Large Eddy Simulations of the Sydney mixed-mode flame with inhomogeneous inlet (FJ200-5GP-Lr75-57) are performed using the Eulerian Stochastic Fields (ESF) transported probability functions method to account for the sub-grid scale turbulence–chemistry interaction, to demonstrate the suitability of the ESF method for mixed-mode combustion. An analytically reduced 19-species methane mechanism is used for the description of the chemical reactions. Prior to the reactive case, simulation results of the non-reactive setup with cold and hot pilot stream are presented, which show differences in the jet breakup and radial species mass fluxes. The reactive case simulations are compared to experimental data and a recently conducted model free quasi-DNS (qDNS), showing very good agreement with the qDNS in terms of scatter data and radial mean values of temperature and species distribution, as well as mixture fraction conditional statistics. Further analysis is dedicated to sub-grid scale statistics, showing that mixture fraction and reaction progress variable are strongly correlated in this flame. The impact of the number of stochastic fields on the filtered temperature and species distribution is investigated; it reveals that the ESF method in conjunction with finite-rate chemistry is very insensitive to the number of employed fields to obtain highly accurate simulation results.

中文翻译：

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欧拉随机场法应用于非均匀入口引燃火焰大涡模拟

使用欧拉随机场 (ESF) 传输概率函数方法对具有非均匀入口的悉尼混合模式火焰 (FJ200-5GP-Lr75-57) 进行大涡模拟，以解释亚网格尺度湍流-化学相互作用，以证明 ESF 方法适用于混合模式燃烧。分析还原的 19 种甲烷机制用于描述化学反应。在反应性案例之前，呈现了具有冷和热先导流的非反应性设置的模拟结果，显示了射流破裂和径向物质质量通量的差异。将反应案例模拟与实验数据和最近进行的无模型准 DNS (qDNS) 进行比较，在散射数据和温度和物种分布的径向平均值以及混合分数条件统计方面，与 qDNS 显示出非常好的一致性。进一步的分析致力于亚网格尺度的统计，表明混合分数和反应进程变量在该火焰中密切相关。研究了随机场数对过滤温度和物种分布的影响；它表明 ESF 方法与有限速率化学相结合，对所用场的数量非常不敏感，以获得高精度的模拟结果。表明混合分数和反应进程变量在该火焰中密切相关。研究了随机场数对过滤温度和物种分布的影响；它表明 ESF 方法与有限速率化学相结合，对所用场的数量非常不敏感，以获得高精度的模拟结果。表明混合分数和反应进程变量在该火焰中密切相关。研究了随机场数对过滤温度和物种分布的影响；它表明 ESF 方法与有限速率化学相结合，对所用场的数量非常不敏感，以获得高精度的模拟结果。