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1.
双级轴向旋流非预混燃烧和流动特性分析   总被引:1,自引:0,他引:1  
本文对双级轴向旋流非预混燃烧器进行了研究,应用CFD数值模拟,探索一级旋流器叶片安装角度和文氏管扩张角的角度变化对燃烧特性和温度场以及流动场的影响规律。研究结果表明:文氏管扩张角依次增大过程中,燃烧室内中心回流区中心前移,旋转射流径向扩张角增大;CH4的浓度沿径向分布更加均匀,降低了燃烧室内最高温度。此外在五种不同文氏管角度和一级旋流器叶片安装角度的结构条件下燃烧室中外回流区域温度均低于内回流区域温度。在一级旋流器叶片安装角为55°、二级旋流器叶片安装角为35°时,燃烧器出现回火现象。  相似文献   

2.
本文用数值方法研究了MSEMD系统轴对称扩压长支管的定常流动特性。在贴体坐标系中用与时间相关的二维流动计算方法对湍流流动的控制方程进行了数值求解,用二阶MacCormack差分方法处理内部节点,用二阶参考平面上的特征线法处理进、出口边界条件,并把计算结果与实测结果进行了比较,它们之间吻合得相当好。  相似文献   

3.
康庄  张立  刘禹维  何宁 《船舶工程》2015,37(5):90-93
顶部张紧式立管(TTR)是油气开发必不可少的立管类型。研究了南海1500米水深半潜式干树深水平台TTR的概念设计,使用ORCAFLEX软件建立TTR的干涉分析非线性时域分析模型,基于Huse尾流模型,分析了浪流方向为0°,45°,90°,135°和180°的100年一遇环境载荷下的立管间距。结果表明,浪流方向为0°时立管最小间距小于TTR最大外径之和,发生干涉,其他方向不发生干涉。TTR为阵列式设计的立管群,应当从多方面因素考虑以避免干涉发生的危险,合理安排立管间距、调整TTF等措施可以有效减小干涉发生的可能。  相似文献   

4.
针对上海某港池工程12°斜桩桩头断裂的动力响应问题,对斜桩每节桩的桩头进行现场应变监测,利用ABAQUS软件对直桩、6°和12°斜桩进行有限元模拟,对比桩锤质量、桩距进行优化前后的桩顶动力学响应,并得出锤击频率、锤击速度对桩顶应变的影响。结果表明,同等锤击荷载作用下,桩的拉、压应变随桩身倾角的增加而增加,12°倾角产生的拉、压应变峰值最大;增大桩锤质量、降低桩锤与桩顶距离,可降低桩顶应变;桩头应变监测值与模拟值的变化趋势一致;有限元模拟把桩锤的冲击力等效成三角荷载的方法是合理的。  相似文献   

5.
黑潮暖流导源于北赤道流.在菲律宾以东,约在北纬12°—13°附近海面,北赤道流分成南、北两支,其中较强大的北支,沿吕宋岛东沿北流,形成黑潮暖流。整个黑潮流系,是沿着北太平洋西边缘朝东北方向流动的一支强  相似文献   

6.
莫剑华 《航海技术》2007,(B03):13-14
随着亚太地区与太平洋岛国间贸易量的持续上升,越来越多的船舶驶经南太平洋、澳洲东部、南部海域,穿梭于太平洋和印度洋驶往各目的港。但冬季的南太平洋航线天气恶劣,风大、流急、浪高,持续时间长,范围广。特别是澳洲南部、新西兰南岛四周36°S~50°S及以南海域,处于南大洋西风带内,盛行西风。  相似文献   

7.
东海船厂和上海船用设备研究所联合承担国家重点企业技术开发项目——液压高空作业平台于1992年8月组装结束调试成功,交用户试用后,于日前通过部级鉴定。该平台的整机行走、转台360°回转、臂架伸缩、变幅、升降、车轿顶升、扩张,以及斗盘180°回转等主要功能均  相似文献   

8.
姚艳萍  林钟明  陈瑞峰 《中国造船》2003,44(Z1):309-316
本文针对BZ28-1单点系泊导管架的结构和载荷特点,采用StruCAD*3D结构分析程序对其进行了结构建模和静力强度计算,并采用适当的许用应力因子对不同工况下导管架的安全性进行了评估.基于结构的对称性,计算中采取了五个典型的波浪入射方向0°,45°,90°,1 35°,180°,每个方向都取最危险的工况,即其他环境载荷与波浪载荷同向.分别针对操作条件、极限风暴条件和极限冰载荷条件,对导管架的杆件和管节点进行了分析计算,给出了各杆件的名义应力比和管节点的冲剪应力比,并对桩的承载力做出了评价.本文对于导管架平台的设计以及在役状况下的安全评估具有一定的参考意义.  相似文献   

9.
钢结构桥梁在遭受撞击后,严重变形钢构件是否适用机械矫正方法尚无明确答案。结合工程实例对机械矫正后的变形钢板力学性能开展试验研究。研究表明:在变形小于25°时,钢板试件屈服强度变化不大,但在变形超过25°时开始下降;在变形达40°时,机械矫正使钢板试件中的微观缺陷增加,并使其表面形成裂纹;机械矫正使钢板试件的冲击韧性随变形程度增加而降低。  相似文献   

10.
矩形硬帆间相互干扰的试验研究   总被引:1,自引:1,他引:0  
本文介绍了矩形硬帆间相互干扰的试验研究结果,在简单描述了试验模型和方法后,先对试验结果作了简单的分析,然后又结合缝翼理论、数值计算和试验结果对硬帆间干扰作了进一步的分析。研究结果表明多帆组合体可有效地提高单位甲板面积上帆的推力。三帆组合体的帆距t=1.25倍弦长、位错角φ=28°时,帆间干扰损失为5~8%,φ=45°时帆间干扰损失最小,在某些风向角上其推力甚至比单帆还大。在二帆组合体上,当前帆与后帆成约-10°夹角时,最为有利。  相似文献   

11.
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.  相似文献   

12.
13.
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;  相似文献   

14.
联合作战计划和执行系统   总被引:2,自引:1,他引:1  
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。  相似文献   

15.
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).  相似文献   

16.
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.  相似文献   

17.
桥梁防撞设施物理模型试验   总被引:1,自引:0,他引:1  
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。  相似文献   

18.
詹明  郑厅厅 《港工技术》2010,47(4):17-19,23
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。  相似文献   

19.
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.  相似文献   

20.
开放式数据挖掘系统模型   总被引:2,自引:0,他引:2  
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。  相似文献   

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