A Comparative Study of Flame Structure, Heat Transfer, and Exhaust Emissions of a Coaxial Burner Fitted with Multiple Air and Fuel Injection Fingers

This research experimentally investigates the flame structure, heat transfer performance, and emissions associated with a multi-injection coaxial swirl burner with various configurations.The configurations vary based on the fingers' position in relation to the exit of the burner gun.The results reveal that the placement of air injection points significantly influences the magnitude and location of the on-axis maximum mean gas temperature.Furthermore, the activation of fuel injectors (while maintaining a constant total fuel input) exhibits varying effects on the axial variations of the mean gas temperature, contingent upon the specific configuration.The axial variations of the heat flux distribution and cumulative heat transfer exhibit a consistent trend across all test cases.The present study revealed (i) a direct relationship between exhaust gas temperature and the fuel feed percentages (FFP) through the fuel fingers and (ii) a nuanced interplay between fingers' configurations and FFP in influencing the combustion performance.