An acoustic attenuator comprises a first attenuation unit, a second attenuation unit, a welded section, and a communication part. A first acoustic damper is provided on an outer surface of a first acoustic liner, which faces toward a side opposite from an object, to form a first damper space that communicates with an internal space of the object. The second attenuation unit is attached to an outer surface of the object. The welded section is provided at least between the first acoustic damper and a second acoustic damper. The welded section secures the second attenuation unit to the first acoustic liner. The communication part is disposed in a position farther from an outer surface of the object than the welded section, allowing communication between the first damper space and a second damper space.

A constant density heat exchanger is provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first flow control device is positioned at the inlet of the chamber and movable between an open position in which a working fluid is permitted into the chamber and a closed position in which the working fluid is prevented from entering the chamber. A second flow control device is positioned at the outlet of the chamber and movable between an open position in which the working fluid is permitted to exit the chamber and a closed position in which the working fluid is prevented from exiting the chamber. A heat exchange fluid imparts thermal energy to the volume of working fluid held at constant density within the chamber by the first and second control devices.

An embodiment of a torch igniter for a combustor of a gas turbine engine includes a combustion chamber oriented about an axis, a cap defining an axially upstream end of the combustion chamber, a tip defining the axially downstream end of the combustion chamber, an igniter wall extending from the cap to the tip and defining a radial extent of the combustion chamber, a structural wall coaxial with and surrounding the igniter wall, an outlet passage defined by the igniter wall within the tip, a glow plug housing configured to receive a glow plug and allow an innermost end of the glow plug to extend into the combustion chamber, and a cooling system. The cooling system includes an air inlet formed within an exterior of the structural wall, a cooling channel forming a flow path through the structural wall at the glow plug housing, and an air passage.

An assembly is provided for a gas turbine engine. This assembly includes a multi-walled structure including a cold wall, a hot wall and a cooling cavity vertically between the cold wall and the hot wall. The cold wall includes a plurality of cold wall apertures fluidly coupled with the cooling cavity. The cold wall apertures are configured to subject the cold wall to a cold wall pressure drop vertically across the cold wall. The hot wall includes a plurality of hot wall apertures fluid coupled with the cooling cavity. The hot wall apertures are configured to subject the hot wall to a hot wall pressure drop vertically across the hot wall that is greater than or equal to the cold wall pressure drop.

A system includes a combustor. The combustor has a combustor wall with a combustor dome at an upstream end of the combustor wall, and an outlet at a downstream end of the combustor wall opposite the upstream end. The combustor wall includes an inner wall portion and an outer wall portion defining an interior of the combustor therebetween. Each of the inner wall portion and outer wall portion extends from the combustor dome to the downstream end of the combustor wall. The combustor wall includes an air cooling passage embedded inside at least one of the inner wall portion and the outer wall portion. The air cooling passage extends from the upstream end of the combustor wall to the downstream end of the combustor wall.

A hybrid three-layer system is presented. The hybrid three-layer system includes a two-layer composite system and an additively manufactured third layer comprising a lattice structure. The composite layer system includes a metallic substrate, a structured surface, and a thermal protection system. The structured surface may be additively manufactured onto the metallic substrate and includes structured surface features formed to project above the metallic substrate. Each of the structured surface features are separated from adjacent structured surface features by grooves. The thermal protection coating may be thermally sprayed onto the structured surface and is bonded to each of the structured surface features. The lattice structure is in contact with a surface of the metallic substrate of the composite layer system.

A gas turbine engine that includes a combustor configured for efficient combustion of fuel for the generation of combustion gases. The engine includes an annular combustor that includes an annular wall that defines a channel configured to conduct hot combustion gases along a flow-path of combustion gases. The annular wall has an exterior first surface and an interior second surface. A plurality of dilution holes is defined through the wall. Each dilution hole is defined by a dilution hole surface that extends between an entry end and an exit end. The entry end is defined by the first surface and the exit end is defined by the second surface such that the dilution hole has a convergent and then divergent cross-sectional profile. The entry end has a first geometric shape and the exit end has a second geometric shape that is different than the second geometric shape.

A combustion chamber assembly includes a through hole on the combustion chamber wall bounded on an outer side of the wall by a hole edge and a combustion chamber shingle having a collar bounding a mixing air hole on the outer side of the wall and protruding with a first collar portion beyond the hole edge on the outer side of the wall. A cooling air opening is formed on an inner circumferential surface of a duct portion of the mixing air hole adjoining the first collar portion and extending in the direction of a combustion space, the cooling air opening leading into a cooling air duct which extends through the duct portion and via which cooling air is guided out of the mixing air hole in a direction of a hot side of the shingle facing the combustion space.

A combustion chamber (15) comprising a wall at least partially defining a combustion zone and having a first surface (41) facing away from the combustion zone and a second surface (43) facing the combustion zone, the wall having at least one effusion cooling aperture (69, 73) extending there-through from the first surface to the second surface, the effusion cooling aperture having an inlet in the first surface and an outlet in the second surface, the first surface having a particle separator (84) at least partially located upstream of the inlet of the effusion cooling aperture, the particle separator projecting away from the first surface and away from the combustion zone.

A torch igniter system for a combustor of a gas turbine engine includes a housing defining a combustion chamber, an ignition source disposed at least partially in the combustion chamber, a fuel injector, a first fluid path connecting a first fuel source to the fuel injector, a second fluid path connecting an air source to the fuel injector, and a third fluid path connecting a second fuel source to the combustion chamber. The fuel injector is configured to inject fuel, air, or a mixture of fuel and air into the combustion chamber and to impinge on the ignition source.