TY - GEN
T1 - Mechanisms of kinetic combustion enhancement by O2(a 1Δg)
AU - Ombrello, Timothy
AU - Sun, Wenting
AU - Won, Sang Hee
AU - Ju, Yiguang
AU - Williams, Skip
AU - Carter, Campbell
PY - 2010
Y1 - 2010
N2 - The isolated enhancement effects of O2(a1Δ g) on lifted flame propagation was investigated experimentally and numerically at reduced pressures. Through quantitative absorption measurements it was found that O2(a1Δg) was produced in excess of 5500 ppm and was isolated from all other plasma-produced species via NO injection before transport to the C2H4 lifted flame. Clear trends of increased flame propagation enhancement with increased O2(a1Δg) concentrations were found, with up to 3% enhancement observed. Numerical simulations with the current O 2(a1Δg) kinetic mechanisms, containing only hydrogen species, showed significant trend deviations from the experimental results, indicating errors in the kinetics. The inclusion of new estimated temperature dependent rates of O2(a1Δg) collisional quenching by hydrocarbon species mitigated the deviation, but require validation. Flow reactor experiments with conditions mimicking the early stages of the flame showed that low temperature oxidation of C 2H4 in the range of 583 K to 728 K mimicked the low temperature kinetic pathways of enhancement through NO sensitization with OH production. Therefore the inclusion of O2(a1Δ g) quenching by hydrocarbon species, as well as low temperature chemistry is necessary for accurate modeling of the enhancement pathways by O2(a1Δg).
AB - The isolated enhancement effects of O2(a1Δ g) on lifted flame propagation was investigated experimentally and numerically at reduced pressures. Through quantitative absorption measurements it was found that O2(a1Δg) was produced in excess of 5500 ppm and was isolated from all other plasma-produced species via NO injection before transport to the C2H4 lifted flame. Clear trends of increased flame propagation enhancement with increased O2(a1Δg) concentrations were found, with up to 3% enhancement observed. Numerical simulations with the current O 2(a1Δg) kinetic mechanisms, containing only hydrogen species, showed significant trend deviations from the experimental results, indicating errors in the kinetics. The inclusion of new estimated temperature dependent rates of O2(a1Δg) collisional quenching by hydrocarbon species mitigated the deviation, but require validation. Flow reactor experiments with conditions mimicking the early stages of the flame showed that low temperature oxidation of C 2H4 in the range of 583 K to 728 K mimicked the low temperature kinetic pathways of enhancement through NO sensitization with OH production. Therefore the inclusion of O2(a1Δ g) quenching by hydrocarbon species, as well as low temperature chemistry is necessary for accurate modeling of the enhancement pathways by O2(a1Δg).
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M3 - Conference contribution
AN - SCOPUS:78649853652
SN - 9781600867392
T3 - 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition
BT - 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition
T2 - 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition
Y2 - 4 January 2010 through 7 January 2010
ER -