Numerical Simulation of Wave Overtopping over Seawalls
ZHOU Qin-jun , WANG Ben-long, LAN Ya-mei, LIU Hua (Department of Engineering Mechanics, Shanghai Jiaotong University, Shanghai 200030,China)
Based on the RANS equation and 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. Numerical simulation of progressive waves and standing waves was carried out to check if the numerical wave generation and absorbing module work well. It truns out that the numerical wave tank can be used to study the interaction of regular waves and structures in two dimensional cases. Wave runup and overtopping over a seawall were reproduced by using the numerical wave tank and compared with the experimental data available. Good agreements were obtained between the numerical results and experimental data. In order to study the scale effects of physical model experiments of overtopping, several numerical models of different values of geometry scale were designed which satisfy Froude similitude. Using the numerical models of different scales, the numerical experimental results show that, if based on Froude similitude, the differences of the computed values of overtopping flux and the predicted values from experimental data increases as the geometry scale increases and the wave breaking in the front of seawalls becomes stronger. It is suggested that the scale effect should be considered carefully when wave overtopping over a seawall is studied in a wave flume.