舰船破舱进水过程时域模拟

舰船破舱进水过程的时域模拟是解决未来舰船破损沉没时间预报、可供救援时间预报、救援措施选择等诸多新挑战的惟一可行方式。目前国内对舰船破损稳性的研究并没有涉及舱内空气对进水的影响。本文对破舱进水过程时域模拟的研究方法进行了探讨。应用Fluent软件对大量二维及三维计算模型进行了破舱进水的时域模拟;探讨空气流对进水过程的影响。对船舶破损口处进水速度的变化进行讨论和探讨。得到结论:在特定情形下,对于空气流的计算模拟必须考虑在内,并且提出了1种减少计算域的研究方案。这些探讨对破舱进水时域模拟研究方法的选择有一定借鉴意义。     

破损舰船瘫船状态倾覆概率评估方法

国际海事组织已基本确定了完整船瘫船状态下的第2层薄弱性倾覆概率评估方法。由于破损舰船在风浪中运动的复杂性,破损舰船瘫船状态下的倾覆概率评估方法还未提出。基于完整船瘫船失效模式评估方法的思想,对破损舰船的横摇运动进行简化,提出一种评价破损舰船瘫船状态下倾覆概率的方法,并利用实船进行计算分析。分析各参数对倾覆概率的影响,研究对称进水和非对称进水这2种情况下的倾覆概率。结果表明:所提的用于评价破损舰船瘫船状态下倾覆概率的方法可行,其中非对称进水更为危险,可为研究破损舰船瘫船稳性提供参考。     

破损进水舰船非线性横摇运动的实验研究

通过设计破损舰船非线性横摇运动实验,对不同状态下的船模进行定频率变波高和定波高变频率的横摇激振试验,探讨舰船横摇运动的水动力特性随横摇频率和横摇幅角变化规律,分析Ⅱ类和Ⅲ类进水舱对破损舰船横摇运动的水动力特性的影响。运用混沌信号识别技术分析破损舰船进水后横摇运动的混沌特性,验证数值仿真的结果,预报破损舰船在规则波中的横摇运动的幅频响应和相频响应。     

舰船破损进水过程的非线性横摇运动仿真

建立了大型舰船破损进水过程的横摇运动模型。该模型描述了破损进水运动和船舶横摇运动的耦合,并运用Runge-Kutta迭代方法对具有进水过程的横摇运动进行数值仿真,并探讨不同参数的影响,从而为舰船防沉抗沉提供理论依据。     

基于横摇过程的舰船破损模式识别算法

在舰船破损进水过程的横摇运动时域模型的基础上,求解得到横摇运动的时域曲线;对此时域曲线通过特征提取得到其破损模式的识别属性;通过案例推理技术建立舰船破损模式识别算法.该识别算法的实现可为舰船抗沉决策提供准确的破损信息,有利于舰船的防沉抗沉.     

舰船船底破损后的外载荷和应力研究

以某舰船为例,用符拉索夫法计算了鱼雷在舰船底部非接触爆炸使舰体结构产生破损后由于进水引起的浮态和载荷变化,给出了鱼雷命中破损后波浪弯矩随不同破损部位、不同进水体积的变化规律。在此基础上计算了鱼雷爆炸使舰体结构产生破损后的应力。研究指出,计算破损舰船结构应力时必须同时考虑破损使结构承载力大大下降和由于进水引起的浮态和载荷变化对舰艇生命力的影响。舰体结构的正应力和剪应力都随着进水体积的增大而增大,鱼雷最危险的命中位置是船中和剪力最大处。研究对舰船生命力的评估有重要意义。     

舰艇沉没概率解析计算模型

对影响沉没概率计算的要素进行分析,给出沉没概率的解析计算模型;然后,对解析计算模型的2个关键问题,即水密区破损概率计算模型和沉没判据模型进行了研究。考虑到武器炸点在三维方向上分布是独立的,建立了水密区破损概率计算的解析模型。分析舰艇沉没的判据指标,并建立基于支持向量数据描述的沉没判别算法。最后,使用此解析计算模型对某船模的沉没概率进行了计算,该算例说明了此解析模型的准确性。     

具有淹水舱的舰船横摇运动建模探讨

舰船在风浪中横摇运动特性是影响舰船航行安全的主要因素,而当舰船由于碰撞、搁浅等意外事故造成船体破损进水后,具有淹水舱的舰船在风浪中的横摇运动将变得更加复杂,更加危险,文章系统地分析了具有淹水舱的舰船在波浪中横摇运动时船和舱内水的能量耦合作用,根据拉格朗日方程建立了具有淹水舱的舰船横摇运动两自由度微分方程,并在此基础上,用Melnikov方法对某实船破损进水后的横摇运动进行了非线性分析,验证了所建模型的实用性,为进一步分析破损进水舰船在风浪中的横摇运动特性提供了可行的数学模型.     

基于遗传算法的舰船破舱浮态调整措施优化研究

为使海上受损舰船得到良好的扶正效果,对若干压载水舱注入水或排出水,使舰船具有良好的浮态与稳性,这对于提高舰船的安全性和战斗力具有极其重要的意义。本文根据海上舰船的实际破损情况,研究了基于遗传算法(GA)的破损进水舰船的优化扶正措施方案的计算方法;采用符号编码的方式,在GA算法中,通过在进化的不同阶段,设置自适应的交叉及变异概率,提高进化速度,便于找到全局最优解,并编程实现,结果表明遗传算法对于舰船破舱进水的扶正优化是有效的。通过对实船破舱扶正措施的优化并与传统方法的优化结果对比,证明了用GA优化破损舰船扶正措施的先进性和工程实用性。     

破损舰船在波浪中的响应预报与试验研究

为研究舰船破损后在波浪中的响应,开展舰船在完整正浮状态以及破损后倾斜状态的模型试验。基于三维线性势流理论,使用三维频域方法对模型破损前后的响应做数值预报。与试验结果相比,数值预报结果符合较好,验证了预报方法的合理性。最后,通过与该舰船模型破损前的响应结果对比,研究分析破损对舰船在波浪中响应的影响。     

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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第34届海洋、离岸及极地工程国际会议(英文)

正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 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;     

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.     

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.     

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。     

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.