Nozzle of a turbomachine provided with chevrons with a non-axisymmetric inner face

Patent metadata

Field	Value
Publication number	US-2016160797-A1
Application number	US-201414904330-A
Country	US
Kind code	A1
Filing date	Jul 15, 2014
Priority date	Jul 18, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

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.

First claim

(canceled)

12 . A cowl for a nozzle having a longitudinal axis L-L, the cowl comprising:
an external wall and an internal wall, the cowl being delimited radially towards an exterior by the external wall and, radially towards an interior, by the internal wall, the internal wall of the cowl having a cross-section with a determined abscissa on the axis L-L defining a neck line on the internal wall, said internal wall converging towards the axis L-L upstream of said cross-section and having, in any axial half-plane, a defined upstream tangent at its intersection with the neck line, said cowl having, downstream of said determined abscissa, indentations in the trailing edge of the cowl which delimit chevrons distributed in the circumferential direction, wherein the downstream direction from said determined abscissa, the internal wall of the cowl diverges radially towards the exterior, in a first axial half-plane passing through the top of an indentation, from the upstream tangent on the tip of the neck line in said first axial half-plane, the external wall of the cowl moves closer, in said first axial half-plane, to the upstream tangent on the tip of the neck line in said first axial half-plane, 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 said second axial half-plane, and a second line, defining the internal wall of the cowl downstream of said determined abscissa in an axial half-plane passing through the top of a chevron, is convex when viewed from the axis L-L.

13 . The cowl for a nozzle according to claim 12 , of which a first line, defining the internal wall of the cowl downstream of said determined abscissa in an axial half-plane passing through the tip of a chevron, is concave when viewed from the axis L-L.

14 . The cowl for a nozzle according to claim 12 , of which a third line, defining the external wall of the cowl downstream of said determined abscissa in an axial half-plane passing through the top of a chevron, is concave when viewed from the axis L-L.

15 . The cowl for a nozzle according to claim 12 , of which the lines defining the external wall of the cowl in any axial half-plane do not have a turning point downstream of said determined abscissa of the neck line.

16 . The cowl for a nozzle according to claim 12 , of which the lines defining the internal wall of the cowl in any axial half-plane do not have a turning point downstream of said determined abscissa of the neck line.

17 . The cowl for a nozzle according to claim 12 , of which the thickness of the cowl on its trailing edge is substantially constant.

18 . A cowl for a nozzle having a longitudinal axis L-L, comprising:
an external wall and an internal wall, the cowl being delimited radially towards an exterior by the external wall and, radially towards an interior, by the internal wall, the internal wall of the cowl having a cross-section with a determined abscissa on the axis L-L defining a neck line on the internal wall, said internal wall converging towards the axis L-L upstream of said cross-section and having, in any axial half-plane, a defined upstream tangent at its intersection with the neck line, said cowl having, downstream of said determined abscissa, indentations in the trailing edge of the cowl which delimit chevrons distributed in the circumferential direction, wherein the downstream direction from said determined abscissa, the internal wall of the cowl diverges radially towards the exterior, in a first axial half-plane passing through the top of an indentation, from the upstream tangent on the tip of the neck line in said first axial half-plane, the external wall of the cowl moves closer, in said first axial half-plane, to the upstream tangent on the tip of the neck line in said first axial half-plane, 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 said 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 said determined abscissa of the neck line.

19 . The cowl for a nozzle according to claim 18 , wherein the lines defining the internal wall, respectively upstream and downstream of the neck line in any axial half-plane, have the same tangent on this neck line.

20 . The cowl for a nozzle according to claim 18 , of which a first line, defining the internal wall of the cowl downstream of said determined abscissa in an axial half-plane passing through the tip of a chevron, is concave when viewed from the axis L-L.

21 . The cowl for a nozzle according to claim 18 , of which a second line, defining the internal wall of the cowl downstream of said determined abscissa in an axial half-plane passing through the top of a chevron, is convex when viewed from the axis L-L.

22 . The cowl for a nozzle according to claim 18 , of which a third line, defining the external wall of the cowl downstream of said determined abscissa in an axial half-plane passing through the top of a chevron, is concave when viewed from the axis L-L.

23 . The cowl for a nozzle according to claim 18 , of which the lines defming the external wall of the cowl in any axial half-plane do not have a turning point downstream of said determined abscissa of the neck line.

24 . The cowl for a nozzle according to claim 18 , of which the thickness of the cowl on its trailing edge is substantially constant.

25 . A nozzle for a turbine engine having a longitudinal axis L-L comprising a cowl according to claim 12 .

26 . The nozzle according to claim 25 , further comprising:
a central body of revolution about the axis L-L.

27 . The nozzle according to claim 26 , in which the radial passage cross-section at a point on a wall of the cowl is defined as the square of the radial distance of said point from the axis L-L minus the square of the radial distance of the axis L-L from the point of the wall of the central body situated on the same radius when said central body is present at the abscissa on the axis L-L of said point, and by the square of the radial distance of said point from the axis L-L when this is not the case, said nozzle being characterised in that, in the downstream direction from said determined abscissa of the neck line, the radial passage cross-section of the internal wall of the cowl increases in an axial half-plane passing through the top of an indentation.

28 . A nozzle for a turbine engine having a longitudinal axis L-L comprising a cowl according to claim 18 .

29 . The nozzle according to claim 28 , further comprising:
a central body of revolution about the axis L-L.

30 . The nozzle according to claim 29 , in which the radial passage cross-section at a point on a wall of the cowl is defined as the square of the radial distance of said point from the axis L-L minus the square of the radial distance of the axis L-L from the point of the wall of the central body situated on the same radius when said central body is present at the abscissa on the axis L-L of said point, and by the square of the radial distance of said point from the axis L-L when this is not the case, said nozzle being characterised in that, in the downstream direction from said determined abscissa of the neck line, the radial passage cross-section of the internal wall of the cowl increases in an axial

Assignees

• Snecma

Inventors

• Langridge Jonathan
• Szydlowski Julien

Classifications

• F05D2250/711

  convex · CPC title

• F05D2250/323

  convergent · CPC title

• F05D2250/184

  sinusoidal · CPC title

• F02K1/34 Primary

  for attenuating noise · CPC title

• F05D2250/324

  divergent · CPC title