Ventilation channels in an afterburner chamber confluence sheet

1. An aviation turbomachine including, upstream from a afterburner chamber: a diffuser defined by a confluence sheet disposed inside a casing, said casing and said confluence sheet defining between them an annular channel for conveying a cold secondary flow, upstream fuel injectors being disposed at the inlet to said diffuser and flame-catchers being disposed downstream from said upstream injectors, said confluence sheet presenting, between the radial plane containing said upstream injectors and the radial plane situated at the rear ends of said flame-catchers, two bends so as to flare downstream in order to slow down the primary flow F 1 downstream from said upstream injectors, wherein an annular scoop is provided around the upstream portion of said confluence sheet in order to extract a flow of air from the cold flow, this extracted flow of air being injected tangentially into the primary flow via a plurality of channels formed in the wall of said confluence sheet between the scoop and said diffuser.

2. A turbomachine according to claim 1 , wherein the channels opening out circumferentially into the wakes from the injectors are of section that is considerably greater than the section of the other channels.

3. A turbomachine according to claim 2 , wherein the scoop is defined on the inside by a shell surrounding the upstream section of the diffuser, and on the outside by the upstream portion of a sheet which, downstream from the shell forms the middle zone and the downstream zone of the confluence sheet, which zones are cooled by the flow of air injected via the channels.

4. A turbomachine according to claim 3 , wherein the shell and the upstream portion present downstream junction zones, and the channels are formed at the interface of said junction zones.

5. A turbomachine according to claim 4 , wherein the channels are formed in the outside face of the shell.