Measurement and Numerical Simulation on the Ignition Delay Times of Nonane (C₉H₂₀) Isomers

Abstract

In this study, ignition delay times (IDTs) of C₉H₂₀ (Nonane) isomers were investigated with a newly developed shock tube facility and numerical simulation with KUCRS. It was found that ignition delay time (IDT) of 2,2,4,4-tetramethylpentane (2244mC₅) is considerably longer than n-nonane (n-C₉) especially in the negative temperature coefficient (NTC) region. The maximum difference is about one order of magnitude at 1000/T = 1.3 for 1.0 MPa and Φ = 1.0, where IDT of n-C9 is 3.6 ms while 29.9 ms for 2244mC₅. Despite the significant difference in IDT, 0-D simulation with the reaction model generated by KUCRS could successfully reproduce the experimental results. According to the reaction path analysis and sensitivity analysis, it was considered that 2244mC₅ tends to form cyclic ether due to its highly branched structure, which inhibits the increase of OH, and thus, chain branching reactions.