Emissions Analysis of the Double Annular Combustor (DAC) NASA Energy Efficient Engine (E³) Program

Emission predictions show that carbon monoxide, unburned hydrocarbons, and smoke remain well below regulatory limits across all operating conditions.

NOx emissions meet targets in the standard cycle but approach regulatory limits in the growth cycle, leaving very little compliance margin.

In conclusion, the Double Annular Combustor represents a major advancement in aircraft emissions control.

While CO, UHC, and smoke performance are excellent, NOx remains the key challenge, requiring further reductions in peak flame temperature and advanced staging concepts in future designs.