Mohamed Samah Y, Cai Liming, Khaled Fethi, Banyon Colin, Wang Zhandong, Al Rashidi Mariam J, Pitsch Heinz, Curran Henry J, Farooq Aamir, Sarathy S Mani
Clean Combustion Research Center, King Abdullah University of Science and Technology , Thuwal, 23955-6900, Saudi Arabia.
Institute for Combustion Technology, RWTH Aachen University , 52062 Aachen, Germany.
J Phys Chem A. 2016 Apr 14;120(14):2201-17. doi: 10.1021/acs.jpca.6b00907. Epub 2016 Mar 31.
Accurate chemical kinetic combustion models of lightly branched alkanes (e.g., 2-methylalkanes) are important to investigate the combustion behavior of real fuels. Improving the fidelity of existing kinetic models is a necessity, as new experiments and advanced theories show inaccuracies in certain portions of the models. This study focuses on updating thermodynamic data and the kinetic reaction mechanism for a gasoline surrogate component, 2-methylhexane, based on recently published thermodynamic group values and rate rules derived from quantum calculations and experiments. Alternative pathways for the isomerization of peroxy-alkylhydroperoxide (OOQOOH) radicals are also investigated. The effects of these updates are compared against new high-pressure shock tube and rapid compression machine ignition delay measurements. It is shown that rate constant modifications are required to improve agreement between kinetic modeling simulations and experimental data. We further demonstrate the ability to optimize the kinetic model using both manual and automated techniques for rate parameter tunings to improve agreement with the measured ignition delay time data. Finally, additional low temperature chain branching reaction pathways are shown to improve the model's performance. The present approach to model development provides better performance across extended operating conditions while also strengthening the fundamental basis of the model.
精确的轻度支链烷烃（如2-甲基烷烃）化学动力学燃烧模型对于研究实际燃料的燃烧行为至关重要。由于新的实验和先进理论表明现有动力学模型的某些部分存在不准确之处，因此提高现有动力学模型的保真度是必要的。本研究基于最近发表的热力学基团值以及从量子计算和实验得出的速率规则，着重更新汽油替代组分2-甲基己烷的热力学数据和动力学反应机理。还研究了过氧烷基氢过氧化物（OOQOOH）自由基异构化的替代途径。将这些更新的影响与新的高压激波管和快速压缩机点火延迟测量结果进行了比较。结果表明，需要修改速率常数以提高动力学建模模拟与实验数据之间的一致性。我们进一步展示了使用手动和自动技术进行速率参数调整以优化动力学模型的能力，从而提高与测量的点火延迟时间数据的一致性。最后，额外的低温链分支反应途径被证明可以改善模型的性能。目前的模型开发方法在扩展的运行条件下提供了更好的性能，同时也加强了模型的基础。
