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arXiv 0904.0713nlin.CD
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旋转衰减turbulence中的间歇效应

Intermittency effects in rotating decaying turbulence

Arkadiusz K. Kuczaj, Bernard J. Geurts, Darryl D. Holm

摘要:

旋转调节湍流,在足够强的旋转的情况下,引起湍流的柱状结构。这会产生显着的变化,在流动特性和色散特性,这使得旋转湍流调制特别相关的大气和海洋流动的背景下。在这里,我们调查的规范流动的湍流在一个周期性的盒子,受到旋转的一个固定的垂直轴。作为参考点,我们考虑均匀各向同性湍流的直接数值模拟。由于在各种旋转速率下的旋转而引起的调制(即,不同的Rossby数)。特别注意的是,在结构功能的缩放的变化来衡量的不透明度,这是改变。在垂直于旋转轴的方向上的纵向结构函数量化的不稳定性的减少将被呈现。这些数值结果与Seiwert等人(2008年)在实验中获得的最新结果非常一致。

英文摘要:

Rotation modulates turbulence causing columnar structuring of a turbulent flow in case of sufficiently strong rotation. This yields significant changes in the flow characteristics and dispersion properties, which makes rotational turbulence modulation particularly relevant in the context of atmospheric and oceanic flows. Here we investigate the canonical flow of turbulence in a periodic box, subjected to rotation about a fixed vertical axis. As point of reference we consider direct numerical simulations of homogeneous isotropic turbulence. Modulation due to rotation at various rotation rates (i.e., different Rossby numbers) is investigated. Special attention is paid to the alteration of intermittency, which is measured in terms of changes in the scaling of the structure functions. A reduction of intermittency quantified with the longitudinal structure functions in the direction perpendicular to the rotation axes will be presented. These numerical findings correspond well to recent results obtained in experiments by Seiwert et al. (2008).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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