Enhanced stretching of material lines by antiparallel vortex pairs in turbulence
Enhanced stretching of material lines by antiparallel vortex pairs in turbulence
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DOI：
10.1016/j.fluiddyn.2003.05.002
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发表时间：
2002-12
影响因子：
1.5
通讯作者：
S. Goto;S. Kida
中科院分区：
文献类型：
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作者：
S. Goto;S. Kida
对不可压缩粘性流体均匀各向同性湍流中物质线的变形进行了数值研究，以了解湍流中物质线拉伸增强的物理机制。它是定性的仔细可视化的数值数据和定量的详细的数值分析表明，管状涡相干结构在小尺度的湍流发挥至关重要的作用，在这种密集的拉伸材料线。特别是，管状涡流往往以反平行的方式彼此对齐，并且一对反平行涡流在它们之间的双曲线停滞点周围的两个区域中强烈拉伸材料线。
Deformations of material lines in homogeneous isotropic turbulence of an incompressible viscous fluid are numerically investigated to understand the physical mechanism of the enhanced stretching of material lines in turbulence. It is shown qualitatively by careful visualizations of numerical data and quantitatively by detailed numerical analysis that tubular vortical coherent structures in small scales of turbulence play crucial roles in such intensive stretching of material lines. In particular, the tubular vortices tend to align to each other in an antiparallel manner, and a pair of antiparallel vortices strongly stretch material lines in two regions around the hyperbolic stagnation points between them.