A.V. Mokhov, B.A.V. Bennett, H.B. Levinsky, and M.D. Smooke,

Proceedings of the Combustion Institute, 31, 997–1004, 2007

Abstract

Raman measurements of C₂H₂ and CO mole fractions in a laminar axisymmetric methane-air diffusion flame are compared with numerical predictions. A high-repetition-rate, high-average-power laser is used to increase signal-to-noise ratio to measure these minor flame species. Computationally, the system of governing equations including detailed chemistry and transport is solved by a damped modified Newton's method. The calculations predict the measured temperature and nitrogen mole fractions quantitatively. While there is agreement within experimental uncertainty between calculated and measured acetylene concentrations, the calculations predict sharper C₂H₂ gradients on the lean side of the radial profiles. Adjusting rate of the reaction between C₂H₂ and OH to values derived in recent experimental and theoretical studies has only a minor impact on the calculated C₂H₂ profiles. The numerical simulations describe the CO profiles qualitatively, underpredicting the measured CO mole fraction by 40%.