Comparative Numerical Analysis to Determine the Distribution of Toxic Pollutants in the SM۱ Flame Assuming Different Methane-air Chemical Mechanisms

The structure of turbulent swirling flow in the SM۱ non-premixed burner has been numerically investigated. The objective of this research is to investigate the reactive fluid flow structure and toxic pollutant distributions in the SM۱ flame by varying the number of chemical species and reactions. For this purpose, the following chemical mechanisms were employed: GRI-Mech ۱.۲, GRI-Mech ۲.۱۱, GRI-Mech ۳.۰, DRM ۱۹, and DRM ۲۲. In all simulations, the steady laminar flamelet model was used to investigate the combustion process. According to the results, the axial velocity, temperature, mixture fraction, , and CO mass fraction show similar distributions when the GRI Mech series, DRM ۱۹, and DRM ۲۲ chemical mechanisms are used. However, the OH mass fraction distribution obtained from GRI-Mech ۳.۰ demonstrates under-prediction compared to the GRI-Mech ۱.۲ and ۲.۱۱. Furthermore, the NO pollutant levels obtained from GRI-Mech ۳.۰ exhibit over-prediction compared to both the GRI-Mech ۲.۱۱ and experimental data. The root mean square error (RMSE) obtained from the numerical simulation results for the NO mass fraction distribution indicates an error on the order of . The results of this study show that the use of the aforementioned chemical mechanisms has no effect on the distribution of fluid flow and major chemical species. Therefore, in the optimization process related to fluid flow and major species in non-premixed burners, chemical mechanisms with fewer species and chemical reactions can be used. However, for modeling minor and toxic pollutants, the choice of chemical mechanism is very important.

کلیدواژه ها:

GRI Mech chemical mechanisms ، Steady laminar-flamelet model ، Turbulent non-premixed flame ، Toxic pollutants ، Swirling SM۱ flame