孤立波作用下组合型港池共振响应的数值研究

港池受到孤立波入射时会在港池内激发多种模态的共振响应。为进一步研究不同平面布置形式港池的响应特性和共振规律，建立不同内外港池长度和连接位置的组合型港池，采用基于Boussinesq方程的波浪数值模型MIKE 21-BW模拟了孤立波作用下组合型港池的共振响应，对数值模拟的结果进行频谱分析和波幅分布测定并与现有理论值比较。结果表明，孤立波正向入射组合型港池激发的主要响应模态的频率和与其长度相等的细长港池的理论固有频率接近，各主要共振模态的振幅与内外港池的长度和两港池口门的距离有密切关系；波浪入射方向和港池内边界反射条件的改变对狭长组合型港池中形成的各共振模态的形状影响不大，但是增大港池宽度会使港池内激发明显的横向共振。最后提出了消减港湾共振的平面布置形式，可为实际工程设计提供指导。

Numerical study on resonance response of a combined harbor to a solitary wave

The muti-modal resonant response will be excited in the harbor during the solitary wave affection. A further research is carried out to study the response characteristics and resonance laws. Firstly, harbors in plan layouts are established with different inner and outer harbor lengths and connecting positions. Then, MIKE 21-BW, a wave numerical model based on Boussinesq equation, is applied to simulate the resonance response of the harbor under solitary waves action. Finally, as compared with the existing theoretical values, the numerical simulation results, especially the amplitude distribution, are analyzed by spectrum method. The results show that the main response frequency of a combined harbor excited by the normal incident solitary wave is close to the theoretical natural frequency of the slender harbor with the same length. Meanwhile, the amplitudes of the main resonance modes are closely related to the length of the inner and outer harbors as well as the distances between two entrances. On the other hand, the directional change of the incident wave and the reflection condition of the boundary within the harbor have little effect on the shaping of each resonance mode in a narrow and long combined harbor. However, with the increasing of the harbor width, transverse resonance becomes obvious at docking zone. Based on the above, a layout plan is proposed to decrease harbor resonance, which would provide guidance for practical engineering design.