基于舰载机起降限制的舰船气流场特性评估方法初探

对具有搭载舰载机能力的舰船而言,其气流场特性的评估取决于对相应舰载机的起降气流条件限制。通过对美国LHA型舰缩比模型的数值建模,结合两种舰载机起降的气流场限制条件对计算结果进行对比分析。在相同定常来流工况下,分别以±15°风向角对该型舰数值模型的两个起降点进行模拟取值,结合直升机和固定翼短距/垂直起落飞机的起降特性和气流限制条件,尝试提出一种评估舰船气流场特性的直观方法,并得出不同甲板气流区域受上层建筑影响的有关结论。     

甲板风对舰船空气尾流影响的数值研究

利用CFD仿真方法对不同甲板风风速和风向角条件下的SFS2、LHA-1及CVN-73空气尾流场进行数值模拟。研究表明,舰船空气尾流场随甲板风风速的变化符合雷诺数独立性原则,这一规律表明,对于感兴趣的风向角,只需要计算一个风速即可,因此可有效减少舰船空气尾流场研究中的工作量。但是,随着风向角的变化,舰船空气尾流场会发生剧烈改变,对于感兴趣的风向角工况必须逐一进行计算。对比分析结果显示,算例中0°~15°的风向角范围是适合舰载直升机起降操作的较理想风向角。研究结果明确了甲板风对舰船空气尾流场特性的影响,可为后续舰船空气尾流场的研究提供参考,为直升机安全操作包线的制定和固定翼飞机的安全着舰提供理论依据。     

大型船舶空气尾流场特性的综合分析

大型船舶空气尾流场对飞机海上降落安全有重要的影响,研究空气尾流场特性对保障飞机安全、大型船舶海上活动有重要的意义。本文分别从数值模拟和实验2种角度综合分析大型船舶空气尾流场特性。研究中根据实际情况将甲板风风向风速差异分为9种工况条件,结果表明:甲板风风向角为-7°时空气尾流场气流扰动相对最弱,对飞机海上降落影响最小;上层建筑后部气流扰动对空气尾流场有明显的影响,而这是以往研究中忽略的因素。研究发现飞机海上降落所经过的下滑道气流场中存在气流转换区和下沉气流显著区,是飞机海上安全降落及空气尾流场防治中需重点关注的区域。     

发动机排烟对海洋平台及周围环境影响的数值模拟

运用Fluent软件,基于组份输运模型,对陆丰13-2钻井生产平台上发动机排烟对海洋平台及周围环境影响进行数值模拟。分别对常风向正常工况及微风不利工况两种情况进行计算,结果表明:在常风向工况下,由于风速较高,烟气浓度分布及温度分布对平台及供应船不会造成安全影响;在微风不利工况下,不利于烟气扩散,烟气易沿下风向扩散的同时,还不断上升到工作平台区域及工作船的部分工作区域。提出排烟管出口应布置在工作甲板以下空间,以避免常风工况烟气通过平台空间扩散;通过分析烟气扩散影响因素,增设挡风墙等措施可以改变烟气扩散区域的流场,在排烟口处加喷水装置可降低排烟温度,有效地降低排烟的影响。分析结果为平台主电站布置及排烟管位置的设计提供参考依据。     

上层建筑形式及布局对舰船空气流场的影响

舰船上层建筑是诱发舰船舰面空气湍流的主要因素,对于具有全通飞行甲板的舰船,其岛式上层建筑的外形及布置则出现了多样化的趋势,对迎风方向后方的气流场形态势必会产生影响.为了解上层建筑外形及布局形式的变化对舰船空气流场,尤其是对舰载机起降影响的初步规律,通过定常同等试验工况条件下,建立多种形式的上层建筑以及变化研究模型上层建筑纵向的布置位置的数值三维模型,对5种模型分别进行数值模拟计算,分析和观察由此产生的气流场变化,对计算结果进行取值分析.通过各模型及原型舰模型间气流场特性的对比,所得出的有关结论与目前实际的舰船产品所采用的布置形式决策是一致的.     

非对称半潜式起重平台流载荷数值分析

基于计算流体力学(CFD)软件FINE/MARINE对非对称半潜式起重平台的流载荷进行了研究,完成了流向角0°～360°(间隔15°)共计25种工况下平台流载荷的计算。重点对流载荷随流向角的变化规律、载荷系数及平台附近流场分布等特性进行了研究。结果表明,在来流速度相同的情况下,流向角变化对平台周围流场分布有较大影响,60°流向角时平台的流载荷最大。通过平台在自由面上的流场分布,可以分析流载荷的变化规律。     

半潜式钻井服务支持平台随机风载荷特性研究

风载荷是海洋平台设计载荷之一,直接关系到平台稳性,确定平台在不同工况下的风荷载对于平台安全设计具有重要的工程意义.该文基于Fluent软件结合自编UDF程序,考虑Davenport、NPD以及API三种典型风谱的影响,利用简谐波叠加法将风谱由频域转换为时域内的随机脉动风速,引入雷诺平均法求解NS方程结合分离涡(DES)湍流模型对半潜式钻井服务支持平台在自存海况下的风力和风倾力矩开展了数值研究,并将数值模拟得到的最大风力及风倾力矩与ABS、DNV以及CCS的计算结果进行了对比验证.计算结果表明:平台受到的风力和风倾力矩与风谱自身特性、平台倾斜角及风向角等因素密不可分;同一工况下采用Davenport与NPD风谱计算时平台受到的平均风力(矩)较为接近;NPD风谱作用时平台受到的随机最大风力(矩)最大;采用API与NPD风谱计算时,各工况下最小风力(矩)随风向角的变化趋势、计算结果均基本一致.     

半潜式钻井服务支持平台随机风载荷特性研究（英文）

风载荷是海洋平台设计载荷之一,直接关系到平台稳性,确定平台在不同工况下的风荷载对于平台安全设计具有重要的工程意义。该文基于Fluent软件结合自编UDF程序,考虑Davenport、NPD以及API三种典型风谱的影响,利用简谐波叠加法将风谱由频域转换为时域内的随机脉动风速,引入雷诺平均法求解NS方程结合分离涡(DES)湍流模型对半潜式钻井服务支持平台在自存海况下的风力和风倾力矩开展了数值研究,并将数值模拟得到的最大风力及风倾力矩与ABS、DNV以及CCS的计算结果进行了对比验证。计算结果表明:平台受到的风力和风倾力矩与风谱自身特性、平台倾斜角及风向角等因素密不可分;同一工况下采用Davenport与NPD风谱计算时平台受到的平均风力(矩)较为接近;NPD风谱作用时平台受到的随机最大风力(矩)最大;采用API与NPD风谱计算时,各工况下最小风力(矩)随风向角的变化趋势、计算结果均基本一致。     

两种飞行甲板形式的舰船空气流场特性比较

搭载固定翼飞机的水面舰船受多种因素的影响,通常会采用多种飞行甲板形式,尤其是在没有配备弹射器但搭载有固定翼飞机的舰船上,是否采用滑跃式起飞甲板,采用后舰面空气流场会有哪些变化是在总布置设计必须要讨论的问题.本文通过在定常条件下,同一船型上采用的2种飞行甲板舰面布置方案进行了多个工况的空气流场模拟计算,对计算结果进行分析,观察模拟出的二维/三位流线形态,对舰船采用不同飞行甲板形式的气流场特性进行了初步的探讨.     

海洋平台稳性计算分析

以自升式钻井平台和在建的FPSO项目稳性计算分析为例,从风模型的建立、风载荷计算及风向角的角度进行FPSO稳性计算,综合考虑不同规范的要求,确定平台完整稳性和破舱稳性衡准,定义开口、破损范围及渗透率等参数,并利用NAPA软件对海洋平台进行配载,计算平台在各种工况下的稳性,明确稳性计算方法的正确性。     

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。