斜坡非淹没刚性植被影响下孤立波爬高的研究

Investigation of solitary wave runup on a slope under the effect of emergent, rigid vegetation

该文通过物理模型实验和数值模拟研究了孤立波与斜坡上非淹没刚性植被的相互作用。物理模型实验在波浪水槽中进行,运用CCD高速相机测量了斜坡上波浪的爬高,分析了入射波波高和植被密度对爬高的影响,结果表明爬高与入射波高的比值近似为常数,其值取决于植被的密度。采用Boussinesq方程成功地模拟了波浪在斜坡上的传播变形及爬高过程:植被的阻水作用通过添加拖曳力项来实现,底床摩擦阻力系数通过模拟孤立波在无植被影响斜坡上的爬高确定,根据实验数据校核数值模型得到不同入射波高下植被的拖曳力系数。研究发现孤立波作用下斜坡上植被的平均拖曳力系数与平底床恒定流的情况并无明显差异。

This study experimentally and numerically investigates the interaction of solitary wave with emergent, rigid vegetation on a slope. A series of laboratory experiments are conducted in a wave flume, and wave runup is measured using a high-speed CCD camera. Effects of incident wave height and vegetation density on the reduction of runup are analyzed. Results show that the ratio of runup to incident wave height is almost constant, and its value depends on the density of the vegetation. A Boussinessq model is successfully employed to simulate wave transformation and runup on the slope. The resistance force exerted by the vegetation is modelled by adding a drag force term, and the bottom friction coefficient is determined by simulating wave process on the slope in the absence of vegetation. Subsequently, the drag coefficient is obtained by calibrating the model with laboratory data. It is found that the average values of drag coefficient make no notable difference from those obtained on the horizontal bottom subjected to the steady flow.