A turbine casing for an exhaust-gas turbine is provided herein. The turbine casing has a connection flange for bearing-casing-side attachment to a bearing casing in which casing-connection holes that are mutually spaced in the circumferential direction are provided, wherein, between adjacent casing-connection holes, material recesses that are open radially inwards towards a central longitudinal axis of the turbine casing are provided in the connection flange. Further provided herein is an exhaust-gas turbine that is equipped with the turbine casing.

A turbocharger is provided with a valve body which is disposed in a suction flow path leading from an inflow port of a housing covering a turbine rotor blade to a scroll portion and composed of a single piece or multiple divided pieces to supply a fluid to the turbine rotor blade with the inner surface thereof formed using a first wall surface and a second wall surface facing the first wall surface as part thereof, extends from the upstream side to the downstream side of the flow of the fluid, is rotatably provided in the housing in a direction toward and away from the first wall surface and the second wall surface, forms an upstream-side narrowed flow path with the first wall surface therebetween at an end on the upstream side, and forms a downstream-side narrowed flow path with the second wall surface therebetween at an end on the downstream side. The valve body has a first surface at the end on the upstream side, which faces the first wall surface, gradually approaches the first wall surface from the upstream side to the downstream side and thereafter gradually goes away therefrom, and a second surface which faces the second wall surface.

A turbocharger is provided with a valve body which is disposed in a suction flow path leading from an inflow port of a housing covering a turbine rotor blade to a scroll portion and composed of a single piece or multiple divided pieces to supply a fluid to the turbine rotor blade with the inner surface thereof formed using a first wall surface and a second wall surface facing the first wall surface as part thereof, extends from the upstream side to the downstream side of the flow of the fluid, is rotatably provided in the housing in a direction toward and away from the first wall surface and the second wall surface, forms an upstream-side narrowed flow path with the first wall surface therebetween at an end on the upstream side, and forms a downstream-side narrowed flow path with the second wall surface therebetween at an end on the downstream side. The valve body has a first surface at the end on the upstream side, which faces the first wall surface, gradually approaches the first wall surface from the upstream side to the downstream side and thereafter gradually goes away therefrom, and a second surface which faces the second wall surface.

A centrifugal compressor, has: an impeller; and a housing including: a shroud extending between a first end and a second end; a structural member having an outer end securable to a casing of the gas turbine engine, an inner end of the structural member intersecting the rear side of the shroud; and a reinforced region at the location where the structural member and the rear side of the shroud intersect, a thickness of the reinforced region in a direction normal to the gaspath side greater than a nominal thickness of the shroud, the reinforced region defining a curved surface extending from a first location on the structural member to a second location on the rear side of the shroud, a portion of the curved surface having a radius that increases from a first radius to a second radius at the second location.

A power generation system for an internal combustion engine includes: a turbocharger capable of performing a turbocharger power generation using rotation of a turbine provided in an exhaust passage of the internal combustion engine; and a control unit including at least one electronic control unit. The control unit is configured to calculate a first power generation instruction value required for the turbocharger, and determine whether or not a magnitude relationship in which generated power of the turbocharger power generation is larger than an increase amount of a pumping loss of the internal combustion engine resulting from the turbocharger power generation is satisfied based on an operational state of the internal combustion engine, and calculate the first power generation instruction value larger when the magnitude relationship is satisfied than when the magnitude relationship is not satisfied.

A power generation system for an internal combustion engine includes: a turbocharger capable of performing a turbocharger power generation using rotation of a turbine provided in an exhaust passage of the internal combustion engine; and a control unit including at least one electronic control unit. The control unit is configured to calculate a first power generation instruction value required for the turbocharger, and determine whether or not a magnitude relationship in which generated power of the turbocharger power generation is larger than an increase amount of a pumping loss of the internal combustion engine resulting from the turbocharger power generation is satisfied based on an operational state of the internal combustion engine, and calculate the first power generation instruction value larger when the magnitude relationship is satisfied than when the magnitude relationship is not satisfied.

Disclosed is a process for producing a blade or vane ring segment for a gas turbine, in particular for an aero engine, and also to a correspondingly produced blade or vane ring segment, the process comprising: forging at least two blanks made of a TiAl material, joining the blanks to form a blade or vane ring by means of an integral connection process, and remachining of the blank composite by material-removing processes.

A method for manufacturing impellers is described. The method provides for manufacturing a plurality of tubular components, each tubular component forming an inner passage, which is shaped as one of the flow passages of the final impeller. The tubular components are assembled together forming a semi-finished impeller. The semi-finished impeller is provided with annular cavities extending around the rotation axis of the impeller and gaps between adjacent tubular components. The gaps and cavities are filled with metal powder and the semi-finished impeller is subject to hot isostatic pressing, to densify the metal powder and form a monolithic final impeller.

A method for manufacturing impellers is described. The method provides for manufacturing a plurality of tubular components, each tubular component forming an inner passage, which is shaped as one of the flow passages of the final impeller. The tubular components are assembled together forming a semi-finished impeller. The semi-finished impeller is provided with annular cavities extending around the rotation axis of the impeller and gaps between adjacent tubular components. The gaps and cavities are filled with metal powder and the semi-finished impeller is subject to hot isostatic pressing, to densify the metal powder and form a monolithic final impeller.

A turbine includes a housing including an inlet, an outlet, and a shroud section having a shroud surface extending between the inlet and the outlet; and a turbine impeller housed in the housing and including a hub and a plurality of blades disposed on an outer peripheral surface of the hub, each of the blades having a side edge extending along the shroud surface. The side edge of each of the blades has a side-edge upstream portion disposed on a side of the inlet, and a side-edge downstream portion disposed on a side of the outlet. The shroud surface has a shroud upstream portion disposed on the side of the inlet and extending along the side-edge upstream portion, and a shroud downstream portion disposed on the side of the outlet and extending along the side-edge downstream portion. The shroud upstream portion has a meridional cross-sectional shape whose inclination angle (θ.sub.1) with respect to an axis (L) of the hub at the side of the inlet is smaller than in a case where the shroud upstream portion has a meridional cross-sectional shape of an arc shape and the shroud downstream portion has a meridional cross-sectional shape of a linear shape along a direction of the axis of the hub.