【作者】 孙雷；

【导师】 董国海； 宗智；

【作者基本信息】 大连理工大学 ， 港口、海岸及近海工程， 2009， 博士

【摘要】 本文基于势流理论,利用边界元方法,对船舶兴波及其作用的问题进行了数值研究。本文的工作主要分为以下几个方面:时域格林函数的计算方法、常航速行驶船舶兴波问题的计算、船兴波对水中固定结构物作用的计算、船舶兴波对漂浮结构物作用的计算、系泊结构物在船兴波作用下的受力及运动响应。本文的结构安排如下:首先,对无限水深时域格林函数、有限水深时域格林函数的计算方法进行了推导,并介绍了时域格林函数的快速算法,用于接下来的时域计算。其次,在势流理论的基础上,应用满足线性自由水面条件的定常移动源格林函数的边界元方法(Kelvin源)对船舶兴波问题进行了计算。该方法可以用于任意物体定常运动的线性兴波问题,包括潜体的兴波问题。应用该方法计算了截断圆柱的绕流问题。应用薄船假定对Wigley船型的兴波进行了计算,结合Noblesse给出的定常移动源格林函数,推导出薄船兴波的远场势函数及其波面高度的解析表达式。该方法可以简单快捷地求解出薄船的远场波形。然后,将时域格林函数法应用于计算结构物在船兴波作用下的绕射问题。这种方法可以计算任意几何形状的物体的绕射作用,以及由波浪在该物体上绕射产生的波浪场。同时,本文还给出了无限水深中结构物(淹没圆球、固定半球、淹没方箱、截断方箱和截断圆柱)在不同频率的规则波作用下的绕射问题,并将其与频域解得到的结果进行比较,由此来验证数值方法的准确性。关于结构物在船兴波作用下的绕射问题,文中给出了几个算例,分别计算了结构物(如淹没圆球、漂浮半球、淹没方箱和截断方箱等)在薄船兴波作用下的绕射问题。通过对计算结果的系统分析总结了在船兴波作用下,结构物所受波浪力大小与船速、结构物与船行进路线之间的距离、船体尺寸等的关系。在前面工作的基础上,将船兴波对固定结构物作用问题拓展到对漂浮结构物作用问题的计算,从理论上对漂浮结构物在船兴波作用下的运动响应及绕射-辐射问题进行了数值计算与分析,使用时域格林函数法对该问题进行求解。这种方法可以计算任意几何形状的物体的绕射-辐射作用,以及由波浪在该物体上绕射产生的波浪场。同时,本文还给出了无限水深中的结构物(如漂浮方箱、Wigley船)在不同频率的规则波作用下的绕射-辐射问题,并将其与频域结果或实验结果进行比较,由此来验证数值方法的准确性。关于结构物在船兴波作用下的绕射-辐射问题,文中给出了相应的算例,通过对计算结果的系统分析总结了在船兴波作用下,结构物的运动响应与船速、结构物与船行进路线之间的距离、船体尺寸等的关系。最后,探讨了系泊浮体在船兴波作用下的运动响应问题。应用时域格林函数计算了一条Wigley船经过另一系泊结构物的受力及运动响应问题。通过对计算结果的系统分析总结了在船兴波作用下,系泊结构物的受力及运动响应与船速、结构物与船行进路线之间的距离、船体尺寸等的关系。更多还原

【Abstract】 A panel method based on potential flow theory has been developed to solve the ship waves-body interactions in the time domain. The thesis includes the evaluations of time -domain Green function, ship waves caused by a ship with uniform speed, ship waves interactions with various structures (fixed structures, floating bodies and moored floating bodies).A Kelvin source panel method is applied to solve the wave-making problems. This model can be evaluated by flow around fixed structures. The results for truncated cylinder incurrent are presented as well as the thin ships. The wave-making model developed in this thesis can be applied to the linear wave-making problems of arbitrary bodies including submerged bodies.Due to the huge CPU and mass storage requirements of the time-domain computation, a fast algorithm for time-domain Green function and its derivatives is presented and applied to the ship waves-body interactions. The model is first examined by the diffraction of simple shape bodies (submerged sphere, hemisphere, submerged box and truncated box). The computed wave forces are compared with the frequency-domain results, and they agree very well. The diffraction problems of fixed structures under thin ship waves are considered. The focal points of the work are analyzing the relationships of distance between ship and structures, ship length, ship beam and ship draft with wave forces induced by ship waves.Then, diffraction-radiation problems are examined in context of simple shape bodies (floating box and Wigley hull) and compared with the frequency-domain results or experimental results. The parameter analysis of ship speed, distance between ship and structures, ship length, ship beam and ship draft with wave forces and motion responses of floating bodies by thin ship waves is implemented.In the final application, Wave loads and motion responses are computed with a Wigley hull passing by a moored truncated cylinder. The diffraction-radiation problems are examined by comparing the time domain results with the frequency domain ones and they agree very well. The parameter analysis of ship speed, distance between ship and structures, ship length, ship beam and ship draft with wave forces and motion responses of moored structure by thin ship waves is also implemented.更多还原