Enhancement of Methane-Air Combustion with Increasing Oxygen Ratio

Increasing combustion efficiency and minimal emissions of pollutants are among the fundamental issues in combustion research. In this regard, the phenomenon of combustion and its influencing factors, such as the fuel / air ratio as one of the most important factors in flame formation, have attracted the attention of many researchers. In this study, the effect of increasing the oxygen ratio over its proportion in the stoichiometric reaction for methane - air combustion was studied. The equations for the conservation of mass, momentum, and energy for a methane-air mixture have been solved by using CFD. A FORTRAN-90 program based on GENMIX will be developed. In order to verify the validity of the present program, the present numerical results were compared with the previous experimental results, and the comparison showed a good agreement. From the results, it was found that increasing the proportion of oxygen leads to an improvement in the temperature distribution inside the combustion cylinder, and there is no effect was observed on the nature of the velocity profiles inside the combustion space. As for the combustion of fuel, there was an improvement in the fuel combustion rate with the increasing in oxygen ratio.