Extents of alkane combustion during rapid compression leading to single and two stage ignition
- Leeds Univ. (United Kingdom). School of Chemistry
- Lawrence Livermore National Lab., CA (United States)
Extents of reactant consumption have been measured during the course of spontaneous ignition following rapid compression of N-pentane and N-heptane and also of PRF 60 (N-heptane = i-octane, 2.2.4 trimethylpentane) in stoichiometric mixtures with air. Compressed gas temperatures of 720-750 K and 845-875 K were studied at reactant densities of 131 mol m{sup minus 3}. At the lower gas temperature there was no evidence of reactant consumption during the course of the compression stroke. Two-stage ignition occurred at these temperatures, but only modest proportions of n-pentane were consumed during the first stage (< 15%) whereas about 40% of proportions of n- heptane reacted under the same conditions. At the higher compressed gas temperature the oxidation of n-pentane began only after the piston had stopped, whereas more than 30% of the n-heptane had already been consumed in the final stage of the compression stroke. The behavior of the PRF 60 mixture differed somewhat from that of N- pentane despite the similarly of the research octane numbers. Although there was a preferential oxidation of n-heptane at T{sub c} = 850K, which persisted throughout the early development of spontaneous ignition during the post-compression period, oxidation of both components of the PRF 60 mixture began before the piston had stopped. Numerical simulations of the spontaneous ignition under conditions resembling those of the rapid compression experiments show that the predicted reactivity from detailed kinetics are consistent with the observed features. Insights into the kinetic interactions that give rise to the relative reactivities of the primary reference fuel components are established
- Research Organization:
- Lawrence Livermore National Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 367247
- Report Number(s):
- UCRL-JC--123380; CONF-960772--23; ON: DE96013664
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
33 ADVANCED PROPULSION SYSTEMS
COMBUSTION KINETICS
COMBUSTION WAVES
COMPRESSION
COMPRESSION RATIO
FUEL CONSUMPTION
HEPTANE
IGNITION
IGNITION QUALITY
IGNITION SYSTEMS
INTERNAL COMBUSTION ENGINES
KNOCK CONTROL
NUMERICAL ANALYSIS
OCTANE
OXIDATION
PENTANE
PRESSURE DEPENDENCE
TEMPERATURE DEPENDENCE