Effect of presumed PDF selection on the numerical result for turbulent diffusion flames

In the present work, the effect of probability density function (PDF) selection and intermittency on the result of the numerical simulation are examined by the simulation of a turbulent methane-air jet diffusion flame, where air is preheated to 1073K. As to the PDFs, beta-function and clipped Gaussian are considered. It is found that intermittency has a large impact on the numerical result, while the choice of PDF has a minor influence. When intermittency is considered, the flame height becomes larger and maximum temperature decreases. Comparison of radial profiles with experimental data shows that it is necessary to consider intermittency also for high temperature air diffusion flames.