中文摘要：

基于线性势流理论,利用高阶边界元法研究了规则波在三维局部渗透海床上的传播。根据Darcy渗透定律推导出渗透海床的控制方程,利用渗透海床顶部和海底处法向速度和压强连续条件得到渗透海床顶部满足的边界条件。根据绕射理论,利用满足自由水面条件的格林函数建立了求解渗透海床绕射势的边界积分方程,采用高阶边界元方法求解边界积分方程进而得到自由水面的绕射势和波浪在局部渗透海床上传播过程中幅值的变化情况。通过与已发表的波浪对圆柱形暗礁的时域全绕射结果对比,证明了本文建立的频域方法计算波幅的正确性和有效性。利用这一模型研究了三维矩形渗透海床区域上波浪的传播特性,并分析了入射波波长、海床渗透特性系数等参数对波浪传播的影响。

英文摘要：

Regular wave propagation on 3-D local permeable seabed is studied by higher-order boundary element method based on the linear potential flow theory.The control equation of permeable seabed is derived from the Darcy law.The boundary condition on the permeable seabeds surface is developed by the continuous conditions of normal velocity and pressure on the interface between permeable seabed and water.The boundary integral equations,which can be solved to obtain the diffraction potentials of permeable seabed,are established by the adoption of wave Green function based on the theory of wave diffraction.Then,when wave pass through the permeable seabed,the diffraction potentials of free surface and the variation of wave amplitude can be calculated after solving the boundary integral equations by higher-order boundary element method.The validity and effectiveness of the present frequency domain method is verified by the results comparison with time domain method,in that case the wave diffractions on cylindrical hump seabed are considered.The characteristic of wave propagation on 3-D local rectangular permeable seabed is investigated by the present numerical method,and the effects of parameters such as wave length and the porosity parameter are discussed further.