Collective organization and screening in two-dimensional turbulence
Collective organization and screening in two-dimensional turbulence
复制标题
二维湍流中的集体组织和筛选
DOI：
10.1103/physrevfluids.6.084601
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发表时间：
2021
影响因子：
2.7
通讯作者：
J. Jim'enez
中科院分区：
文献类型：
--
作者：
J. Jim'enez
最近的证据表明，衰减的二维湍流中的涡旋可以分为小型移动涡旋和大型准静止涡旋，本文研究了后者可能被视为“晶体”的证据，其形成体现了能量向更大尺度的逆级联。一些有序的诊断被应用于表面上无序的大漩涡。结果表明，它们的几何排列比随机排列更加规则，它们的移动速度比简单平均场参数的预期要慢，并且它们的能量明显低于相同涡旋的随机重组。这可以追溯到通过相反符号的涡流的优先关联来屏蔽长程相互作用，并且有人认为这是由于互转涡流的相互捕获，其机制更接近潮汐破坏而不是静电屏蔽。最后，简要研究了这些“随机晶体”与湍流动力系统表示的固定点之间的可能关系。
Following recent evidence that the vortices in decaying two-dimensional turbulence can be classified into small–mobile, and large–quasi-stationary, this paper examines the evidence that the latter might be considered a ‘crystal’ whose formation embodies the inverse cascade of energy towards larger scales. Several diagnostics of order are applied to the ostensibly disordered large vortices. It is shown that their geometric arrangement is substantially more regular than random, that they move more slowly than could be expected from simple meanfield arguments, and that their energy is significantly lower than in a random reorganisation of the same vortices. This is traced to screening of long-range interactions by the preferential association of vortices of opposite sign, and it is argued that this is due to the mutual capture of corrotating vortices, in a mechanism closer to tidal disruption than to electrostatic screening. Finally, the possible relation of these ‘stochastic crystals’ to fixed points of the dynamical system representation of the turbulence flow is briefly examined.