Safran Aircraft Engines

Snecma

Aircelle Limited

Safran Nacelles

Jonathan Langridge

Julien Szydlowski

Matthieu Leyko

Denis Guillois

Guillaume Bodard

Sebastien Pascal

Loic Chapelain

Irwin Kernemp

Sébastien Pascal

Gérard Clere

Loïc Chapelain

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.

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

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.

An afterbody for a turbojet engine having a central axis, provided with a nozzle comprising two doors facing each other between two lateral beams. The doors pivot around axes defining a pivot direction, between a retracted position, in which a middle portion of the downstream edge of the doors forms the edge of the outlet section of the nozzle combined with the downstream edges of the two lateral beams, and a deployed position, in which the middle portions of the downstream edges of the pivoting doors come together so as to block the channel between the two lateral beams in order to reverse the thrust of the turbojet engine gases. The edge of the outlet section of the nozzle further having a crown of noise-reducing chevrons alternating with indentations and the afterbody.

Afterbody for a turbojet engine comprising a nozzle provided with a thrust reverser system that incorporates a crown of noise-reducing chevrons

According to the invention, the method for defining the shape of a convergent-divergent nozzle of longitudinal axis L-L comprising a convergent part connected, at a throat, to a divergent part the downstream free end of which comprises scallops delimiting noise-reducing chevrons distributed in the circumferential direction, comprises defining beforehand the divergent part of the nozzle using a divergent first portion, a divergent second portion and a convergent portion, attributing an initial value to dimensional parameters defining the chevrons and the three portions, calculating performance criteria and checking that the calculated performance criteria satisfy predefined performance conditions.

Method for defining the shape of a turbomachine convergent-divergent nozzle, and corresponding convergent-divergent nozzle

Growing community of inventors

Melun, France

Jonathan Langridge