孤立波在岸礁地形上传播与爬坡数值模拟研究

Numerical modelling of solitary wave propagation and runup over fringing reefs

为准确模拟孤立波在岸礁地形上的传播和爬坡,采用基于完全非线性Boussinesq方程开发的Funwave-TVD模型,探究模型的可行性,并利用验证后的模型进一步研究岸礁各地形因素对孤立波爬高的影响。研究结果表明:模型能准确模拟孤立波在岸礁陡变地形上的传播及变形,摩擦系数对礁前陡坡及礁坪上的波浪传播模拟影响不大,但对爬坡预测的敏感性较强;模型空间步长可适当增大,提高计算效率;随着礁坪宽度的增大以及礁后斜坡的变缓,孤立波爬坡高度下降明显,而礁前陡坡坡度变化对孤立波爬坡高度影响不大。

In order to model the solitary wave transformation and runup over fringing reefs accurately,a fully nonlinear Boussinesq wave model Funwave-TVD was utilized in this study.Explore the feasibility of the model.The calibrated model was then applied to study the effects of reef bathymetry parameters on the solitary wave runup.The results show that the solitary wave transformation over fringing reefs can be reasonably reproduced by the present model.The bottom friction coefficient has little effect on the solitary wave propagation over the forereef face and reef flat,but is sensitive to the capture of the runup height.Grid size can be increased properly to improve the computation efficiency.The maximum runup height decreases significantly as the reef-flat width increases and the backreef slope gets mild,which is insensitive to the forereef slope angle.