After burner

Claim 1

In and for a gas turbine engine comprising an expansion turbine discharging a high-velocity, high-temperature exhaust gas flow, an afterburner installation comprising means bounding an afterburner duct located downstream of said expansion turbine and through which duct said exhaust gas flow passes, a source of afterburner fuel, and a system for supplying the afterburner duct with afterburner fuel from said fuel source to bring about combustion of said fuel in said afterburner duct and for stabilizing said combustion, said supplying and stabilizing system consisting of a plurality of hollow tubular structures each distinct from said means bounding the afterburner duct and arranged totally within said afterburner duct, so as to be immersed in said high-velocity, high-temperature exhaust gas flow, each said tubular structure comprising four portions arranged in series relationship including: a first entry portion extending peripherally in the longitudinal direction of the afterburner duct and having one intake orifice which faces upstream relative to the direction of said exhaust gas flow, and through which a fraction from said exhaust gas flow is collected and penetrates into the interior of said tubular structure; the interior of said entry portion being further connected, in the vicinity of said intake orifice, wIth said source of afterburner fuel; a second portion extending generally transversely of the longitudinal direction of the afterburner duct; a third portion extending generally in the longitudinal direction of the afterburner duct, upstream of said second portion relative to said exhaust gas flow direction; and a fourth discharge portion extending generally transversely of the longitudinal direction of said duct, and having a plurality of exit orifices each of which faces downstream relative to said exhaust gas flow direction; whereby, in operation, each tubular structure is traversed, along substantially its whole length extending from its first portion to its fourth portion, by a mixture of gas and fuel which is preheated by heattransfer from the high-velocity, high-temperature exhaust gas flow in which said structure is immersed, which preheated mixture escapes in the form of a plurality of preheated jets which spontaneously ignite after entering the afterburner duct and form a stabilized flame front, without any necessity for recourse to any other film stabilizing means.