Rights statement: This is the author’s version of a work that was accepted for publication in International Journal of Hydrogen Energy. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Hydrogen Energy, 40 (45), 15709-15722 2015 DOI: 10.1016/j.ijhydene.2015.08.112
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - A computational study of preferential diffusion and scalar transport in nonpremixed hydrogen-air flame
AU - Jiang, Jieyu
AU - Jiang, Xi
AU - Zhu, Min
N1 - This is the author’s version of a work that was accepted for publication in International Journal of Hydrogen Energy. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Hydrogen Energy, 40 (45), 15709-15722 2015 DOI: 10.1016/j.ijhydene.2015.08.112
PY - 2015/12/7
Y1 - 2015/12/7
N2 - The nonpremixed hydrogen-air reacting flow is simulated using three-dimensional direct numerical simulation coupled with flamelet generated manifolds based on detailed chemical kinetics. From the comparisons between one computational case taking into account preferential diffusion and another case with unity Lewis number assumption, the instantaneous results show that the flow is more vortical in the absence of preferential diffusion. This indicates that preferential diffusion may smooth the flame under certain circumstances when coupled with the intrinsic hydrodynamic instability. The flame compositional structures are also influenced by preferential diffusion in a significant manner. Further, the statistical information suggests that turbulent scalar flux is affected by preferential diffusion. The phenomenon of counter-gradient diffusion of both the conserved and non-conserved scalars can be detected for the two cases. The gradient model for scalar closure is found to be incapable of accurately predicting the scalar transport in nonpremixed hydrogen flames.
AB - The nonpremixed hydrogen-air reacting flow is simulated using three-dimensional direct numerical simulation coupled with flamelet generated manifolds based on detailed chemical kinetics. From the comparisons between one computational case taking into account preferential diffusion and another case with unity Lewis number assumption, the instantaneous results show that the flow is more vortical in the absence of preferential diffusion. This indicates that preferential diffusion may smooth the flame under certain circumstances when coupled with the intrinsic hydrodynamic instability. The flame compositional structures are also influenced by preferential diffusion in a significant manner. Further, the statistical information suggests that turbulent scalar flux is affected by preferential diffusion. The phenomenon of counter-gradient diffusion of both the conserved and non-conserved scalars can be detected for the two cases. The gradient model for scalar closure is found to be incapable of accurately predicting the scalar transport in nonpremixed hydrogen flames.
KW - Nonpremixed hydrogen flames
KW - Direct numerical simulation
KW - Preferential diffusion
KW - Turbulent scalar transport
KW - Counter-gradient diffusion
U2 - 10.1016/j.ijhydene.2015.08.112
DO - 10.1016/j.ijhydene.2015.08.112
M3 - Journal article
VL - 40
SP - 15709
EP - 15722
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
SN - 0360-3199
IS - 45
ER -