Detailed and Compact Combustion Kinetic Models for Iso-dodecane and Gevo Alcohol-to-Jet (ATJ) Alternative Fuel

摘要

Over a broad range of conditions and experimental configurations, recent experimental work has shown quantitative similarities between the pre-vaporized combustion behaviors of iso-dodecane (iC12: 2, 2, 4, 6, 6-pentamethylheptane), iso-octane (iC8: 2,2,4-trimethylpentane), iso-cetane (iC16: 2, 2, 4, 4, 6, 8, 8-heptamethylnonane), and a 50/50 (molar) iC8/iC16 mixture. Such similarity-typically within experimental uncertainties - suggests that these fuels share a significant subset of combustion chemistry related to fuel destruction into nearly equal fluxes of iso-C4 fragments. This proposition is used to develop a compact (43 species) kinetic model to describe iC12 combustion by using detailed chemistry models for iC16 and iC8, since at present, no detailed iC12 oxidation model appears in the literature. Though not tuned to match experimental measurements, present iC12 compact model simulations compare favorably to recent experimental ignition delay time and extinction strain rate measurements for iC12, as well as laminar burning velocity measurements for iC8 and iC16. Favorable performance of the benchmark iC8/iC16 mixture kinetic model against iC12 experimental measurements suggests that, lacking a suitable iC12 kinetic model, pre-vaporized combustion modeling efforts employing detailed or reduced kinetic models may substitute a 50/50 blend of iC8/iC16 for iC12. This has implications for modeling involving Gevo alcohol-to-jet (ATJ) fuel, for which iC12 serves as a simple single-component surrogate.