艉轴倾角对水润滑艉轴承冷却性能的影响

应用Fluent有限元软件,建立计入轴线倾斜的水润滑艉轴承水膜CFD模型,研究艉轴倾角、冷却水流速、轴承间隙和艉轴转速对水润滑轴承冷却性能的影响规律,为水润滑轴承结构优化设计提供参考。结果表明,将冷却水流速、轴承间隙和艉轴转速控制在一定范围内可以有效地降低轴承温度;艉轴倾角增大会导致严重的轴承边缘效应、局部水膜变薄、轴承温度急剧升高、工作环境恶化。     

水槽结构对水润滑尾轴承润滑性能的影响研究

水槽结构对船舶水润滑尾轴承使用性能有着重要的影响。本文基于数值分析方法,应用MATLAB软件就水槽数量、布置对轴承承载能力、摩擦系数的影响状况进行探讨。结果表明:水槽越宽,轴承的承载能力和摩擦系数就越小;同时,水槽在轴承圆周上的布置方式也是影响轴承性能的重要因素,当有水槽布置在尾轴正下方时,轴承的摩擦系数和承载能力均呈现下降趋势。     

水槽布置方式对水润滑轴承摩擦性能的影响

为研究水槽布置方式对高分子材料水润滑轴承摩擦系数和进出水口温差的影响,以自来水为润滑介质,在尾轴承台架试验机上进行试验,测定全开槽结构与半开槽结构轴承在不同工况下的摩擦系数和进出水口温差,并对试验结果进行双因素有交互作用的方差分析。结果表明:相比全开槽结构轴承,在同一工况下,半开槽结构轴承的摩擦系数和进出水口温差更小;轴承水槽布置方式由全开槽变为半开槽时,转速、负荷及其交互作用对摩擦系数影响的显著程度会增加,对进出水口温差影响的显著程度会降低。     

尾轴高分子水润滑轴承强制冷却水的断流报警装置设计

近年来,船舶高分子尾轴承已得到越来越广泛的应用,船舶尾轴承采用尼龙、赛龙等合成材料,其中,应用赛龙尾轴承材料日益增多。赛龙是由高性能热固树脂合成的均质聚合物,具有弹性好、耐磨性好、耐腐蚀和不会剥落的特点,但其导热性差,且不耐高温。赛龙轴承浸入水或水溶液的温度不得超过60℃,否则会产生水解作用使轴承变软,因此赛龙轴承冷却水温在50℃以下,冷却水流量大于16D(公升/分钟)。文中根据高分子材料的运行特点,设计出防止冷却水断流的报警装置,可以给广大轮机管理人员在判断尾轴承断流,或者尾轴后部缠渔网时提供一些参考。     

基于FSI的尾轴倾角对水润滑轴承润滑特性的影响

应用流固耦合方法,在考虑水润滑尾轴承内部结构和内部流场相互作用的情况下,研究尾轴倾角对轴承水润滑特性的影响,探讨轴承、尾轴与水膜间的流固耦合问题。应用ADINA有限元软件,建立尾轴承流固耦合模型,求解尾轴承水膜压力分布,以及轴承的压力分布、径向变形和有效应力,分析尾轴倾角对尾轴承润滑特性的影响规律。结果表明:当计入尾轴倾角时,尾轴承最大水膜压力出现在轴承尾端,倾角越大,最大水膜压力也越大,且随着尾轴倾角的增大,水膜压力以及轴承的压力、径向变形和有效应力也逐渐增大。     

船用水润滑艉轴承的润滑承载特性

船用水润滑艉轴承由于其节能环保、结构简单和维护便利等优点一直作为船舶推进系统的研究热点。本文主要总结了船用水润滑艉轴承润滑承载特性方面的内容,轴承的润滑承载性能主要通过偏心率、最小水膜厚度、水膜压强和摩擦系数等参数描述。分别说明了工况参数、结构参数、材料参数对轴承承载润滑特性参数的影响,分析了上述三个方面的参数对轴承承载润滑参数的影响规律。其中,工况参数包括负载、速度、温度等,结构参数包括间隙、长径比、轴承直径、导水槽结构等方面,材料参数主要为材料的弹性模量和泊松比等。本文可以对船舶水润滑艉轴承的研究工作提供参考。     

浮运围堰下沉过程中紊流宽度试验研究

通过局部动床概化水槽试验,采用MicroADV流速仪测量瞬时流速,得到浮运围堰下沉过程中围堰侧面纵向、横向和垂向紊动强度的分布情况。分析浮运围堰入水深度、行进流速、行进水深对紊流宽度的影响。结果表明:在试验条件下,浮运围堰入水深度对紊流宽度影响较大;行进流速、行进水深对紊流宽度影响较小。在试验范围内,围堰单独作用时水流相对紊流影响宽度D/B随围堰相对入水深度H c/H0的增加而增大,基本为线性关系。     

考虑表面粗糙度与轴瓦变形的水润滑轴承动力特性系数计算

本文在传统轴承动力学分析模型的基础上考虑了水润滑轴承轴瓦的刚度、阻尼和轴承质量以及可能存在的接触刚度、阻尼,推导了考虑表面粗糙度和轴瓦变形的扰动压力雷诺方程,对比了混合润滑模型与动力润滑模型、弹流润滑模型的轴承动力特性系数并分析其差异,研究了倾角、粗糙度等参数综合作用下水润滑轴承动力特性系数的变化规律。结果表明,最小膜厚比大于某一阈值时粗糙度增加可提高水膜动力特性系数,轴瓦变形会使动力特性系数减小,同时也会扩大使水膜刚度、阻尼获得增幅的粗糙度范围,但削弱了粗糙度对承载方向刚度、阻尼的增幅效果。此外,在承受载荷一定的条件下,粗糙轴承的动力特性系数在倾角较大时明显小于光滑轴承的对应值。     

基于ADINA的水润滑轴承结构改进研究

应用有限元软件ADINA分别建立了传统水润滑橡胶轴承及其改进结构的CFD和FSI模型,分析比较水流轴向流速、轴的周向转速等参数对轴瓦变形和水膜压力分布的影响规律。计算结果表明：本文提出的轴承改进结构承载力较传统的水润滑轴承提高20%。具有较好的工程应用前景。     

水润滑特性和弹性接触应力对尾轴承使用寿命的影响

船舶尾轴承润滑状态和尾部弹性接触应力是影响水润滑尾轴承使用寿命的重要因素。本文应用紊流润滑理论研究了水润滑尾轴承的润滑状况以及应用弹性理论研究分析了国产材料MCS-2-1和铁梨木的弹性接触应力。理论分析和试验结果表明:水润滑尾轴承属于部分接触的半液体润滑状态,局部最大接触压力是设计比压的几十倍乃至百倍。为了延长尾轴承使用寿命,必须选用强度高、弹性模数低且具有一定自润滑性能的材料;在结构上可增大实际接触面积;改善水的润滑性质。采取这些措施都将收到一定的效果。     

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.