Reduction of Reaction Mechanism for n-Tridecane Based on Knowledge of Detailed Reaction Paths 2016-01-2238

n-Tridecane is a low boiling point component of gas oil, and has been used as a single-component fuel for diesel spray and combustion experiments. However, no reduced chemical kinetic mechanisms for n-tridecane have been presented for three-dimensional modeling. A detailed mechanism developed by KUCRS (Knowledge-basing Utilities for Complex Reaction Systems), contains 1493 chemical species and 3641 reactions. Reaction paths during ignition process for n-tridecane in air computed using the detailed mechanism, were analyzed with the equivalence ratio of 0.75 and the initial temperatures of 650 K, 850 K, and 1100 K, which are located in the cool-flame dominant, negative-temperature coefficient, and blue-flame dominant regions, respectively. Based on knowledge derived from the reaction path analysis, a skeletal mechanism containing 49 species and 85 reactions, was developed and validated for representing ignition characteristics over a wide range of initial conditions computed using the detailed mechanism. The skeletal mechanism includes C₃H₇, C₂H₅, and CH₃ as representative fragmental alkyl radicals, C₇H₁₄, C₃H₆, and C₂H₄ as representative alkenes, and C₃H₇CHO and CH₂O as representative aldehydes. C_3-series reactions beginning with O₂ addition to C₃H₇, were expressed using parameters for C₆-series reactions, which took similar reactions for larger alkyl radicals into consideration. Ignition delay times and low-temperature oxidation induction times with the initial temperatures between 600 K and 1200 K using the skeletal mechanism, and their dependences on pressure and equivalence ratio in lean and stoichiometric cases agree well with those using the detailed mechanism. However, the agreement becomes worse as equivalence ratio is increased in rich cases.