Fuel NO for gaseous fuels
 

Does anybody have experience in modeling Fuel-NO from gaseous fuels (i.e. when the fuel itself contains a reactive nitrogen species, e.g. ammonia)? This is not covered by the built-in Fluent model when using non-premixed combustion.

I have tried running an available reaction mechanism (GRI-Mech) as a pre-processor for a steady-diffusion flamelet problem, but the results were extremely poor compared to experimental data. In fact, a test showed that this procedure will already lead to grossly overestimated levels of NO via the thermal (Zeldovich) mechanism. So far, detailed chemistry-turbulence-interaction models (eddy-dissipation-concept) have not worked too well for me, but I'm afraid I'll have to try them again.

Any experience or thoughts on the matter are appreciated!