TY - JOUR
T1 - A reduced multicomponent diffusion model
AU - Xin, Yuxuan
AU - Liang, Wenkai
AU - Liu, Wei
AU - Lu, Tianfeng
AU - Law, Chung K.
N1 - Funding Information:
This work was supported by the Combustion Energy Frontier Research Center , an Energy Frontier Research Center funded by the US Department of Energy, Office of Basic Energy Sciences under Award Number DESC0001198. The work at the University of Connecticut was supported by the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, US Department of Energy under Grant DE-SC0008622. It is a pleasure to acknowledge Prof. Hai Wang for valuable discussions.
Publisher Copyright:
© 2014 The Combustion Institute.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - The diffusion models for multicomponent mixtures are investigated in planar premixed flames, counterflow diffusion flames, and ignition of droplet flames. Discernable discrepancies were observed in the simulated flames with the mixture-averaged and multicomponent diffusion models, respectively, while the computational cost of the multicomponent model is significantly higher than that of the mixture-averaged model. A systematic strategy is proposed to reduce the cost of the multicomponent diffusion model by accurately accounting for the species whose diffusivity is important to the global responses of the combustion systems, and approximating those of less importance. The important species in the reduced model are identified with sensitivity analysis, and are found to be typically among those in high concentrations with exception of a few radicals, e.g. H and OH, that are known to participate in critical reactions. The reduced model is validated in simulating the propagation of planar premixed flames, extinction of counterflow non-premixed flames and ignition of droplet flames. The reduced model was shown to feature similar accuracy to that of the multicomponent model while the computational cost was reduced by a factor of approximately 5 for an n-heptane mechanism with 88 species.
AB - The diffusion models for multicomponent mixtures are investigated in planar premixed flames, counterflow diffusion flames, and ignition of droplet flames. Discernable discrepancies were observed in the simulated flames with the mixture-averaged and multicomponent diffusion models, respectively, while the computational cost of the multicomponent model is significantly higher than that of the mixture-averaged model. A systematic strategy is proposed to reduce the cost of the multicomponent diffusion model by accurately accounting for the species whose diffusivity is important to the global responses of the combustion systems, and approximating those of less importance. The important species in the reduced model are identified with sensitivity analysis, and are found to be typically among those in high concentrations with exception of a few radicals, e.g. H and OH, that are known to participate in critical reactions. The reduced model is validated in simulating the propagation of planar premixed flames, extinction of counterflow non-premixed flames and ignition of droplet flames. The reduced model was shown to feature similar accuracy to that of the multicomponent model while the computational cost was reduced by a factor of approximately 5 for an n-heptane mechanism with 88 species.
KW - Diffusion model
KW - Model reduction
KW - Multicomponent diffusion
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U2 - 10.1016/j.combustflame.2014.07.019
DO - 10.1016/j.combustflame.2014.07.019
M3 - Article
AN - SCOPUS:84911453122
SN - 0010-2180
VL - 162
SP - 68
EP - 74
JO - Combustion and Flame
JF - Combustion and Flame
IS - 1
ER -