A dimensional-decomposition approach, decomposing 3D into 3×1D for turbulent (reacting) flows are motivated, discussed and investigated. In the three-dimensional Linear Eddy Model (LEM3D), three orthogonally intersecting arrays of 1D domains are coupled to capture the 3D characteristics of fluid flows. The currently used recouplings for LEM3D are enlightened and thoroughly discussed. A study of the flame front of a freely propagating laminar premixed flame shows that the flame stabilizes at the upstream face of the initial solution when both the advective and auxiliary recouplings are activated. Furthermore, results from LEM3D simulations of a vitiated co-flow burner are re-visited providing a more detailed discussion of the noted early mixing and reaction of the hydrogen fuel of the burner. The main conclusion of the present work is that the auxiliary coupling based on rotations of the 3D control volumes introduces very large gradients in the near-field geometry of jets, leading to a significant amount of artificial diffusion and locally increased burning rates. This implies that applications of LEM3D should be restricted to sub-regions where high-resolution treatment of scalar mixing and reaction is of particular interest.

中文翻译：

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湍流反应流的维数分解

激发、讨论和研究了一种将 3D 分解为 3×1D 以用于湍流（反应）流的维度分解方法。在三维线性涡流模型 (LEM3D) 中，三个正交相交的一维域阵列耦合以捕获流体流动的 3D 特性。目前用于 LEM3D 的重新耦合得到启发和深入讨论。对自由传播的层流预混火焰的火焰前沿的研究表明，当对流和辅助再耦合都被激活时，火焰稳定在初始溶液的上游面。此外，重新访问了损坏的共流燃烧器的 LEM3D 模拟结果，提供了对燃烧器氢燃料的上述早期混合和反应的更详细讨论。目前工作的主要结论是，基于 3D 控制体积旋转的辅助耦合在射流的近场几何形状中引入了非常大的梯度，导致大量的人工扩散和局部增加的燃烧率。这意味着 LEM3D 的应用应仅限于对标量混合和反应的高分辨率处理特别感兴趣的子区域。