Shock Tube Measurements and Kinetic Study of Methyl Acetate Ignition

Using a shock tube facility, ignition delay times of methyl acetate (MA) were measured covering the temperature range of 1120–1760 K, equivalence ratio range of 0.5–2.0, pressure range of 1.2–10 atm, and fuel mole fraction range of 0.5–2.0%. An Arrhenius correlation for all of the measured data was obtained through multiple linear regression. The correlation was further compared to the literature correlation [Akih-Kumgeh, B.; Bergthorson, J. M. Combust. Flame 2011, 158 (6), 1037−1048.], and discrepancy was found between the two studies. Four existing chemical kinetic models were used to simulate the measurements, and results suggested that the Princeton model and the Yang model gave better predictions on current ignition data compared to the Westbrook model and the Akih-Kumgeh model. By updating the base model of the Princeton model, a combined model was obtained, and it gave the best prediction on current experimental data among all available models. Sensitivity analysis and reaction pathway analysis were conducted on the basis of the models that give reasonable predictions, i.e., the Princeton model, the combined model, and the Yang model, to gain a further insight into the ignition process of MA and make a comprehensive comparison on different kinetic models.本研究采用激波管装置，对乙酸甲酯（methyl acetate, MA）的点火延迟时间进行了测量，实验覆盖的参数范围如下：温度区间1120~1760 K，当量比区间0.5~2.0，压力区间1.2~10 标准大气压（atm），燃料摩尔分数区间0.5%~2.0%。通过多元线性回归方法，得到了适配所有实测数据的阿伦尼乌斯关联式（Arrhenius correlation）。将该关联式与已有文献中的关联式[Akih-Kumgeh, B.; Bergthorson, J. M. 《燃烧与火焰》2011年，第158卷第6期，第1037−1048页]进行对比后，发现两项研究之间存在明显差异。选取4种现有的化学动力学模型对本次实测数据开展模拟，结果表明：相较于韦斯特布鲁克模型（Westbrook model）与阿基-库姆盖模型（Akih-Kumgeh model），普林斯顿模型（Princeton model）和杨模型（Yang model）对本次点火延迟数据的预测效果更优。通过对普林斯顿模型的基础框架进行更新，得到了一种组合模型，该模型在所有现有可用模型中对本次实验数据的预测效果最佳。针对预测表现良好的普林斯顿模型、组合模型与杨模型开展敏感性分析与反应路径分析，以进一步揭示乙酸甲酯的点火过程机理，并对不同动力学模型进行全面对比。