A Semi-Analytical Potential Solution for Wave Resonance in Gap Between Floating Box and Vertical Wall
A Semi-Analytical Potential Solution for Wave Resonance in Gap Between Floating Box and Vertical Wall
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DOI：
10.1007/s13344-020-0068-7
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发表时间：
2020-12
影响因子：
1.6
通讯作者：
Yong Liu;Huajun Li;Lin Lu;Ai-jun Li;L. Tan
中科院分区：
文献类型：
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作者：
Yong Liu;Huajun Li;Lin Lu;Ai-jun Li;L. Tan
基于势流理论，通过使用速度势分解和匹配的本征函数展开，针对固定浮箱和垂直壁之间的狭窄间隙中的波共振提出了耗散半解析解。通过在间隙入口引入二次压力损失条件，在势流解中对盒子附近的能量耗散进行建模。这种处理方法受到河道流中横截面突变的经典局部水头损失公式的启发，其中假设能量耗散与高雷诺数流的局部速度的平方成正比。无量纲能量损失系数根据实验数据进行校准。并且发现它对入射波高和波频率不敏感。利用标定的能量损失系数，利用本耗散半解析解计算间隙中的谐振波高和反射系数。预测与实验数据非常吻合。案例研究表明，最大相对能量耗散发生在谐振频率附近，这导致反射系数最小。作用在盒子和垂直壁上的水平波浪力也在共振频率附近达到最大值，而作用在盒子上的垂直波浪力在那里突然减小到一个小值。
Based on potential flow theory, a dissipative semi-analytical solution is developed for the wave resonance in the narrow gap between a fixed floating box and a vertical wall by using velocity potential decompositions and matched eigenfunction expansions. The energy dissipation near the box is modelled in the potential flow solution by introducing a quadratic pressure loss condition on the gap entrance. Such a treatment is inspired by the classical local head loss formula for the sudden change of cross section in channel flow, where the energy dissipation is assumed to be proportional to the square of local velocity for high Reynolds number flows. The dimensionless energy loss coefficient is calibrated based on experimental data. And it is found to be insensitive to the incident wave height and wave frequency. With the calibrated energy loss coefficient, the resonant wave height in gap and the reflection coefficient are calculated by the present dissipative semi-analytical solution. The predictions are in good agreement with experimental data. Case studies suggest that the maximum relative energy dissipation occurs near the resonant frequency, which leads to the minimum reflection coefficient. The horizontal wave forces on the box and the vertical wall attain also maximum values near the resonant frequency, while the vertical wave force on the box decreases abruptly there to a small value.