斜坡上孤立波碎波指针之数值研究

Investigations on the Breaking Criterion for Solitary Waves on a Slopping Beach Using BEM

为探讨孤立波波浪受海岸渐变之斜坡地形影响所产生之碎波效应,本文以边界元素法利用Lagrange描述水粒子运动之方法,配合对时间项前进差分之方式来探讨孤立波于斜坡上之碎波型态、碎波指针、碎波波高、碎波水深及碎波速度等。研究结果显示这些物理量可以经由几个基本参数包括海底斜坡之坡度、入射波之波高与波形之尖锐度等来加以表示,并提出一些关于孤立波碎波指针之数值近似经验公式,经与其它学者所发表之结果大致上均有相当吻合的趋势。

Studies of the breaking criterions for solitary waves on a slope are presented here in this paper. Boundary element method is used to model the processes of shoaling and breaking of solitary waves on various slopes. Empirical formulae that can be used to characterize the breaking of solitary waves are presented, including the breaking index, the wave height, the water depth, and the maximum particle velocity at the point of breaking.