中文摘要：

建立了基于二阶完全非线性Boussinesq水波方程的二维波浪破碎数值模型,对沙坝海岸上产生的裂流进行了数值模拟研究。首先将文献[1]中给出的一组二阶完全非线性Boussinesq方程进行扩展,在动量方程中引入紊动粘性项模拟波浪破碎引起的能量耗散,采用窄逢法处理海岸动边界问题,并考虑了混合子网格效应以及水底摩擦。然后,在矩形网格上离散控制方程,采用有限差分方法和混合四阶Adams-Bashforth-Moulton预报矫正格式建立了数值模型。应用所建立模型对一带沟槽沙坝海岸上产生裂流的实验进行数值模拟,将计算的波高、增减水、时均流速、时均流场等与实验数据进行了比较。数值结果与实验结果吻合较好,这说明建立的数值模型是准确有效的,为下一步应用该模型模拟实际海岸上的裂流提供了研究基础。

英文摘要：

A 2D wave breaking model based on second order fully nonlinear Boussinesq-type equations is developed to simulate the rip current generated on a barred beach.Firstly,a set of equations with fully nonlinearity characteristics is extended,i.e.,eddy viscosity method and slot method are adopted to mimic energy dissipation of breaking waves and moving shoreline boundary respectively,subgrid mixing and bottom friction are also incorporated.The governing equations are then discretized on a rectangle gird system and numerically solved using finite difference method and a fourth order predictor-corrector Adams-Bashforth-Moulton time integration scheme.The rip current generated on a barred beach from a laboratory measurement is simulated and the computed wave height,wave setup and setdown,mean velocities and mean velocity filed are compared against experimental data.The satisfactory agreements demonstrate the accuracy and efficiency of the model,and the present study set a solid base for future study.