A heat shield for a gas turbine engine includes a radial heat shield flange that extends in a circumferential direction and forms a ring. A plurality of bosses extend from a first axial side of the radial heat shield flange. There is a plurality of guide pins. One of the plurality of guide pins extends from a corresponding one of the plurality of bosses.

Tail cone apparatus and methods for reducing nozzle surface temperatures of aircraft engines are disclosed. An example apparatus includes a tail cone to be coupled to an aircraft engine. The tail cone includes a central axis, a cone section, and a plurality of fins. The fins are spaced about the central axis and extend outwardly from an outer surface of the cone section.

Tail cone apparatus and methods for reducing nozzle surface temperatures of aircraft engines are disclosed. An example apparatus includes a tail cone to be coupled to an aircraft engine. The tail cone includes a central axis, a cone section, and a plurality of fins. The fins are spaced about the central axis and extend outwardly from an outer surface of the cone section.

A center plug for attenuating noise in a gas turbine engine includes an inner skin, a forward bulkhead, and aft bulkhead, and a noise attenuation panel. The inner skin has a substantially cylindrical shape and extending along an axial centerline. The forward bulkhead is disposed proximate a forward end of the inner skin. The forward bulkhead is connected to and extends radially outward from the inner skin. The aft bulkhead is disposed proximate an aft end of the inner skin. The aft bulkhead is connected to and extending radially outward from the inner skin. The noise attenuation panel is positioned intermediate the inner skin and partially divides a region bounded by the inner skin, the forward bulkhead and the aft bulkhead into.

For example, a controller of an Active Acoustic Control (AAC) system may be configured to process input information including AAC configuration information, and a plurality of noise inputs representing acoustic noise at a plurality of noise sensing locations. For example, the controller may be configured to process the input information to determine a sound control pattern to control sound within a sound control zone based on the plurality of noise inputs. For example, the controller may include a Neural-Network (NN) trained to generate an NN output based on an NN input, wherein the NN input is based on the AAC configuration information. For example, the controller may be configured to generate the sound control pattern based on the NN output, and to output the sound control pattern to one or more acoustic transducers.

In a cowl for a nozzle, an internal wall has a cross-section with a determined abscissa on the axis defining a neck line on the internal wall. The cowl has, downstream of the determined abscissa, indentations in the trailing edge which delimit chevrons distributed in the circumferential direction. The internal wall of the cowl diverges radially towards the interior, in a second axial half-plane passing through the tip of a chevron, from the upstream tangent on the point of the neck line in the second axial half-plane, and the lines defining the internal wall of the cowl in any axial half-plane do not have a turning point downstream of the determined abscissa of the neck line.

In a cowl for a nozzle, an internal wall has a cross-section with a determined abscissa on the axis defining a neck line on the internal wall. The cowl has, downstream of the determined abscissa, indentations in the trailing edge which delimit chevrons distributed in the circumferential direction. The internal wall of the cowl diverges radially towards the interior, in a second axial half-plane passing through the tip of a chevron, from the upstream tangent on the point of the neck line in the second axial half-plane, and the lines defining the internal wall of the cowl in any axial half-plane do not have a turning point downstream of the determined abscissa of the neck line.

A nozzle of a turbomachine is provided with chevrons with a non-axisymmetric inner face. A cover for the nozzle of longitudinal axis L-L includes an internal wall having a section with a predetermined abscissa on the L-L axis defining, on the wall, a neck line. The cover has, downstream from the abscissa, indentations in the trailing edge of the cover delimiting chevrons distributed in the circumferential direction, in which, on the cover, from the abscissa the internal wall moves away radially towards the outside of the upstream tangent, to the top of an indentation, the outer wall of the cover moves towards the upstream tangent to the top of an indentation, and the internal wall moves away radially towards the inside of the upstream tangent, to the tip of a chevron.

A nozzle of a turbomachine is provided with chevrons with a non-axisymmetric inner face. A cover for the nozzle of longitudinal axis L-L includes an internal wall having a section with a predetermined abscissa on the L-L axis defining, on the wall, a neck line. The cover has, downstream from the abscissa, indentations in the trailing edge of the cover delimiting chevrons distributed in the circumferential direction, in which, on the cover, from the abscissa the internal wall moves away radially towards the outside of the upstream tangent, to the top of an indentation, the outer wall of the cover moves towards the upstream tangent to the top of an indentation, and the internal wall moves away radially towards the inside of the upstream tangent, to the tip of a chevron.

Fluidic propulsion system enclosures are described, including a high-pressure gas source container, a high-pressure gas source inlet, an ambient air inlet, a thruster container, a thruster outlet in fluid communication with the high-pressure gas source inlet and the ambient air inlet, and a housing substantially surrounding and interconnecting the high-pressure gas source container and the thruster container. The enclosure may include sound and/or energy abatement baffles within the housing, which may be arranged between the high-pressure gas source container and the thruster container.