Persistent small scale anisotropy in homogeneous shear flows.
Persistent small scale anisotropy in homogeneous shear flows.
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DOI：
10.1103/physrevlett.75.3114
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发表时间：
1995-10
影响因子：
8.6
通讯作者：
Alain Pumir;B. Shraiman
中科院分区：
文献类型：
--
作者：
Alain Pumir;B. Shraiman
在雷诺数Re≤ 11300范围内，对均匀剪切流（平均速度U→= Syx ^）中的湍流速度脉动进行了数值研究。在这个范围内，涡量的z分量的偏度与雷诺数无关，这表明在非常高的雷诺数下仍存在一些小尺度的各向异性。在两点相关函数中看不到这种各向异性。一个类比得出与早期的结果与平均梯度的被动标量的湍流混合。湍流边界层这项工作的相关性进行了讨论。
The turbulent velocity fluctuations in a homogeneous shear flow (mean velocity U→= S y x^) are studied numerically, in the range of Reynolds number 2600≤ Re≤ 11 300. The skewness of the z component of vorticity is independent of the Reynolds number in this range, suggesting that some small scale anisotropy remains at very high Reynolds numbers. This anisotropy is not seen in the two-point correlation functions. An analogy is drawn with earlier results on turbulent mixing of a passive scalar with a mean gradient. The relevance of this work for turbulent boundary layers is discussed.