TY - JOUR
T1 - High temperature ignition and combustion enhancement by dimethyl ether addition to methane-air mixtures
AU - Chen, Zheng
AU - Qin, Xiao
AU - Ju, Yiguang
AU - Zhao, Zhenwei
AU - Chaos, Marcos
AU - Dryer, Frederick L.
N1 - Funding Information:
The authors thank Professor H.J. Curran at the University of Ireland for providing his chemical mechanism. This work was partially supported by PRF#39162-AC9 and Air Force Research F49620-04-1-0038 and the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, US Department of Energy under Grant No. DE-FG02-86ER13503.
PY - 2007
Y1 - 2007
N2 - The effects of dimethyl ether (DME) addition on the high temperature ignition and burning properties of methane-air mixtures were studied experimentally and numerically. The results showed that for a homogeneous system, a small amount of DME addition to methane resulted in a significant reduction in the high temperature ignition delay. The ignition enhancement effect by DME addition was found to exceed that possible with equivalent amounts of hydrogen addition, and it was investigated by using radical pool growth and computational singular perturbation analysis. For a non-premixed methane-air system, it was found that two different ignition enhancement regimes exist: a kinetic limited regime and a transport limited regime. In contrast to the dramatic ignition enhancement in the kinetic limited regime, the ignition enhancement in the transport limited regime was significantly less effective. Furthermore, laminar flame speeds as well as Markstein lengths were experimentally measured for methane-air flames with DME addition. The results showed that the flame speed increases almost linearly with DME addition. However, the Markstein length and the Lewis number of the binary fuel change dramatically at small DME concentrations. Moreover, comparison between experiments and numerical simulations showed that only the most recent DME mechanism well reproduced the flame speeds of both DME-air and CH 4-air flames.
AB - The effects of dimethyl ether (DME) addition on the high temperature ignition and burning properties of methane-air mixtures were studied experimentally and numerically. The results showed that for a homogeneous system, a small amount of DME addition to methane resulted in a significant reduction in the high temperature ignition delay. The ignition enhancement effect by DME addition was found to exceed that possible with equivalent amounts of hydrogen addition, and it was investigated by using radical pool growth and computational singular perturbation analysis. For a non-premixed methane-air system, it was found that two different ignition enhancement regimes exist: a kinetic limited regime and a transport limited regime. In contrast to the dramatic ignition enhancement in the kinetic limited regime, the ignition enhancement in the transport limited regime was significantly less effective. Furthermore, laminar flame speeds as well as Markstein lengths were experimentally measured for methane-air flames with DME addition. The results showed that the flame speed increases almost linearly with DME addition. However, the Markstein length and the Lewis number of the binary fuel change dramatically at small DME concentrations. Moreover, comparison between experiments and numerical simulations showed that only the most recent DME mechanism well reproduced the flame speeds of both DME-air and CH 4-air flames.
KW - Dimethyl ether
KW - Ignition enhancement
KW - Laminar flame speed
KW - Markstein length
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U2 - 10.1016/j.proci.2006.07.177
DO - 10.1016/j.proci.2006.07.177
M3 - Conference article
AN - SCOPUS:34250798954
VL - 31 I
SP - 1215
EP - 1222
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
SN - 1540-7489
IS - 1
T2 - 31st International Symposium on Combustion
Y2 - 5 August 2006 through 11 August 2006
ER -