Experimental measurements of adiabatic burning velocity and NO formation in (CH4 + H2) + (O2 + N2) flames are presented. The hydrogen content in the fuel was varied from 0 to 35% and the oxygen content in the air from 20.9 to 16%. Nonstretched flames were stabilized on a perforated plate burner at 1 atm. The heat flux method was used to determine burning velocities under conditions when the net heat loss of the flame is zero. Adiabatic burning velocities of methane + hydrogen + nitrogen + oxygen mixtures were found in satisfactory agreement with the modeling. The NO concentrations in these flames were measured in the burnt gases at a fixed distance from the burner using probe sampling. In lean flames, enrichment by hydrogen has little effect on [NO], while in rich flames, the concentration of nitric oxide decreases significantly. Dilution by nitrogen decreases [NO] at any equivalence ratio. Numerical predictions and trends were found in good agreement with the experiments. Different responses of stretched and nonstretched flames to enrichment by hydrogen are demonstrated and discussed.
|Journal||Combustion and Flame|
|Publication status||Published - 2007|
Coppens, F. H. V., Ruyck, de, J., & Konnov, A. A. (2007). The effects of composition on the burning velocity and nitric oxide formation in laminar premixed flames of CH4 + H2 + O2 + N2. Combustion and Flame, 149(4), 409-417. https://doi.org/10.1016/j.combustflame.2007.02.004