A major challenge is to respond to current and prospective public concerns regarding the pollution and physical changes to the environment caused by aircraft engine emissions. Indeed, one of the major problems that civil aeronautics will have to face over the next twenty to thirty years is to accommodate the predicted growth in demand of air transport without adverse effects on the environment. To overcome this problem will require both the development of advanced, environmentally friendly technologies and the conduct of scientific researches to increase the understanding of basic phenomena. A particular concern relates to the possibility that emissions of oxides of nitrogen (IsTOX) and other minor species from aircraft flying in the upper troposphere and lower stratosphere (8 - 25 km), whether from current subsonic or, in the future, from possible supersonic operations, may make a significant contribution to global warming and ozone generation or depletion. In the preceding phases of this Framework programme (Pilot Phase /1/ and Interim Phase 121) three major methods of Nitrogen oxide reduction were identified. These methods differ not only in their NOX reduction potential, but also in their complexity and technical feasibility.
The first concept with the lowest NOX reduction potential incorporates the lean combustion method without premixing in a staged - Double Annular Combustor Ÿ design. The second method also uses lean combustion but improvements in NOX reduction can be obtained by introducing a premix duct so that a Lean. Premixed and Prevaporized combustion system is developed. The third concept, applying the Rich burn Quick Quench Lean burn combustion seems to lead to a smaller technical risk than LPP still providing a substantial amount in NOX reduction work in the Interim Phase of the programme showed that Double Annular technology can offer an overall NOx reduction of 30% to 40% relative to conventional Single Annular Combustor. For the first time, LPP systems have been tested during the Interim Phase at pressure levels up to 20 bar (small engines) and 17 bar for large engines respectively, without experiencing any damage by operating with excellent homogeneity providing extraordinarily low NOx emission rates (more than 90% of NOx reduction at 7 bar/6:50K) RQL combustors were tested up to 40 bar and 900K entry temperature reaching a N'Ox r BE97-4420
Funding SchemeCSC - Cost-sharing contracts
86961 Chasseneuil Du Poitou
10127 Torino (Turin)
SW1E 6AT London