High-pressure methane oxidation behind reflected shock waves Academic Article uri icon

abstract

  • Experiments on CH4 oxidation behind reflected shock waves were conducted at elevated pressures, and the results compared to a detailed kinetics model. Mixtures of CH4 and O2 dilute in either argon or nitrogen were studied over a wide range of stoichiometry (=0.5-4.0), bath gas dilution (90.0-99.5%), pressure (9-480 atm), and temperature (1410-2040 K), corresponding to total concentrations from 5.6×10-5 to 3.6×10-3 mol/cm3. Reaction progress was monitored using narrow-line laser absorption of OH at 306 nm, infrared emission of CH4 near 3.4 μm, and pressure measurements. The measured species time-histories and pressure traces were assembled into an extensive database of characteristic reaction times, peak OH mole fractions, and ignition delay times that can be used for comparisons with detailed kinetics mechanisms. The chemical kinetics model utilized in the present comparisons is the latest GRI mechanism, GRI-Mech 1.2. As a whole, agreement between the model predictions and the experimental measurements is good, particularly for ignition delay times. However, based on the results of certain CH4 profiles, improvements in the model for high-pressure, fuel-rich conditions are needed. Sensitivity and species contribution analyses were used to identify the most important reactions at pressures up to 500 atm, some of which require more accurate rate coefficients. As pressure increases, the CH3 removal pathways are altered, the CH3 formation pathways remain the same, and reactions involving HO2 become important. © 1996 Combustion Institute.

author list (cited authors)

  • Petersen, E. L., Röhrig, M., Davidson, D. F., Hanson, R. K., & Bowman, C. T.

citation count

  • 55

publication date

  • January 1996