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.

The invention relates to an assembly for an aircraft turbomachine, comprising a central element (1) for the ejection of gas, and a connecting flange (9) interposed between, upstream, a gas outlet (22a) made of metal for a turbomachine, and, at the downstream end, the central element (1). The connecting flange comprises an annular portion (9a) and flexible tabs (11) having axially: a first end (111a) where the tab is connected to the said annular portion, and a second free end (111b), projecting radially inwardly with respect to the first end and to which said tab is attached with the central element (1).

Methods, apparatus, systems and articles of manufacture are disclosed for a structure of an engine component, including a first plurality of unit cells offset from a neutral plane in a first direction, a second plurality of unit cells offset from the neutral plane in a second direction, a plurality of nodes joining ones of the first plurality of unit cells and ones of the second plurality of unit cells, wherein the first plurality of unit cells and the second plurality of unit cells are arranged in pairs such that ones of the first plurality of unit cells are laterally adjacent to and interconnected with ones of the second plurality of unit cells, and wherein the structure is a stiffened structure.

One embodiment includes a multistage infrared suppression exhaust system for an aircraft, including: a stage one including a first exhaust conduit to receive a first exhaust air flow at a first temperature-pressure product T.sub.1P.sub.1, a second exhaust conduit to receive a second exhaust air flow at a second temperature-pressure product T.sub.2P.sub.2, and a flow integrator mechanically configured to mix the first exhaust air flow with the second exhaust air flow in an integration chamber while preventing back flow into the second exhaust conduit; and a stage two including a stage two cooling airflow to cool the mixed first and second exhaust air flows.

A center plug includes an inner skin, the inner skin extending along an axial centerline; an outer skin positioned radially outside the inner skin; a forward bulkhead connected to and extending radially outward from the inner skin; an aft bulkhead connected to and extending radially outward from the inner skin; and an acoustic panel, the acoustic panel including a first sheet having a first plurality of perforated walls and a first plurality of non-perforated walls, a second sheet having a second plurality of perforated walls and a second plurality of non-perforated walls, the first sheet being sandwiched together with the second sheet to form an N-shaped structure having a combined plurality of perforated walls and a combined plurality of non-perforated walls.

A preceramic resin formulation comprising a polycarbosilane preceramic polymer and an organically modified silicon dioxide preceramic polymer. A ceramic material comprising a reaction product of the polycarbosilane preceramic polymer and organically modified silicon dioxide preceramic polymer is also described. Articles comprising the ceramic material are also described, as are methods of forming the preceramic resin formulation and the ceramic material.

An acoustic panel is provided that includes a perforated first skin, a second skin and a corrugated structure. The corrugated structure is between and is connected to the perforated first skin and the second skin. The corrugated structure includes a first baffle, a first septum, first material and second material that is configured with the first material. The first baffle is formed by an uninterrupted portion of the first material. The first septum is formed by a portion of the second material that is exposed through an interruption in the first material.

A structural and/or acoustic panel including an inner skin, an outer skin, a honeycomb structure and at least one sealing flange. The sealing flange has a U-shaped section directed toward the honeycomb structure and is clamped with the honeycomb structure between the inner and the outer skins. A method for manufacturing such a panel by soldering the component elements thereof is also disclosed.

A method may comprise: laying up a first plurality of plies of material comprising thermoplastic resin and fiber to form an inner skin preform, the inner skin preform being a continuous sheet including alternating peaks and valleys; laying up a second plurality of plies of material comprising thermoplastic resin and fiber to form an outer skin preform; and joining the inner skin preform to the outer skin preform.

A waste heat capture system that can be used with at least a gas turbine engine. The system includes: an air scoop connected to a first component, the air scoop configured to direct air from a first duct to an interior compartment of the first component; a second duct along an exterior of the first component; and a thermoelectric material connected to an interior surface of the first component. The interior compartment of the first component is on a first side of the thermoelectric material and the exterior of the first component is on a second side of the thermoelectric material. The first duct is configured to receive air having a first temperature range, and the second duct is configured to receive air having a second temperature range, wherein the second temperature range is an order of magnitude higher than the first temperature range.