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arXiv 2510.00564physics.flu-dynphysics.geo-ph
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地转涡旋对惯性波的吸收与反射

Absorption and reflection of inertial waves by a geostrophic vortex

Landau Institute for Theoretical Physics, Russian Academy of Sciences(俄罗斯科学院朗道理论物理研究所);National Research University Higher School of Economics(国立高等经济大学)

Nikolay A. Ivchenko, Sergey S. Vergeles

AI总结:

本研究针对快速旋转流体中惯性波与地转涡旋的相互作用,推导分析了涡旋背景下的柱面波方程,明确了波吸收/反射的角动量条件,修正了临界层附近的短波近似并建立了考虑粘性耗散的模型。

摘要:

我们研究了快速旋转流体系统中惯性波与地转流的相互作用。根据文献[1,2]中的实验条件,我们考虑由靠近流场侧边界的源激发、进入存在地转涡旋流区域的惯性波。本文推导并分析了波动方程,该方程描述了在被视为轴对称差速旋转的平均涡旋流背景下,会聚与发散柱面波的传播过程。我们证明,在无粘极限下,单色波在被临界层内部吸收之前,不会对涡旋流施加任何力矩。在会聚波中,只有携带与涡旋旋转符号相同的角动量的波才会被吸收;角动量符号相反的会聚波仅会被涡旋反射。只有当涡旋流在该位置的角速度足够快时,波的吸收才有可能发生。波在临界层附近的行为可以用平均流为直线剪切流的知名模型来描述。我们表明,短波极限下的传统波列近似在该层附近并不适用,因此对其进行了修正,推导了合适的方程并重新表述了波作用守恒律。针对临界层附近区域,我们推导了一个考虑粘性耗散的模型,并研究了粘性效应对单色波和波列吸收的影响。

英文摘要:

We study interaction of inertial waves with geostrophic flow in a rapidly rotating fluid system. In accordance with experimental conditions in [1, 2], we consider inertial waves, which were excited by a source being near side boundary of the flow and enter the region where geostrophic vortex flow is present. The wave equation is derived and analyzed in the paper that describes the propagation of convergent and divergent cylindrical waves on the background of mean vortex flow, which is considered as an axisymmetric differential rotation. We show that a monochromatic wave does not exert any torque on the vortex flow in the inviscid limit until it is absorbed inside the critical layer. Among convergent waves those only are absorbed which carries angular momentum of the same sign as one's of the rotation in the vortex. Convergent waves with the opposite sign of angular momentum are just reflected from the vortex. The absorption of a wave is possible only if the vortex flow is characterized by fast enough angular velocity there. The behavior of the wave near the critical layer can be described by the well-known model where the mean flow is rectilinear shear flow. We show that the conventional wave train approximation for the short-wave limit is not applicable in the vicinity of the layer and revise it, deriving the proper equation and reformulating the conservation law of wave action. For the vicinity of critical layer, a model which accounts for the viscous dissipation is derived; viscous effects are studied for absorption both of monochromatic wave and wave train.

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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