TY - JOUR
T1 - An assessment of gas-phase reaction mechanisms and soot models for laminar atmospheric-pressure ethylene-air flames
AU - Mehta, R. S.
AU - Haworth, D. C.
AU - Modest, M. F.
N1 - Funding Information:
This work has been supported by the National Science Foundation under grant #CTS-0121573. The authors thank Dr. Hai Wang (University of Southern California) for discussions about convergence issues in OPPDIF, and Dr. Michael Frenklach (University of California, Berkeley) for help with PREMIX. The first author thanks Dr. Stephen Turns and Kshitij Deshmukh (The Pennsylvania State University) for valuable discussions.
PY - 2009
Y1 - 2009
N2 - A comprehensive assessment of gas-phase reaction mechanisms and soot models has been performed for atmospheric-pressure laminar ethylene-air flames. Soot modeling is based on a method of moments with interpolative closure. Computed soot volume fractions are compared with experimental measurements for eight flames: four premixed flames from two different burners, and four opposed-flow diffusion flames from two different burners. Seven gas-phase reaction mechanisms have been explored with variations in four key soot model parameters: PAH-based versus acetylene-based nucleation; PAH condensation included versus excluded; surface reactivity steric factor specification; and surface radicals depleted versus conserved. Computed soot volume fractions are most sensitive to variations in the surface reactivity factor and to whether the surface radicals are depleted or conserved. The motivation for this study has been to determine which models should be used for simulations of luminous turbulent flames; there computational efficiency is of paramount importance. A reduced 33-species mechanism together with acetylene-based nucleation, surface reactivity factor variation proposed by [J. Appel, H. Bockhorn, M. Frenklach, Combust. Flame 121 (2000) 122-136], and conserved surface radicals yields acceptable soot volume fractions over a broad range of conditions with an order of magnitude reduction in computational cost compared to a larger 100-species gas-phase reaction mechanism.
AB - A comprehensive assessment of gas-phase reaction mechanisms and soot models has been performed for atmospheric-pressure laminar ethylene-air flames. Soot modeling is based on a method of moments with interpolative closure. Computed soot volume fractions are compared with experimental measurements for eight flames: four premixed flames from two different burners, and four opposed-flow diffusion flames from two different burners. Seven gas-phase reaction mechanisms have been explored with variations in four key soot model parameters: PAH-based versus acetylene-based nucleation; PAH condensation included versus excluded; surface reactivity steric factor specification; and surface radicals depleted versus conserved. Computed soot volume fractions are most sensitive to variations in the surface reactivity factor and to whether the surface radicals are depleted or conserved. The motivation for this study has been to determine which models should be used for simulations of luminous turbulent flames; there computational efficiency is of paramount importance. A reduced 33-species mechanism together with acetylene-based nucleation, surface reactivity factor variation proposed by [J. Appel, H. Bockhorn, M. Frenklach, Combust. Flame 121 (2000) 122-136], and conserved surface radicals yields acceptable soot volume fractions over a broad range of conditions with an order of magnitude reduction in computational cost compared to a larger 100-species gas-phase reaction mechanism.
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U2 - 10.1016/j.proci.2008.06.149
DO - 10.1016/j.proci.2008.06.149
M3 - Conference article
AN - SCOPUS:67649277633
SN - 1540-7489
VL - 32 I
SP - 1327
EP - 1334
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
IS - 1
T2 - 32nd International Symposium on Combustion
Y2 - 3 August 2008 through 8 August 2008
ER -