From modulational instability to focusing dam breaks in water waves
From modulational instability to focusing dam breaks in water waves
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DOI：
10.1103/physrevfluids.5.034802
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发表时间：
2020-03-27
影响因子：
2.7
通讯作者：
Randoux, Stephane
中科院分区：
文献类型：
--
作者：
Bonnefoy, Felicien;Tikan, Alexey;Randoux, Stephane
我们报告的水波实验中进行了一个长的坦克，我们认为在一个大型的矩形障碍物的形式与信封的非线性深水表面重力波的演变。我们的实验表明，对于一个范围内的初始参数，非线性波包是不解体的Benjamin-Feir不稳定性，但表现出特定的，强烈的非线性调制，从边缘的波包向中心以有限的速度传播。使用数值工具的非线性谱分析的实验数据，我们确定所观察到的包络波结构与聚焦色散溃坝流，一种特殊类型的色散冲击波最近描述的框架中的半经典极限的一维聚焦非线性薛定谔方程（1D-NLSE）。我们的实验结果与半经典1D-NLSE理论的预言在定量上是一致的。这是第一次观察到的持续色散冲击波动力学在调制不稳定的水波系统。
We report water wave experiments performed in a long tank where we consider the evolution of nonlinear deep-water surface gravity waves with the envelope in the form of a large-scale rectangular barrier. Our experiments reveal that, for a range of initial parameters, the nonlinear wave packet is not disintegrated by the Benjamin-Feir instability but exhibits a specific, strongly nonlinear modulation, which propagates from the edges of the wave packet toward the center with finite speed. Using numerical tools of nonlinear spectral analysis of experimental data, we identify the observed envelope wave structures with focusing dispersive dam break flows, a peculiar type of dispersive shock waves recently described in the framework of the semiclassical limit of the 1D focusing nonlinear Schrodinger equation (1D-NLSE). Our experimental results are shown to be in a good quantitative agreement with the predictions of the semiclassical 1D-NLSE theory. This is the first observation of the persisting dispersive shock wave dynamics in a modulationally unstable water wave system.