The choice of turbulence models and kinetic mechanisms plays an important role in accurate simulation results of the combustion reaction. This study developed a combustion experiment system and a micromix combustor model to examine their effects. Three turbulence models coupled with two near-wall treatments, Scalable Wall Functions and Enhanced Wall Treatment, were employed for numerical analysis. Their predictive capabilities were assessed by comparing the flame central temperature, radial temperature distribution at different heights, and NO emission with the experimental data. Five hydrogen reaction mechanisms, GRI-1999, KONNOV-2007, Rasmussen-2008, CRECK-2012 and Zhang-2017, were compared on the basis of the best-performing turbulence model and the near-wall treatment. The Realizable k-ε model with Enhanced Wall Treatment was found to exhibit the closest simulation results to the experimental data, less than 10% error for flame central temperature prediction. The mechanism comparison revealed that variations in equivalence ratios and thermal inputs significantly impacted the combustion characteristics. CRECK-2012 provided the most accurate temperature prediction with the mean relative error below 0.2. In conclusion, the Realizable k-ε model with Enhanced Wall Treatment and CRECK-2012 mechanism are recommended for accurate modeling of hydrogen micromix combustion.
Deng et al. (Fri,) studied this question.