TY - GEN
T1 - Counterflow diffusion flames of general fluids
T2 - 45th AIAA Aerospace Sciences Meeting 2007
AU - Ribert, Guillaume
AU - Zong, Nan
AU - Yang, Vigor
AU - Pons, Laetitia
AU - Darabiha, Nasser
AU - Candel, Sébastien
N1 - Funding Information:
This work was partly sponsored by the Air Force Office of Scientific Research under Grant FA 9550-04-1-0014, and partly sponsored by NASA through a Constellation University Institutes Project (CUIP) Grant. The authors gratefully acknowledge the support and advice given by Mitat Birkan, Claudia Meyer, Jeff Rybak, and Kevin Tucker.
PY - 2007
Y1 - 2007
N2 - A comprehensive framework has been established to study laminar counterflow diffusion flames for general fluids over the entire regime of thermodynamic states. The model incorporates a unified treatment of fundamental thermodynamics and transport theories into an existing model, the DMCF code, for treating detailed chemical kinetic mechanisms and multi-species transport. The resultant scheme can thus be applied to fluids at any state. Both subcritical and supercritical conditions are considered. As a specific example, diluted and undiluted H2/O2 flames are investigated at pressures of 1-250 atm and oxygen inlet temperatures of 100 and 300 K. The effects of pressure p and strain rate a on the energy release rate q̇s, extinction limit, and flame structure are examined. In addition, the impact of cross-diffusion terms, such as the Soret and Dufour effects, on the flame behavior is assessed. Results indicate that the flame thickness δ and heat release rate correlate well with the square root of the pressure multiplied by the strain rate as δf ∼/√pa and q̇s ∼ √pa. The extinction strain rate exhibits a quasi-linear dependence with p. Significant real-fluid effects take place in the transcritical regimes, as evidenced by the rapid property variations in the local flowfield. Their net influence on the flame properties, however, appears to be limited due to the ideal-gas behavior of fluids in the high-temperature zone.
AB - A comprehensive framework has been established to study laminar counterflow diffusion flames for general fluids over the entire regime of thermodynamic states. The model incorporates a unified treatment of fundamental thermodynamics and transport theories into an existing model, the DMCF code, for treating detailed chemical kinetic mechanisms and multi-species transport. The resultant scheme can thus be applied to fluids at any state. Both subcritical and supercritical conditions are considered. As a specific example, diluted and undiluted H2/O2 flames are investigated at pressures of 1-250 atm and oxygen inlet temperatures of 100 and 300 K. The effects of pressure p and strain rate a on the energy release rate q̇s, extinction limit, and flame structure are examined. In addition, the impact of cross-diffusion terms, such as the Soret and Dufour effects, on the flame behavior is assessed. Results indicate that the flame thickness δ and heat release rate correlate well with the square root of the pressure multiplied by the strain rate as δf ∼/√pa and q̇s ∼ √pa. The extinction strain rate exhibits a quasi-linear dependence with p. Significant real-fluid effects take place in the transcritical regimes, as evidenced by the rapid property variations in the local flowfield. Their net influence on the flame properties, however, appears to be limited due to the ideal-gas behavior of fluids in the high-temperature zone.
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M3 - Conference contribution
AN - SCOPUS:34250845932
SN - 1563478900
SN - 9781563478901
T3 - Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting
SP - 16845
EP - 16858
BT - Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting
Y2 - 8 January 2007 through 11 January 2007
ER -