多向聚焦波作用下透水潜堤消波特性数值模拟研究

Numerical study on performance of submerged permeable breakwater under impacts of multi-directional focused wave groups

本文采用非静压模型NHWAVE建立高精度三维波浪数值水槽,对多向聚焦波作用下透水和不透水潜堤消波特性进行数值模拟研究。通过计算结果与实验数据的对比,验证了该模型模拟多向聚焦波产生传播及多孔介质内流动的能力,进一步考虑了有效波高、水深、谱峰周期和传播角度等因素对潜堤消波特性的影响。结果表明:潜堤对多向聚焦波的最大波幅、最大水位、沿水深平均最大流速和波能均有显著消减作用,且透水潜堤因孔隙介质的存在消波性能更好。随着有效波高增大,堤顶处波浪破碎点前移,不透水潜堤消波性能受波高影响较大。水深越大,潜堤消波性能越低。透水潜堤对长周期波浪消减效果较差。传播角度越小,聚焦位置处波幅越大,波浪非线性作用越强。研究结果可为我们进一步保护沿海设施免受极端海洋环境的影响提供一定的参考。

In this study,a high-precision three-dimensional wave numerical flume is established using the non-hydrostatic model NHWAVE to simulate the wave dissipation characteristics of permeable and impermeable submerged breakwaters under the influence of multidirectional focused waves.The ability of the model to simulate the propagation of multidirectional focused wave generation and flow within porous media is verified by comparing the calculated results with experimental data,and the effects of different wave parameter conditions(significant wave height,water depth,peak wave period and spreading angle)are considered.The results show that the submerged breakwater has a significant effect on the maximum wave amplitude,maximum water level,maximum depth-averaged velocity and wave energy of the multi-directional focused waves,and the permeable submerged breakwater has better wave dissipation performance due to the presence of porous media.As the significant wave height increases,the wave breaking point at the top of the breakwater moves forward,and the wave attenuation of impermeable submerged breakwater is greatly influenced by wave height.With the increase of the water depth,the wave attenuation of submerged breakwater is lower.The permeable breakwater is less effective in long period wave attenuation.The smaller the spreading angle,the larger the wave amplitude at the focus,and the stronger the wave nonlinear effect.The research results can provide some reference for us to further protect coastal facilities from the impact of extreme marine environment.