随机横浪中特征波群作用下破损船舶倾覆机理研究

海浪常以波群的形式存在，即几个波高大的浪连在一起出现。项目申请人前期研究预示着：破损船舶在随机海浪中倾覆行为应与其所遭遇的波群特性密切相关。然而，实际海浪中波群特征的随机性、以及不同进水阶段船舶水动力特征的多样性使得破损船舶倾覆问题异常复杂。为了揭示破损船舶在随机海浪中倾覆机理，本项目拟对随机横浪中船舶破舱进水和船舶运动相互耦合动力学建模方法、以及特征波群作用下船舶倾覆问题开展研究。首先，建立基于势流和粘性流理论双向耦合求解船体远场和近场的时域非线性水动力模型，以突破随机波浪中破损船舶运动计算精度和效率难以兼顾的技术瓶颈。其次，提出基于特征波群激励的破损船舶倾覆预报分析方法，具体工作包括：随机波群构建及模拟、特征波群寻获、波浪群性对进水演变及船舶行为影响分析、倾覆机理探究、水池试验及理论方法验证，以弥补传统研究中忽略波浪群性对破损船舶倾覆行为影响的不足，为相关理论和试验方法发展提供新思路。

Wave groups, which are sequences of high waves, are often observed in the sea waves. Our previous study indicated that the capsizing of a damaged ship in random sea waves was closely related to the characteristics of wave groups that the ship encounters. Note that the randomness of wave group characteristics and the diversity of ship hydrodynamic characteristics in different flooding stages make the problem of damaged ship capsizing in random waves extremely complicated. In order to reveal the capsizing mechanism of a damaged ship in random sea waves, the present research project focus on the modeling of interactive dynamics of floodwater and damaged ship motion in beam waves as well as the problem of ship capsizing under the action of characteristic wave groups. First, a non-linear time-domain hydrodynamic model is established, aiming to break through the technical bottleneck in the simulation of damaged ship motion in random waves with high computational accuracy and efficiency. To this end, this model couples the potential flow and viscous flow theories in two ways to solve the far and near fields of ship. Second, an approach to analyze the capsizing behaviour of a damaged ship under the excitation of characteristic wave groups is proposed. The work includes generation and simulation of random wave groups, definition of characteristic wave groups, analysis of the influence of wave groups on the flooding evolution and ship dynamic behavior, investigation of capsizing mechanism, model test in water tank and verification of proposed method. The aim is to make up for the lack of ignoring the wave group effects on the capsizing of damaged ships in traditional research, and to bring new concept into the development of theory and experimental method in related area.