流向Morison型波浪力的高阶矩分析

Analysis of higher moments for in-line Morison wave forces

通过理论研究定量地说明流向Morison波浪力,即拖曳力和惯性力的高阶统计矩随采样次数增加的规律。主要应用二阶Stokes波理论,推导了流向Morison波浪力的前四阶累积量。计算了作用于实际海底管线上的流向Morison波浪力的偏斜度和峰度。结果表明,随着采样次数的增加,拖曳力和惯性力的偏斜度和峰度驱于收敛。文中给出的方法为后续理论工作奠定了基础。

By means of theoretical study, this paper is to quantitatively describe the varying law of the higher moments of in-line Morison wave forces, i.e., drag force and inertia force, as the number of sampling increases. The second-order Stokes wave theory is mainly applied herein to deriving the first four cumulants of the in-line Morison wave forces. In the case study, the theory in this paper is adopted to calculate the skewness and kurtosis of the drag force and inertia force acted upon a practical subsea pipeline. It can be seen from the results that, as the number of sampling increases, the skewness and kurtosis of the drag force and inertia force tend to converge. The approach in this paper serves as a foundation for the theoretical work in the future.