抛石防波堤堤内波浪运动的数值模拟

将抛石防波堤认为离散介质结构,根据抛石防波堤内块体随机堆放的特点生成断面,对块体间的孔隙域划分网格。基于二维粘性不可压缩流体的N-S方程和流体自由表面处理的VOF方法,建立了波浪作用下堤身内部和前后流场的有限元数值模拟模型,对堤内的波浪运动进行了数值模拟。数值计算结果与波浪水槽模型实验结果基本吻合。对不同孔隙率和块体粒径的抛石堤计算结果表明,抛石堤内的波浪场受到很多参数的影响,孔隙率越大波长越长透射系数也越大,块体上的受力随着防波堤孔隙率以及块体平均半径的增加而减小。

NUMERICAL SIMULATION ON WAVE MOTION INSIDE RUBBLE MOUND BREAKWATER

The rubble mound breakwater is considered as a discrete medium structure according to the fact that the blocks in the section of the breakwater are generated randomly, and that the porosity region among the blocks of the breakwater is meshed into grids. Based on the N-S equation for the planar viscous incompressible fluid and the VOF method for the disposal of the free surface, the finite element method model of fluid field inside of, in the front of and in the rear part of the breakwater under the wave effect is established separately, the numerical simulation of the wave motion inside the breakwater is carried out. Numerical results agree well with the wave tank test results in trend. Numerical results of the breakwater with different porosities and different block radius show that the fluid field inside of the breakwater is affected by many parameters, that the transmission coefficient increases with higher porosity and longer wavelength, and that the forces on the blocks decrease with the increase of porosity and average radius.