Enhanced mixing tube elements

Abstract

The present application provides a fuel nozzle for use with a flow of air and a flow of fuel in a gas turbine engine. The fuel nozzle may include a plenum, a mixing tube element positioned within the plenum, and an enhanced mixing feature positioned within the mixing tube element so as to promote mixing of the flow of air and the flow of fuel. The enhanced mixing feature may include a swirler.

We claim: 
     
         1 . A fuel nozzle for use with a flow of air and a flow of fuel in a gas turbine engine, comprising:
 a plenum;   a mixing tube element positioned within the plenum; and   an enhanced mixing feature positioned within the mixing tube element so as to promote mixing of the flow of air and the flow of fuel;   the enhanced mixing feature comprising a swirler.   
     
     
         2 . The fuel nozzle of  claim 1 , wherein the mixing tube element comprises a conduit. 
     
     
         3 . The fuel nozzle of  claim 2 , wherein the conduit comprises an air inlet, a fuel inlet, and a fuel-air outlet. 
     
     
         4 . The fuel nozzle of  claim 3 , wherein the air inlet is positioned on the conduit in a first direction and the fuel inlet is positioned on the conduit at a perpendicular second direction. 
     
     
         5 . The fuel nozzle of  claim 1 , further comprising a plurality of mixing tube elements positioned in an annular array. 
     
     
         6 . The fuel nozzle of  claim 1 , wherein the swirler comprises a plurality of vanes extending from a central hub to an outer shell. 
     
     
         7 . The fuel nozzle of  claim 6 , wherein the vanes are angled. 
     
     
         8 . The fuel nozzle of  claim 3 , wherein the swirler is pressed fit into the conduit downstream of the air inlet and the fuel inlet. 
     
     
         9 . The fuel nozzle of  claim 1 , wherein the swirler provides swirl to the flow of air and the flow of fuel to promote good mixing. 
     
     
         10 . The fuel nozzle of  claim 1 , wherein the enhanced mixing feature comprises a plurality of swirlers.