Effects of water vapor addition on NO reduction of n-decane/air flames

NO producing mechanism and effects of additional water vapor on NO reduction of n-decane/air flames were examined numerically in the present study. A new phenomenon was found that the variation trend of contribution of chemical effect of water vapor on NO reduction with pressure changes with the equivalence ratio. To illustrate this, NO emissions without and with water vapor addition were examined. Results showed that the new phenomenon is because that NO-producing pathways vary with both equivalence ratio and pressure, and hence the reactions through which the added water vapor influences NO production also vary with equivalence ratio and pressure.