沿水平向运动的水中截断圆柱体辐射波浪问题的解析解答

根据线性势波理论,分析了水中截断圆柱体作水平简谐运动时结构周围的辐射波浪。利用分离变量法,分别得到了含有未知常数的三个流体子域速度势的简谐表达形式,并采用一个较为简单的匹配方法使其在流体子域的共同边界上满足压力和法向速度的连续条件。于是求解得到了速度势,进而可得到由等效附加质量和附加阻尼表示的柱体侧面上的动水力。不仅能考虑自由表面波对动水压力的影响,也适用于位于任意水深处的截断圆柱体。实例分析表明,该方法具有较高的计算精度;同时对于截断圆柱体,采用Morison方程中的动水附加惯性力项会高估柱体侧面上的动水力。

RADIATION WAVE LOADINGS ON A TRUNCATED CYLINDER DUE TO SWAY MOTION

Radiation wave surrounding a horizontally submerged truncated circular cylinder with harmonic sway motion is analyzed using the linear potential wave theory. Using the method of separation of variables, harmonic expressions of the velocity potential in terms of the unknown constants are obtained in three subregions of the domain occupied by the water. A simple matching technique is used to satisfy the continuity of pressures and normal velocities at the common boundary of the subregions. The velocity potential is thus obtained, and consequently, the hydrodynamic force on the side of the cylinder expressed as a function of equivalent added mass and damping is determined. The solution presented not only is able to consider the gravity wave on the water surface, but also can be applied to truncated circular cylinder submerged in the arbitrary depth of water. Results of examples illustrated the accuracy of the solution and showed that using coefficient of hydrodynamic added mass in Morison equation would over-evaluate the hydrodynamic force on the side of the cylinder.