Convergent-divergent flap pair for a variable-geometry turbojet engine nozzle, the flaps of which each comprise a cooling air circulation duct

Patent metadata

Field	Value
Publication number	US-11739712-B2
Application number	US-202017753181-A
Country	US
Kind code	B2
Filing date	Aug 27, 2020
Priority date	Aug 30, 2019
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

In a convergent-divergent flap pair for a turbojet engine nozzle of the variable-geometry convergent-divergent type, the convergent flap and the divergent flap including respective ducts for circulation of cooling air connected to one another to allow cooling of each of the flaps. The duct of the divergent flap includes an impingement cooling cavity defined by two walls of lateral ends provided with air passage orifices through which the impingement cooling cavity opens towards the outside.

First claim

What is claimed is:

1. A convergent-divergent flap pair for a turbojet engine nozzle of a variable-geometry convergent-divergent type, comprising a convergent flap, and a divergent flap mounted pivotably on the convergent flap about a pivot axis, whereby the convergent-divergent flap pair is capable of going from a first extreme angular configuration, in which the convergent flap and the divergent flap make between them a maximum salient angle, to a second extreme angular configuration, in which the convergent flap and the divergent flap make between them a minimum salient angle smaller than the maximum salient angle,
wherein the convergent flap includes a respective inner wall, having a respective inner surface for channelling combustion gas and a respective outer surface, and a respective outer wall,
wherein the convergent flap includes a respective duct for circulation of cooling air defined between the respective outer surface of the respective inner wall of the convergent flap, and the respective outer wall of the convergent flap,
wherein the divergent flap includes a respective inner wall, having a respective inner surface for channelling the combustion gas and a respective outer surface, and a respective outer wall,
wherein the divergent flap includes a respective duct for circulation of cooling air defined between the respective outer surface of the respective inner wall of the divergent flap, and the respective outer wall of the divergent flap, and connected to the respective duct for circulation of the cooling air of the convergent flap,
wherein the divergent flap further includes a multiperforated plate provided with impingement cooling orifices, and extending between the respective inner wall and the respective outer wall of the divergent flap, whereby the multiperforated plate divides the respective duct for circulation of the cooling air of the divergent flap into:
a cavity for circulation of cooling air, defined between the respective outer wall of the divergent flap and the multiperforated plate, and connected to the respective duct for circulation of cooling air of the convergent flap, and
an impingement cooling cavity defined between the multiperforated plate and the respective outer surface of the respective inner wall of the divergent flap, to allow a cooling of the respective inner wall of the divergent flap by impingement of jets of air formed through the impingement cooling orifices from air circulating in the cavity for circulation of the cooling air,

wherein the divergent flap includes two opposite respective lateral end walls each connecting the respective inner wall of the divergent flap to the respective outer wall of the divergent flap, so that each of the cavity for circulation of cooling air and the impingement cooling cavity is further defined by the two respective lateral end walls of the divergent flap,
wherein each of the two respective lateral end walls of the divergent flap is provided with air passage orifices through which the impingement cooling cavity opens towards an outside.

2. The convergent-divergent flap pair according to claim 1 , wherein the divergent flap includes a respective downstream end wall providing at least one opening by which the impingement cooling cavity opens downstream.

3. The convergent-divergent flap pair according to claim 2 , wherein the respective downstream end wall of the divergent flap connects the respective outer wall of the divergent flap to the multiperforated plate of the divergent flap.

4. The convergent-divergent flap pair according to claim 1 , wherein the divergent flap includes a closing wall connecting the multiperforated plate of the divergent flap to the respective inner wall of the divergent flap in such a way as to close an upstream end of the impingement cooling cavity of the divergent flap.

5. A nozzle of a variable-geometry convergent-divergent type for a turbojet engine, comprising convergent-divergent flap pairs distributed around an axis of the nozzle and at least some of which are convergent-divergent flap pairs according to claim 1 , and a channel for circulation of the combustion gas defined at least by the respective inner surfaces for channelling the combustion gas of the respective inner walls of the respective convergent flaps and of the respective divergent flaps of the convergent-divergent flap pairs.

6. A turbojet engine for an aircraft, comprising a reheat channel surrounded by a cooling plenum separated from the reheat channel by a thermal protection liner, and the nozzle according to claim 5 ,
wherein the respective ducts for circulation of the cooling air of the convergent flaps of the convergent-divergent flap pairs of the nozzle are connected to the cooling plenum surrounding the reheat channel.

7. The nozzle according to claim 5 , wherein the convergent-divergent flap pairs form follower convergent-divergent flap pairs, the nozzle further comprising controlled convergent-divergent flap pairs arranged in alternation circumferentially with the follower convergent-divergent flap pairs and comprising respective divergent flaps comprising the respective inner walls for channelling combustion gas having respective inner surfaces for channelling the combustion gas defining the channel for circulation of the combustion gas.

8. The nozzle according to claim 7 , wherein the air passage orifices of the lateral end walls of the respective divergent flaps of the follower convergent-divergent flap pairs open into the channel for circulation of the combustion gas, facing the respective inner walls for channelling the combustion gas of the respective divergent flaps of the controlled convergent-divergent flap pairs.

9. The nozzle according to claim 8 , wherein the respective divergent flaps of the controlled convergent-divergent flap pairs are flaps with a simple skin.

Assignees

• Safran Aircraft Engines

Inventors

• Leglaye François
• Lacombe Florent Luc
• Malbois Pierre André Gabriel
• Oblaza Sylvain Marcel
• Kohn Thierry

Classifications

• F02K1/1223 Primary

  of two series of flaps, the upstream series having its flaps hinged at their upstream ends on a fixed structure and the downstream series having its flaps hinged at their upstream ends on the downstream ends of the flaps of the upstream series · CPC title

• F02K1/822

  Heat insulating structures or liners, cooling arrangements, e.g. post combustion liners; Infrared radiation suppressors · CPC title

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title

• F05D2240/128

  Nozzles · CPC title

• F05D2250/323

  convergent · CPC title