Coherent Lagrangian vortices: the black holes of turbulence
Coherent Lagrangian vortices: the black holes of turbulence
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DOI：
10.1017/jfm.2013.391
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发表时间：
2013-09-01
影响因子：
3.7
通讯作者：
Beron-Vera, F. J.
中科院分区：
文献类型：
--
作者：
Haller, G.;Beron-Vera, F. J.
介绍了二维湍流中相干物质涡的一个简单的变分原理。涡旋边界作为平均拉格朗日应变的闭合定常曲线被寻找。这个问题的解决方案被证明在数学上等同于宇宙学中围绕黑洞的光子球。流体光子球满足显式微分方程组，其最外极限环为最优拉格朗日涡旋边界。作为应用，我们在南大西洋发现了超相干物质旋涡，这产生了对阿古拉斯环的具体拉格朗日输送估计。
We introduce a simple variational principle for coherent material vortices in two-dimensional turbulence. Vortex boundaries are sought as closed stationary curves of the averaged Lagrangian strain. Solutions to this problem turn out to be mathematically equivalent to photon spheres around black holes in cosmology. The fluidic photon spheres satisfy explicit differential equations whose outermost limit cycles are optimal Lagrangian vortex boundaries. As an application, we uncover super-coherent material eddies in the South Atlantic, which yield specific Lagrangian transport estimates for Agulhas rings.