Amplitude decay and energy dissipation due to the interaction of internal solitary waves with a triangular obstacle in a two-layer fluid system: the blockage parameter
Amplitude decay and energy dissipation due to the interaction of internal solitary waves with a triangular obstacle in a two-layer fluid system: the blockage parameter
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DOI：
10.1007/s00773-009-0060-7
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发表时间：
2009-09
影响因子：
2.6
通讯作者：
Chengdong Chen
中科院分区：
文献类型：
--
作者：
Chengdong Chen
在波浪水槽中研究了凹地型内孤立波在水下三角形障碍物上的传播特性。我们观察到在一个两层层状流体系统中，由于底部的障碍物引起了ISW凹陷的变形和破裂。利用波浪振幅、两层厚度和淹没障碍物高度等物理因素对波障相互作用进行了分析。破波与实验前设置的输入参数有关。提出了一种基于堵塞参数ζ的分类方案。isw -障碍相互作用的不同程度在视觉上被分为三种示意图形式（ζ< 0.55为弱遭遇；0.55 <ζ< 0.7为中等遭遇；0.7 <ζ为破波）。此外，利用反射系数和透射系数探讨了对ISW振幅和能量变化的影响。波障相互作用过程中的波特性（波幅反射、能量反射、波幅透射和能量透射）与阻塞参数呈近似线性关系。受水下障碍物的影响，透射波总是由一个先导脉冲（孤立波）和一个色散波列组成。此外，由于底部摩擦，先导脉冲的能量收支减少了至少5%，在强断裂的情况下可能接近50%。
Experiments were carried out in a wave flume to examine the propagation of depression-type internal solitary waves (ISWs) over a submerged triangular-shaped obstacle. We observed the distortion and breaking of the ISW depression in a two-layer stratified fluid system as induced by the obstacle on the bottom. Physical factors, such as the amplitude of the wave, the thickness of the two layers, and the height of the submerged obstacle were utilized in our analysis of the wave–obstacle interaction. Wave breaking was determined in relation to input parameters arranged before the experimental runs. A classification scheme based on the blockage parameterζwas proposed. The various degrees of ISW-obstacle interaction were visually classified with three schematic forms (ζ< 0.55 for a weak encounter; 0.55 <ζ< 0.7 for a moderate encounter; and 0.7 <ζfor wave breaking). Furthermore, the reflection and transmission coefficients were utilized to explore the resultant influence on changes in amplitude and energy of an ISW. The wave characteristics (e.g., amplitude-based wave reflection, energy-based reflection, amplitude-based transmission, and energy-based transmission) during the wave–obstacle interaction showed an approximately linear relation with the blockage parameter. Influenced by the submarine obstacle, the transmitted waves were found to always consist of a leading pulse (solitary wave) followed by a dispersive wave train. Moreover, due to bottom friction the energy budget of the leading pulse was reduced by a factor of at least 5% which could approach 50% in cases with strong breaking.