Interplay of waves and eddies in rotating stratified turbulence and the link with kinetic-potential energy partition
Interplay of waves and eddies in rotating stratified turbulence and the link with kinetic-potential energy partition
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旋转层状湍流中波和涡流的相互作用及其与动势能分配的联系
DOI：
10.1209/0295-5075/112/49001
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
A. Pouquet
中科院分区：
文献类型：
--
作者：
R. Marino;D. Rosenberg;C. Herbert;A. Pouquet
本文采用世界一流的直接数值模拟方法，对稳定分层旋转流中的波涡相互作用进行了研究。引人注目的是，我们发现，从涡波为主的动力学的转变发生在波数kR，这并不取决于雷诺数，这表明波和涡模式之间的能量分配是不敏感的湍流的发展在较小的尺度。我们还表明，KR是可比的波数在动能和潜在的模式之间的交流稳定在接近均分，强调势能的作用，如在大气和海洋中所示。此外，kR变化的弗劳德数的倒数所解释的缩放预测建议，与最近的观测和建模的中间层，低热层和海洋。
The interplay between waves and eddies in stably stratified rotating flows is investigated by means of world-class direct numerical simulations using up to 30723 grid points. Strikingly, we find that the shift from vortex- to wave-dominated dynamics occurs at a wave number kR which does not depend on the Reynolds number, suggesting that the partition of energy between wave and vortical modes is not sensitive to the development of turbulence at the smaller scales. We also show that kR is comparable to the wave number at which exchanges between kinetic and potential modes stabilize at close to equipartition, emphasizing the role of potential energy, as conjectured in the atmosphere and the oceans. Moreover, kR varies as the inverse of the Froude number as explained by the scaling prediction proposed, consistently with recent observations and modeling of the Mesosphere–Lower Thermosphere and of the ocean.