Early Oxidation Kinetics of N-Dodecane under High-Temperature Conditions.

Abstract

n-Dodecane(C₁₂H₂₆) is a typical surrogate fuel for aviation kerosene used in high-performance aero engines. The combustion kinetics of n-dodecane at temperatures above the critical point condition is the focus of attention in the aerospace field. In this paper, the first-principles molecular dynamics method is used to study the high-temperature oxidation of C₁₂H₂₆. Before C-C bond dissociation, C₁₂H₂₆ is oxidized to form oxidized C₁₂ species containing multiple C═O, -OH, -O-, and -COOH groups, while releasing a large amount of energy. In addition, before the C-C bond dissociation of each C₁₂H₂₆, there are four main types of reactions: H-abstraction, H-addition, intramolecular H transfer, and O-addition. The H-abstraction and O-addition reactions have the highest frequencies. O₂ molecules and H, OH, HO₂, and O radicals also play important roles in promoting the oxidation of C₁₂H₂₆. The first investigation of the early oxidation reaction mechanism of C₁₂H₂₆ provides novel insights into the complex oxidation kinetics of long-chain alkanes.