50000DWT半潜船总体设计综述

50000DWT半潜船是船院为中远航运开发设计的新一代大型半潜船,具有载货能力强、操作灵活方便、安全环保等显著特点。文章介绍该船的总体设计,首先简要介绍半潜船的基础知识、半潜船运输市场的现状和发展前景,其次介绍该船的设计概况和主要技术特点,然后分析了规则规范的选取和适用情况,最后重点从总体布置设计和总体性能计算两个方面进行展开,对该船总体设计上的特点和难点、与常规货船的差异、所采取的技术措施、运营中的安全保障、操作要点等进行了详细的分析比较和论证。     

Possible remedies for intact stability hazards involving contemporary small inland passenger ferries in Bangladesh

On the basis of previous studies, a series of hazards involving the typical small inland passenger ferries operating in inland Bangladeshi waters have been identified. In particular, stormy weather conditions, overloading, and the risk of crowding to one side have been determined as the typical events that are likely to lead to capsizing in the intact condition. In this article, possible hazard mitigation measures are discussed, both from the regulatory and from the design point of view, for a small inland ferry that is very similar to one that actually capsized in the past. The addressed design options involve ballasting and hull modification by means of additional buoyancy above the waterline. From a regulatory point of view, it is proposed that the present weather criterion in force in Bangladesh be modified by increasing the wind speed to be accounted for and by considering the concurrent effects of wind, rolling, and the crowding of people to one side.     

两个气泡相互作用的某些动力特性研究

文章采用边界积分方法模拟三维水下气泡的动力特性,详细阐述气泡计算的数学模型和数值实施过程,探究了三种不同浮力参数情况下(无重力、弱浮力、强浮力)气泡的演变情况。计算结果表明,在不同的浮力参数下,气泡形状和射流特点有着显著的区别,射流形成和发展与重力有着密切的联系。文中计算了两气泡在不同距离和不同强度参数下的相互作用的特点,为气泡动力特性的研究提供了参考。     

脐带缆深水安装的参数影响分析(英文)

随着水深的增加引起外部压力的增大和脐带缆的重量相应增加,且由于海洋环境载荷和浮体的运动引起复杂的动力特性使得脐带缆的受力复杂,其安全性受到很大的挑战,故深水安装是脐带缆的关键问题之一。文章详细分析了安装过程中不同浮力块的布置方式(不同尺寸,长度和布置位置)和波浪与流的方向对脐带缆的影响。利用悬链线方程构建自由悬挂的脐带缆的模型,然后施加浮力与环境载荷得到动态脐带缆的安装模型。通过对比分析表明,浮力块的布置方案和波浪与流的方向对脐带缆的安装都有很大的影响,上述这些参数在安装中需要给予重视。     

固体浮力材料在船闸闸门上的应用

介绍了一种新的方案,将浮力材料安装在闸门底部主梁区隔内,抵消闸门的部分自重。对浮力材料的分类、行业应用、材料特性进行介绍。对浮力材料与钢浮箱进行比较,证明浮力材料在船闸钢闸门上应用的可行性,可以在新建大型闸门、老旧船闸改造中推广应用。     

深水钻井的“人工海底”技术开发和中国南海预试验井的实施

介绍了中海油田服务股份有限公司在中国南海进行的预试井活动,讨论了将用于深水油山钻井作业的人工海底新技术.深水钻井市场在最近10年中处于不断扩张的过程,目前世界上用于深水和超深水钻采作业的钻井船和甲台数目不足.中国目前也需要更多的设备用于深水海洋的钻采作业.中海油田服务股份有限公司目前拥有的一些半潜式钻井平台可以在水深浅于475m的水深中进行作业.自从2004年以来,中海油田服务股份有限公司与挪威公司合作,进行人工海底技术的研究和改进,这种技术发展的目标是,利用较浅水作业的钻井平台,进行水深1 000～1 500 m的油气田的钻井作业.介绍了该种技术研究和改进的过程,相关装备的生产和更新.2008年6月,在中国南海的500m水域应用人工海底技术进行了预试验井的作业.2009年,中海油田服务股份有限公司将在中国南海的同一海域进行另一次更深入的实际钻井作业.     

水下滑翔机浮力系统的机理和调节性能

为掌握温差能驱动水下滑翔机浮力系统的调节性能,对浮力系统的工作机理和浮力调节部件的体积变化规律进行了动态分析.分析提供的数据和结果,为优化阀口的通流面积确定了具体方向,并保证了浮力调节系统达到设计的标准;获得的浮力调节时间长度数据为阀门闭合控制的动作设计提供了确切依据.     

沉管隧道主体结构设计关键技术分析研究

从管段分节、起浮与干舷、抗浮、结构强度及连接技术方面对沉管隧道主体结构设计进行了论述,提出了各部分的设计思路、影响因素和计算方法,总结了在沉管隧道主体结构设计时认识到的关键技术,可为今后的沉管隧道主体结构设计提供参考。     

The wind-forced response on a buoyant coastal current: Observations of the western Gulf of Maine plume

The freshwater plume in the western Gulf of Maine is being studied as part of an interdisciplinary investigation of the physical transport of a toxic alga. A field program was conducted in the springs of 1993 and 1994 to map the spatial and temporal patterns of salinity, currents and algal toxicity. The observations suggest that the plume's cross-shore structure varies markedly as a function of fluctuations in alongshore wind forcing. Consistent with Ekman drift dynamics, upwelling favorable winds spread the plume offshore, at times widening it to over 50 km in offshore extent, while downwelling favorable winds narrow the plume width to as little as 10 km.Using a simple slab model, we find qualitative agreement between the observed variations of plume width and those predicted by Ekman theory for short time scales of integration. Near surface current meters show significant correlations between cross-shore currents and alongshore wind stress, consistent with Ekman theory. Estimates of the terms in the alongshore momentum equation calculated from moored current meter arrays also indicate a dominant Ekman balance within the plume. A significant correlation between alongshore currents and winds suggests that interfacial drag may be important, although inclusion of a Raleigh drag term does not significantly improve the alongshore momentum balance.     

分布式浮块在深水油气田开发中的应用

概 要：分布式浮块DBM(Distributed buoyancy module)主要为深水柔性管线提供上浮力,以维持柔性管线所需的波形,文中重点分析了DBM浮块、夹具结构及测试要求等,为DBM在我国深水油气田的应用及发展提供参考。