论文标题
跨度对经过圆柱体的流动性质的影响
Span effect on the turbulence nature of flow past a circular cylinder
论文作者
论文摘要
在二维（2D）和三维（3D）流中，湍流的演化和能量级联反应显着差异。研究已经调查了无障碍湍流的这些差异，但是固体边界对3D至2D湍流动力学之间的跨界有重要影响。在这项工作中，我们调查了在RE = 10000处经过圆柱体的湍流的跨度影响。发现即使对于高度各向异性的几何形状，3D小规模的结构也从墙壁上分离出来。此外，如果跨度为直径的50％或更少，则kármán涡流的天然大规模旋转迅速将这些结构旋转。我们表明，这与跨度短于模式B不稳定性波长的短相关。相互冲突的3D小规模结构和2DKármán涡流导致2D和3D湍流动力学，可以根据域几何各向异性在尾流的某些位置共存。
Turbulent flow evolution and energy cascades are significantly different in two-dimensional (2D) and three-dimensional (3D) flows. Studies have investigated these differences in obstacle-free turbulent flows, but solid boundaries have an important impact on the cross-over between 3D to 2D turbulence dynamics. In this work, we investigate the span effect on the turbulence nature of flow past a circular cylinder at Re=10000. It is found that even for highly anisotropic geometries, 3D small-scale structures detach from the walls. Additionally, the natural large-scale rotation of the Kármán vortices rapidly two-dimensionalises those structures if the span is 50% of the diameter or less. We show this is linked to the span being shorter than the Mode B instability wavelength. The conflicting 3D small-scale structures and 2D Kármán vortices result in 2D and 3D turbulence dynamics which can coexist at certain locations of the wake depending on the domain geometric anisotropy.
