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.

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.

A manufacturing method is provided. During this method, a preform component is provided for a turbine engine. The preform component includes a substrate. A meter section of a cooling aperture is formed in the substrate. An internal coating is applied onto a surface of the meter section. An external coating is applied over the substrate. A diffuser section of the cooling aperture is formed in the external coating and the substrate to provide the cooling aperture.

An assembly is provided for an aircraft propulsion system. This assembly includes a nacelle inner structure that extends axially along and circumferentially about an axial centerline. 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. An aft end portion of the cowl is also configured to form an outer radial periphery of a compartment exhaust to the internal compartment. The aft end portion of the cowl includes a plurality of axial fingers arranged circumferentially about the axial centerline in an array.

An exhaust gas liner for a gas turbine includes an annular inner shell and an annular outer shell, which are arranged concentrically around a machine axis of the gas turbine to define an annular exhaust gas channel in between. The inner shell and/or said outer shell are composed of a plurality of liner segments, which are attached to a support structure. To compensate thermal expansion and achieving resistance against dynamic loads, the liner segments are fixed to the support structure at certain fixation spots, which are distributed over the area of said liner segments, such that said liner segments are clamped to said support structure through a whole engine thermal cycle without hindering thermal expansion.

A method of machining cooling holes includes providing a workpiece in which a cooling hole is to be formed. The cooling hole, once formed, defines distinct first and second sections. The workpiece is secured in a fixture that is mounted in a first machine. In the first machine, a laser is used to drill a through-hole in a wall of the workpiece. The through-hole is spatially common to the first and second sections of the cooling hole. After drilling the through-hole, the fixture with the workpiece secured therein is removed from the first machine and mounted in a second machine. In the second machine, ultrasonic machining is used to expand a portion of the through-hole to form the second section. An abrasive slurry used in the process is drained through the through-hole during the ultrasonic machining.

A manufacturing method is provided. During this method, a preform component is provided for a turbine engine. The preform component includes a substrate comprising electrically conductive material having an outer coating comprising non-electrically conductive material applied over a surface of the substrate. A preform aperture is formed in the preform component using an electrical discharge machining electrode. The preform aperture includes a meter section of a cooling aperture in the substrate. The preform aperture also includes a pilot hole in the outer coating. A diffuser section of the cooling aperture is formed in at least the outer coating using a second machining process.

A method includes forming a ceramic matrix composite component by infiltrating an array of ceramic-based fibers with a ceramic-based matrix; forming a plurality of cooling holes in the ceramic matrix composite component; applying a slurry of particles in a carrier fluid to the ceramic matrix composite component such that the slurry passes through the cooling holes and wicks into the ceramic matrix composite material; and processing the ceramic matrix composite component to remove the carrier fluid, thereby leaving a filler at a wall surface of the plurality of cooling holes. A component is also disclosed.

A propulsion assembly having a propulsion system including an exhaust nozzle fastened to the nozzle wall on the outside thereof so as to define between them a chamber, and a heat exchanger system ensuring an exchange of heat energy between the hot combustion gases circulating in the exhaust nozzle and the colder fuel circulating in the supply pipe at least in part by thermal radiation through the nozzle wall. The heat exchanger system has a pipe portion arranged in the chamber and the exchange of heat energy takes place at this pipe portion. With such an arrangement, the heat energy of the combustion gases is transferred to the fuel for better combustion.

An exhaust liner assembly including an interface between moveable parts includes a seal liner having a plurality of slots. The size of each slot varies with the circumferential position of the liner assembly to provide a stable cavity pressure within the interface to create a stable barrier about the entire circumference of the exhaust liner assembly.