基于RANS方程的海堤越浪数值模拟

基于FLUENT商业化软件,以RANS方程为控制方程,基于有限体积法,采用k-epsilon湍流模型,运用一种“解析松弛”方法实现了适用于VOF方法的数值源造波技术。在该数值波浪水槽中对规则波在不可渗透简单斜坡堤上越浪过程进行了数值模拟,将越浪量计算值同物理实验结果及基于非线性浅水方程的数值结果进行了比对。结果表明：该数值模型能够较好地复演海堤越浪过程,同基于非线性浅水方程的数值结果相比,能更有效地模拟含有强烈卷吸、射流和破碎的海堤越浪问题。

Numerical simulation of wave overtopping over seawalls using the RANS equations

Based on the Reynolds-Averaged Navier-Stokes(RANS) equation,the finite volume method and standard turbulence k-epsilon model,a numerical wave tank was presented in the frame of FLUENT through modifying the source terms of momentum equations by distributed sources associated with the incoming waves.The volume of fluid method(VOF) is used to trace the free surface.Regular wave overtopping over the crest of an impermeable coastal structure located on a sloping beach is predicted numerically by using the numerical model developed previously for predicting wave run-up on such a structure located on the horizontal seabed.The computed average overtopping rates are shown to be in good agreement with available small-scale test data and the results calculated by the non-linear shallow water(Hu et al.(2000)) model.The model is valid.Compared to the AMAZONE(Hu et al.(2000)) model based on NLSW equation,it can effectually solve the problems,which include the violent deformation,jet and breaking of the free surface.