Patent ID: 8479519

Claim:
A method for assembling a gas turbine engine, said method comprising: providing a fuel nozzle including a diffusion tip that includes a body having a substantially circular cross sectional area that extends along a centerline axis, wherein the body includes an outer surface, an inner surface that is opposite the outer surface, an inlet surface that is adjacent to an end of the body and that is radially inwardly from the body inner surface, and a discharge surface that is opposite the inlet surface; defining a plurality of diffusion apertures within the diffusion tip such that each of the plurality of diffusion apertures extends from the discharge surface to the inlet surface are oriented to discharge a diffusion flow from the fuel nozzle, wherein the plurality of diffusion apertures include a first array of circumferentially-spaced diffusion apertures and a second array of circumferentially-spaced diffusion apertures that are spaced radially outwardly from the first array, and wherein the second array includes at least one diffusion aperture oriented obliquely with respect to a radial axis that extends radially outwardly from the diffusion tip centerline axis; and further defining the plurality of diffusion apertures within the diffusion tip such that at least a portion of the diffusion apertures are oriented inwardly at an angle β (beta) and such that at least another portion of the diffusion apertures are oriented outwardly at an angle α (alpha), wherein angles β and α are oblique angles defined between a centerline axis of a respective aperture and a radius extending perpendicular to a centerline axis of the diffusion tip; further defining the plurality of diffusion apertures to include at least one convergent tapered aperture and at least one divergent tapered aperture; and coupling the fuel nozzle within the combustor assembly.