NASA/GE advanced low emissions combustor program

The Advanced Low Emissions Combustor Program consisted of the design and testing of advanced combustor concepts utilizing lean, premixed, prevaporized fuel and variable geometry. The objective was to evaluate the potential of these combustor systems to provide very low pollutant emissions levels, superior performance and high durability relative to contemporary combustor designs. Four full annular combustor concepts were designed and fabricated for a 30:1 pressure ratio high bypass turbofan engine. The four full annular combustors with active variable geometry were tested at pressures up to approximately 0.7 MPa with Jet A fuel. The two most promising concepts were also tested in a high pressure sector combustor test rig capable of operation at the maximum engine pressures. The high pressure sector combustor tests were conducted with Jet A and a fuel with reduced hydrogen content. Results of the sector combustor tests are presented in this paper. The potential for very low emissions with premixed fuel was demonstrated. However, autoignition or flashback within the premixing systems was encountered at high pressures. Further development effort is required to address this problem area.