Fuel nozzle assembly for reduced exhaust emissions

A fuel nozzle assembly for a gas turbine engine combustor for staged combustion, said nozzle assembly comprising:

• a primary fuel injector having a surrounding annular passageway that includes a plurality of circumferentially-disposed swirl vanes to provide a surrounding primary coaxial swirl region of incoming primary combustion air about a fuel spray emanating from the primary fuel injector for improved fuel-air mixing in a primary combustion region;
• an annular ring coaxial with the primary fuel injector and spaced radially outwardly therefrom to define a secondary combustion region, the ring having a plurality of circumferentially-spaced, elongated, axially-extending openings to provide a secondary coaxial swirl region of incoming secondary combustion air that swirls radially outwardly of the primary coaxial swirl region;
• and
• an annular housing positioned between the annular ring and the primary fuel injector, the annular housing enclosing a plurality of circularly-disposed secondary fuel injectors and including an end wall that faces in a downstream direction and an annular outer wall having a plurality of radial openings to allow fuel to issue from the secondary fuel injectors into the secondary swirl region, the housing including an annular inner wall spaced inwardly of and coaxial with the outer wall, the inner wall flaring outwardly to define an outer diffuser region downstream of the primary fuel injector and terminating in a radially-outwardly-extending flange spaced axially downstream of the end wall to define a gap therebetween, and a plurality of circularly-disposed, spaced, cooling air apertures in the end wall to allow passage therethrough of cooling air for cooling the outwardly extending flange.