基于CFD的船舶球首型线自动优化

在满足排水量及航速要求情况下设计出性能优良的船体型线,降低船体阻力、节能降耗是造船界一直所追求的目标。船舶球首的大小、位置和形状对船体兴波影响非常大,因此文章通过船型参数化融合方法,生成一系列球首型线,并以兴波阻力最小为目标,采用遗传算法实现球首型线的自动优化。将上述方法应用于某集装箱船球首型线的自动优化,并进行船舶静水阻力实验,实验表明优化船型在设计航速附近总阻力降低明显,说明文中采用的基于CFD船型自动优化方法是可行的。     

基于CATIA二次开发的球首参数化设计

为实现在船舶型线设计中快速生成船舶球首,以船舶球首为研究对象,通过定义控制球首形状的纵向边界线、横向边界线、横剖面形状,设置相关控制参数,以CATIA为开发平台,VB为开发工具,对其进行二次开发,编制球首参数化设计程序,迅速地生成球首三维模型。     

舰艇新型球鼻首结构设计探索

从材料选型入手对舰艇新型球鼻首的结构设计进行探索,研究结构和声学性能要求,提出性能优良的球鼻首结构方案,以备新型舰艇球鼻首的实际建造和后续发展.     

球鼻首分段施工方法的分析

在各种船型球鼻首分段建造方法的基础上,针对2 300车位汽车滚装船的球鼻首分段的结构特点,提出一种全新的球鼻首分段的建造方法。通过与传统建造方法的对比分析,发现以中纵壁板为胎建造此类球鼻首分段的建造方法,建造周期短,安全性高。     

基于Grasshopper的参数化球鼻艏生成方法

针对在球鼻艏减阻优化设计循环中手动建模方法无法满足需要的问题,提出了利用软件Grasshopper开发一种新的参数化球鼻艏生成可自动变形的球鼻艏的方法。该方法首先定义了球鼻和主船体之间的过渡区域,通过过渡区域的自由变形,实现了球鼻与主船体的光顺连接。然后实现生成的球鼻艏可以根据输入参数的变化自动修改形状。最后将该方法应用在一艘集装箱船体上。结果表明:该方法可以高效地应用于商业船舶的参数化球鼻艏建模。     

舰船球鼻首结构试验研究

作为船体中比较特殊的双曲结构,舰船首部的球鼻首相关的结构试验规范很少.为探索试验方法,开展了一系列的实物试验研究,通过合理实施途径进行试验,得到直接测试数据,并验证设计的合理性.针对舰船球鼻首进行的3项试验:静态压力试验、抛落试验和爆炸试验,介绍了试验前的准备工作、测点布置、过程和响应情况,为特殊结构的设计和试验规范的制定打下基础.     

浅谈球鼻首在川江的应用

本文介绍了球鼻首在川江的应用及实用经验。     

基于BP网络的球鼻首参数化优化

本文以某集装箱船为研究对象,对降速航行后的球鼻首进行优化。采用Catia建立船体三维模型,为了产生不同形状的球鼻首,选取球鼻特征参数来描述其基本结构;采用拉丁超立方试验抽样方法得到12组不同形状的球鼻首,提出运用非线性拟合能力较强的BP网络构建球鼻首参数和阻力系数之间的关系模型;采用遗传算法对训练后的网络进行极值寻优。结果显示,优化船型的阻力系数显著降低,说明该方法对球鼻首的优化有一定的借鉴意义。     

玻璃钢球鼻首导流罩结构设计

介绍了玻璃钢球鼻首导流罩的结构设计方案流程,重点探讨了球鼻首构架形式设计,并利用MSC-Nastran大型有限元分析软件对导流罩强度和稳定性进行校核计算。结果表明:该方案可以满足声纳导流罩的强度和声学性能要求,为以后进行玻璃钢球鼻首导流罩的设计提供参考。     

基于多种组合优化算法外形优化设计

针对船型特征参数和特征参数曲线对船体阻力性能的影响,首先利用CAESES软件建立完全参数化船体模型,并用FINE/Marine软件进行水动力性能计算,并与试验结果进行比较,验证了数值模拟的可靠性。对船型进行优化时,以设计航速2.02 m/s下的总阻力为优化目标,利用2种组合优化算法进行分析,发现第1种Sobol算法和NSGA-II算法组合优化算法具有优势。船型优化后球鼻首发生了显著变化,球鼻首变为抬首型球鼻首,其中,球鼻首的长度和宽度变化对船体阻力影响不大,基本上可以忽略。在设计航速下,优化后的总阻力减少14.89%,摩擦阻力减少0.43%,剩余阻力减少36.9%。     

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;     

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。     

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）.     

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.     

桥梁防撞设施物理模型试验

物理模型试验是预报防撞设施所受撞击力及优化设计方案的主要方法之一。结合杭州湾大桥柔性防撞设施及东海大桥独立式防撞体设计方案,阐述了船—防撞体撞击试验的基本原理、方法、试验方案及相关试验结果。提出了柔性防撞系统的优化方案。试验结果表明,该方案经济有效,可供预报类似桥梁防撞设施撞击力时参考。     

印尼某电厂码头水工建筑物设计

印尼某电厂项目码头水工建筑物包括码头、防波堤和护岸等主要组成部分。在该项目水工建筑物的设计过程中,综合考虑当地的自然条件、施工能力和材料来源等因素,不断优化结构选型和结构断面。根据不同使用要求,护岸分别采用直立式和斜坡式2种结构型式,推荐的设计方案节省投资、施工方便,可供同类工程设计参考。     

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.     

开放式数据挖掘系统模型

目前国内已经出现了少量的数据挖掘相关产品。国内数据挖掘软件无论从数量还是质量上比较，都与国外软件存在着较大的差距。随着数据仓库技术的普及，数据挖掘应用的需求越来越强烈，如何缩短这种差距，研发数据挖掘软件产品成为国内业界的一个重要问题。通过引用目前国际通用数据挖掘标准技术来构建开放式的数据挖掘系统模型，该系统模型从可扩展性、可重用性、易用性等方面得到了加强。