AIRBLAST FUEL INJECTOR

摘要

An airblast fuel injector for a gas turbine engine fuel spray nozzle has, in order from radially inner to outer, a coaxial arrangement of an inner air swirler passage, an annular fuel passage, an annular outer air swirler passage, and an annular shroud air swirler passage. The injector further has an annular shroud having an inner surface profile. Relative to the overall axial direction of flow through the injector the shroud inner surface profile has a convergent section followed by a divergent section, the transition of which forming a first inwardly directed annular nose. The injector further has an annular wall having an outer surface profile, and having an inner surface profile. Relative to the overall axial direction of flow through the injector the wall outer surface profile has a convergent section followed by an outwardly turning section which faces across the shroud air passage to the first nose.

主权项

1. An airblast fuel injector for a fuel spray nozzle of a gas turbine engine, the injector having, in order from radially inner to outer, a coaxial arrangement of an inner air swirler passage, an annular fuel passage, an annular outer air swirler passage, and an annular shroud air swirler passage, fuel exiting the fuel passage being atomised into a spray by surrounding swirling air exiting the inner, outer and shroud air passages, wherein:
the injector has an annular shroud having an inner surface profile which defines a radially outer side of the shroud air passage, relative to the overall axial direction of flow through the injector the shroud inner surface profile having a convergent section corresponding to a convergent portion of the shroud air passage, the convergent section of the shroud inner surface profile being followed by a divergent section of the shroud inner surface profile, the transition from the convergent section to the divergent section of the shroud inner surface profile forming a first inwardly directed annular nose; and the injector further has an annular wall having an outer surface profile which defines a radially inner side of the shroud air passage, and having an inner surface profile which defines a radially outer side of the outer passage, relative to the overall axial direction of flow through the injector the wall outer surface profile having a convergent section corresponding to the convergent portion of the shroud air passage, the convergent section of the wall outer surface profile being followed by an outwardly turning section which faces across the shroud air passage to the first nose.