论文标题
对使用最佳有限元投影的统一了解尺度解析模拟和近壁建模
A unified understanding of scale-resolving simulations and near-wall modeling of turbulent flows using optimal finite element projections
论文作者
论文摘要
这项工作的主要目的是开发一个统一的框架，该框架可以用作镜头，以定量评估和增强广泛的湍流模型，即。大型涡流模拟（LES），混合雷诺平均/LES方法和壁模型（WM）LES。以湍流通道流为例，通过在适用于这些方法的不同分辨率下的投影中评估了壁分辨率限制，混合架/LES限制和WMLES限制的最佳性。这些最佳的先验估计值与文献中报道的现有后验解决方案具有相似的特征。使用最佳解决方案作为参考，开发了一致的精度指标，用于解决比例解决方法，并进行评估。我们进一步以近壁底层下分辨率的角度来表征WMLES中的滑动速度，并发展了普遍的缩放关系。 A-Priori测试的见解用于增强现有的基于滑动墙模型。各种后验测试揭示了与动态滑动壁模型相比的出色性能。提供了改进的滑动壁模型的指导，包括动态过程的目标。
The main objective of this work is to develop a unified framework that can be used as a lens to quantitatively assess and augment a wide range of coarse-grained models of turbulence, viz. large eddy simulations (LES), hybrid Reynolds-averaged/LES methods and wall-modeled (WM)LES. Taking a turbulent channel flow as an example, optimality is assessed in the wall-resolved limit, the hybrid RANS/LES limit and the WMLES limit, via projections at different resolutions suitable for these approaches. These optimal a priori estimates are shown to have similar characteristics to existing a posteriori solutions reported in the literature. Consistent accuracy metrics are developed for scale-resolving methods using the optimal solution as a reference, and evaluations are performed. We further characterize the slip velocity in WMLES in terms of the near-wall under-resolution and develop a universal scaling relationship. Insights from the a-priori tests are used to augment existing slip-based wall models. Various a posteriori tests reveal superior performance over the dynamic slip wall model. Guidance for the development of improved slip-wall models is provided, including a target for the dynamic procedure.
