Aircraft Turbine Engine NOx Emission Limits: Status and Trends

Abstract

Within recent years, the NOx emissions of aircraft engines have received increased attention. More stringent limits on the NOx emissions of future subsonic civil aircraft engines are being considered. A 20 percent increase in the stringency of the existing ICAO standard has been proposed and, for the longer-term, the possibility of further increased stringency is being studied. For future supersonic civil aircraft engines, very stringent goals have been established. To meet these goals, combustor designs with ultralow NOx levels are required. Extensive efforts are, therefore, underway to develop low NOx combustors for use in future generations of both subsonic and supersonic aircraft engines.