三孤立波在缓坡上爬高及相互作用的实验研究  

An experimental study of runup and interaction of triple solitary waves on a gentle slope

作　　者：彭勇 吴卫[1] 刘桦[1,2] PENG Yong;WU Wei;LIU Hua(School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;MOE Key Laboratory of Hydrodynamics,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240 [2]上海交通大学水动力学教育部重点实验室,上海200240

出　　处：《水动力学研究与进展（A辑）》2018年第4期445-454,共10页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金项目(11632012);国家973计划项目(2014CB046203)~~

摘　　要：海啸波经极缓的大陆架传播至近岸浅水区时可激发由多个孤立波组成的波列。为了研究多个孤立波在斜坡上爬高和相互作用规律,该文选择坡度为1/20的斜坡模型在波浪水槽进行了等波幅三孤立波爬高的物理模型实验。采用大冲程推板式造波机和改进的Goring造波方法,有效地实现了不同波峰间距和不同相对波幅时等波幅三孤立波的造波。采用高速摄像机记录每个孤立波的爬高过程,得到每个孤立波的爬高值;定性分析了爬高过程中孤立波破碎及其相互作用对爬高的影响规律。实验结果表明:第二个孤立波和第三个孤立波受先导波回落水流的影响,破碎位置向离岸方向移动;首波的爬高放大系数基本不受后续来波的影响,其爬高放大系数与同等工况下单孤立波的测量值一致;第二个孤立波和第三个孤立波的爬高放大系数与相邻的波峰间距有关,当波峰间距增大时,爬高放大系数先减少后增加;当波峰间距增至某临界值后时,第三个孤立波的爬高放大系数将大于第二个波的爬高放大系数。最后,依据本次实验结果,提出了等波幅三孤立波在缓坡上爬高的经验公式。Tsunami could generate a train of solitary waves after propagating over a wide continental shelf of gentle slope.In order to understand the runup and interaction of several successive solitary waves in coastal region,the propagation and runup the triple solitary waves of equal amplitude on a plane beach of 1：20 slope are studied in a wave flume.The triple solitary waves are generated by the modified Goring methods and a wavemaker of long stroke in the wave flume,for the triple solitary waves of equal wave amplitude.The runup processes of the triple solitary waves are recorded by two high speed cameras.The effect of breaking on the maximum runup of individual wave is discussed.It turns out that,because of the influence of the down wash flow induced by the leading wave,the breaking points of the following waves will move to offshore and the runup amplification coefficient of the leading one is greater than that of the second wave and third wave.As the relative space between two successive peaks increases,the runup amplification coefficient of the first wave is identical with that of the single solitary wave of the same relative amplitude.However,it is found that the runup amplification coefficient of the third wave and the second wave decreases at the range of the small relative peak distance,reaches a minimum value,and then increase gradually.If the relative space between two peaks is great enough,the runup of the third solitary wave is greater than that of the second one.Finally,an empirical formula is proposed to evaluate the runup of individual solitary waves of the triple solitary waves on a gentle slope.

关 键 词：三孤立波 缓坡 实验 爬高 破碎 

分 类 号：U656.2[交通运输工程—港口、海岸及近海工程]