An assembly is provided for a gas turbine engine. This gas turbine engine assembly includes a split case structure. The split case structure includes a first wall, a second wall, a first case segment and a second case segment. The first wall extends axially along and circumferentially about an axial centerline. The second wall extends axially along and circumferentially about the axial centerline. The second wall is radially outboard of and axially overlaps the first wall. The first case segment is configured to form a first portion of the first wall and a first portion of the second wall. The second case segment is configured to form a second portion of the first wall and a second portion of the second wall. The second case segment is circumferentially adjacent and attached to the first case segment at a joint.

In a method for manufacturing an article, the article has a body having: a first face; and a first bevel surface extending from the first face. A plurality of first channels along the first bevel surface extending from the first face. A ceramic coating is along the inner diameter surface and the first bevel surface. Each of the first channels are machined in the body by plunging a rotating bit into the first surface and drawing the rotating bit down the bevel surface. The coating is thereafter applied.

A liquid rocket engine cools a thruster body by pumping propellant through cooling channels integrated in the thruster body between internal and external surfaces. One or more of the cooling channel surfaces has a variable depth along a thrust axis to mix propellant flow and destroy thermal stratification, such as a depth that varies with a repeated contiguous sinusoidal form along the thrust axis. Fuel passed through the cooling channels injects from the combustion chamber wall towards a central portion of the combustion chamber to cross impinge with oxygen injected at the combustion chamber head so that a toroidal vortex forms to enhance propellant mixing. The cooling channels are formed by milling at the combustion body exterior, filling the channels with wax, then electroplating metal to enclose the channels.

A liquid rocket engine cools a thruster body by pumping propellant through cooling channels integrated in the thruster body between internal and external surfaces. One or more of the cooling channel surfaces has a variable depth along a thrust axis to mix propellant flow and destroy thermal stratification, such as a depth that varies with a repeated contiguous sinusoidal form along the thrust axis. Fuel passed through the cooling channels injects from the combustion chamber wall towards a central portion of the combustion chamber to cross impinge with oxygen injected at the combustion chamber head so that a toroidal vortex forms to enhance propellant mixing.

A method for forming a QCr0.8 alloy tapered cylindrical ring, including: heating a standard QCr0.8 alloy cylindrical part followed by upsetting and stretching at least twice to obtain a primary blank; heating the primary blank followed by upsetting and chamfering to obtain a secondary blank, where a diameter of a top end is greater than that of a bottom end; subjecting the secondary blank to backward extrusion to form a preform; machining the preform to remove a flash and a bottom residue; subjecting a bottom end of the preform to local bulging to enable a shape and a size thereof to match that of a drive roller in a forming tooling, so as to form a profiled ring blank; and rolling the profiled ring blank by a radial-axial ring rolling machine with the forming tooling to form the tapered cylindrical ring.

An acoustic core has a plurality of cell walls formed of an additive-manufacturing material and a resonant space defined by the plurality of cell walls. At least some of the resonant cells have a multitude of sound-attenuating protuberances formed of the additive-manufacturing material of the cell walls protruding into the resonant space with a random or semi-random orientation and/or size. The sound-attenuating protuberances may be formed by orienting an additive-manufacturing tool with respect to a toolpath to form a contour of a workpart, in which the toolpath includes a plurality of overlapping toolpath passes configured so as to intentionally introduce an amount of additive-manufacturing material to the workpart that exceeds a domain occupied by the contour. As the amount of additive-manufacturing material intentionally introduced exceeds the domain occupied by the contour, a portion of the additive-manufacturing material may incidentally form the plurality of sound-attenuating protuberances.

An article has a body having: a first face; and a first bevel surface extending from the first face. A plurality of first channels along the first bevel surface extending from the first face. A ceramic coating is along the inner diameter surface and the first bevel surface.

An acoustic core has a plurality of cell walls formed of an additive-manufacturing material and a resonant space defined by the plurality of cell walls. At least some of the resonant cells have a multitude of sound-attenuating protuberances formed of the additive-manufacturing material of the cell walls protruding into the resonant space with a random or semi-random orientation and/or size. The sound-attenuating protuberances may be formed by orienting an additive-manufacturing tool with respect to a toolpath to form a contour of a workpart, in which the toolpath includes a plurality of overlapping toolpath passes configured so as to intentionally introduce an amount of additive-manufacturing material to the workpart that exceeds a domain occupied by the contour. As the amount of additive-manufacturing material intentionally introduced exceeds the domain occupied by the contour, a portion of the additive-manufacturing material may incidentally form the plurality of sound-attenuating protuberances.

A retaining ring anti-migration system and method. A retaining ring anti-migration system for a centrifugal pump shaft includes a pair of trap sleeves that enclose a pair of retaining rings, one retaining ring around each end of the shaft enclosed by one trap sleeve, the pair of retaining rings configured to bound axial migration of the shaft both upwards and downwards. A retaining ring anti-migration system includes a retaining ring seated in a shaft groove extending circumferentially around an electric submersible pump (ESP) shaft, a trap sleeve extending around the ESP shaft adjacent to the retaining ring, the trap sleeve including a sleeve body secured to the ESP shaft such that the trap sleeve rotates with the ESP shaft, and a jacket extending axially from the sleeve body over an outer diameter of the retaining ring with a clearance between the shaft and the jacket.

A barrier device is provided for an inlet cowl for an aircraft engine including an inner barrel circumferentially surrounding an opening in the inlet cowl formed along an axis of rotation of the aircraft engine, through which air passes to the aircraft engine, the inner barrel including a face sheet disposed on a radially inward side of the inner barrel relative to the axis. The barrier device includes a containment doubler of the inner barrel, disposed on a radially outward side of the inner barrel, and a blade fragment barrier including one or more strips disposed between the containment doubler and the face sheet, so as to extend circumferentially at least partially around the opening and to occupy a radial distance between the containment doubler and the face sheet.