US-12618383-B2 - Assembly for an exhaust cone of an aircraft turbomachine

US12618383B2US 12618383 B2US12618383 B2US 12618383B2US-12618383-B2

Abstract

An assembly for an exhaust cone of an aircraft turbomachine, including a first annular wall, and first partitions and second partitions defining between them a plurality of acoustic boxes distributed around the first wall, an assembly formed by the first and the second partitions being fastened to the first wall with first fastening members arranged upstream and with second fastening members arranged downstream, the first fastening members being offset circumferentially with respect to the second fastening members.

Inventors

Tony MIOSSEC
Fabien Bravin
Vincent DEVANLAY
Marc VERSAEVEL
Valentin SIMEON

Assignees

SAFRAN NACELLES

Dates

Publication Date: 20260505
Application Date: 20221202
Priority Date: 20211203

Claims (11)

1 . An assembly of an exhaust cone of an aircraft turbomachine, comprising: a first annular wall centered on a longitudinal axis running axially from upstream to downstream, and first partitions and second partitions extending substantially perpendicularly from the first annular wall, wherein the first partitions extend generally in an axial direction and are distributed circumferentially around the first annular wall, wherein the second partitions extend generally in a circumferential direction between pairs of adjacent first partitions of the first partitions and are distributed circumferentially around the first annular wall in at least one circumferential row, wherein the first annular wall, the first partitions, and the second partitions define therebetween a plurality of acoustic enclosures distributed around the first annular wall and absorbing combustion gas noises from the aircraft turbomachine, wherein an arrangement formed by the first and the second partitions is fixed to the first annular wall with first fixing members arranged upstream relative to second fixing members and the second fixing members arranged downstream relative to the first fixing members, the first fixing members including all fixing members disposed at a same first axial location and the second fixing members including all fixing members disposed at a same second axial location, the first fixing members and the second fixing members forming mechanical point connections, and wherein each first fixing member of the first fixing members is offset circumferentially relative to each second fixing member of the second fixing members.
2 . The assembly according to claim 1 , wherein the first fixing members are mounted between the second partitions of a most upstream circumferential row of the at least one circumferential row and an upstream portion of the first annular wall.
3 . The assembly according to claim 2 , wherein the first fixing members are mounted on only a downstream side of the second partitions in the axial direction and/or wherein each first fixing member of the first fixing members is separated from an adjacent first fixing member circumferentially adjacent thereto by one or two first partition of the first partitions.
4 . The assembly according to claim 1 , wherein the first fixing members are mounted between the first partitions and an upstream portion of the first annular wall.
5 . The assembly according to claim 4 , wherein the first fixing members are mounted upstream of the at least one circumferential row of the second partitions and/or the first fixing members are mounted on each side of the first partitions in the circumferential direction.
6 . The assembly according to claim 1 , wherein the second fixing members are mounted between the first partitions and a downstream portion of the first annular wall downstream of the at least one circumferential row of the second partitions.
7 . The assembly according to claim 6 , wherein the second fixing members are mounted on each side of the first partitions in the circumferential direction or wherein each second fixing member of the second fixing members is mounted on only one side of the first partitions in the circumferential direction, opposite another second fixing member of the second fixing members.
8 . The assembly according to claim 1 , wherein the second partitions are curved partitions comprising at least one arcuate portion in the axial direction in an upstream or downstream orientation.
9 . An exhaust cone comprising the assembly according to claim 1 .
10 . An aircraft turbomachine, comprising the exhaust cone according to claim 9 .
11 . The assembly according to claim 1 , wherein a distance between each of the pairs of adjacent first partitions of the first partitions at a radially outer end edge of the first partitions and at a most upstream circumferential row of the at least one circumferential row of the second partitions is less than a distance between each of the pairs of adjacent first partitions of the first partitions at a mid-height between radially inner and outer end edges thereof and at a most downstream circumferential row of the at least one circumferential row of the second partitions.

Description

TECHNICAL FIELD The invention relates to an assembly for an exhaust cone of an aircraft turbomachine, an exhaust cone for an aircraft turbomachine comprising such as assembly, as well as an aircraft turbomachine comprising such an exhaust cone. PRIOR ART Conventionally, an aircraft turbomachine comprises, from upstream to downstream in the gas flow direction in an axial direction, a fan, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine and an exhaust nozzle comprising an exhaust case and an exhaust cone connected, upstream, to the exhaust case. This exhaust cone comprises an annular upstream part fitted with acoustic enclosures to reduce the noise produced by the combustion of gases and/or the rotation of various turbine stages and propagating along the turbomachine, as well as a conical downstream part. These acoustic enclosures are formed by a first radially inner annular wall, a second radially outer annular wall and by straight partitions extending generally radially between the first and second walls and defining between them a honeycomb structure. The partitions are also assembled by brazing to the first wall. The acoustic enclosures formed in this way have small dimensions and a small volume, of around 1 cm3 to 2 cm3. However, the use of such acoustic enclosures is not always appropriate. For example, it is ill-suited to absorbing low-frequency noise, which is the case for combustion noise. In addition, the brazed connection between the partitions and the first wall is not suitable for all types of material, such as ceramic matrix composites. It is also not appropriate for using different materials for the partitions and the first and second walls and for absorbing the forces generated by the differential thermal expansion between the partitions and the first and second walls as a result of using such different materials. DISCLOSURE OF THE INVENTION The present invention aims to overcome the aforementioned issues. To this end, one object of the invention is an assembly for an exhaust cone of an aircraft turbomachine, comprising a first annular wall centred on a longitudinal axis running axially from upstream to downstream, a plurality of first partitions and second partitions extending substantially perpendicularly from the first wall, wherein the first partitions extend generally in the axial direction and are distributed circumferentially around the first wall, wherein the second partitions extend generally in a circumferential direction between the pairs of first adjacent partitions and are distributed circumferentially around the annular wall in at least one circumferential row, and wherein the first wall, the first partitions and the second partitions define between them a plurality of acoustic enclosures distributed around the first wall. According to a first aspect of the invention, an arrangement formed by the first and the second partitions is fixed to the first wall by means of first fixing members arranged upstream and second fixing members arranged downstream, and in that the first fixing members are offset circumferentially relative to the second fixing members. According to alternative embodiments of this first aspect of the invention which can be considered together or separately: the first fixing members are mounted between second partitions of the most upstream circumferential row and an upstream portion of the first wall;the first fixing members are mounted on one side only, on the downstream side, of said second partitions in the axial direction;each first fixing member is separated from the first fixing members circumferentially adjacent thereto by one or two first partitions;the first fixing members are mounted between first partitions and an upstream portion of the first wall;the first fixing members are mounted upstream of the circumferential rows of second partitions;the first fixing members are mounted on each side of said first partitions in the circumferential direction;the second fixing members are mounted between first partitions and a downstream portion of the first wall downstream of the circumferential rows of second partitions;the second fixing members are mounted on each side of said first partitions in the circumferential direction;each second fixing member is mounted on one side only of said first partitions in the circumferential direction, opposite another second fixing member. According to a second aspect of the invention, which may or may not be combined with the first aspect, the second partitions are curved partitions comprising at least one arcuate portion in the axial direction upstream or downstream. According to alternative embodiments of this second aspect of the invention which can be considered together or separately: the arcuate portions of the second partitions of at least one of the circumferential rows define a pattern that repeats along said circumferential row and the pat