TY - JOUR
T1 - Flame propagation and counterflow nonpremixed ignition of mixtures of methane and ethylene
AU - Liu, W.
AU - Kelley, A. P.
AU - Law, C. K.
N1 - Funding Information:
This research was supported by the US Army Research Office and the US Air Force Office of Scientific Research under the technical monitoring of Dr. Ralph A. Anthenien and Dr. Julian M. Tishkoff, respectively. The participation of Dr. Yun Huang with the experimental aspects of the investigation is very much appreciated.
PY - 2010/5
Y1 - 2010/5
N2 - The ignition temperature of nitrogen-diluted mixtures of methane and ethylene counterflowing against heated air was measured up to five atmospheres. In addition, the stretch-corrected laminar flame speeds of mixtures of air, methane and ethylene were determined from outwardly-propagating spherical flames up to 10 atmospheres, for extensive range of the lean-to-rich equivalence ratio. These experimental data, relevant to low- to moderately-high-temperature ignition chemistry and high-temperature flame chemistry, respectively, were subsequently compared with calculations using two detailed kinetic mechanisms. A chemical explosive mode analysis (CEMA) was then conducted to identify the dominant ignition chemistry and the role of ethylene addition in facilitating nonpremixed ignition. Furthermore, the hierarchical structure of the associated oxidation kinetics was examined by comparing the sizes and constituents of the skeletal mechanisms of the pure fuels and their mixtures, derived using the method of directed relation graph (DRG). The skeletal mechanism was further reduced by time-scale analysis, leading to a 24-species reduced mechanism from the detailed mechanism of USC Mech II, validated within the parameter space of the conducted experiments.
AB - The ignition temperature of nitrogen-diluted mixtures of methane and ethylene counterflowing against heated air was measured up to five atmospheres. In addition, the stretch-corrected laminar flame speeds of mixtures of air, methane and ethylene were determined from outwardly-propagating spherical flames up to 10 atmospheres, for extensive range of the lean-to-rich equivalence ratio. These experimental data, relevant to low- to moderately-high-temperature ignition chemistry and high-temperature flame chemistry, respectively, were subsequently compared with calculations using two detailed kinetic mechanisms. A chemical explosive mode analysis (CEMA) was then conducted to identify the dominant ignition chemistry and the role of ethylene addition in facilitating nonpremixed ignition. Furthermore, the hierarchical structure of the associated oxidation kinetics was examined by comparing the sizes and constituents of the skeletal mechanisms of the pure fuels and their mixtures, derived using the method of directed relation graph (DRG). The skeletal mechanism was further reduced by time-scale analysis, leading to a 24-species reduced mechanism from the detailed mechanism of USC Mech II, validated within the parameter space of the conducted experiments.
KW - Counterflow ignition
KW - Laminar flame speeds
KW - Mechanism hierarchy
KW - Methane-ethylene mixture
KW - Spherical flames
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U2 - 10.1016/j.combustflame.2009.11.002
DO - 10.1016/j.combustflame.2009.11.002
M3 - Article
AN - SCOPUS:77349084881
SN - 0010-2180
VL - 157
SP - 1027
EP - 1036
JO - Combustion and Flame
JF - Combustion and Flame
IS - 5
ER -