Prediction of NO formation in turbulent combustion using presumed joint PDF model

CH4/air diffusion turbulent combustion was numerically simulated using a presumed joint PDF model. The predicted results of temperature and species concentrations agree well with the experimental data. Based on this reasonable prediction of turbulent combustion, the extended Zeldovich mechanics for the thermal NO formation and the presumed joint PDF model for turbulent reaction are adopted to predict NO formation in CH4/air diffusion turbulent combustion. Comparison between the experimental data and the prediction results using the presumed joint PDF model and Arrhenius model shows that the predicted NO values using the PDF model agree well with the experimental data, while those using Arrhenius model were largely underestimated. Therefore, the presumed joint PDF model can provide quantitative simulation of thermal NO in consideration of effects of both turbulent diffusion and chemical dynamics.