A spectroscopic imaging system for flame radical profiling

This paper presents the development of an instrumentation system for visualizing and characterizing free radicals in combustion flames. The system combines optical splitting and filtering, intensified imaging and image processing techniques, providing a solution for the monitoring of flame radicals (OH*, CN*, CH*, and C₂*) simultaneously and continuously. Computing algorithms are developed to analyze the images and quantify the radiative characteristics of the radicals. Experimental results are obtained from a gas-fired combustion rig to demonstrate the effectiveness of the system. The information obtained by the system can be used to establish the relationships between radical characteristics and the chemical and physical properties of the fuels and combustion products, helping to obtain an in-depth understanding of pollutant formation processes, and leading to an optimized combustion process.