Abstract The fidelity of Large Eddy Simulations (LES) depends strongly on the closures of the sub-grid scale (SGS) stress tensor. Although it is well known that the SGS stresses in LES are not aligned with the strain rate tensor, the most widely used models are still of eddy viscosity type, due to their robust behavior in LES and reasonable performance in a posteriori testing. The unstable behavior of more advanced anisotropic models, that is typically found in LES, has been attributed to either the fact that these models provide backscatter or to the fact that they do not provide a sufficient amount of dissipation. Based on recent advances in the field, an alternative modeling strategy is suggested, which can be used to regularize an arbitrary anisotropic (e.g. scale similarity type) model. The resulting model is easy to implement, can be written in compact form and is free of model parameters. The model has been tested a-posteriori and results are presented for a Taylor-Green-Vortex, a free plane jet and a turbulent channel flow of friction Reynolds numbers 395, 590 and 934. The results are compared to well-known eddy viscosity models and when applicable, to simulations without explicit LES model. The new model exhibits good performance for a variety of mesh resolutions and for all configurations. Furthermore, a-priori analysis results in the context of liquid atomization indicate that the model might be suitable as well in more complex physical scenarios. The a-priori analysis performance of the model is found to be nearly equivalent to the underlying structural anisotropic model in terms of its correlation coefficient, but the model is free of backscatter and provides good stability in LES.

中文翻译：

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用于大涡模拟的正则化、参数自由尺度相似类型模型

摘要 大涡模拟 (LES) 的保真度在很大程度上取决于亚网格尺度 (SGS) 应力张量的闭合。虽然众所周知，LES 中的 SGS 应力与应变率张量不一致，但最广泛使用的模型仍然是涡粘性类型，因为它们在 LES 中的稳健行为和后验测试中的合理性能。更先进的各向异性模型的不稳定行为（通常在 LES 中发现）归因于这些模型提供反向散射的事实或它们不提供足够的耗散量的事实。基于该领域的最新进展，提出了一种替代建模策略，该策略可用于规范任意各向异性（例如尺度相似性类型）模型。由此产生的模型很容易实现，可以写成紧凑的形式并且没有模型参数。该模型已经过后验测试，结果显示为 Taylor-Green-Vortex、自由平面射流和摩擦雷诺数为 395、590 和 934 的湍流通道流。将结果与众所周知的涡粘性模型进行比较适用时，用于没有显式 LES 模型的模拟。新模型在各种网格分辨率和所有配置下都表现出良好的性能。此外，液体雾化背景下的先验分析结果表明该模型可能也适用于更复杂的物理场景。发现模型的先验分析性能在其相关系数方面几乎等同于基础结构各向异性模型，