Mixer assembly for a gas turbine engine

1. A mixer assembly for a gas turbine engine, comprising:

a main mixer, comprising:

an annular inner radial wall;

an annular outer radial wall surrounding at least a portion of the annular inner radial wall, wherein the annular outer radial wall incorporates a first outer radial wall swirler with a first axis oriented substantially radially to a centerline axis of the mixer assembly; and

a forward wall substantially perpendicular to and connecting the annular inner radial wall and the annular outer radial wall forming an annular cavity, wherein the forward wall incorporates a first forward wall swirler with a second axis oriented substantially axially to the centerline axis of the mixer assembly;

a plurality of fuel injection holes in the forward wall between the first outer radial wall swirler and the first forward wall swirler, wherein the first outer radial wall swirler is on a first side of the plurality of fuel injection holes and the first forward wall swirler is on a second side of the plurality of fuel injection holes; and

a pilot mixer, at least a portion of which is surrounded by the main mixer, the pilot mixer comprising an annular housing having an outer surface that forms the annular inner wall of the main mixer.

2. The mixer assembly of claim 1 , wherein

the first outer radial wall swirler further comprises a first plurality of vanes forming a first plurality of air passages, wherein the first plurality of vanes are oriented at an angle with respect to the first axis to cause the air passing through the first outer radial wall swirler to rotate in a first direction; and

the first forward wall swirler further comprises a second plurality of vanes forming a second plurality of air passages, wherein the second plurality of vanes are oriented at an angle with respect to the second axis to cause the air passing through the first forward wall swirler to rotate in a second direction.

3. The mixer assembly of claim 2 , wherein the first direction is substantially opposite of the second direction.

4. The mixer assembly of claim 1 , further comprising a fuel manifold in flow communication with the plurality of fuel injection holes.

5. The mixer assembly of claim 1 , wherein the first side is substantially opposite of the second side.

6. The mixer assembly of claim 1 , wherein the annular outer radial wall incorporates a plurality of outer radial wall swirlers with a first axis oriented substantially radially to the centerline axis of the mixer assembly;

the plurality of fuel injection holes in the forward wall being between the plurality of outer radial wall swirlers and the first forward wall swirler, the plurality of outer radial wall swirlers being on the first side of the plurality of fuel injection holes and the first forward wall swirler being on the second side of the plurality of fuel injection holes.

7. The mixer assembly of claim 6 , wherein the plurality of outer radial wall swirlers comprises:

a first outer radial wall swirler comprising a first plurality of vanes forming a first plurality of air passages, wherein the first plurality of vanes are oriented at an angle with respect to the first axis to cause the air passing through the first outer radial wall swirler to rotate in a first direction; and

a second outer radial wall swirler comprising a second plurality of vanes forming a second plurality of air passages, wherein the second plurality of vanes are oriented at an angle with respect to the first axis to cause the air passing through the second outer radial wall swirler to rotate in a second direction.

8. The mixer assembly of claim 7 , wherein the first direction is substantially opposite of the second direction.

9. The mixer assembly of claim 7 , wherein the plurality of outer radial wall swirlers further comprises a third outer radial wall swirler comprising a third plurality of vanes forming a third plurality of air passages, wherein the third plurality of vanes are oriented at an angle with respect to the first axis to cause the air passing through the third outer radial wall swirler to rotate in a third direction, the first direction being substantially the same as the third direction.

10. The mixer assembly of claim 6 , wherein the first forward wall swirler comprises a first plurality of vanes forming a first plurality of air passages, wherein the first plurality of vanes are oriented at an angle with respect to the second axis to cause the air passing through the first forward wall swirler to rotate in a fourth direction.

11. The mixer assembly of claim 10 , further comprising a second forward wall swirler proximate the first forward wall swirler.

12. The mixer assembly of claim 11 , wherein the second forward wall swirler further comprises a second plurality of vanes forming a second plurality of air passages, wherein the second plurality of vanes are oriented at an angle with respect to the second axis to cause the air passing through the second forward wall swirler to rotate in a fifth direction, the fourth direction being substantially opposite of the fifth direction.

13. A mixer assembly for a gas turbine engine, comprising:

a main mixer, comprising:

an annular inner radial wall;

an annular outer radial wall surrounding at least a portion of the annular inner radial wall, wherein the annular outer radial wall incorporates a first outer radial wall swirler with a first axis oriented substantially radially to a centerline axis of the mixer assembly; and

a forward wall substantially perpendicular to and connecting the annular inner radial wall and the annular outer radial wall forming an annular cavity, wherein the forward wall incorporates a first forward wall swirler with a second axis oriented substantially axially to the centerline axis of the mixer assembly;

a plurality of fuel injection holes in the forward wall between the first outer radial wall swirler and the first forward wall swirler, wherein the first outer radial wall swirler is on a first side of the plurality of fuel injection holes and the first forward wall swirler is on a second side of the plurality of fuel injection holes; and

a pilot mixer, at least a portion of which is surrounded by the main mixer, the pilot mixer comprising an annular housing having an outer surface that forms the annular inner wall of the main mixer, wherein the plurality of fuel injection holes are oriented substantially perpendicularly to the first axis.

14. A mixer assembly for a gas turbine engine, comprising:

a main mixer, comprising:

an annular inner radial wall;

an annular outer radial wall surrounding at least a portion of the annular inner radial wall, wherein the annular outer radial wall incorporates a first outer radial wall swirler with a first axis oriented substantially radially to a centerline axis of the mixer assembly; and

a forward wall substantially perpendicular to and connecting the annular inner radial wall and the annular outer radial wall forming an annular cavity, wherein the forward wall incorporates a first forward wall swirler with a second axis oriented substantially axially to the centerline axis of the mixer assembly;

a plurality of fuel injection holes in the forward wall between the first outer radial wall swirler and the first forward wall swirler, wherein the first outer radial wall swirler is on a first side of the plurality of fuel injection holes and the first forward wall swirler is on a second side of the plurality of fuel injection holes; and

a pilot mixer, at least a portion of which is surrounded by the main mixer, the pilot mixer comprising an annular housing having an outer surface that forms the annular inner wall of the main mixer, wherein the plurality of fuel injection holes are oriented substantially perpendicularly to the second axis.

15. A mixer assembly for a gas turbine engine comprising:

a main mixer comprising:

an annular inner radial wall;

an annular outer radial wall surrounding at least a portion of the annular inner radial wall, the annular outer radial wall incorporating a first outer radial wall swirler with a first axis oriented substantially radially to a centerline axis of the mixer assembly;

a forward wall substantially perpendicular to and connecting the annular inner radial wall and the annular outer radial wall forming an annular cavity, wherein the forward wall incorporates a first forward wall swirler with a second axis oriented substantially axially to the centerline axis of the mixer assembly;

a plurality of fuel injection holes in the forward wall between the first outer radial wall swirler and the first forward wall swirler, wherein the first outer radial wall swirler is on a first side of the plurality of fuel injection holes and the first forward wall swirler is on a second side of the plurality of fuel injection holes;

the forward wall comprising a first wall portion extending radially inwardly from the annular outer radial wall, a second wall portion extending parallel to the annular inner radial wall, the first forward wall swirler being formed between the second wall portion and the annular inner radial wall and a third wall portion extending between the radially inner end of the first wall portion and a downstream end of the second wall portion, the third wall portion sloping in a downstream direction from the first wall portion.

16. The mixer assembly of claim 15 , wherein

the first outer radial wall swirler further comprises a first plurality of vanes forming a first plurality of air passages, wherein the first plurality of vanes are oriented at an angle with respect to the first axis to cause the air passing through the first outer radial wall swirler to rotate in a first direction; and

the first forward wall swirler further comprises a second plurality of vanes forming a second plurality of air passages, wherein the second plurality of vanes are oriented at an angle with respect to the second axis to cause the air passing through the first forward wall swirler to rotate in a second direction.

17. The mixer assembly of claim 16 , wherein the first direction is substantially opposite of the second direction.

18. The mixer assembly of claim 16 , further comprising a pilot mixer, at least a portion of which is surrounded by the main mixer, the pilot mixer comprising an annular housing having an outer surface that forms the annular inner wall of the main mixer.

19. A method of atomizing fuel in a mixer assembly of a gas turbine engine comprising:

providing a main mixer that is configured to:

inject fuel into the mixer assembly through a plurality of fuel injection holes located in a forward wall of the main mixer, the forward wall being located between a first outer radial wall swirler and a first forward wall swirler, wherein the fuel is atomized and dispersed by airflow from the first outer radial wall swirler and is subsequently atomized and dispersed by airflow from the first forward wall swirler, wherein the first outer radial wall swirler is on a first side of the plurality of fuel injection holes and the first forward wall swirler is on a second side of the plurality of fuel injection holes, the first side being opposite the second side, and the airflow from the first outer radial wall swirler is swirled in a first direction and the airflow from the first forward wall swirler is swirled in a second direction that is opposite to the first direction; and

wherein the forward wall extends radially outward with respect to a first axis of the mixer assembly, the forward wall connecting an annular inner radial wall with an annular outer radial wall, the annular inner radial wall and the annular outer radial being spaced from each other to define an annular main mixer cavity, the annular outer radial wall incorporating the first outer radial wall swirler and the forward wall incorporating the first forward wall swirler.

20. The method as in claim 19 , wherein the first outer radial wall swirler is a plurality of radial wall swirlers incorporated into the annular outer radial wall and the first forward wall swirler is a plurality of forward wall swirlers located in the forward wall.