A numerical study on the ability to predict the heat release rate, equivalence ratio and NO emission using chemiluminescence in counterflow premixed methane flames

Chemiluminesce nce emission from flames ha s been implemented to monitor and control heat release rate (HRR) , local equivalence ratio (ER) and key pollutant emissions in gas turbine c ombustors and automotive engines. In the present study, in order t o simultaneously simulate the chemiluminescence of OH * , CH * (A), C 2 * and CO 2 * (where * denotes the excited state) and to obtain insight on the relation between chemiluminescence, heat release , equivalence ratio and NO emission , numerical studies on 1 - D counterflow premixed methane flames were conducted. A new detailed reaction mechanism, incorporating sub - reaction models for excited state OH * , CH * (A), C 2 * and CO 2 * radicals was assembled in thi s study. T hree detailed reaction mechanisms available in the literature for C1 – C3 hydrocarbons were employed in the current work. Results show that OH * , CH * (A) and CO 2 * chemiluminescence can accurately reproduce the heat release rate trend , while t he OH * /C H * (A) chemi luminescent intensity ratio var ies non - monotonically with the equivalence ratio . Further, it is shown that t he CO 2 * and C 2 * chemiluminescence can be utilized to indicate the levels of NO emissions. However, the choice of the fuel oxidant chemica l mechanism can highly influence the model’s ability to predict the behavior of the aforementioned combustion parameters through chemiluminescence simulations