基于格子Boltzmann方法的斜坡堤越浪数值模拟研究

Numerical simulation of wave overtopping over the sloping seawall based on the lattice Boltzmann method

准确确定越浪量对于斜坡堤设计有重要意义。利用格子Boltzmann方法(LBM),并采用主动吸收式速度入口造波、出流边界消波、VOF方法追踪自由表面以及静态Smagorinsky模型模拟紊流运动,建立二维数值波浪水槽,对光滑斜坡堤上规则波与不规则波越浪进行数值模拟。模拟结果与试验值及其他数值模型结果比较表明,二维LBM数值波浪水槽具有模拟斜坡堤越浪的能力,但对于破碎较为剧烈的越浪过程模拟,该模型还存在一定的不足,未来可从提高自由表面模型精度等方面进一步改善其性能。

It is one of important factors of the accurate determination of the overtopping discharges for the design of sloping seawall.Based on the lattice Boltzmann method,a two-dimensional numerical wave flume was developed using the wave-maker with active absorption velocity at inlet,the wave eliminating method at outflow boundary,the volume of fluid algorithm to track the free surface and the static Smagorinsky model to simulate turbulence.The numerical wave flume was applied to simulate the wave overtopping over smooth sloping seawall due to regular and irregular waves.Comparisons among the simulation results,the experimental data and other numerical model results show that the numerical wave flume using the two-dimensional LBM has the ability to simulate wave overtopping of sloping seawall,though some deficiencies exit in the simulation of the wave-breaking process.In the future,the performance of the model can be improved through methods such as improving the accuracy of the free surface model.