波浪与带有窄缝结构作用的非线性数值模拟

针对波浪与带有窄缝结构作用产生的流体共振问题,采用基于域内源造波技术的时域高阶边界元方法并在窄缝内流体引入人工阻尼,建立了自由水面满足完全非线性边界条件的二维时域数值波浪水槽模型。求解中采用混合欧拉-拉格朗日方法追踪流体瞬时水面,运用四阶龙格库塔方法更新下一时间步的波面和速度势,利用加速度势的方法来求得作用结构上的瞬时波浪荷载。通过与已发表文献的数值与实验结果对比,验证了模型的准确性。同时通过大量的数值计算研究了共振条件入射波浪非线性对反射波高、透射波高和窄缝内波高、及结构波浪荷载和压力分布的影响。

Nonlinear numerical simulation of wave action on objects with narrow gap

Based on a time-domain higher-order boundary element method (HOBEM) with wave genera-tion by the inner-domain source, a two-dimensional time-domain numerical wave flume is developed to in-vestigate the fluid resonance due to the interaction between wave and objects with a narrow gap. In the nu-merical model, the artificial damping is introduced into the fluid at gap and the fully nonlinear boundary conditions are satisfied on the instantaneous free surface. In the solving process, the mixed Eulerian-La-grangian method is adopted to track the transient water surface and the 4th Runga-Kutta technique is used to refresh the velocity potential and free surface at the next time step. The acceleration potential technique is adopted to calculate the transient wave loads along the wetted object surface. By comparison with the published experimental and numerical data, the proposed model is validated. Numerical experiments are performed to study the effects of the incident wave nonlinearity on reflection wave height, transmission wave height, wave height at narrow gap, wave loads and pressure distribution at resonance.