EVOLUTION OF VORTEX STATISTICS IN 2-DIMENSIONAL TURBULENCE
EVOLUTION OF VORTEX STATISTICS IN 2-DIMENSIONAL TURBULENCE
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DOI：
10.1103/physrevlett.66.2735
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发表时间：
1991-05-27
影响因子：
8.6
通讯作者：
YOUNG, WR
中科院分区：
文献类型：
--
作者：
CARNEVALE, GF;MCWILLIAMS, JC;YOUNG, WR
自由发展的二维湍流由相干涡主导。 这些涡旋的密度随时间衰减，rho约为t-xi，其中xi几乎等于0.75。 提出了一种新的标度理论，它表示的所有统计性质的xi。 因此，涡旋的平均环量以t-xi/2的形式增加，其平均半径以t-xi/4的形式增加。 总能量不变，涡度拟能随t-xi/2减小，涡度峰度随t-xi/2增大。 这些结果都支持流体方程的数值模拟和修改后的点涡模型的解决方案。
Freely evolving two-dimensional turbulence is dominated by coherent vortices. The density of these vortices decays in time as rho approximately t-xi with xi almost-equal-to 0.75. A new scaling theory is proposed which expresses all statistical properties in terms of xi. Thus the average circulation of the vortices increases as t-xi/2 and their average radius as t-xi/4. The total energy is constant, the enstrophy decreases as t-xi/2, and the vorticity kurtosis increases as t-xi/2. These results are supported both by numerical simulations of the fluid equations and by solutions of a modified point-vortex model.