In the past combustion computational fluid dynamics (CFD) in the framework of aeroengines mainly concentrated on high power conditions of combustors using diffusion type flames.
The demand to lower emissions from jet engines powering passenger aircrafts has prompted a variety of research programmes devoted to this subject. In parallel to the optimisation of conventional combustors with respect to pollutant emissions, particularly nitrogen oxides, novel concepts have been invented, investigated and developed to different degrees of maturity. This presentation starts with a comprehensive overview on the requirements, discusses the NO formation mechanisms and presents concepts to overcome them. An assessment of the various concepts is made taking into account their specific advantages and drawbacks.