Correlation of OH fluorescence and OH chemiluminescence with burning velocity of methane-hydrogen premixed flames

Recently, hydrogen is paid the most attention all over the world, because the CO2 emission can be reduced by an increase of its usage. In our previous study, hydrogen has been added in the premixed methane-air flame. The OH chemiluminescence intensity and the burning velocity were experimentally obtained, using a Bunsen burner. For further study, we investigated OH concentration by using the OH-PLIF technique. Especially, the OH fluorescence intensity was measured by keeping the burning velocity constant. The premixed gas velocity of CH4-H2-air mixture was 1.3 m/s. For comparison, OH chemiluminescence intensity was measured. Results showed that even when the hydrogen ratio in the total fuel of methane and hydrogen was changed, the OH fluorescence intensity was almost constant. On the other hand, OH chemiluminescence intensity decreased monotonically. Conclusively, different from the OH chemiluminescence intensity, the OH fluorescence intensity can be a good marker to evaluate the burning velocity in the combustion of mixed fuel of hydrogen and methane.