A comparison of weakly and fully non-linear models of the shoaling of a solitary internal wave
A comparison of weakly and fully non-linear models of the shoaling of a solitary internal wave
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DOI：
10.1016/j.ocemod.2004.02.002
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发表时间：
2005
期刊：
影响因子：
3.2
通讯作者：
R. Small;R. Hornby
中科院分区：
文献类型：
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作者：
R. Small;R. Hornby
本研究探讨内孤立波的行为跨越大陆坡存在的季节性温跃层。一个完全非线性的计算流体动力学（CFD）模型，弱非线性理论之间的比较。以前的观测表明，孤立波的振幅是上限，因为他们通过大陆坡，这可能是由于层流动力学，或由于湍流的影响。在大陆坡，计算流体动力学和二阶变深度KdV（vEKdV）预测与孤立波振幅有限变化的观测结果吻合良好。一阶变深度KdV理论明显高估了最终振幅。在波浪形状方面，CFD模拟的波浪从深水中的KdV形状变为浅水中的EkdV解决方案，如观察所示。CFD和vEKdV波的相速度与在400-500 m深的沃茨中观察到的相速度相似，但略低于在140 m深的水域中观察到的相速度。使用标准k，ε湍流模型进行的CFD预测表明，湍流对振幅的影响很小。这些初步结果表明，在这种情况下，波帽是由于层流，大振幅孤立波动力学和湍流混合是独立的。
This study investigates the behaviour of internal solitary waves crossing a continental slope in the presence of a seasonal thermocline. Comparisons are made between a fully non-linear computational fluid dynamics (CFD) model, and weakly non-linear theory. Previous observations suggested that the amplitudes of solitary waves are capped as they pass across the continental slope, which may be due to laminar dynamics, or due to the effect of turbulence. Across the continental slope, CFD and second order variable depth KdV (vEKdV) predictions agree well with observations of a limited change in solitary wave amplitude. First order variable depth KdV theory overpredicts the final amplitude significantly. In terms of the wave shape, the CFD modeled wave changes from a KdV shape in deep water towards an EkdV solution in shallow water, as observations suggest. The phase speed of the CFD and vEKdV waves are similar to that observed in waters of 400–500 m deep, but are slightly lower than observed in 140 m depth. CFD predictions using a standard k, ε turbulence model showed that turbulence had little effect on the amplitude. These preliminary results indicate that in this situation wave capping is due to laminar, large amplitude solitary wave dynamics and is independent of turbulent mixing.