Towards an improved spatial representation of a boundary layer from the attached eddy model
Towards an improved spatial representation of a boundary layer from the attached eddy model
复制标题
DOI：
10.1103/physrevfluids.5.034601
复制
发表时间：
2020-03
期刊：
影响因子：
--
通讯作者：
F. Eich;C. D. de Silva;I. Marusic;C. Kähler
中科院分区：
文献类型：
--
作者：
F. Eich;C. D. de Silva;I. Marusic;C. Kähler
本研究比较了预测的合成流场所附的涡流模型的代表性结构的基础上捕获的实验数据，使用粒子图像测速的湍流边界层。为此，壁平行和横流平面场进行了定性和定量分析，分别通过检查瞬时流动特性和统计两点相关函数。我们的研究结果表明，虽然单点流动统计与实验数据吻合良好，瞬时流场和多点统计之间的比较附加涡模型和实验显示的空间相干性的差异。基于这些观察结果，提出了一个修改的附加涡流模型中的代表性涡流的位置，结合这些流动结构，这已被广泛报道在湍流边界层的曲折。我们的研究结果表明，这种微妙的修改提供了一个优越的上级空间表示的湍流边界层从附加涡模型，减少周期性的影响和高估的空间相干性。展向速度分量的空间表示也有类似的改进。
This study compares the predicted synthetic flow fields generated based on the representative structures of the attached eddy model to experimental data captured using Particle Image Velocimetry of a turbulent boundary layer. To this end, wall-parallel and cross-stream planar fields are analyzed qualitatively and quantitatively by examining instantaneous flow features and by statistical two-point correlation functions, respectively. Our results reveal that although single-point flow statistics are in good agreement with the experimental data, a comparison of instantaneous flow fields and multipoint statistics between the attached eddy model and experiments shows differences in the spatial coherence. Based on these observations, a modification to the placement of the representative eddies in the attached eddy model is proposed that incorporates the meandering of these flow structures, which has been extensively reported in turbulent boundary layers. Our results reveal that this subtle modification provides a superior spatial representation of a turbulent boundary layer from the attached eddy model by reducing periodic effects and the overestimated spatial coherence. Similar improvements are also reported for the spatial representation of the spanwise velocity component.