. The air diffuser system comprises one or more passages extending through the impeller from the front side to the rear side, the or each passage having a first opening at the rear side and a second opening at the front side of the impeller.

Abstract: An electronic device includes a fan field replaceable unit (FRU). The fan FRU includes a fan FRU chassis defining an airflow pathway through the fan FRU. A fan within the fan FRU chassis causes air to flow along the airflow pathway. The fan FRU further includes an edge connector located at a front face of the fan FRU out of the way of the airflow pathway. Accordingly, the edge connector does not block airflow through the fan FRU thus maximizing the efficiency of the fan FRU and the cooling of the electronic device.

Abstract: A centrifugal fan includes a housing and an impeller. The housing includes a first surface and a flow channel wall. The first surface has a surrounding section and an air inlet section. The surrounding section encircles the air inlet section. The flow channel wall defines a flow chamber and an air outlet, and at least a sidewall of the flow channel wall has a tongue portion close to the air outlet. The impeller is rotatably connected within the flow chamber. The surrounding section plus the air inlet section is an area on the first surface, on which the impeller is projected, and the surrounding section has a convex structure.

Abstract: A single suction type centrifugal includes: a casing having a spiral shape; and an impeller housed in the casing and provided with a plurality of blades and an impeller main plate to which the blades are fixed. The casing includes a suction side plate having a suction port, and a motor fixing side plate to which a motor is fixed. A center portion of the impeller main plate is fixed to the motor, and a main plate opening is formed in the impeller main plate between the blades and a center portion of the impeller main plate. A plane which passes end portions of the blades on a motor fixing side plate side and is perpendicular to a rotary shaft of the motor is assumed as a blade end portion imaginary plane. A constriction portion is formed where a distance between the blade end portion imaginary plane and the motor fixing side plate is narrowed between the main plate opening and the blades.

Abstract: A fan includes a housing and a motor. The housing has a compartment, at least one lateral air inlet and at least one lateral air outlet. The lateral air inlet and lateral air outlet communicate with the compartment. The motor has a stator and an impeller. The impeller is coupled with the stator and includes a hub and a plurality of blades coupled with a top face of the hub. Each blade has first and second ends. The first ends of the blades face outwards, and the second ends of the blades define an air-guiding room encompassed by a virtual geometric pattern formed by a virtual line linking the second ends of the blades. The virtual geometric pattern has a maximal diameter. A gap is formed between the second ends of two adjacent blades. The gap is smaller than the maximal diameter of the virtual geometric pattern.

Abstract: A turbine, including: a volute and an impeller. The volute includes: a volute gas inlet, a volute gas feeding flow passage, and a volute gas outlet. The impeller includes: blades, an impeller gas feeding flow passage, an impeller gas inlet, an impeller gas outlet, and a partition plate. The impeller gas feeding flow passage includes: an inner flow passage and an outer flow passage. The impeller is disposed inside the volute. The blades are disposed on an outer part of the impeller. The partition plate is circumferentially disposed between the impeller gas inlet and the impeller gas outlet. The partition plate divides the impeller gas feeding flow passage into the inner flow passage and the outer flow passage.

Abstract: A fan blade structure applied to a centrifugal fan is provided. The fan blade structure includes a wheel hub and an annular vane. The wheel hub includes a plurality of connecting brackets, and the annular vane includes multiple crests and troughs which interlace to form a continuous curved surface. The continuous curved surface has an outer ring surface and an inner ring surface. The connecting brackets are connected to the inner ring surface and drive the annular vane to rotate.

Abstract: A centrifugal blower for an air conditioner may include a centrifugal fan rotatably coupled to a motor, and a bell mouth guiding air into the centrifugal fan. The centrifugal fan may include a hub fixed to a rotary shaft of the motor, a main plate provided at an outer circumferential surface of the hub, a shroud having a suction opening surrounding the rotary shaft, the shroud positioned opposite the main plate to define a main gas flow path, and a plurality of wings arranged along the circumferential direction of the suction opening between the main plate and the shroud. A rear axial end portion of the bell mouth may be inserted into the shroud through the suction opening so as to form a predetermined radial gap with the suction opening. The rear portion of the bell mouth may include a plurality of alternately formed protruding portions and recessed portions, with the protruding portions and the recessed portions inserted into the shroud.

Abstract: A notebook computer 1 is provided with: a casing in which a CPU is accommodated; a heat-dissipating component 37 having a plurality of fins; and a fan 31, and operates such that heat transferred from the CPU to the heat-dissipating component 37 is heat-exchanged with air supplied from the fan 31, and released to the exterior of the casing. The heat-dissipating component 37 is disposed at an air outlet 32b of the fan 31. An opening 35 is formed, between the air outlet 32b and a fan main unit 33, in a fan case 32. First shutter means 39 is provided on a discharge outlet surface of the heat-dissipating component 37. With this structure, increase in cost and weight can be restrained, and dust on the heat-dissipating component can be removed with a simplified structure.

Abstract: The invention relates to a bearing housing body group (1) of an exhaust-gas turbocharger, having a housing (2) for a bearing arrangement of a rotor shaft (3); having a turbine wheel (4) on one end (5) of the rotor shaft (3); having a compressor wheel (6) on the opposite end (7) of the rotor shaft (3); and having a compressor-wheel-side housing cover (8) which can be fixed by means of a fastening device (9) in a compressor-wheel-side housing opening (10), wherein the fastening device (9) is designed as a bayonet connection.

Abstract: In one embodiment a blower comprises a case comprising a first surface, a second surface opposite the first surface, and a side wall extending between portions of the first surface and the second surface, wherein the side wall comprises an air inlet and an air outlet, an impeller disposed in the case and rotatable about an axis of rotation extending through a hub, wherein the impeller comprises a plurality of blades which define a gap with the hub, wherein portions of the side wall are disposed at least a first distance from the axis of rotation and the impeller is to define a circumferential airflow path within the case, wherein the impeller is to create an airflow in the circumferential airflow path between the air inlet and the air outlet, and a feature disposed in the gap to impede recirculation of air in the case.

Abstract: A centrifugal compressor for which ???>0° and 0°<?<34°, when the angle formed by a diffuser inlet hub-side line (5a) and the radial direction at a point B in the meridian plane is ?, and the angle formed by a tangent line (3b) and the radial direction at a point A of an impeller hub-side line (3a) nearest the inlet of the diffuser (5) is ?. Thus, skewing of the velocity distribution of a gas within the diffuser of the centrifugal compressor is eliminated.