弱非线性内孤立波在斜坡上的传播演化特性  

Propagation Evolution Characteristics of Weakly Nonlinear Internal Solitary Waves on Slopes

作　　者：郅长红 陈科[1,2] 尤云祥[1,2] ZHI Changhong;CHEN Ke;YOU Yunxiang(Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration,Shanghai Jiao Tong University,Sanya 572000,Hainan,China;State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学三亚崖州湾深海科技研究院,海南三亚572000 [2]上海交通大学海洋工程国家重点实验室,上海200240

出　　处：《上海交通大学学报》2021年第8期916-923,共8页Journal of Shanghai Jiaotong University

基　　金：三亚崖州湾科技城管理局深海科技先导创新项目《南海内波环境中深海装备安全保障预警系统技术研发》。

摘　　要：采用简化的变系数内孤立波传播方程来描述弱非线性内孤立波在不同坡度斜坡上的传播演化过程.结果表明:弱非线性内孤立波在通过斜坡的传播过程中产生了不同程度的分裂现象,分裂为首波和尾波列.在通过斜坡的传播过程中内孤立波主要受到由地形诱导产生的浅化效应和能量耗散作用.对于非线性较弱的内孤立波,地形导致的浅化效应占主导作用,振幅逐渐增大并趋于稳定,而波速逐渐减小并趋于稳定.在相同的地形条件下,随着初始振幅增大,振幅的增加量减小,波速的减小量增加.随着斜坡坡度的增大,非线性内孤立波在传播过程中受到的能量耗散作用逐渐大于浅化效应,使得内孤立波在传播过程中振幅先增大后减小.当经过临界点(上下层流体深度相同的点)后,内孤立波由下凹型转变为上凸型.The propagation equation of variable-coefficient internal solitary waves was used to describe the propagation and evolution of weakly nonlinear internal solitary waves(ISWs)on slopes with different slopes.The results show that weakly nonlinear ISWs suffer from fission during the climbing process and split into the prominent wave and the trailing wave train.The ISWs are mainly influenced by the shoaling effect and the energy dissipation caused by terrain induction.For the ISWs with weak nonlinearity,the shoaling effect caused by topography is dominant,and causes the increase in wave amplitude and the decrease in wave speed.The wave amplitude and the wave speed,meanwhile,tend to be stable.Under the same terrain condition,as the initial wave amplitude increases,the increase in wave amplitude decreases,and the decrease in wave speed increases.As the slope increases,the energy dissipation effect of the nonlinear internal solitary wave in the propagation process is gradually greater than the shoaling effect,which makes the wave amplitude of the internal solitary wave increase first and then decrease in the propagation process.The ISWs change from concave to convex as the wave passes over the turning point(where the depth of the upper layer is the same as that of the lower layer).

关 键 词：内孤立波 两层流体 变系数内孤立波传播方程 斜坡地形 浅化作用 

分 类 号：O352[理学—流体力学]