波浪中破损船舶的运动响应研究

波浪中破损船舶的运动会同时受到波浪激励和进出水的影响,而船体运动也会影响进出水过程,二者的相互影响机理十分复杂.本文重点研究波浪中破舱进出水对船舶运动响应的影响,文中首先基于势流理论建立了考虑破舱进出水的4DOF(横荡-垂荡-横摇-纵摇)相互耦合时域预报方法,在计算中假设舱内的液面水平,利用修正的伯努利方程模拟破舱进/出水,利用Ikeda's经验公式修正阻尼系数.然后以一艘ITTC破损稳性标模为例,研究了波浪中考虑破舱进出水的数学模型以及破舱进出水对运动响应的影响,并研究了不同自由度、破舱口位置对运动响应的影响.研究表明,本文基于势流理论建立的时域预报方法可以定量的预报破损船舶的运动响应.

A study on the motion behavior of damaged ship in waves

The motion responses of damaged ship are affected not only by external wave excitation, but also by internal liquid loads induced by water flooding. Simultaneously, the dynamics of floodwater motion are also affected by the ship motion. Its underlying mechanism is still not well understood due to the complicated dynamics between the floodwater and the damaged ship. This paper focuses on the study of the effects of the inflow and outflow of water through the damage openings on damaged ship motion behavior. Firstly, four degrees of freedom models based on the potential flow theory with modified Bernoulli' equation for floodwater motion were used for the simulation of damaged ship. Secondly, taking ITTC standard model as an example, the mathematical model for the damaged ship behavior in waves and the effects of floodwater on ship behavior were studied. In addition, the effects of different freedoms and the location of damage opening on the motion responses were also analyzed. The research show that the 4DOF models combined with reasonable modelling of roll damping can predict satisfactorily results.