Influences of boundary layer scale separation on the vorticity transport contribution to turbulent inertia
Influences of boundary layer scale separation on the vorticity transport contribution to turbulent inertia
复制标题
边界层尺度分离对涡量传递对湍流惯性贡献的影响
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
J. Klewicki
中科院分区：
文献类型：
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作者：
C. Morrill;J. Klewicki
在感兴趣的流动中，湍流惯性的平均效应可以表示为两个速度涡度相关的差。如果湍流惯性要对平均动力学产生净影响，则该差异必须充分非零。其中一种相关性与尺度效应的变化有关，而另一种相关性则与平流涡度输送有关。研究了尺度分离增加对涡量输送的影响。通过实验室和现场数据的使用，壁面法向速度v和展向涡量ωz的波动之间的尺度分离被示出为随着距壁面的距离和雷诺数而增加。这些量之间的时间延迟相关性表明，它们的平均相位只有轻微的变化会导致动量平均输运的显著变化。光谱用于探索之前观察到的v和ωz之间的尺度选择。对应于峰值的波长...
In the flows of interest, the mean effect of turbulent inertia can be expressed as the difference of two velocity vorticity correlations. This difference must be sufficiently non-zero if turbulent inertia is to have a net influence on the mean dynamics. One of the correlations is physically related to change of scale effects, while the other is related to advective vorticity transport. The vorticity transport mechanism is studied under the influence of increasing scale separation. Through the use of both laboratory and field data, the scale separation between the fluctuations of wall-normal velocity, v, and spanwise vorticity ωz, are shown to increase with distance from the wall and Reynolds number. Time-delayed correlations between these quantities reveal that only slight variations in their average phase would cause significant variations in the mean transport of momentum. Spectra are used to explore previous observations of scale selection between v and ωz. The wavelengths corresponding to the peaks in...