Propagation and extinction of premixed C{sub 5}-C{sub 12}n-alkane flames

Journal Article · Mon Feb 15 04:00:00 EST 2010 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2009.06.011· OSTI ID:21262166

Ji, Chunsheng; Dames, Enoch; Wang, Yang L; Wang, Hai; Egolfopoulos, Fokion N ^[1]

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1. Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA 90089-1453 (United States)

Laminar flame speeds and extinction strain rates of premixed C{sub 5}-C{sub 12}n-alkane flames were determined at atmospheric pressure and elevated unburned mixture temperatures, over a wide range of equivalence ratios. Experiments were performed in the counterflow configuration and flow velocities were measured using Laser Doppler Velocimetry. The laminar flame speeds were obtained using a non-linear extrapolation technique utilizing numerical simulations of the counterflow experiments with detailed descriptions of chemical kinetics and molecular transport. Compared to linearly extrapolated values, the laminar flame speeds obtained using non-linear extrapolations were found to be 1-4 cm/s lower depending on the equivalence ratio. It was determined that the laminar flame speeds of all n-alkane/air mixtures considered in this investigation are similar to each other and sensitive largely to the H{sub 2}/CO and C{sub 1}-C{sub 4} hydrocarbon kinetics. Additionally, the resistance to extinction decreases as the fuel molecular weight increases. Simulations of the experiments were performed using the recently developed JetSurF 0.2 reaction model consisting of 194 species and 1459 reactions. The laminar flame speeds were predicted with good accuracy for all the n-alkane-air mixtures considered. The experimental extinction strain rates are well predicted by the model for fuel-lean mixtures. For stoichiometric and fuel-rich mixtures, the predicted extinction strain rates are approximately 10% lower than the experimental values. Insights into the physical and chemical processes that control the response of n-alkane flames are provided through detailed sensitivity analyses on both reaction rates and binary diffusion coefficients. (author)

• OSTI ID: 21262166
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 2 Vol. 157; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ACCURACY
AIR
ATMOSPHERIC PRESSURE
COMBUSTION KINETICS
COUNTERFLOW SYSTEMS
DIFFUSION
EXTRAPOLATION
FLAME EXTINCTION
FLAME PROPAGATION
LAMINAR FLAMES
MIXTURES
MOLECULAR WEIGHT
NONLINEAR PROBLEMS
PENTANE
SENSITIVITY ANALYSIS
SIMULATION
STRAIN RATE
Surrogate fuels
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
VELOCITY