Extended localized structures and the onset of turbulence in channel flow
Extended localized structures and the onset of turbulence in channel flow
复制标题
扩展的局部结构和通道流中湍流的开始
DOI：
10.1103/physrevfluids.3.011902
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发表时间：
2018-01-31
影响因子：
2.7
通讯作者：
Xiong, X. M.
中科院分区：
文献类型：
--
作者：
Tao, J. J.;Eckhardt, Bruno;Xiong, X. M.
本文用数值计算的方法表明，在平面Poiffille流中，在定向渗流普适类所定义的平衡湍流阈值之前，局部湍流带形式的稀疏湍流状态，在流动区域足够大时，或者通过有限域中能带相互作用引起的能带扩展与能带断裂和衰减之间的动态平衡。带的宽度和倾斜角在其斜向扩展过程中保持统计不变，这是一个对随机干扰不敏感的过程。
In this letter, it is shown numerically that in plane Poiseuille flow and before the threshold of equilibrium turbulence defined by the directed-percolation universality class, a sparse turbulent state in form of localized turbulent band can sustain either by continuous increase of the turbulence fraction due to band extension when the flow domain is large enough, or by a dynamic balance between the band extension and the band breaking and decay caused by the band interaction in a finite domain. The width and tilt angle of the band keep statistically invariant during its oblique extension, a process which is not sensitive to random disturbances.