Swirler with recessed fuel filmer and air assist fuel nozzle

1 . An assembly for a gas turbine engine, comprising:

a swirler comprising an outer wall, an inner wall, an outer passage and an inner passage, the outer wall circumscribing the inner wall and extending axially along an axis to a distal outer wall end, the inner wall extending axially along the axis to a distal inner wall end that is axially recessed within the swirler from the distal outer wall end, the outer passage formed by and radially between the inner wall and the outer wall, and the inner passage formed by and radially within the inner wall;

a fuel nozzle projecting into the inner passage, the fuel nozzle comprising:

a plurality of fuel passages, wherein each of the plurality of fuel passages extends to a respective one of a plurality of fuel outlets; and

a plurality of air passages, wherein each of the plurality of air passages extends within the fuel nozzle from a respective one of a plurality of air inlets to a respective one of a plurality of air outlets; and

a nozzle guide plate mounting the fuel nozzle to the swirler, and disposed axially between the plurality of air inlets and the plurality of air outlets;

wherein the plurality of fuel outlets is axially aligned with the inner wall and arranged circumferentially about the axis in an annular array, the plurality of air outlets is axially upstream of and radially outboard of the plurality of fuel outlets, and the plurality of air outlets is axially arranged circumferentially about the axis in an annular array, and

wherein the plurality of fuel outlets is configured to direct a jet of fuel out from the fuel nozzle along a first trajectory toward the inner wall, and the plurality of air outlets is configured to direct a jet of air out from the fuel nozzle into the inner passage along a second trajectory that crosses the first trajectory of the jet of fuel.

2 . The assembly of claim 1 , wherein

the first trajectory comprises a radial component and an axial component that is less than the radial component.

3 . The assembly of claim 1 , wherein a first of the plurality of air outlets is circumferentially aligned with a first of the plurality of fuel outlets about the axis within twenty degrees.

4 . The assembly of claim 1 , wherein the second trajectory is parallel with the axis or less than thirty degrees angularly offset from the axis.

5 . The assembly of claim 1 , wherein

the plurality of fuel outlets are configured to direct fuel into the inner passage; and

the plurality of air outlets are configured to direct air into the inner passage to interact with the fuel.

6 . The assembly of claim 1 , wherein the fuel nozzle is further configured with a central fuel outlet that is coaxial with the axis.

7 . The assembly of claim 1 , wherein

the swirler includes a first set of vanes and a second set of vanes;

the first set of vanes are arranged with the outer passage; and

the second set of vanes are arranged with the inner passage.

8 . The assembly of claim 7 , wherein

the swirler further includes a third set of vanes arranged with the inner passage; and

the third set of vanes are axially offset from the second set of vanes.

9 . The assembly of claim 8 , wherein

the second set of vanes are configured to swirl air in a first direction about the axis; and

the third set of vanes are configured to swirl air in a second direction about the axis that is opposite the first direction.

10 . The assembly of claim 1 , wherein

the distal outer wall end is disposed a first distance along the axis from a tip of the fuel nozzle;

the distal outer wall end is disposed a second distance along the axis from the distal inner wall end;

the outer passage has a diameter at the distal outer wall end;

a first value is equal to the first distance minus the second distance; and

a quotient of the first value divided by the diameter is less than one.

11 . The assembly of claim 10 , wherein the quotient is between 0.35 and 0.68.

12 . The assembly of claim 1 , wherein

the distal outer wall end is disposed a distance along the axis from a tip of the fuel nozzle;

the outer passage has a diameter at the distal outer wall end; and

a quotient of the distance divided by the diameter is less than one.

13 . The assembly of claim 1 , wherein

the distal outer wall end is disposed a first distance along the axis from a tip of the fuel nozzle;

the distal outer wall end is disposed a second distance along the axis from the distal inner wall end;

the outer passage has a diameter at the distal outer wall end; and

a quotient of the second distance divided by the diameter is between 0.07 and 0.15.

14 . The assembly of claim 1 , wherein the swirler further comprises

an upstream swirler segment adjacent an upstream end of the swirler;

an intermediate swirler segment abutted axially against the upstream swirler segment and including the inner wall; and

a downstream swirler segment abutted axially against the intermediate swirler segment and including the outer wall.

15 . The assembly of claim 1 , wherein the second trajectory of the jet of air crossing the first trajectory of the jet of fuel causes a first portion of the jet of fuel to impinge on the inner wall and a second portion of the jet of fuel to flow without impingement on the inner wall.

16 . An assembly for a gas turbine engine, comprising:

a swirler comprising an outer wall, an inner wall, an outer passage and an inner passage, the outer wall circumscribing the inner wall and extending axially along an axis to a distal outer wall end, the inner wall extending axially along the axis to a distal inner wall end that is axially recessed within the swirler from the distal outer wall end, the outer passage formed by and radially between the inner wall and the outer wall, the inner passage formed by and radially within the inner wall, and the swirler configured to direct counter swirling air into the inner passage;

a fuel nozzle projecting into the inner passage, the fuel nozzle comprising:

a plurality of fuel passages, wherein each of the plurality of fuel passages extends to a respective one of a plurality of fuel outlets; and

a plurality of air passages, wherein each of the plurality of air passages extends within the fuel nozzle from a respective one of a plurality of air inlets to a respective one of a plurality of air outlets; and

a nozzle guide plate mounting the fuel nozzle to the swirler, and disposed axially between the plurality of air inlets and the plurality of air outlets;

wherein the plurality of air outlets is axially upstream of and radially outboard of the plurality of fuel outlets, the plurality of fuel outlets is configured to direct fuel out of the fuel nozzle along a first trajectory toward the inner wall, and the plurality of air outlets is configured to direct air out of the fuel nozzle into the inner passage along a second trajectory to impinge against the fuel in the first trajectory along with the counter swirling air.

17 . A fuel injector assembly with an axis, comprising:

a swirler configured with an outer wall, an inner wall, an outer passage and an inner passage, the outer wall extending circumferentially about the inner wall and extending axially along the axis to a distal outer wall end, the inner wall extending axially along the axis to a distal inner wall end, the outer passage radially between the inner wall and the outer wall, and the inner passage radially within the inner wall;

an air assist fuel nozzle projecting into the inner passage, the air assist fuel nozzle comprising:

a plurality of fuel passages, wherein each of the plurality of fuel passages extends to a respective one of a plurality of fuel outlets; and

a plurality of air passages, wherein each of the plurality of air passages extends within the air assist fuel nozzle from a respective one of a plurality of air inlets to a respective one of a plurality of air outlets; and

a nozzle guide plate mounting the air assist fuel nozzle to the swirler, and disposed axially between the plurality of air inlets and the plurality of air outlets;

wherein the plurality of air passages are axially upstream of the plurality of fuel passages; and

wherein the distal outer wall end is disposed a first distance along the axis from a tip of the fuel nozzle, the distal outer wall end is disposed a second distance along the axis from the distal inner wall end, the outer passage has a diameter at the distal outer wall end, a first value is equal to the first distance minus the second distance, and a quotient of the first value divided by the diameter is less than one,

wherein the plurality of fuel outlets is configured to direct a jet of fuel out from the air assist fuel nozzle along a first trajectory toward the inner wall, and the plurality of air outlets is configured to direct a jet of air out from the air assist fuel nozzle into the inner passage along a second trajectory that crosses the first trajectory of the jet of fuel.