基于波能量平衡方程模拟波浪在柔性植物区的传播与变形

Wave Propagation and Transformation in Flexible Vegetated Water Based on the Wave Energy Balance Equation

基于CMS-Wave波浪数学模型,通过在其波浪能量平衡方程中引入植被波能损耗项,并考虑了波浪的折射、反射、破碎、波流相互作用及底摩擦等作用,计算了有植被作用下的波浪传播与变形.该模型的求解以波能平衡方程为基础,采用有限差分法进行数值离散,并应用Gauss-Seidel迭代法计算离散的方程组,得到计算域的波高、周期以及波向等波浪要素信息.首先通过模拟一维简单地形和二维复杂地形的波浪传播,对模型的适应性及有效性进行评估;随后对不规则非破碎和破碎波浪在柔性植物区的传播变形进行模拟,计算结果表明,修正的CMS-Wave模型能够精确地计算植被影响下波浪在复杂地形的传播与变形,这可对近一步研究近海湿地植被的消波效应及湿地海域极端风浪的防灾减灾提供技术支撑.

The CMS-Wave model was developed to simulate the wave propagation in vegetated waters. A wave energy dissipation term was empirical and was derived to represent the resistance induced by wetland vegetation in the spectral wave energy equation. The wave model was a two-dimensional spectral wave action model and took into account the effect of wave breaking, shoaling, refraction, diffraction, wave-current interaction and bottom friction. The finite difference method was used to solve the wave-action density N, the Gauss Seidel iteration method was used to calculate the discretized equations and then the information of wave height, wave period and wave angle are obtained. Firstly, the wave model is used to calculate accurately the wave propagation in simple and complex topography, the adaptability and availability can be evaluated as well. Secondly the propagation of irregular no-broken and breaking waves over the flexible vegetated zone can be calculated and analyzed in this study. The calculated results show the good performance of the improved wave model in predicting wave propagation and transformation over vegetated waters complex topography. The wave model is expected to provide the technical support for the study of wave attenuation and disasters prevention under extreme waves in real wetland coastal water.