A Time-Domain Boundary Element Method for Wave Diffraction in a Two-Layer Fluid
A Time-Domain Boundary Element Method for Wave Diffraction in a Two-Layer Fluid
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DOI：
10.1155/2012/686824
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发表时间：
2012-07
期刊：
影响因子：
--
通讯作者：
Y. Gou;Xinjia Chen;B. Teng
中科院分区：
文献类型：
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作者：
Y. Gou;Xinjia Chen;B. Teng
基于高阶边界元法建立了有限水深两层流体中波浪绕射问题的时域数值模型。在两层流体中，对于给定频率的入射波，存在两种可能的入射波模式（表面波模式和内波模式）。对于表面波模式，流体质点的流体动力学特性类似于单层流体。对于内波模式，利用匹配条件定义了一个新的关于界面上、下流体速度势的函数，建立了一组线性方程组，用四阶龙格-库塔法计算了波浪力和波浪剖面的时程。在自由表面和界面上均采用人工阻尼层，以避免波浪的反射。以截断圆柱体和矩形驳船为例，对该时域算法的精度进行了检验，结果表明该方法是有效的。
A time-domain numerical model is established based on the higher-order boundary element method (HOBEM) to simulate wave diffraction problem in a two-layer fluid of finite depth. There are two possible incident wave modes (surface-wave mode and internal-wave mode) exist in the incident wave for a prescribed frequency in a two-layer fluid. For surface-wave mode, the hydrodynamic characters of fluid particles are similar to single-layer fluid. For the internal-wave mode, through the definition of a new function respected to velocity potentials of upper and lower fluid on the interface by using matching condition, a single set of linear equations is set up to compute the time histories of wave forces and wave profiles by using a fourth-order Runge-Kutta method. An artificial damping layer is adopted both on the free surface and interface to avoid the wave reflection. Examinations of the accuracy of this time-domain algorithm are carried out for a truncated cylinder and a rectangular barge, and the results demonstrate the effectiveness of this method.