Combustion system for a gas turbine engine

Abstract

A combustor for a gas turbine engine includes a pilot fuel injector and a plurality of circumferentially located main injectors for injecting fuel and air into a combustion chamber defined by a liner wall of a combustor basket. A combustion zone is located in the combustion chamber where the fuel and air are ignited to produce hot combustion gases. A plurality of vortex generators are located in circumferentially spaced relation on the liner wall and comprise structures extending radially inward into the combustion chamber to create vortices at predetermined circumferential locations downstream from where the fuel and air are ignited to effect a reduction in emissions of the combustion gases.

What is claimed is: 
     
         1 . A combustor for a gas turbine engine, the combustor including a pilot fuel injector and a plurality of circumferentially located main injectors for injecting fuel and air into a combustion chamber defined by a liner wall of a combustor basket; a combustion zone located in the combustion chamber where the fuel and air are ignited to produce hot combustion gases; and a plurality of vortex generators located in circumferentially spaced relation on the liner wall and comprising structures extending radially inward into the combustion chamber to create vortices at predetermined circumferential locations downstream from where the fuel and air are ignited to effect a reduction in emissions of the combustion gases. 
     
     
         2 . The method of  claim 1 , wherein the vortex generators are located on the combustion chamber to mix cooler and hotter portions of the combustion gases to effect the reduction in emissions of the combustion gases. 
     
     
         3 . The combustor of  claim 2 , wherein the predetermined circumferential locations of the vortex generators correspond to an axial location downstream of formation of a stabilized flame in the combustion chamber. 
     
     
         4 . The combustor of  claim 1 , wherein the predetermined circumferential locations of the vortex generators are axially aligned with an area of fuel and air combustion in the combustion chamber. 
     
     
         5 . The combustor of  claim 1 , wherein including a plurality of through holes formed in the liner wall and resonator structures located over at least some of the through holes on a radially outward facing side of the liner wall, and the vortex generators located over at least some of the through holes at substantially the same axial location as the resonator structures. 
     
     
         6 . The combustor of  claim 5 , wherein the vortex generators include surfaces having apertures for passage of cooling air out of the vortex generator into the combustion chamber. 
     
     
         7 . The combustor of  claim 1 , wherein the main injectors are equally spaced from each other in a circular pattern upstream from the combustion zone, and the vortex generators are generally equally spaced in a circular pattern at an axial location of the combustion zone. 
     
     
         8 . The combustor of  claim 1 , wherein the vortex generators comprise tetrahedral shaped protrusions extending from the liner wall. 
     
     
         9 . The combustor of  claim 6 , wherein the vortex generators include two triangular shaped side walls converging in a downstream direction, and a ramp surface extending between converging edges of the side walls. 
     
     
         10 . The combustor of  claim 7 , wherein the ramp surface angles radially inward in the downstream direction. 
     
     
         11 . A method of reducing emissions in a combustor having a pilot fuel injector and a plurality of circumferentially located main injectors for injecting fuel and air into a combustion chamber defined by a liner wall of a combustor basket, the method comprising:
 igniting the fuel and air in a combustion zone located in the combustion chamber to produce hot combustion gases; and   creating vortices at predetermined circumferential locations downstream from where the fuel and air are ignited by providing a plurality of vortex generators comprising structures extending radially inward into the combustion chamber and located in circumferential locations downstream from where the fuel and air are ignited to effect a reduction in emissions of the combustion gases.   
     
     
         12 . The method of  claim 11 , wherein the vortex generators are hollow structures having an interior area and including providing cooling air to the interior area of the vortex generators. 
     
     
         13 . The method of  claim 12 , wherein the vortex generators comprise resonators providing acoustic damping. 
     
     
         14 . The method of  claim 11 , wherein the vortex generators mix cooler and hotter portions of the combustion gases to effect the reduction in emissions of the combustion gases. 
     
     
         15 . The combustor of  claim 11 , wherein the predetermined circumferential locations of the vortex generators are axially aligned with an area of fuel and air combustion in the combustion chamber. 
     
     
         16 . The combustor of  claim 11 , wherein the main injectors are equally spaced from each other in a circular pattern upstream from the combustion zone, and the vortex generators are generally equally spaced in a circular pattern at an axial location of the combustion zone. 
     
     
         17 . The combustor of  claim 11 , wherein the vortex generators comprise tetrahedral shaped protrusions extending from the liner wall. 
     
     
         18 . The combustor of  claim 17 , wherein the vortex generators include two triangular shaped side walls converging in a downstream direction, and a ramp surface extending between converging edges of the side walls. 
     
     
         19 . The combustor of  claim 18 , wherein the ramp surface angles radially inward in the downstream direction. 
     
     
         20 . The combustor of  claim 11 , wherein the vortices mix the combustion gases to effect a reduction in the flame length downstream of the vortex generators.