Prediction of flame structure and pollutant formation of Sandia flame D using Large Eddy Simulation with direct integration of chemical kinetics
Prediction of flame structure and pollutant formation of Sandia flame D using Large Eddy Simulation with direct integration of chemical kinetics
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使用大涡模拟与化学动力学直接积分预测桑迪亚火焰 D 的火焰结构和污染物形成
DOI：
10.1016/j.combustflame.2017.08.028
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发表时间：
2018
影响因子：
4.4
通讯作者：
P. Pepiot
中科院分区：
文献类型：
--
作者：
T. Jaravel;E. Riber;B. Cuenot;P. Pepiot
大涡模拟（LES）与直接整合的约化化学动力学，包括NO化学进行桑迪亚火焰D。这种方法可以详细分析火焰结构和污染物的形成。用有向关系图方法和准稳态近似得到了解析约化化学。根据GRI 2.11和GRI 3.0的详细机理，得到了甲烷-空气氧化反应的两个ARC，包含22个物种。他们正确地预测燃料消耗速度，以及在层流预混和非预混火焰在大气条件下的NO和CO浓度。研究发现，NO的产生强烈地依赖于详细的机制，与GRI 3.0在丰富的预混火焰和扩散火焰中显着较高。然后，这两个ARC用于Sandia flame D的高分辨率LES。数值计算结果与实验结果在气动力、混合比和温度分布方面符合得很好。CO浓度也很好地预测与两个ARC。对于NO，使用基于GRI 2.11的ARC获得了与测量值的令人满意的一致性，而使用基于GRI 3.0的ARC获得了显著的过度预测，与两个GRI版本之间在层流情况下观察到的差异一致。包括与参考层流火焰的比较的火焰结构的详细调查表明，火焰结构基本上是非预混的。先导射流的存在改变了混合过程，导致火焰结构落在两个极端的非预混燃烧状态之间，对应于富中心射流与来自先导的热气体或新鲜空气的同向流的相互作用。相关的层流扩散火焰表明，这种特殊的火焰结构影响污染物的形成，具有强烈的影响CO的生产。
Large Eddy Simulation (LES) with direct integration of reduced chemical kinetics including NO chemistry is performed on the Sandia flame D. This approach allows a detailed analysis of the flame structure and pollutant formation. The Analytically Reduced Chemistries (ARCs) are obtained using Directed Relation Graph method with Error Propagation (DRGEP) and Quasi-Steady-State (QSS) approximation. Two ARCs containing both 22 species are derived for methane–air oxidation, from GRI 2.11 and GRI 3.0 detailed mechanisms. They correctly predict fuel consumption speed, as well as NO and CO concentrations in laminar premixed and non-premixed flames at atmospheric conditions. It is found that the NO production strongly depends on the detailed mechanism, being significantly higher with GRI 3.0 in rich premixed flames and in diffusion flames. The two ARCs are then used in highly-resolved LES of the Sandia flame D. The numerical results are in very good agreement with the experiment in terms of aerodynamics, mixture fraction and temperature profiles. The CO concentration is also well predicted with the two ARCs. For NO, a satisfactory agreement with the measurements is obtained with the ARC based on GRI 2.11, while a significant over-prediction is obtained with the GRI 3.0-based ARC, consistently with the differences observed in laminar cases between the two GRI versions. A detailed investigation of the flame structure including a comparison with reference laminar flames reveals that the flame structure is essentially non-premixed. The presence of the pilot jet alters the mixing process, leading to a flame structure that falls between two extreme non-premixed combustion regimes corresponding to the interaction of the rich central jet with either the hot gases from the pilot, or the coflow of fresh air. The associated laminar diffusion flamelets indicate that this particular flame structure influences the formation of pollutants, with a strong impact on CO production.
影响因子：
4.4
作者：
Bulat, G.;Jones, W. P.;Marquis, A. J.
通讯作者：
Marquis, A. J.