非结构化网格下大范围波生流模拟和应用

Numerical simulation of large-scale wave-induced current on unstructured meshes and its application

波浪破碎引起的沿岸流是近岸海域的关键水动力因素。利用基于缓坡方程得到的光程函数方程和波作用守恒方程建立了考虑绕射效应的大范围波浪传播模型,模型可以考虑流场的影响;将波浪模型计算得到的辐射应力、波浪紊动系数等参数添加到三维水动力模型中,得到大范围近岸波生流的计算模型。模型中流场和波浪可以共用计算网格,且可同步耦合计算;模型基于非结构化网格,可以拟合复杂岸线的变化。模型对波生沿岸流、环流和逆流进行了验证,同时对实际海域的波生流进行了计算,结果表明:该模型对近岸波浪破碎引起的波生流具有很好的精度和适用性,可用于实际工程的计算。

The breaking wave induced near-shore current is a crucial hydrodynamic issue in near-shore zone. Using the eikonal equa- tion and the wave action balance equation based on the mild-slope equation, a new numerical large-scale wave model is built consider- ing the wave diffraction and flied current effect. The depth-dependent radiation stress and the wave-induced turbulences derived from the wave model are added to a three-dimensional hydrodynamic module, which can simulate the wave-induced current in large-scale nearshore region. In the module the flow field and the wave can share the computational grid, and coupling calculation can be synchro- nized; and the module is based on unstructured meshes, which provides great flexibility for modeling the wave-induced current in the complex geomorphology with the complicated boundary. The applicability of the proposed model to calculate the wave-induced long shore current, circulation and counterblow, and the wave-driven current in the actual water regions is evaluated. Numerical results show that the present model makes better accuracy and applicability in modeling the breaking wave induced near-shore current, and can be applied in the actual project.