Combustion of n-butane and isobutane in an internal combustion engine: A comparison of experimental and modeling results

Conference · Wed Dec 13 00:00:00 EST 1989

DOI:https://doi.org/10.1016/S0082-0784(06)80363-2· OSTI ID:6966527

Wilk, R D ^[1]; Pitz, W J; Westbrook, C K ^[2]; Addagarla, S; Miller, D L; Cernansky, N P ^[3]; Green, R M ^[4]

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1. Union Coll., Schenectady, NY (USA)
2. Lawrence Livermore National Lab., CA (USA)
3. Drexel Univ., Philadelphia, PA (USA)
4. Sandia National Labs., Livermore, CA (USA)

n-Butane and isobutane are used in a test engine to examine the importance of molecular structure in determining knock tendency. The experimental results are interpreted using a detailed chemical kinetic model. Temporally resolved samples were withdrawn from the combustion chamber, providing measured histories of the concentrations of a wide variety of reactant, olefin, carbonyl, and other intermediate and product species. Calculations show that RO{sub 2} isomerization reactions are more important contributors to chain branching in n-butane oxidation than in isobutane oxidation. Chain branching in isobutane oxidation is dependent on H-atom abstraction reactions involving HO{sub 2} and CH{sub 3}O{sub 2} radicals that occur at higher temperatures than RO{sub 2} isomerization reactions. Therefore, an isobutane mixture must be raised to a higher temperature than a n-butane mixture to achieve the same overall rate of reaction. 23 refs., 4 figs.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: DOE/CE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6966527
• Report Number(s): UCRL-102496; CONF-900704-3; ON: DE90005993
• Resource Relation: Journal Volume: 23; Journal Issue: 1; Conference: 23. Combustion Institute symposium on combustion, Orleans (France), 22-27 Jul 1990
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
INTERNAL COMBUSTION ENGINES
KNOCK CONTROL
2-METHYLPROPANE
BUTANE
CHEMISTRY
COMBUSTION KINETICS
COMBUSTION PROPERTIES
OXIDATION
REACTION KINETICS
ALKANES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CONTROL
ENGINES
HEAT ENGINES
HYDROCARBONS
KINETICS
ORGANIC COMPOUNDS
330100* - Internal Combustion Engines
400800 - Combustion
Pyrolysis
& High-Temperature Chemistry