The investigation of CO2 effect on the characteristics of a methane diffusion flame

Image processing is used to investigate the effect of mixing carbon dioxide with methane on flame properties by digitally analysing the flame chemiluminescence emission. The images are captured by a high speed colour camera, which is able to record and monitor the spatial and temporal changes in flame chemiluminescence when adding different amounts of carbon dioxide to methane from the moment of ignition to any specific time during combustion. Results confirmed that by increasing carbon dioxide, the flame temperature and soot level are reduced and the flame height is getting longer. On the other hand it has been qualitatively observed that the ignition time is increased. Also, the presence of soot that only emits infrared light is observed during the ignition period. The average value of B/G ratio is calculated through digital image processing. It is found that B/G ratio increases by adding more CO2.