Numerical investigation of temperature field and laminar flame structure of inclined impinging jets of methane and hydrogen

Nowadays, premixed flames are broadly utilized in various residential/industrial applications. Therefore, simultaneously increasing the quality of combustion and reducing the pollution of these flames is of great importance. In this study, collisions of two flame jets of H2/CH4 have been simulated; and flame structure, temperature, and NOx emission are reported at different conditions. The main purpose of this work was to study the effect of angle between the burners and the effect of air and fuel preheating on the key design factors of impinging jets. It was observed that by increasing the angle between two burners, mixing and recirculating flow is enlarged, and the maximum flame temperature and NOx production is increased accordingly. By increasing the angle from 0 to 180 degrees, the maximum flame temperature of methane and hydrogen increases by 11.5 and 12.4%, respectively. Preheating showed that with 400 K increase in the fuel and inlet air temperature, the maximum flame temperature for methane and hydrogen increases 6% and 4%, respectively, which eventually results in a higher NOx.