改进的非线性波传播数值模型的验证和应用

Verification and application of the improved numerical model for nonlinear wave propagation

基于吸收入射边界上反射波的方法,并通过将统一边界条件表达式推广到适应不规则波的情况,改进了非线性波传播的数值模型。将利用模型的线性版本(略去非线性项)所计算得到的台阶地形上波浪的反射和透射系数与相应的解析解进行了定量比较。在斜坡地形上数值模拟了不规则波的传播,并将数值结果和物理模型实验值进行了比较。在下游边界分别为开边界和全反射边界的等水深的水槽内数值模拟了不规则波的传播变形,讨论了非线性作用的影响。在侧边界和下游边界均为全反射的固壁边界、二维的等水深水域内,数值模拟了波浪斜向入射时所产生的波浪变形。计算结果表明,对上述各种算例,改进后的非线性波传播数值模型均能进行有效地数值模拟。

Adopting the approach of absorbing the reflected waves on the incident boundary, and by extending the general boundary conditions suitable to irregular wave, the numerical model of propagation of non-linear wave is improved. In the wave flume with step bottom, the calculated reflection and transmission coefficients based on the linear version of numerical model are compared to the analytical results respectively. The irregular wave propagation is numerically simulated on a constant slope beach,and the calculated results are compared to the experimental ones. For the case of a wave flume with uniform depth and with open or fully reflected downstream boundary, the deformation of the irregular waves during propagation is numerically simulated. Non-linear influences are discussed. Under the assumption that the wave basin with uniform depth and its lateral and downstream boundary being fully reflectible, the oblique incident waves are numerically simulated. The calculated results show that the improved model can effectively simulated the tested cases. The nonlinear effects are also discussed in the relevant calculated cases.