【作者】 姜大宁；

【导师】 唐友刚；

【作者基本信息】 天津大学 ， 船舶与海洋结构物设计制造， 2005， 硕士

【摘要】 钢筒组块由四个大直径圆筒组成,底部充气实施海上拖航。本文研究气浮钢筒组块拖航过程中的稳性和波浪中的运动特性。本文考虑气浮钢筒组块的几何参数、充气压力,及不同的吃水,引入气浮力折减系数的概念,研究与静稳性有关的参数和稳性指标的计算方法,基于船舶静力学的理论方法,提出了钢筒组块静稳性的计算方法,计算了四个直径10.5m的钢筒组成的结构模块在6种不同吃水及不同充气高度下的稳性指标,得到了模块的初稳性高,评估了不同浮态下的稳性。考虑波浪参数和充气压力,研究气浮钢筒的绕射和辐射波浪载荷,以及结构系统运动响应的数值预报方法。将水柱考虑成运动活塞,密闭高压气体考虑为气弹簧,提出了钢筒组块的运动分析计算模型。采用波浪的势流理论,通过展开的特征函数和匹配渐进法确定钢筒组块的绕射速度势,进而得到作用在钢筒组块上的波浪载荷,通过采用展开的特征函数和匹配渐进法得到钢筒组块辐射速度势,进而求得钢筒组块在微幅振荡运动时的附加质量系数和附加阻尼系数。针对直径10.5米的四个钢筒组成的模块,计算得到了其波浪载荷及运动响应,计算结果表明了本文方法的可行性。更多还原

【Abstract】 The steel cylinder block is made up of four large diameter cylinder. To aerate atthe bottom, and the block is towed in wave. The static stability and motion responseof steel cylinder block in the wave are studied in this paper.The concept of air floating decrease coefficient was introduced and thecomputing method about correlative parameters and stability indications of staticstability were studied considering the geometry parameters, air pressure and differentdrafts. Based on the theoretical methods of the statics of the ship, computing methodon static stability of steel cylinder block is given, the stability properties of thestructure block made up of four steel cylinders whose diameter is 10.5m werecalculated under six kinds of drafts and different aeration heights, the initialmetacenetric height of the structure block was obtained, and the stability wasevaluated under different floating conditions.The wave loads computing method and the mathematical prediction method ofthe structure system motion response were studied by using diffraction theory,radiation theory considering the wave parameters ,air pressure. The water column wassimplified into moving piston and the high pressure is dealt with gas springs, then thecomputation model of motion for steel cylinder block was put forward. Thediffraction velocity potential was solved by wave potential flow theory and theboundary progressive matching method, then the wave loads acted on the steelcylinder block were gained. By the boundary progressive matching method, theradiation potential of the steel cylinder block was calculated, the added-masscoefficient and added-damping coefficient of the steel cylinder were obtained . At last,the wave loads and motion response of the structure block made up of four steelcylinders were calculated. The results show that the method in the paper is practical.更多还原