波浪在V形贯底式防波堤上绕射的解析研究

给出了V形贯底式防波堤对波浪绕射计算的解析方法．假定防波堤刚性、薄壁、不透浪，水深恒定．假想存在一个圆柱面，把流场划分为3个区域，在每个区域上将速度势用特征函数展开，在它们的公共边界上进行匹配．匹配的原则是公共边界上速度、压力连续，得到关于未知系数的一组线性代数方程组，解出未知系数，即可求得流域中任意一点的速度势和波高．通过与已有的平直岛式防波堤绕射解析解比较，说明该方法是正确可靠的．数值结果给出了不同入射波频率及防波堤两臂不同张角时防波堤周围波幅的等高线图．结果表明：V形贯底式防波堤具有很好的防浪效果，通常情况下，掩护区域内的波高仅为入射波波高的20％～50％．

Analytical Research on the Wave Diffraction on V-type Bottom-Mounted Breakwaters

An analytical method was developed to study the wave diffraction effects on V-type bottom-mounted breakwaters. The breakwater is assumed to be rigid, thin, impermeable and located in water of constant depth. The fluid domain is divided into three regions by an imaginary interface. The velocity potential in each region is expanded by eigenfunctions. By satisfying continuity of pressure and normal velocity across the imaginary fluid interface, a set of linear algebraic equations can be obtained to determine the unknown coefficients for eigenfunctions. The accuracy of the present model is verified by a comparison with existing results for the case of an isolated breakwater. Numerical results, in the form of contour maps of the relative wave amplitude around the breakwater, were presented for a range of wave and breakwater (parameters.) The results show the V-type bottom-mounted breakwater is generally effective in defending (against) waves. In general, the wave height in the protected area is about 20%~50% of incident wave height.