基于数值和实验方法的非透浪梳式防波堤的水动力学特性研究

采用源函数造波法建立了三维数值波浪水槽模型,模拟了不同随机种子数(NW)下的随机波浪,与目标谱对比的结果证明当NW=200时,采用文中的数值方法可以得到较好的模拟精度;建立了随机波浪对一种非透浪梳式防波堤作用的数值模型,通过数值模拟结果和实验结果的比较,验证了该数值模型的有效性。对该非透浪的梳式防波堤的水力学特性进行了实验研究,并应用上述数值方法对结构的所受冲击波浪力机理进行了分析,数值结果证明在该结构的危险水位下,由结构的翼板和胸墙下底板所构成的异型空腔结构是导致翼板上产生较大冲击压力的主要因素。在此基础上,为了消减翼板的冲击压力,提出一种改进的结构型式,最后对该改进结构的翼板上波浪力特性和波浪反射系数进行了实验研究。

Experimental and Numerical Study on Hydrodynamic Performance of Impermeable Comb-Type Breakwater

In this study, the hydrodynamic characteristics of a typical impermeable comb-type breakwater and its improved structure are investigated with experimental and numerical methods. A 3-D numerical wave tank is firstly developed by using a source wave-generation method. Irregular waves were simulated with different random wave modes number Nw and it is demonstrated that the simulated wave spectra with Nw=200 agree well with the target spectra. The characteristics of wave pressure distribution on the impermeable comb-type breakwater are then studied by experiments.The numerical model is further employed to analyze the mechanics of the impact wave forces on this comb-type breakwater. It is found that the existence of the cavity composed of adjacent side-plates and super-structure is the main cause of the high impact wave pressure on the side-plates under dangerous water levels. Finally, an improved impermeable comb-type breakwater with ‘I’ type baffle is proposed to reduce the maximum wave pressure.The wave pressure on side-plates and the wave reflection coefficient of the improved structure are investigated.