Chemical explosive mode analysis for a turbulent lifted ethylene jet flame in highly-heated coflow
Chemical explosive mode analysis for a turbulent lifted ethylene jet flame in highly-heated coflow
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DOI：
10.1016/j.combustflame.2011.05.023
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发表时间：
2012
影响因子：
4.4
通讯作者：
Zhaoyu Luo;C. Yoo;E. Richardson;Jacqueline H. Chen;C. Law;T. Lu
中科院分区：
文献类型：
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作者：
Zhaoyu Luo;C. Yoo;E. Richardson;Jacqueline H. Chen;C. Law;T. Lu
将最近发展起来的化学爆炸模式（CEM）分析方法（CEMA）推广应用于通过三维直接数值模拟（DNS）获得的湍流提升乙烯射流火焰的详细结构和稳定机制。结果表明，CEM是一个关键的功能，在点火以及消光现象，并因此的存在下，CEM可以被利用一般作为一个标志物的爆炸性，或预点火，混合物。CEMA首先在包括自燃和完全搅拌反应器的0-D反应器（分别是典型的均相点火和熄灭应用）和乙烯-空气的1-D预混层流火焰中进行了演示。然后，它被用来分析从3-D DNS数据中提取的2-D展向切片。火焰结构清晰可视化CEMA，而它是更难以辨别从传统的计算诊断方法，使用单个物种的浓度或温度。自燃被确定为目前的湍流提升乙烯射流火焰的主要稳定机制，并在不同的火焰区的局部CEM的主要化学物种和反应的贡献进行了量化。在详细的南加州大学（USC）机理的基础上，发展了乙烯-空气体系的22组分高精度简化机理。
The recently developed method of chemical explosive mode (CEM) analysis (CEMA) was extended and employed to identify the detailed structure and stabilization mechanism of a turbulent lifted ethylene jet flame in heated coflowing air, obtained by a 3-D direct numerical simulation (DNS). It is shown that CEM is a critical feature in ignition as well as extinction phenomena, and as such the presence of a CEM can be utilized in general as a marker of explosive, or pre-ignition, mixtures. CEMA was first demonstrated in 0-D reactors including auto-ignition and perfectly stirred reactors, which are typical homogeneous ignition and extinction applications, respectively, and in 1-D premixed laminar flames of ethylene–air. It is then employed to analyze a 2-D spanwise slice extracted from the 3-D DNS data. The flame structure was clearly visualized with CEMA, while it is more difficult to discern from conventional computational diagnostic methods using individual species concentrations or temperature. Auto-ignition is identified as the dominant stabilization mechanism for the present turbulent lifted ethylene jet flame, and the contribution of dominant chemical species and reactions to the local CEM in different flame zones is quantified. A 22-species reduced mechanism with high accuracy for ethylene–air was developed from the detailed University of Southern California (USC) mechanism for the present simulation and analysis.