A Numerical Study on the Relation of OH*, CH*, and C2* Chemiluminescence and Heat Release in Premixed Methane Flames

Chemiluminescence (CL) - self emitted radiation from electronically excited molecules - is seen as an attractive option for combustion diagnostics. A successful implementation of CL as a diagnostics tool requires reliable knowledge on the relation between chemiluminescence and heat release. We present results from a numerical study using a detailed kinetic mechanism, for CH4-oxidation [1], incorporating the OH*, CH*, and C2* species. Simulations of one-dimensional premixed laminar flames are performed in lean to rich fuel conditions and at different pressures. The displacement of the peak heat release location from the peak of the excited species concentrations are investigated for its applicability as a potential heat release marker. The results indicate that OH* and CH* are important as a marker for the heat release zone. However, the C2* provides poor estimate on heat release location prediction.