TY - CONF
T1 - Sensitivity to chemical kinetics models in time-evolving turbulent non-premixed flames
AU - Yang, Suo
AU - Ranjan, Reetesh
AU - Yang, Vigor
AU - Sun, Wenting
AU - Menon, Suresh
N1 - Funding Information:
This work was funded partly by NASA (Grant NNX15AU96A), and partly by the William R.T. Oakes Endowment of the Georgia Institute of Technology.
Publisher Copyright:
© 2017 Eastern States Section of the Combustion Institute. All rights reserved.
PY - 2017
Y1 - 2017
N2 - To investigate the sensitivity of simulation predictions to chemical kinetics, GRI-Mech 3.0 and an 11-species syngas model, are compared by performing 3D finite-rate kinetics-based direct numerical simulations (DNS) of temporally evolving turbulent non-premixed flames. Dynamic adaptive chemistry and correlated transport techniques are applied for efficient simulation. Significant deviations (86∼100 K difference in the temperature field) indicate high sensitivity to the chemical kinetics. This sensitivity to the chemical kinetics is magnified relative to a 1D steady laminar simulation by the effects of unsteadiness and turbulence (up to 7 times for temperature, up to 12 times for CO, up to 13 times for H2, up to 7 times for O2, up to 5 times for CO2, and up to 13 times for H2O), with the deviations in species concentrations, temperature, and reaction rates forming a nonlinear positive feedback loop under the considered reacting flow conditions. The deviations between the two models majorly caused by: (a) GRI-Mech 3.0 contains more species and related kinetic pathways than the 11-species model; (b) reaction rate coefficients are different for the same reactions. Both (a) and (b) are sensitive to unsteadiness and other turbulence effects. However, (b) is the dominant part and is more sensitive.
AB - To investigate the sensitivity of simulation predictions to chemical kinetics, GRI-Mech 3.0 and an 11-species syngas model, are compared by performing 3D finite-rate kinetics-based direct numerical simulations (DNS) of temporally evolving turbulent non-premixed flames. Dynamic adaptive chemistry and correlated transport techniques are applied for efficient simulation. Significant deviations (86∼100 K difference in the temperature field) indicate high sensitivity to the chemical kinetics. This sensitivity to the chemical kinetics is magnified relative to a 1D steady laminar simulation by the effects of unsteadiness and turbulence (up to 7 times for temperature, up to 12 times for CO, up to 13 times for H2, up to 7 times for O2, up to 5 times for CO2, and up to 13 times for H2O), with the deviations in species concentrations, temperature, and reaction rates forming a nonlinear positive feedback loop under the considered reacting flow conditions. The deviations between the two models majorly caused by: (a) GRI-Mech 3.0 contains more species and related kinetic pathways than the 11-species model; (b) reaction rate coefficients are different for the same reactions. Both (a) and (b) are sensitive to unsteadiness and other turbulence effects. However, (b) is the dominant part and is more sensitive.
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M3 - Paper
AN - SCOPUS:85048968694
T2 - 10th U.S. National Combustion Meeting
Y2 - 23 April 2017 through 26 April 2017
ER -