Abstract: The invention relates to a primary cowl for a turbofan comprising a primary body generating a primary stream to be ejected through a primary nozzle, and a secondary body generating a secondary stream to be ejected through a secondary nozzle, the primary cowl being shaped so as to be positioned downstream from the primary body and to define, on the inside of the turbofan, the path followed by the primary stream downstream from the primary nozzle and, on the outside, the path followed by the secondary stream downstream from the secondary nozzle. The primary cowl comprises a coupling to a system for supplying a pressurized gas and at least one perforation for injecting the pressurized gas, through the perforation, into the secondary stream. The primary cowl preferably comprises a ring which has perforations and which is rotated about the axis of rotation of the turbofan.

Abstract: A turboshaft engine supporting pylon covered with a porous material and a turboshaft engine/pylon assembly. The pylon supports a turboshaft engine on an aircraft, and includes an outer surface covered at least partially with a porous material to reduce amplitude of acoustic waves leaving the turboshaft engine. The assembly includes a turboshaft engine and a pylon, in which the pylon extends longitudinally from upstream to downstream and includes an upper part for securing to the aircraft, a lower part for securing to the turboshaft engine, and an absorption part extending in an exhaust stream from the turboshaft engine and including an internal absorption part extending inside the turboshaft engine and an external absorption part extending downstream of the turboshaft engine. The outer surface of the upstream end of the external absorption part of the pylon is covered with a porous material to limit noise formation downstream of the engine.

Abstract: The invention relates to a primary cowl for a turbofan comprising a primary body generating a primary stream to be ejected through a primary nozzle, and a secondary body generating a secondary stream to be ejected through a secondary nozzle, the primary cowl being shaped so as to be positioned downstream from the primary body and to define, on the inside of the turbofan, the path followed by the primary stream downstream from the primary nozzle and, on the outside, the path followed by the secondary stream downstream from the secondary nozzle. The primary cowl comprises a coupling to a system for supplying a pressurised gas and at least one perforation for injecting the pressurised gas, through the perforation, into the secondary stream. The primary cowl preferably comprises a ring which has perforations and which is rotated about the axis of rotation of the turbofan.

Abstract: A turboshaft engine supporting pylon covered with a porous material and a turboshaft engine/pylon assembly. The pylon supports a turboshaft engine on an aircraft, and includes an outer surface covered at least partially with a porous material to reduce amplitude of acoustic waves leaving the turboshaft engine. The assembly includes a turboshaft engine and a pylon, in which the pylon extends longitudinally from upstream to downstream and includes an upper part for securing to the aircraft, a lower part for securing to the turboshaft engine, and an absorption part extending in an exhaust stream from the turboshaft engine and including an internal absorption part extending inside the turboshaft engine and an external absorption part extending downstream of the turboshaft engine. The outer surface of the upstream end of the external absorption part of the pylon is covered with a porous material to limit noise formation downstream of the engine.

Abstract: The invention relates to an exhaust nozzle for a bypass airplane turbojet comprising an annular central body, an annular primary cover surrounding the central body to define a hot stream flow channel, and an annular secondary cover surrounding the primary cover to define a cold stream flow channel, each of the central body and the secondary cover comprising a stationary portion and a movable portion connected to a downstream end of the stationary portion, the movable portion of the central body being suitable for being retracted longitudinally upstream relative to the stationary portion, and the movable portion of the secondary cover being suitable for being deployed longitudinally downstream relative to the stationary portion.

Abstract: The invention relates to a cowl for a turbomachine nozzle, the cowl including a plurality of repetitive patterns disposed to extend a trailing edge of said cowl and spaced circumferentially apart from one another. Each pattern is in the form of a quadrilateral having a base that is formed by a portion of the trailing edge of the cowl and two vertices that are spaced downstream from the base and that are connected thereto via two sides, each side having the shape of a parabola. Each pattern is asymmetrical relative to a midplane of the pattern containing a longitudinal axis of said cowl, and it comprises a first portion inclined radially towards the inside of the cowl, and a second portion inclined radially towards the outside of the cowl.