Procedures to apply NOX correlation methods to engine concepts with staged, lean combustor technology

Reduction of NOx Emissions has been an important goal in combustor technology development for many years. RQL technology has been able to control NOx emissions even with increasing cycle pres-sure and temperature which are needed to improve engine efficiency and reduce CO2 emissions. To be able to provide input data for local air quality as well as atmospheric and climate modelling, correlation methods have been developed, which allow for estimating the emissions of the global fleet on the basis of publically available data only. Only recently new engine types with advanced low NOx combustion technology have been certified and similar types from other manufacturers are expected to follow. These engines make use of lean combustion technology and usually feature some sort of fuel staging to provide the combustion stability required for aircraft engines. As a result, standard application procedures of correlation methods cannot be applied for modelling emissions of these types of engines. Therefore new, alternative procedures have been developed and analyzed, which take into account the specific properties and parameters that influence NOx production in staged, lean-burn combustion systems.