Numerical simulation of methane-air equivalence ratio effect on premixed low swirl stabilized flame

A numerical simulation devoted to premixed methane-air low swirl stabilized flames obtained from a low swirl burner configuration is presented in this paper. A relatively wide range of methane-air equivalence ratios varying from 0.6 to 1.4 is considered. Several parameters identified as governing the flame structure, namely; velocity and temperature fields, methane (CH4) distribution and (thermal) nitric oxide (NO) formation are analyzed and compared to experimental available results. Turbulence is taken into account using RANS (Reynolds Average Navier-Stokes) standard k-epsilon model coupled to partially premixed model dedicated to combustion. Comparisons with literature results show satisfactory agreement for all studied flame parameters. It is particularly established that a compromise between maximum temperature and minimum (thermal) NO emissions can be ensured for low swirl burners with the flame maintained stable. Furthermore, several low swirl burners' characteristics are recovered.