The SAGE6 demonstration project aimed to develop and mature a lean burn combustion system. An essential enabler to development of such technology was an accurate and reliable computational tool for prediction of emissions. Lean burn provides significant benefits in terms of NOx emissions. However, the emissions of CO, UHC and soot limit the operation of the combustor at different conditions. Reliable predictions of emission trends led to optimised combustor designs in a cost effective way. Today’s capabilities, however, are still inadequate to produce accurate and reliable predictions in direct support of lean burn system design. The DREAMCODE project aimed to develop and improve computational methods that can be used in the design process of low emission combustors. Improved models and methods were developed to predict emissions accurately and reliably. To that end, the following essential elements of a CFD combustion emission tool were considered:

• Detailed chemistry models for jet fuel surrogates are necessary to describe the complicated chemical processes of fuel oxidation and emission formation in the gas phase.
• Soot models are indispensable to describe the complex physical and chemical phenomena of soot particle formation.
• Chemistry reduction methods are inevitable to reduce the computational cost of the complex chemistry model for application in CFD codes.
• Spray break-up models are necessary to model the liquid fuel break-up, which has a dramatic effect on emissions.
• Turbulence-chemistry interaction models have to account for the effects that occur on length scales which cannot be resolved by the computational mesh.

These 5 models were improved and integrated in a CFD code for the validation on real aero engine gas turbine combustors.