Abstract: A method for redistributing an area of residual stress around a machined central aperture in an engine component. The method includes changing tensile stress to compressive stress at an area circumscribing the machined aperture. The method can be applied to, for example, a forged engine component such as a rotating disk or an impeller part for a gas turbine engine.

Abstract: A method of treating a hole in a metallic component includes the following steps in sequence: forming an hole having a first diameter in the component; expanding the hole to a second diameter using a cold expansion process, so as to induce residual compressive stresses in the material surrounding the hole; shot peening the hole; and final machining the hole to a finished diameter.

Abstract: A system for asymmetric flow extraction is described and claimed, the system comprising a flow path, a bleed slot in the flow path, a bleed cavity for receiving at least a portion of the fluid extracted from the flow path and a bleed passage in flow communication with the bleed slot and the bleed cavity wherein the bleed passage has at least one deflector having a shape such that the width of the bleed passage cross section varies in a direction normal to the direction of fluid flow in the bleed passage. In another embodiment, the deflector has an aerodynamic surface having a shape such that the flow passage between the aerodynamic surface and a surface located away from it has a cross sectional shape that is non-axisymmetric. In another embodiment, the bleed passage comprises an assembly of a plurality deflectors, arranged circumferentially.

Abstract: A system for asymmetric flow extraction is described and claimed, the system comprising a flow path, a bleed slot in the flow path, a bleed cavity for receiving at least a portion of the fluid extracted from the flow path and a bleed passage in flow communication with the bleed slot and the bleed cavity wherein the bleed passage has at least one deflector having a shape such that the width of the bleed passage cross section varies in a direction normal to the direction of fluid flow in the bleed passage. In another embodiment, the deflector has an aerodynamic surface having a shape such that the flow passage between the aerodynamic surface and a surface located away from it has a cross sectional shape that is non-axisymmetric. In another embodiment, the bleed passage comprises an assembly of a plurality deflectors, arranged circumferentially.

Abstract: A variable stator vane assembly and a bushing thereof. The bushing includes a metal bushing body and a wear-resistant coating. The assembly includes a rotatable trunnion and a first metal bushing. The trunnion is capable of being located in a through hole extending between outer and inner surfaces of a compressor casing of a gas turbine engine. The first metal bushing is capable of being located in the through hole proximate the outer surface to surround a first portion of the trunnion when the trunnion is located in the through hole. The first metal bushing and the first portion have wear-resistant coatings which are in mutual contact, apart from any intervening lubricant, when the trunnion and the first metal bushing are located in the through hole and the trunnion is rotating with respect to the first metal bushing.