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.

在这项工作中，我们将对传统的部分搅拌堆（PaSR）燃烧模型与两个分别称为准层流有限速率（QLFR）模型和层流有限速率（LFR）模型的隐式燃烧模型进行详细的比较。采用大型涡流模拟（LES），并选择Adelaide Jet in Hot Co-flow（AJHC）燃烧器作为验证案例。在隐式燃烧模型中，滤波后的源项直接来自化学项，不包括湍流效应。结果表明，对于温度和物种质量分数的均值和均方根，这两个隐式模型的行为与常规PaSR模型相似，并且所有模型都提供了非常令人满意的预测，尤其是对于平均值。这证明在低Damköhler数（Da≤1.0）系统中使用隐式燃烧模型是合理的。与LFR模型相比，QLFR模型可以减少大约三倍的计算成本。此外，两个4步全局机理与KEE58机理之间的比较证明了有限速率化学在MILD燃烧中的重要性。