On Lagrangian single-particle statistics
On Lagrangian single-particle statistics
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DOI：
10.1063/1.4711397
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发表时间：
2012-05
影响因子：
4.6
通讯作者：
G. Falkovich;Haitao Xu;A. Pumir;E. Bodenschatz;Luca Biferale;G. Boffetta;A. Lanotte;F. Toschi
中科院分区：
文献类型：
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作者：
G. Falkovich;Haitao Xu;A. Pumir;E. Bodenschatz;Luca Biferale;G. Boffetta;A. Lanotte;F. Toschi
在湍流中，能量级联和能量通量的思想，由精确的Kolmogorov关系证实，导致速度空间相关函数的标度规律的确定。在这里，我们问是否类似的想法可以应用于时间相关性。我们批判性地回顾了在统计均匀、平稳和各向同性湍流惯性范围内单个流体粒子的速度统计的相关理论和实验结果。我们强调，对于第二个结构函数，D2(t)≡[v(t)−v(0)] 2 '∝et,r，广泛使用的关系仅依赖于维度参数：D2(t)与能量级联的关系是未知的，无论是在二维湍流中还是在三维湍流中。最新的实验和数值结果表明，在高雷诺数下，导数dD 2(t) dt具有从t≈2τ η开始的有限非零斜率。分析∞
In turbulence, ideas of energy cascade and energy flux, substantiated by the exact Kolmogorov relation, lead to the determination of scaling laws for the velocity spatial correlation function. Here we ask whether similar ideas can be applied to temporal correlations. We critically review the relevant theoretical and experimental results concerning the velocity statistics of a single fluid particle in the inertial range of statistically homogeneous, stationary and isotropic turbulence. We stress that the widely used relations for the second structure function, D2(t) ≡� [v(t) − v(0)] 2 �∝ et ,r elies on dimensional arguments only: no relation of D2(t) to the energy cascade is known, neither in two- nor in three-dimensional turbulence. State of the art experimental and numerical results demonstrate that at high Reynolds numbers, the derivative dD 2(t) dt has a finite non-zero slope starting from t ≈ 2τ η. The analysis ∞