The invention concerns a transition duct for a multi-stage compressor of a gas turbine engine. Regions of the inner surface of the duct are provided with a predetermined and dissimilar surface roughness to optimise gas flow efficiency within the duct.

A seal assembly includes a seal arc segment that defines first and second seal supports and radially inner and outer sides with the radially outer side including radially-extending sidewalls and a radially inner surface that joins the radially-extending sidewalls. The radially-extending sidewalls and the radially inner surface define a pocket. The seal assembly includes a carriage that defines first and second support members with the first support member supporting the seal arc segment in a first ramped interface and the second support member supporting the seal arc segment in a second ramped interface. The radially inner surface has a higher surface roughness than the radially extending sidewalls.

A process for additively controlled surface features of a gas turbine engine casing. The process comprises forming the casing having an inner surface and an outer surface opposite the inner surface; forming a surface feature on the casing proximate the inner surface, wherein the surface feature comprises a structure on the inner surface configured to align or misalign with respect to a flow direction of a working fluid in a flow path of the casing.

A guide baffle of a turbomachine, including a cast or turned main body and guide blades applied to the main body via a generative manufacturing method.

A method of manufacturing a component from a nickel-based superalloy comprises the steps of: providing a vacuum induction casting furnace; positioning a component mould onto a chill plate within the furnace; casting a component blank; peening the surface of the component blank; applying a surface modification technique to the surface of the component blank; solution heat treating the component blank at or above the -solvus temperature for the superalloy; and precipitation heat treating the component blank.

Airfoil and hydrofoils systems with structures having a surface texture defined by fractal geometries are described. Raised portions or fractal bumps can be included on the surfaces, forming a surface texture. The surface textures can be defined by two-dimensional fractal shapes, partial two-dimensional fractal shapes, non-contiguous fractal shapes, three-dimensional fractal objects, and partial three-dimensional fractal objects. The surfaces can include indents having fractal geometries. The indents can have varying depths and can be bordered by other indents, or bumps, or smooth portions of the airfoil or hydrofoil structure. The fractal surface textures can reduce vortices inherent from airfoil and hydrofoil structures. The roughness and distribution of the fractal surface textures reduce the vortices, improving laminar flow characteristics and at the same time reducing drag. The systems are passive and do not require applied power.

A service tube assembly, has: a service tube having a threaded end portion and an outer shoulder adjacent to the threaded end portion, the outer shoulder having a frustoconical shoulder face converging towards the tube axis and away from the threaded end portion; a mating part threadingly engaged by the threaded end portion, the mating part having a seat face converging towards the service tube and towards the threaded end portion; a locking member extending from a first end to a second end, the first end including a notch receiving the outer shoulder, the notch circumscribed by a frustoconical notch face abutting the frustoconical shoulder face to create a frustoconical-to-frustoconical contact surface between the locking member and the outer shoulder, the second end in abutment against the seat face; and a mechanical fastener releasably holding the locking member in abutment against both of the outer shoulder and the mating part.

A turbocharger gas casing includes a scroll part forming a plurality of scroll passages at a same position in an axial direction of the turbine. The plurality of scroll passages include a first scroll passage. The first scroll passage is configured so that an extension line of a line segment connecting a farthest position from a rotational axis of the turbine at an inlet for an exhaust gas of the first scroll passage and a position of a tip of a tongue part formed on an inner peripheral side of the first scroll passage does not intersect a rotor blade of the turbine in a cross section of the turbine orthogonal to the axial direction.

An article includes a body that has a coating thereon. The coating has a first portion disposed on a first section of the body and a second portion disposed on a second, different section of the body. The first portion has a first microstructure and the second portion has a second, different microstructure.

A turbine engine rotor shaft includes at least one portion having an outer periphery having a determined diameter forming a free surface for heat exchange with the environment of said rotor. The outer periphery includes a plurality of irregularities which are designed to provide a heat exchange surface of the shaft of the rotor which is greater than a surface of the periphery of a cylinder having the same determined average diameter.