Contribution of the N2O pathway to NOx emissions in aeronautical gas turbines

A model is presented to account for NO emissions due to both the thermal and the nitrous oxide pathways, and to quantify emissions of N2O itself, a powerful greenhouse agent. The model is applied to the combustor of a typical aeronautical gas turbine, at both take-off and cruise conditions. The combustor is assumed to operate in the nonpremixed regime, and fuel is approximated as propane. Effects of finite-rate chemistry are introduced via the stretched laminar flamelet approach. Results indicate that the nitrous oxide pathway contributes in between 8 and 12.8% of total NOx emissions (at cruise and take-off, respectively), while emissions of N2O itself, though representing only 0.9% of total NOx at take-off, attains about 3% during cruise. Further refinements of the model are suggested. © 2002 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.