可控被动式减摇水舱气阀控制规律研究

可控被动式减摇水舱是对被动式减摇水舱的一种改进.文章在可控被动式减摇水舱系统数学模型的基础上,推导了最佳控制相位的理论依据,并对气阀开启和关闭时刻的选取进行了研究.对不规则波的仿真结果表明,根据船舶的横摇角速度进行气阀控制,满足最佳控制相位是行之有效的,它使可控被动式减摇水舱的减摇能力最大,减摇效果更佳.     

可控式被动减摇水舱最佳相位PD控制策略研究

在"船舶-可控式被动减摇水舱"系统数学模型的基础上,综合船舶横摇运动信息设计最佳相位PD控制器,并对可控式被动减摇水舱气阀的开启和关闭进行控制。在不规则波下的仿真结果表明,与常规控制相比,采用最佳相位PD控制策略能够取得更好的减摇效果,最大程度上发挥可控式被动减摇水舱的减摇能力。     

可控被动式减摇水舱控制策略研究

从未减摇和装减摇水舱后的船舶运动方程出发,对可控被动式减摇水舱的水舱控制策略进行了研究,指出应从充分发挥减摇水舱的性能角度出发,选择水舱的最佳控制策略。从能量最少角度考虑,当波浪频率远离船舶谐摇频率时,可以考虑选择关闭水舱的方式进行控制。仿真结果表明,存在一个最佳控制策略,能够使水舱的性能得到充分发挥,这时水舱减摇效果最高。     

可控被动式减摇水舱随机控制策略研究

在"船舶-可控被动式减摇水舱"系统数学模型基础上,根据安装减摇水舱的船舶在随机海浪作用下的横摇运动特点,利用成型滤波器以及在线辨识方法对"船舶-可控被动式减摇水舱"系统横摇运动进行预报,并利用预报信息以及实时测量信号对减摇水舱内液体进行控制,实现船舶横摇运动与水舱内液体运动的相位控制,使减摇水舱在不同航态以及不同海情下均有较好的减摇效果.     

横荡对被动式减摇水舱运动的影响研究

被动式减摇水舱是减少船舶摇摆的重要装置之一,目前对它的研究大多数都只针对单纯横摇运动。而本文在考虑了横荡对水舱运动的影响后,基于U型被动式减摇水舱理论推导了耦合横荡的“船舶一水舱”系统的数学模型,并通过仿真和试验研究证实了考虑横荡对水舱的影响是很必要的,更符合于实际情况。     

基于气阀控制的频率自适应减摇水舱系统研究

文章在建立减摇水舱内气体和液体两相流动的运动模型基础上,研究了水舱顶部气体连通道的横截面积大小与水舱内液体振荡参数之间的关系,通过调节截面开口控制水舱内液体运动固有频率,使之与船舶横摇频率相适应.分别利用被动式PD控制和模糊控制实现气阀开关式和气阀开口连续式两种调频策略.仿真研究表明,两种调频策略均使可控被动式水舱的有效减摇范围拓宽,并在不同的频率范围内有各自的优势.     

参数频率响应法在"双水舱"系统中的应用

使用两个具有不同固有频率的被动式U型减摇水舱能给横稳心高变化范围很宽的船舶提供很好的减摇效果,本文给出了参数频率响应法,推导了装备两个具有不同固有频率的被动式U型减摇水舱的船舶横摇频率响应函数,分析了影响船舶横摇频率响应幅值的水舱参数。通过仿真详细研究了水舱参数对船舶横摇减摇的影响。研究结果对于双被动式U型减摇水舱的设计具有重要的指导作用。     

海工辅助船可控被动式减摇水舱设计

为减小船舶摇荡,特别是横向摇荡,在提高船舶安全性的同时满足乘客对船舶舒适性的要求,以海工辅助船为研究对象,设计一种可控被动式减摇水舱。按照"双共振"原理,考虑海工辅助船在海上作业时所处的各种环境,以U型可控被动式减摇水舱为基本模型,根据固有周期的经验估算公式,计算出减摇水舱的基本参数,设计轻型海工辅助船减摇装置,并对其效果进行分析。研究结果表明,采用该减摇装置能达到较好的减摇效果。     

基于PAC的可控被动式减摇水舱控制系统设计

根据可控被动式减摇水舱的基本原理和工作特点,分析气动系统原理,设计控制策略、PAC外部接线、I/O逻辑表、程序控制流程等,实现了可控被动式减摇水舱的水阀—气阀联合控制。该系统具有能耗低、噪音小、寿命长、可靠性好、操作容易等特点。     

基于GPC的气控被动式减摇水舱研究

在建立减摇水舱内气体和液体两相流动的运动模型基础上,研究了水舱顶部气体连通道的截面面积大小与水舱内液体振荡参数之间的关系.利用广义预测控制(Generalized Predictive Control, GPC)对水舱内液体运动参数进行在线滚动寻优计算,并通过调节截面开口大小实现参数的调节,以此控制水舱内液体的流动,使之与船舶横摇运动相适应,对抗外部海浪干扰.仿真研究表明,与传统的开关式气阀控制策略相比,新的控制策略可以明显提高被动可控式减摇水舱的减摇效果,在较宽的频率范围内对船舶进行有效减摇.     

33rd International Conference on Ocean,Offshore and Arctic Engineering （OMAE2014）

正San Francisco,California,June 8-13,2014.OMAE 2014 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to:·meet and present advances in technology and its scientific support;·to exchange ideas and experiences whilst promoting technological progress and its application in industry·to promote international cooperation in ocean,offshore and arctic engineering.In line with the tradition of excellence of previous OMAE conferences,more than 900 technical papers are planned for presentation.Outreach for Engineers Specialty Forum This Specialty Forum is designed for students and professionals who may not be familiar with the Ocean and Offshore industry,as well as those who have just recently specialized in this field.     

Errata

正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.     

Journal of Marine Science and Application 2014 Sum. Contents

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联合作战计划和执行系统

全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划：时间不限的精密预案计划生成作战计划、方案计划或职能计划；时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础，加速应付危机的能力。     

Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.     

The 11th International Conference on Hydrodynamics (ICHD 2014)

正19–24 October 2014 SingaporeCONFERENCE THEMES The overall aim of the ICHD Conference is to provide a forum for participants from around the world to review,discuss and present the latest developments in the broad discipline of hydrodynamics and fluid mechanics.The first International Conference on Hydrodynamics(ICHD)was initiated in 1994 in Wuxi,China.Since then,9 more ICHD conferences were held subsequently in Hong Kong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,Shanghai and St Petersburg.Evidently the ICHD conference has become an important event among academics,researchers,engineers and operators,working in the fields closely related to the science and technology of hydrodynamics.The 11th ICHD will be held in Singapore in 2014.     

第十二届深水操作会议和展览会(英文)

正November 4-6,2014Moody Gardens HotelConvention Center/Galveston,TX The Deepwater Operations Conference and Exhibition is celebrating its 12th anniversary this year.This growing event will continue the tradition of excellence in addressing operational challenges involved in developing deepwater resources.We will return to the Moody Gardens Hotel and Convention Center on November 5-7,2014 in Galveston,Texas.     

Eastbound or westbound ?

In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama？
The answer is China South Port Group （Hong Kong, Shenzhen and Guangzhou）.     

Impact of regulation on the performances of long-distance transport services: A comparison of the different approaches in Sweden and Norway

Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.     

某海港码头的撞损修复

依据码头撞击受损区域调查检测结果,对受损构件提出合理的修复方案,为码头的安全运行提供保障。