A centrifugal compressor for compressing a fluid in a gas phase or a supercritical phase includes: a rotational shaft; an axial flow path extending along an axial direction of the centrifugal compressor; a radial flow path communicating with the axial flow path and extending along a radial direction of the centrifugal compressor on a downstream side of the axial flow path; an impeller at least partially disposed in the radial flow path and configured to rotate together with the rotational shaft to increase pressure of the fluid flowing in the radial flow path; and a pre-compression unit disposed in the axial flow path at a position distant from a leading edge of the impeller on an upstream side of the leading edge and configured to increase the pressure of the fluid in advance before the fluid is introduced to the leading edge.

A centrifugal compressor includes: a rotational shaft; a main casing surrounding at least a part of the rotational shaft, the main casing having an inlet and an outlet separated from each other in an axial direction of the rotational shaft and an annular space surrounding a section of the rotational shaft at a side of the inlet and communicating with the inlet; at least one impeller disposed in a fixed state to the rotational shaft inside the main casing; a flow guide member disposed inside the annular space and extending along the axial direction of the rotational shaft; a plurality of injection holes disposed along the flow guide member and separated from one another along the axial direction of the rotational shaft; and a flow path which extends inside the annular space and through which a cleaning fluid to be supplied to the plurality of injection holes is capable of flowing.

A straddled vehicle including a radiator, a radiator fan disposed behind the radiator and configured to generate air passing through the radiator and flowing rearward, a fan cover disposed behind the radiator fan and including a lateral blowing port configured to blow out sidewards the air flowing rearward from the radiator, a side cover covering the radiator laterally and having an opening formed therein, an inner panel disposed between the side cover and the radiator, to thereby define an accommodation space between the inner panel and the side cover, and an electrical component disposed in the accommodation space. The inner panel includes a slope that is located rearward of the radiator, slants with respect to a right-and-left direction of the straddled vehicle, is configured to lead the air blown out from the lateral blowing port to the opening in the side cover, and divides the accommodation space.

A centrifugal compressor includes a shaft defining an axis, an impeller mounted to the shaft for rotation about the axis, and a diffuser section including a first wall, a second wall, and an opening defined between the first wall and the second wall. The opening of the diffuser section is arranged in fluid communication with the impeller. The first wall is rotatable about the axis and rotation of the first wall about the axis is mechanically driven.

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.

Provided is a blowing device capable of improving a noise reduction effect as compared with a conventional case, and a combustion device including the blowing device is provided. In a rear side shroud of an impeller configuring a blowing device, a first inclined surface portion that is inclined so as to be located frontward toward the radial outer side is formed in a front surface portion of the rear side shroud in a region close to the outer peripheral edge, while a second inclined surface portion that is inclined so as to be located rearward toward the radial outer side is formed in a front surface portion of the rear side shroud in a region closer to the center than the first inclined surface portion.

Provided is a blowing device capable of improving a noise reduction effect as compared with a conventional case, and a combustion device including the blowing device is provided. In a rear side shroud of an impeller configuring a blowing device, a first inclined surface portion that is inclined so as to be located frontward toward the radial outer side is formed in a front surface portion of the rear side shroud in a region close to the outer peripheral edge, while a second inclined surface portion that is inclined so as to be located rearward toward the radial outer side is formed in a front surface portion of the rear side shroud in a region closer to the center than the first inclined surface portion.

A fluidic actuator is configured to be mounted to an airfoil surface. The actuator includes a rotor supported within a housing. The rotor contains at least one generally radially extending nozzle that converges from an entry at an interior circumference of the rotor to an exit at an exterior circumference thereof, the converging shape of the nozzle assuring high velocity airflow at the nozzle exit. In one form, each nozzle also includes a curved path by which high-pressure air is enabled to induce spinning of the rotor. The fluidic actuator further includes a diffuser through which high-pressure air from the nozzles is cyclically ejected from those of the nozzles instantaneously exposed to the diffuser. In one form, the rotor spins at 300 revolutions per second and provides nozzle ejections effective to avoid boundary layer separation; i.e. to maintain an attached boundary layer flow over the airfoil.

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, the impeller being attached to a shaft rotatable about a shaft rotation axis, a motor arranged to rotate the shaft in order to rotate the impeller, and a diffuser disposed in the outlet portion downstream of the impeller. The recirculation structure is configured and arranged to impart a swirl to a flow of refrigerant into the inlet portion, with a velocity of a recirculation flow caused by the swirl being higher than a velocity of the flow of the refrigerant in the inlet portion.

A centrifugal compressor includes a casing. An impeller is arranged within the casing. The impeller is rotatable about an axis. A diffuser section is arranged within the casing. The diffuser section is positioned axially downstream from an outlet of the impeller and includes a forward portion fixed relative to the impeller and an aft portion distinct from the forward portion.