Adjustable gaseous fuel injector

A fuel injector for a gas turbine engine combustor, the fuel injector having an axial centerline, comprising:

• a swirler having a shaft and a collar, wherein the shaft extends from a first axial end of the swirler to the collar and the collar extends from a second axial end of the swirler to the shaft;
• wherein the shaft includes an inner bore that extends from the first axial end to a throat section, wherein the throat section (TS) has a TS inner radial surface that defines a passage through the throat section;
• wherein the collar includes a plurality of first apertures, wherein each said first aperture of the plurality of first apertures extends between a rear aperture end disposed at a rear surface of the collar and a front aperture end disposed at a front surface of the collar, wherein each said first aperture of the plurality of first apertures is disposed downstream of, and radially outside of, the throat section;
• a tube member configured to be received within the inner bore of the shaft, the tube member including a mounting stage;
• and
• a distributor having a stem attached to a head, the stem is engaged with the mounting stage, and wherein the head has an end surface and a side surface, the side surface extends between the end surface and the stem, and the head has a diameter that decreases from the end surface to the stem;
• wherein the distributor is selectively positionable relative to the throat section.

A method of calibrating a fuel injector within a gas turbine engine combustor, the method comprising:

• providing an adjustable fuel injector that includes:
• a swirler having a shaft and a collar, wherein the shaft extends from a first axial end of the swirler to the collar and the collar extends from a second axial end of the swirler to the shaft;
• wherein the shaft includes an inner bore that extends from the first axial end to a throat section, wherein the throat section (TS) has a TS inner radial surface that defines a passage through the throat section;
• wherein the collar includes a plurality of apertures, wherein each said aperture of the plurality of apertures extends between a rear aperture end disposed at a rear surface of the collar and a front aperture end disposed at a front surface of the collar, wherein each said aperture of the plurality of apertures is disposed downstream of, and radially outside of, the throat section;
• a mounting stage disposed in the inner bore;
• and
• a distributor having a stem attached to a head, the stem is engaged with the mounting stage, and wherein the head has an end surface and a side surface, the side surface extends between the end surface and the stem, and the head has a diameter that decreases from the end surface to the stem;
• wherein the distributor is selectively positionable relative to the throat section;
• calibrating the adjustable fuel injector (AFI) by positioning the distributor relative to the throat section of the adjustable fuel injector.