Wagnon Scott W, Barraza-Botet Cesar L, Wooldridge Margaret S
†Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.
‡Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.
J Phys Chem A. 2015 Jul 16;119(28):7695-703. doi: 10.1021/acs.jpca.5b01029. Epub 2015 Apr 2.
Chemical structure and bond location are well-known to impact combustion reactivity. The current work presents new experimental autoignition and speciation data on the three trans-hexene isomers (1-hexene, trans-2-hexene, and trans-3-hexene), which describe the effects of the location of the carbon-carbon double bond. Experiments were conducted with the University of Michigan rapid compression facility to determine ignition delay times from pressure time histories. Stoichiometric (ϕ = 1.0) mixtures at dilution levels of buffer gas:O2 = 7.5 (mole basis) were investigated at an average pressure of 11 atm and temperatures from 837 to 1086 K. Fast gas sampling and gas chromatography were also used to quantitatively measure 13 stable intermediate species formed during the ignition delay period of each isomer at a temperature of ∼900 K. The measured ignition delay times and species measurements were in good agreement with previous experimental studies at overlapping conditions. The results were modeled using a gasoline surrogate reaction mechanism from Lawrence Livermore National Laboratory, which contains a submechanism for the trans-hexene isomers. The model predictions captured the overall autoignition characteristics of the hexene isomers well (within a factor of 2), as well as the time histories of several of the intermediate species (e.g., propene). However, there were discrepancies between the model predictions and the experimental data for some species, particularly for the 3-hexene isomer.
化学结构和键的位置对燃烧反应性的影响是众所周知的。当前的工作展示了关于三种反式己烯异构体（1-己烯、反式-2-己烯和反式-3-己烯）的新的自燃和物种形成数据，这些数据描述了碳-碳双键位置的影响。实验是在密歇根大学的快速压缩装置上进行的，以根据压力随时间的变化历史来确定点火延迟时间。在平均压力为11个大气压、温度为837至1086K的条件下，研究了缓冲气体与氧气的稀释比为7.5（摩尔比）的化学计量比（ϕ = 1.0）混合物。还使用快速气体采样和气相色谱法定量测量了在约900K温度下每种异构体点火延迟期间形成的13种稳定中间物种。在重叠条件下，测得的点火延迟时间和物种测量结果与先前的实验研究结果吻合良好。使用劳伦斯利弗莫尔国家实验室的汽油替代反应机理对结果进行了建模，该机理包含反式己烯异构体的子机理。模型预测很好地捕捉到了己烯异构体的整体自燃特性（在2倍范围内），以及几种中间物种（如丙烯）随时间的变化情况。然而，模型预测与某些物种的实验数据之间存在差异，特别是对于3-己烯异构体。
