Routes of formation and destruction of nitrogen oxides in CH 4 /H 2 jet flames in a hot coflow

The formation/destruction mechanisms of nitric oxides (NOx) in CH4/H2 jet flames in a hot coflow are systematically investigated by numerical modeling. All calculations use the Eddy Dissipation Concept (EDC) model coupled with GRI-Mech 2.11. The modeling is validated by the measurements of Dally et al. [Proc. Combust. Inst. 29 (2002) 1147–1154]. Dependences of the NOx formation/destruction routes on YO2∗, Tcof∗ and YH2∗ are examined, where YO2∗, Tcof∗ and YH2∗ are the coflow oxygen concentration and temperature, and the hydrogen fraction in the fuel mixture, respectively. The following is obtained.