This study presents an algebraic combustion closure for Large eddy simulation (LES) exhibiting attributes of simplicity and simultaneous accuracy under realistic combustion conditions. The model makes use of the interlink between the reaction and dissipation rates in premixed turbulent combustion but relaxes the thin flame assumption by considering finite-rate chemistry effects in the small-scale turbulence structure. The core idea of the approach is to approximate the reaction progress in the unresolved spectrum of wave lengths and to use it within a filtered reaction rate expression. The model is implemented in OpenFOAM 4.0 and is tested on a turbulent, premixed flame behind a bluff-body, applying an LES approach for turbulence modelling. The cross comparison of velocity, temperature and composition data with experiments and a well-investigated combustion model in literature reveals competitive performance of the new model. Especially in the near-field of the bluff body flame, corresponding to thin and moderately thickened flame regions, its ability to capture the flame structure is highly promising. The chosen, partly explicit approach to recover the temperature from the transported sensible enthalpy, involving a strong coupling between filtered reaction and heat release rate, also shows advantages over obtaining the temperature from presumed probability density functions.

本研究提出了一种用于大涡模拟 (LES) 的代数燃烧闭包，在现实燃烧条件下表现出简单性和同时准确性的属性。该模型利用了预混湍流燃烧中反应速率和耗散速率之间的相互联系，但通过考虑小尺度湍流结构中的有限速率化学效应放宽了稀薄火焰假设。该方法的核心思想是在未分辨的波长光谱中近似反应进程，并在过滤的反应速率表达式中使用它。该模型在 OpenFOAM 4.0 中实现，并在钝体后面的湍流预混合火焰上进行测试，应用 LES 方法进行湍流建模。速度的交叉比较，温度和成分数据以及实验和文献中经过充分研究的燃烧模型揭示了新模型的竞争性能。尤其是在钝体火焰的近场，对应较薄和适度增厚的火焰区域，其捕捉火焰结构的能力非常有前景。选择的、部分明确的方法从传输的显焓中恢复温度，涉及过滤反应和放热速率之间的强耦合，也显示出优于从假定的概率密度函数获得温度的优势。它捕获火焰结构的能力非常有希望。选择的、部分明确的方法从传输的显焓中恢复温度，涉及过滤反应和放热速率之间的强耦合，也显示出优于从假定的概率密度函数获得温度的优势。它捕获火焰结构的能力非常有希望。选择的、部分明确的方法从传输的显焓中恢复温度，涉及过滤反应和放热速率之间的强耦合，也显示出优于从假定的概率密度函数获得温度的优势。