A centering device (10) for centering a turbine housing (40) with respect to a central axis (33) of a radial turbine of a turbo system is described. The centering device (10) includes a ring-shaped body (11) having an outer diameter D1 and an inner diameter D2, wherein a ratio of D1/D2 is ≤2. Additionally, the centering device (10) includes two or more centering elements (16) provided on a side surface (12) of the ring-shaped body (11) for engaging with respective complementary centering elements (21) provided on a bearing housing (20). The two or more centering elements (16) are configured for allowing a radial thermal expansion of the ring-shaped body (11) during engagement of the two or more centering elements (16) with the respective complementary centering elements (21). Further, a turbo system, including such a centering device as well as a method of centering a turbine housing are described.

A turbine is provided with: a turbine wheel configured to rotate about an axis O1; a turbine housing accommodating the turbine wheel and defining an annular nozzle passage on the outer peripheral side of the turbine wheel; and a plurality of low solidity nozzle vanes 6 arranged in the nozzle passage at an interval in the circumferential direction. Circumferentially adjacent low solidity nozzle vanes 6 are disposed at different radial positions in a connection position of each of the low solidity nozzle vanes 6 with a hub-side wall surface of the hub-side wall surface and a shroud-side wall surface which define the nozzle passage.

A variable capacity turbocharger includes: a nozzle flow path which allows a gas to pass from a scroll flow path toward a turbine impeller; a shroud side ring and a hub side ring which face each other in a rotation axis direction of the turbine impeller and form a nozzle flow path therebetween; a bearing hole which is provided in the shroud side ring; a bearing hole which is provided in the hub side ring; and a nozzle vane which is disposed in the nozzle flow path and is supported by both bearing holes, wherein a center axis line of the bearing hole is located on the inside in a radial direction in relation to a center axis line of the bearing hole at a room temperature and the center axis line is located on the outside in the radial direction in relation to the center axis line when a predetermined temperature difference is generated between the shroud side ring and the hub side ring during operation.

A turbine section of a turbomachine includes a housing that houses and supports the rotating group for rotation about an axis. The housing defines a circumferential inlet passage that extends about the axis. The housing defines a turbine wheel upstream area that is disposed downstream of the circumferential inlet passage and upstream of the turbine wheel. The housing defines an outlet that is downstream of the turbine wheel. Furthermore, the turbine section includes a first flow path that extends from the circumferential inlet passage, through the turbine wheel upstream area, across the turbine wheel, to the outlet. Moreover, the turbine section includes a recirculation flow path that extends from the circumferential inlet passage, through the turbine wheel upstream area, and back to the circumferential inlet passage.

A turbine assembly comprising a housing comprising first and second volutes which define a respective first and second flow passage. A circumferential outlet portion of each volute is defined by first and second tongues. The housing further comprises a first aperture in which a vane assembly is received. The vane assembly comprises a plurality of vanes circumferentially distributed about a turbine wheel-receiving bore, each vane comprising a leading edge and a trailing edge. Each vane has a fixed orientation. The vanes comprise a first vane and a second vane. The first vane having its leading edge disposed in closest proximity to a tip of the first tongue. The second vane having its leading edge disposed in closest proximity to a tip of the second tongue. The leading edge of each vane at least partly overlaps the tip of the proximate tongue circumferentially.

A fuel cell fluid machine includes a rotary shaft, an electric motor, a compression unit, and a rotation assist unit. The rotation assist unit includes a turbine wheel and a turbine housing. Exhaust gas discharged from a fuel cell stack is introduced to the turbine chamber. The exhaust gas then flows in the radial direction of the rotary shaft and is discharged in the axial direction of the rotary shaft. This rotates the turbine wheel. A diameter of the turbine wheel and a diameter of the shroud surface gradually increase from an upstream side to a downstream side in a flowing direction of the exhaust gas.

A nozzle assembly of a turbocharger includes a nozzle and a ring-shaped body. The nozzle has flow passages extending through the nozzle and configured to direct air received from a volute housing of the turbocharger through the nozzle to turbine blades of the turbocharger. The ring-shaped body is coupled with the nozzle and is configured to rotate around the nozzle. The ring-shaped body includes blocking segments that block the flow of the air and openings between the blocking segments that permit the air to flow through the ring-shaped body. The ring-shaped body is configured to rotate relative to the nozzle to change how many of the flow passages in the nozzle are blocked by the blocking segments of the ring-shaped body.

A turbine assembly includes a turbine housing and a turbine wheel disposed within the turbine housing. The turbine wheel includes a rotational axis and a plurality of blades. The turbine assembly includes a turbine shroud disposed between the turbine housing and the turbine wheel along a radial direction. The turbine shroud is separate from the turbine housing. The turbine shroud includes an annular portion extending generally in an axial direction with respect to the rotational axis and a plate portion intersecting the annular portion to form a convex curved surface. At least a portion of the blades is disposed in at least a portion of the annular portion. Each blade includes a leading edge and a tip portion. Each leading edge is angled with respect to the rotational axis, and each tip portion forms a concave portion that curves around the curved surface of the turbine shroud.

An arrangement for intentionally mistuning a cavity formed adjacent an impeller in a turbomachine, the arrangement including at least two bladed elements defined within a perimeter of a casing wall adjacent the impeller, wherein the bladed elements are configured to mistune cavity acoustic modes to minimize acoustic pulsations in the cavity.

A return stage of a radial turbo fluid energy machine, in particular of a radial turbo compressor, having an axis of rotation, the return stage has an annular flow channel for feeding a flowing process fluid from a flow opening of a first impeller to a flow opening of a second impeller arranged downstream. In order to increase efficiency, the flow channel is defined by bounding surface areas, of which at least one certain rough area extending in the circumferential direction has a surface roughness that is increased in relation to the her areas.