Large Eddy Simulation of MILD combustion using finite rate chemistry: Effect of combustion sub-grid closure
Large Eddy Simulation of MILD combustion using finite rate chemistry: Effect of combustion sub-grid closure
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DOI：
10.1016/j.proci.2018.09.033
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发表时间：
2019
影响因子：
3.4
通讯作者：
Zhiyi Li;A. Cuoci;A. Parente
中科院分区：
文献类型：
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作者：
Zhiyi Li;A. Cuoci;A. Parente
在这项工作中，我们提出了一个详细的比较传统的部分搅拌反应器（PaSR）燃烧模型和两个隐式燃烧模型，命名为准层流有限速率（QLFR）模型和层流有限速率（LFR）模型，分别。本文采用大涡模拟方法，以阿德莱德射流热协流（AJHC）燃烧器为算例进行了数值模拟。在隐式燃烧模型中，过滤的源项直接来自化学项，而不包括湍流效应。结果表明，这两个隐式模型的行为类似于传统的PaSR模型，平均值和均方根的温度和物种的质量分数，所有的模型提供了非常令人满意的预测，特别是平均值。这证明了在低Damköhler数（Da ≤ 1.0）系统中使用隐式燃烧模型的合理性。与LFR模型相比，QLFR模型允许减少约三倍的计算成本。通过与KEE58机制的比较，进一步证明了有限速率化学在MILD燃烧中的重要性。
In this work, we present a detailed comparison between the conventional Partially Stirred Reactor (PaSR) combustion model and two implicit combustion models, named Quasi Laminar Finite Rate (QLFR) model and Laminar Finite Rate (LFR) model, respectively. Large Eddy Simulation (LES) is employed and the Adelaide Jet in Hot Co-flow (AJHC) burner is chosen as validation case. In the implicit combustion models, the filtered source term comes directly from the chemical term, without inclusion of turbulence effects. Results demonstrate that the two implicit models behave similarly to the conventional PaSR model, for the mean and root-mean-square of the temperature and species mass fractions, and that all models provide very satisfactory predictions, especially for the mean values. This justifies the use of implicit combustion models in low Damköhler number (Da ≤ 1.0) systems. The QLFR model allows to reduce the computational cost of about three times, compared to the LFR model. Moreover, the comparison between two 4-step global mechanisms and the KEE58 mechanism proves the importance of finite rate chemistry in MILD combustion.