The Stability of Internal Gravity Waves of Finite Width
The Stability of Internal Gravity Waves of Finite Width
复制标题
有限宽度内重力波的稳定性
DOI：
10.11345/nctam.64.9
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
T.Kataoka
中科院分区：
文献类型：
--
作者：
T.Hanada;T.Kataoka
重力内波从大气和海洋中的波源以“梁”的形式传播。相应的解是欧拉方程的精确解。在本研究中，我们考虑一束光与两个平面波之间的三波共振（三波相互作用）。三个平面波之间的三重共振是众所周知的，但它们的动力学时，其中之一是梁至今尚未阐明。根据最近的研究，不稳定性的发生不仅取决于它们的振幅，而且取决于梁的“宽度”。我们通过数值模拟欧拉方程证明了这一事实，并阐明了宽度对波束稳定性的影响。
Internal gravity waves propagate in a form of ‘beam’from a wave source in the atmosphere and the ocean. The corresponding solution is an exact solution of the Euler equations. In the present study, we consider ‘triad resonance’(3-wave interaction) among one beam and two plane waves. The triad resonance among three plane waves is well-known to occur, but their dynamics when one of them is a beam has not been elucidated so far. According to recent studies, occurrence of instability depends not only on their amplitudes but also on ‘width’of the beam. We demonstrate this fact by numerical simulation of the Euler equations and clarify the effect of width on the stability of wave beam.