Nonrobustness of the two-dimensional turbulent inverse cascade.
Nonrobustness of the two-dimensional turbulent inverse cascade.
复制标题
二维湍流逆级联的非鲁棒性。
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
R.K. Scott
中科院分区：
文献类型：
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作者：
R.K. Scott
本文在准定常状态下研究了二维Navier-Stokes湍流中的逆能量级联，在kf-1尺度上施加小尺度、带限强迫，特别注意强迫雷诺数Re对大尺度能量分布的影响。逆能量级联的强度，或转移到更大尺度的能量输入的分数，随着Re成比例的增加而单调增加，变量kmax 2kf 2，其中kmax是最大分辨波数。此外，作为Re增加超过一个临界值，这是一个直接的涡度拟能级联到小尺度首先实现，在能量级联范围内的能谱陡峭的k-53到k-2的依赖。陡峭被解释为一个更大的趋势，相干涡形成的情况下，强迫尺度得到充分解决的结果。在谱空间中，它与逆能量传递的非定域性有关。
The inverse energy cascade in two-dimensional Navier-Stokes turbulence is examined in the quasisteady regime, with small-scale, band-limited forcing at scale kf-1, with particular attention to the influence of forcing Reynolds number Re on the energy distribution at large scales. The strength of the inverse energy cascade, or fraction of energy input that is transferred to larger scales, increases monotonically toward unity with increasing Re proportional, variantkmax2kf2, where kmax is the maximum resolved wave number. Moreover, as Re increases beyond a critical value, for which a direct enstrophy cascade to small scales is first realized, the energy spectrum in the energy-cascading range steepens from a k-53 to k-2 dependence. The steepening is interpreted as the result of a greater tendency for coherent vortex formation in cases when forcing scales are adequately resolved. In spectral space, it is associated with nonlocality of the inverse energy transfer.