A method for forming a vertically cracked thermal barrier coating is disclosed including positioning an article relative to a heat source. The article includes a thermal barrier coating disposed on a first surface of a substrate, and the substrate includes a second surface distal across the substrate from the first surface. Heat is applied locally to at least one discrete portion of the second surface of the substrate. At least one vertical crack in the thermal barrier coating is formed disposed over the at least one discrete portion. An article is disclosed including a substrate and a vertically-cracked thermal barrier coating disposed on the substrate. The vertically cracked thermal barrier coating includes at least one vertical crack in the thermal barrier coating and at least one of a low density of less than 85% of a theoretical density for the thermal barrier coating and a selective crack distribution.

A fairing for a power generation machine, the fairing comprising: a first layer comprising a metallic material; a second layer comprising a composite; and a third layer positioned between the first layer and the second layer, the third layer being configured to attenuate acoustic waves over a predetermined frequency range.

An acoustic core may include an array of resonant cells configured as a plurality of resonant cell groups. The resonant cell groups may include a plurality of resonant cells configured as a partitioned resonant cell that include a converging resonant cell and a diverging resonant cell. The converging resonant cell and the diverging resonant cell may be defined by a plurality of cell walls integrally formed with one another and a partition integrally formed with the plurality of cell walls. The partition may at least partially delimit the converging resonant cell from the diverging resonant cell. The converging resonant cell may define an upper resonant space delimited by the partition and a top face of the array of resonant cells. The diverging resonant cell may define a lower resonant space delimited by the partition and a bottom face of the array of resonant cells.

An assembly for an aircraft turbojet engine is described. The assembly includes a central gas-exhaust element and a connecting flange interposed between, upstream, a metallic outlet of a turbojet engine and, downstream, the central element. The connecting flange consists of an annular part and flexible lugs having axially: a first end where the lug is connected to the annular part, and a second free end, projecting radially outwards from the first end and towards which the lug is fixed with the central element.

An assembly is provided for an aircraft propulsion system. This assembly includes a nacelle inner structure and a deflection limiter. The nacelle inner structure includes an internal compartment and a cowl. The internal compartment is configured to house a core of a gas turbine engine. The cowl is configured to form an outer radial periphery of the internal compartment. The cowl is also configured to form an outer radial periphery of a compartment exhaust to the internal compartment at an aft end of the cowl. The deflection limiter is attached to the cowl. The deflection limiter is configured to limit radial outward movement of the cowl.

An engine exhaust nozzle for a jet engine offers a controllable variable mixing of engine exhaust and the surrounding airflow. The engine exhaust nozzle includes a nozzle, slots at the downstream end of the nozzle, curved vanes extending radially inward from the inner surface of the nozzle and adjacent to the slots, and a cover connected to the outside of the nozzle and movable with respect to the nozzle so as to open and close the slots. When the slots are opened, near-field mixing is enhanced between the jet exhaust and the surrounding air, thus reducing mixing further downstream and the noise associated therewith, thus reducing the overall noise transmitted to the ground. When the slots are closed, the nozzle propulsive efficiency improves at the expense of increased noise.

A device for securing at least one thermal protection mat to an internal fixed structure of a nacelle includes at least one removable fastening element for securing the at least one thermal protection mat to the internal fixed structure designed to be arranged between the mat and the internal fixed structure. The device includes at least one gripping element connected to the removable fastening element to project relative to the mat on the opposite side to the internal fixed structure, the removable fastening element being intended to be detached from the internal fixed structure by a pulling force exerted on the gripping element.

A structure for the nacelle of an aircraft propulsion unit includes a first skin and stiffeners arranged to hold acoustic treatment modules against the first skin. Each acoustic treatment module includes a honeycomb core and a second skin, such that the honeycomb core is sandwiched between the first skin and the second skin. Such a structure allows the structural reinforcement function provided by the stiffeners to be separated from the acoustic treatment function performed by the acoustic treatment modules which are simply bearing on the first skin.

An acoustic panel is provided that includes a perforated first skin, a second skin and a core. The core includes a first wall, a second wall and a stiffener. The core forms a plurality of cavities that extend vertically between the perforated first skin and the second skin and that extend laterally between the first wall and the second wall. The plurality of cavities include a first cavity. The stiffener projects partially into the first cavity and is connect to the first wall and the second wall.

Flexible aft cowls are disclosed. In some examples, an aircraft engine having a flexible aft cowl is disclosed. In some examples, the aircraft engine comprises an aft cowl having a flexible portion defining a throat area adjacent an engine core nozzle of the aircraft engine. In some examples, the flexible portion to move radially between a first radial position in response to pressure within a nacelle not exceeding a pressure threshold and a second radial position in response to pressure within the nacelle exceeding the pressure threshold. In some examples, the throat area defined by the flexible portion is greater when the flexible portion is in the second radial position than when the flexible portion is in the first radial position.