受复杂多变的海况和航行环境的影响,船用液化天然气((Liquefied Natural Gas,LNG)燃料罐在船舶航行过程中承受着交变应力的作用,面临着疲劳损伤风险.为分析船用LNG燃料罐的疲劳损伤情况和使用寿命,以某18 m3船用LNG燃料罐为研究对象,采用有限元分析方法找到其最大应力热点,根据装置的长期分布载荷谱、材料的疲劳曲线和疲劳累积损伤准则计算得到LNG燃料罐的疲劳损伤数据并对其进行量化分析.研究结果显示,该LNG燃料罐的疲劳性能满足中国船级社(China Classification Society,CCS)规范的设计要求,采用的燃料罐疲劳损伤量化分析方法是可行的,可供船用LNG燃料罐的工程设计参考.

With the large-scale development of the liquid carriers to meet the increasing demand of natural resources, the risks resulted from liquid sloshing such as the local structure damage and deteriorating stability subsequently have a sharp increase. In this paper, the dynamic response of the partially-loaded liquid tank in regular waves is investigated both experimentally and numerically. In the experiments, the model of the liquid tank is restrained to two degrees of movement including both heave and pitch. The experiments are carried out in the wave flume with different wave heights and periods, and PIT 3D motion capture system is adopted to track the motion of the liquid tank. For the numerical simulation, VOF method combined the technique of overset meshes is applied to solve the multi-phase flow during the liquid sloshing. By comparison, it can be found that the experimental and numerical results have a good agreement in most cases and the frequency when the phenomenon of liquid sloshing becomes the most violent is less than the natural frequency of the liquid tank.

In view of the problems of clean electricity consumption of berthing ships and rapid response of power supply of some ports,small islands,and offshore platforms,the development status of large Liquefied Natural Gas(LNG)generating ships and their main systems are expounded,the relevant design experience of LNG ships at home and abroad is cited,and the hull,LNG piping system,and power-propulsion complex system of 20 MW LNG generating ship are designed with the modular design method,which can provide the optional solutions to the main difficulties in the design of the ship.

考虑不同的底边形状对楔形体入水砰击的影响,对平板自由落水的砰击问题进行数值模拟分析,将数值计算结果与试验结果进行对比,验证了该数值方法的有效性.在此基础上,探究不同下落高度和不同底边形状对楔形体入水砰击的影响.分析和对比不同参数的楔形体入水过程中的加速度以及砰击压力的变化,表明初始高度对砰击压力峰值的影响较大,外凸型楔形体的砰击压力主要集中在底部,而内凹型楔形体整体所受的砰击压力较为均匀.

以一家生产工艺成熟船企的20000 m3液化天然气船(LNG)液罐安装过程为例,分析LNG船液罐安装工程的特点和重点关注问题,介绍液罐安装技术中有关安全防护的关键点,结合行业相关规范要求提出相应的安全防护工艺.实践证明,该安全防护工艺对此类船舶的液罐安装安全防护工作有一定指导和参考价值.

Taking KCS ship model as an example, using numerical tank technology and commercial CFD software, the free heave and trim motion of ship model sailing in infinite depth of still water is simulated in the time domain. Based on the coupled solution of ship motion equation and fluid flow equation, the VOF method is used to deal with the nonlinear free liquid surface, and the overlapping grid technique is used to deal with the grid. Finally, the relevant conditions of the ship model such as resistance, heave and trim are obtained, and the detailed information of the flow field including free surface wave, ship surface wave height and ship surface dynamic pressure are obtained at the same time, which is helpful to understand the mechanism of ship heave and trim motion. The calculated results are compared with the relevant experimental data, and the agreement with the experimental data is good.

针对全球化绿色环保运动风起云涌的态势,有效实施国际海事组织2020年1月1日起全球船用燃油限硫规定,减少船舶大气污染物排放,促进绿色航运发展,推进应用LNG等清洁燃料,国内外研发LNG运输及加注型船舶的潮流汹涌澎湃、突出海上加注技术的船型研究逐渐成为航运业关注的焦点.

This study adopts the numerical simulations of Moving Particle Semi-Implicit Methods (MPS), which are meshless methods based on Lagrange particles. Using Lagrange particle has an advantage that it can avoid numerical dissipation problems without directly discretizing the convection term in the governing equation. First of all, a numerical model of a liquid sloshing tank without baffles is used to confirm the effectiveness of the MPS by comparing the numerical results with the experimental data of Kang and Li. And the pressure curves obtained with MPS method were in good agreement with the experimental findings, which confirmed its effectiveness. On that basis, simulations of liquid sloshing movements with one baffle, two symmetrical baffles, and three baffles are performed, respectively. The results indicate that the addition of vertical baffles in the tanks effectively enhanced the ability to reduce liquid sloshing.

船舶航行安全问题,尤其是在恶劣的天气条件下,一直以来都受到水上运输行业的特别关注和重视,也是船舶安全评估的关键课题之一.本文结合模糊综合评判法和层次分析方法,采用组合权重方法,将影响船舶航行安全的主客观因素结合在一起,形成了针对船舶航安全性评估的模糊层次综合评估方法,并以船舶机舱消防系统为例来验证了该方法的有效性.

针对集装箱船大型化所面临的诸多问题,本文就超大型集装箱船支撑式横舱壁处的过渡结构进行疲劳强度研究.以1艘12200 TEU集装箱船为例,利用MSC.Patran进行有限元建模,采用疲劳分析软件MSC.Fatigue进行载荷自动加载,应用简化应力分析法分别对3种不同结构形式进行疲劳强度的计算,求得了每种结构形式在热点处的累计损伤度和疲劳寿命,并进行比对分析,得到了一种相对更为优秀的结构形式.

The phenomenon of a water mound can show up in the process of water-exit of the missile [1], and the a water mound will break and splash in a very short time, which will exert an extra force on the missile and therefore will affects the movement of the missile as well as the gesture when the missile comes out the water. Therefore, investigation into the water-exit process of the missile is of great significance to the launch of the underwater missiles. The traditional grid methods always fail to simulate the whole the water-exit process because of the large deformation of the mesh. The paper adopts a meshless method, called Moving Particle Semi-Implicit method (MPS), to study the water-exit process of the missile. Based on verifying it by the dam break simulation, MPS is applied to simulate the water mound during the water-exit process, which is aiming at providing some reference for the relevant theoretical research.

支线型集装箱船在布置数量较多的水冷式冷藏集装箱情况下,如何保证冷藏集装箱水冷却流量平衡分配并确保冷藏集装箱冷藏效果成为设计的关键点.文章结合某2200标准箱集装箱船实例,介绍了冷藏集装箱船的水冷却系统的设计、注意事项及试验方法.为今后大中型集装箱船冷藏箱冷却水系统应用提供设计依据.

为了解决制罐的效率和质量问题,将吹气分离、真空吸料、板料厚度的判定等技术应用到上料冷轧机构的研制中.开展了制罐过程存在的分张、成圆、双张检测等技术问题的分析,并提出了吹气分离、真空吸料和板料厚度的判定方法等,设计出了电阻焊机中的新型真空吸料机构、双张检测机构、成圆机构和输送机构,从而最终研制出一种制罐用的上料冷轧机构.研究结果表明:该上料冷轧机构在制罐过程的的吸料、送料、双张检测、罐身成圆及输送环节都具有较好的协调控制;它提高了制罐的效率和质量,增强制罐机的工作性能和可靠性.

:为了解决三片罐罐身出现裂口 、三片罐罐身两端不齐、焊机轮系的不稳定和罐身焊接时搭接量不稳定的问题,研发了可变速送罐的三片罐电阻焊设备.该型设备采用了可变速送罐机构、稳定的焊机轮系、新型铜线压扁机构和新型定径规,可以很好地控制送罐速度,保证焊接轮系的稳定性、控制铜线的压扁尺寸和保证搭接质量,大大提升了电阻焊机的工作稳定性,减少了废品罐出现的次数,提高了三片罐的焊接质量.

Noise and vibration reduction in the hull design,is becoming more important.Take the 2 750 TEU container ship as an example,expounded on the overall vibration,free vibration,forced vibration and lo-cal vibration analysis to calculate the whole ship's natural frequency and excitation frequency.This method of calculation for the same ship's design and vibration analysis was provided.

精度造船技术对提高造船企业的经济效益和市场竞争力有重大推动作用,该技术在地方船厂的应用尚处于初级阶段。本文以2750TEU首制船为例,阐述了精度造船技术的基本理论与应用方法,介绍精度造船技术的应用经验。