Statistical properties of wave kinematics in long-crested irregular waves propagating over non-uniform bathymetry
Statistical properties of wave kinematics in long-crested irregular waves propagating over non-uniform bathymetry
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非均匀测深传播的长峰不规则波波运动学的统计特性
DOI：
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
O. Gramstad
中科院分区：
文献类型：
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作者：
C. Lawrence;K. Trulsen;O. Gramstad
实验和数值证据表明，非均匀测深可以显著改变不规则波场中海面高程的统计特性。随着长波峰的不规则波传播到较浅的水域，在上坡边缘附近，“无赖”波的可能性增加。本文用蒙特卡罗方法研究了长峰不规则波在浅滩上传播时的波浪运动学统计问题。波传播模型采用高阶谱方法，波运动学计算采用变分Boussinesq模型。当波在不均匀的水深测量中传播时，水平流体速度的统计可能与表面高程的统计不同。当深度在足够浅的水域中突然变化时，我们注意到强烈的非高斯统计。我们发现下坡区附近的水平速度峰度增大。此外，还从峰度和偏度两个方面讨论了不同入射波对底坡的影响。最后，我们研究了在更深的区域中倾斜底部的水平速度的峰度和偏度的演化。还给出了这些统计量的垂直变化。
Experimental and numerical evidence have shown that nonuniform bathymetry may alter significantly the statistical properties of surface elevation in irregular wave fields. The probability of “rogue” waves is increased near the edge of the upslope as long-crested irregular waves propagate into shallower water. The present paper studies the statistics of wave kinematics in long-crested irregular waves propagating over a shoal with a Monte Carlo approach. High order spectral method is employed as wave propagation model, and variational Boussinesq model is employed to calculate wave kinematics. The statistics of horizontal fluid velocity can be different from statistics in surface elevation as the waves propagate over uneven bathymetry. We notice strongly non-Gaussian statistics when the depth changes abruptly in sufficiently shallow water. We find an increase in kurtosis in the horizontal velocity around the downslope area. Furthermore, the effects of the bottom slope with different incoming waves are discussed in terms of kurtosis and skewness. Finally, we investigate the evolution of kurtosis and skewness of the horizontal velocity over a sloping bottom in a deeper regime. The vertical variation of these statistical quantities is also presented.