短周期规则波浪在透水鱼礁型潜堤群上的传播特性

Propagation Characteristics of Short Period Regular Wave over Perforated Reef-type Submerged Breakwater Group

摘要:

为探究系列以周期性分布的单排透水鱼礁型潜堤群对波浪传播变形以及波生湍流场的响应特性，通过水槽试验和数值模拟，对短周期规则波作用下不同间距布设的鱼礁型潜堤群波浪传播特性展开了研究。试验测定了短周期入射波况下无间距鱼礁型潜堤群的波面高度及其变化过程，波浪在发生浅水变形后波能耗散波高显著减小，但由于堤顶淹没水深较大波浪仍保持准对称性的正弦波形态向前传播。基于光滑粒子流体动力学（smoothed particle hydrodynamic，SPH）方法建立了验证后的二维无反射数值波浪水槽，模拟了间距比为0.5~3.0的鱼礁型潜堤群的波浪传播过程。数值结果表明：鱼礁型潜堤群的间距对波浪反射影响非常大，各工况下鱼礁型潜堤群的反射系数均大于0.75；透射系数总体上随着间距比的增大而减小。特别地，当间距比为2.5时，堤顶波高骤升，反射系数达到最大，透射系数几乎最小，这是由于波浪与鱼礁型潜堤群发生了同频共振的布拉格反射效应，此时迎浪堤上方的上涌流范围和流速也达到最大。

Abstract:

Based on flume experiment and numerical simulation， wave transformation and wave-induced current characteristics over a series of periodic distribution of single row perforated reef-type breakwater group with different disposal spaces were studied under short period regular incident wave condition. Wave surface and wave height of reef-type breakwaters without disposal space were measured in a short period incident wave. Wave height is significantly reduced due to the wave energy dissipation caused by wave shoaling effect， but the wave still maintains a quasi-symmetrical sinusoidal wave and propagates for-ward due to the large submergence on the breakwaters. Further， a non-reflected numerical wave model was developed using smoothed particle hydrodynamic （SPH） method and verified by experimental data， which was served to simulate the regular wave propagation over reef-type breakwaters with disposal spacing ratio of 0.5~3.0. The results show that reflection coefficients of all scenarios are above 0.75， indicating that disposal spacing between reef-type breakwaters has a large impact on wave reflection. Transmission coefficients generally decrease with disposal spacing between reef-type breakwaters increasing. It is noticeable that when the spacing ratio is 2.5， the wave reaches the same frequency as breakwaters， triggering the Bragg resonance reflection effect and resulting in the wave height on breakwater-top rising sharply， which causes almost the strongest wave reflection and transmission， and the largest upwelling zone with strong turbulence on the first seaward breakwater.