Turbulent channel without boundaries: the periodic Kolmogorov flow.
Turbulent channel without boundaries: the periodic Kolmogorov flow.
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无边界的湍流通道：周期性柯尔莫哥洛夫流。
DOI：
10.1103/physreve.89.023004
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
G. Boffetta
中科院分区：
文献类型：
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作者：
S. Musacchio;G. Boffetta
柯尔莫戈罗夫流提供了虚通道流的一个理想实例：它没有边界，但它在每半个波长上都有明确定义的平均流。我们利用这一显著特征来研究平均流和体流的湍流阻力之间的相互作用。通过一组雷诺数增加时的直接数值模拟，我们给出了整体湍流阻力与平均流动幅度的关系。进一步，我们给出了逐级能量平衡的详细分析，它描述了动能如何在流动的不同区域之间重新分配，同时向小耗散尺度输送。我们的结果使我们能够获得对大尺度空间能量传输的准确预测。
The Kolmogorov flow provides an ideal instance of a virtual channel flow: It has no boundaries, but it possesses well defined mean flow in each half wavelength. We exploit this remarkable feature for the purpose of investigating the interplay between the mean flow and the turbulent drag of the bulk flow. By means of a set of direct numerical simulations at increasing Reynolds number, we show the dependence of the bulk turbulent drag on the amplitude of the mean flow. Further, we present a detailed analysis of the scale-by-scale energy balance, which describes how kinetic energy is redistributed among different regions of the flow while being transported toward small dissipative scales. Our results allow us to obtain an accurate prediction for the spatial energy transport at large scales.