规则波作用下斜坡堤越浪量的数值模拟

Numerical simulation of wave overtopping over sloping seawall under regular wave

台风过境产生极端波浪造成斜坡式海堤越浪,现有计算越浪量的经验公式都存在适用性的问题。为探求台风天气下舟山区域斜坡堤越浪量计算公式,基于VOF方法,对Navier-Stokes方程和k-ε方程进行求解,建立速度边界造波和阻尼消波的数值波浪水槽。在水槽中建立斜坡堤模型,通过改变影响越浪量的相关因素,模拟台风浪条件下规则波作用于斜坡堤发生越浪。将数值模拟结果与物理模型试验结果进行对比,分析确定各因子与越浪量系数的定量关系,提出一种新的计算越浪量系数的经验公式。结果表明,经验公式突出波陡与越浪量的对数关系,相对水深越大,相对堤顶超高越大,μ′值越小,越浪量越小。

The extreme waves generated by the typhoon cause the overtopping of the sloping seawall.However,the existing empirical formulas for calculating the wave overtopping discharge have the applicability.In order to find out the formula for calculating the amount of overtopping of the sloping seawall in Zhoushan area under typhoon weather,we solve the Navier-Stokes and k-εequations based on the VOF method,establish the numerical wave flume with boundary velocity wave generation and wave damping absorber,build the model of slope seawall in the flume,and simulate the condition of regular waves acting on slope seawall under the typhoon weather by changing the relevant factors affecting wave overtopping discharge.We compare the numerical simulation results with the experimental results of the physical model,analyze the quantitative relationship between each factor and the overtopping coefficient,and propose a new empirical formula for calculating the overtopping coefficient.The results show that the empirical formula presents the logarithmic relationship between the steepness of outburst wave and the wave overtopping discharge.The larger the relative water depth is,the larger the relative height of the dike is,and the smaller theμ′value is,the smaller the wave overtopping is.