Efficient reduced mechanism proposed for the MILD combustion

In the present work, the effects of the reduced anddetailed mechanisms on the results of the MILDcombustion and its runtime in a Jet in Hot Colfow (JHC)burner are numerically investigated. The five childreduced mechanisms of Luca (۱۶), Cazères (۲۶), LU (۳۰),DRM (۲۲), and Cazères (۳۶) along with their parents, thedetailed mechanisms of GRI ۲.۱۱ and GRI ۳.۰ areinvestigated. Since, Luca (۱۶), DRM (۲۲), Cazères (۲۶),and LU (۳۰) have not reactions of NO formation, thepostprocessing model is imposed, and for others, NO isdirectly predicted. The results show that distribution ofthe OH and temperature do not change significantly forvarious mechanisms due to involving most of thereactions producing most of the heat release rate.However, the distribution of CO and NO havediscrepancy for Luca (۱۶) and Cazères (۲۶) due to thelack of reactions. Moreover, the child mechanisms resultsare similar to their parent. The postprocessing modelcannot correctly predict NO near the burner exit. Fromruntime examination associated with considering anacceptable CO and the temperature prediction, it is foundthat the reduced mechanisms of DRM (۲۲) and Cazères(۲۶) are more efficient mechanism for the non-NOxsimulations but with directly NO predictions, the reducedmechanism of Cazères (۳۶) is efficient due to taking ashorter time.

Keywords:

MILD combustion , JHC burner , Reducedchemical mechanism , NO prediction , Simulation runtime