Combustor mixing assembly

Abstract

A mixing assembly includes a pilot mixer and a main mixer. The main mixer includes a main housing, a fuel manifold positioned between a pilot housing and the main housing, a mixer foot extending outward from a forward end of the main housing, and a main swirler body including a plurality of vanes. The main swirler body surrounds the main housing and defines an annular mixing channel between the main housing and the main swirler body, and being coupled to the mixer foot. An annular main fuel ring extends axially aft from the mixer foot into the annular mixing channel. The mixer foot extends farther from the main housing than the main fuel ring. At least one of the mixer foot or the main fuel ring includes a plurality of fuel injection ports positioned to discharge fuel into a central portion of the annular mixing channel.

What is claimed is: 
     
         1 . A mixing assembly for a combustor, comprising:
 a pilot mixer including an annular pilot housing having a hollow interior extending along a mixer centerline, and a pilot fuel nozzle mounted in the pilot housing; and   a main mixer including:
 a main housing surrounding the pilot mixer, the main housing having a forward end and an aft end; 
 a fuel manifold positioned between the pilot housing and the main housing; 
 a mixer foot extending outward from the forward end of the main housing; 
 a main swirler body including a plurality of vanes, the main swirler body surrounding the main housing such that an annular mixing channel is defined between the main housing and the main swirler body, and being coupled to the mixer foot; and 
 an annular main fuel ring extending axially aft from the mixer foot into the annular mixing channel, wherein the mixer foot extends farther from the main housing than the main fuel ring, 
 wherein at least one of the mixer foot or the main fuel ring includes a plurality of fuel injection ports positioned to discharge fuel into a central portion of the annular mixing channel. 
   
     
     
         2 . The mixing assembly according to  claim 1 , wherein the main fuel ring is positioned in the central portion of the annular mixing channel. 
     
     
         3 . The mixing assembly according to  claim 1 , wherein the main fuel ring includes the plurality of fuel injection ports. 
     
     
         4 . The mixing assembly according to  claim 1 , wherein the mixer foot includes the plurality of fuel injection ports. 
     
     
         5 . The mixer assembly according to  claim 4 , wherein the plurality of fuel injection ports are oriented to discharge fuel at a radially inboard surface of the main fuel ring. 
     
     
         6 . The mixing assembly according to  claim 4  wherein:
 the mixer foot includes an array of main fuel vanes; and 
 the plurality of fuel injection ports are disposed in the main fuel vanes. 
 
     
     
         7 . The mixing assembly according to  claim 6 , wherein the main fuel vanes are oriented to produce a swirl to a flow of air passing through the main fuel vanes. 
     
     
         8 . The mixing assembly according to  claim 1 , wherein an aft portion of the main fuel ring includes a plurality of corrugations. 
     
     
         9 . The mixing assembly according to  claim 1 , wherein the main swirler body includes a radial-inflow swirler positioned radially outboard of the main fuel ring. 
     
     
         10 . The mixing assembly according to  claim 9 , wherein the mixer foot includes an array of main fuel vanes, and the main fuel vanes are oriented to produce a swirl to a flow of air passing through the main fuel vanes. 
     
     
         11 . A combustor for a gas turbine engine, comprising:
 an annular inner liner having an inner liner upstream end and an inner liner downstream end;   an annular outer liner spaced apart from the annular inner liner and having an outer liner upstream end and an outer liner downstream end; and   a mixing assembly disposed at the inner liner upstream end and the outer liner upstream end, the mixing assembly comprising:
 a pilot mixer including an annular pilot housing having a hollow interior extending along a mixer centerline, and a pilot fuel nozzle mounted in the pilot housing; and 
 a main mixer including:
 a main housing surrounding the pilot mixer, the main housing having a forward end and an aft end; 
 a fuel manifold positioned between the pilot housing and the main housing; 
 a mixer foot extending outward from the forward end of the main housing; 
 a main swirler body including a plurality of vanes, the main swirler body surrounding the main housing such that an annular mixing channel is defined between the main housing and the main swirler body, and being coupled to the mixer foot; and 
 an annular main fuel ring extending axially aft from the mixer foot into the annular mixing channel, wherein the mixer foot extends farther from the main housing than the main fuel ring, 
 wherein at least one of the mixer foot or the main fuel ring includes a plurality of fuel injection ports positioned to discharge fuel into a central portion of the annular mixing channel. 
 
   
     
     
         12 . The combustor according to  claim 11 , wherein the main fuel ring is positioned in the central portion of the annular mixing channel. 
     
     
         13 . The combustor according to  claim 11 , wherein the main fuel ring includes the plurality of fuel injection ports. 
     
     
         14 . The combustor according to  claim 11 , wherein the mixer foot includes the plurality of fuel injection ports. 
     
     
         15 . The combustor according to  claim 14 , wherein the plurality of fuel injection ports are oriented to discharge fuel at a radially inboard surface of the main fuel ring. 
     
     
         16 . The combustor according to  claim 14  wherein:
 the mixer foot includes an array of main fuel vanes; and 
 the plurality of fuel injection ports are disposed in the main fuel vanes. 
 
     
     
         17 . The combustor according to  claim 16 , wherein the main fuel vanes are oriented to produce a swirl to a flow of air passing through the main fuel vanes. 
     
     
         18 . The combustor according to  claim 11 , wherein an aft portion of the main fuel ring includes a plurality of corrugations. 
     
     
         19 . The combustor according to  claim 11 , wherein the main swirler body includes a radial-inflow swirler positioned radially outboard of the main fuel ring. 
     
     
         20 . The combustor according to  claim 19 , wherein the mixer foot includes an array of main fuel vanes, and the main fuel vanes are oriented to produce a swirl to a flow of air passing through the main fuel vanes.