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全方位推进器与首侧推器综合作用对船舶操纵性能的影响 总被引:2,自引:0,他引:2
以船模自由自航模试验为基础,对采用全方位推进器和首侧推器的船舶特殊操纵性能进行了试验研究,对其原地掉头、纯横移、斜移等操纵方式进行了探索和研究。同时,通过测量首侧推器作用力随航速变化规律,分析了首侧推器在该类船舶上的应用情况,供设计者参考。 相似文献
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近岸环境下船舶侧推器的水动力性能数值分析 总被引:1,自引:0,他引:1
《船海工程》2015,(1)
对船舶在近岸环境下航行时侧推器的水动力性能进行数值模拟研究。建立艏艉侧推器与船体的整体模型,利用基于RANS方程求解的粘性流数值方法,采用MRF模型,计算不同航速下艏艉侧推器的性能参数、侧推器附近流场,以及船舶在近岸航行时的横向力与艏摇力矩。结果表明,近岸航行时侧推器的实际效能会因船速的变化而变化,船速的不断增加会使船舶与岸壁之间的吸引力超过侧推器的推力,从而导致碰撞。 相似文献
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通过对船舶侧推器构造的介绍、效应的分析及在引航工作中对侧推器实际使用经验的总结,提出船舶港内靠离泊时侧推器使用的注意事项,为侧推器的实际操纵提供有力帮助。 相似文献
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侧向推进器简称侧推器,是一种横向推进装臵,其浆叶安装在贯穿船体的横向导管内,浆叶旋转时产生的水流对船舶产生横向推力。是船舶操纵的重要设备,其与车、舵配合作为船舶靠离码头、转向、精准定位等船舶操纵的主要手段,极大的提高船舶操纵的灵活性和可靠性,在客滚船、平台服务三用拖轮上得到广泛应用。一般侧推器的螺旋桨是由柴油机或电动机直接驱动。使用电动机驱动的侧推器因为功率大,控制系统复杂,是船上使用、管理的薄弱环节。 相似文献
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侧向推进器水动力性能数值分析与验证 总被引:2,自引:0,他引:2
为研究侧向推进器的水动力性能,采用CFD方法以四叶Ka型螺旋桨侧向推进器模型实验为依据进行了仿真验证,结果吻合度高。在此基础上,模拟和分析零航速时不同螺距比、盘面比、通道长度和船艏两侧倾斜角度对侧向推进器流场和水动力性能的影响。结果表明:侧推器通道长度对侧推器效率影响较大,在2D时,效率最高;侧推器进出口处两侧倾斜角度对性能也有影响,船艏水线与侧推器轴线的夹角大则效率高。另外,研究了有航速时,首侧推器受航速影响的规律并分析了侧推器失效的原理。 相似文献
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价值观是指人们对价值的性质标准、构成和评价的基本看法和态度,是指导人的行为的一系列基本准则和信条。构建海事核心价值观是时代发展的要求,更是海事自身发展的需要。 相似文献
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This chapter presents a summary of the findings of the workshop on ‘Analytical and Institutional Methods and Frameworks’. The paper discusses the nature of the analytical methods used in the papers presented and the purposes for which they were employed, which were generally to either assist in the planning and operation of public transport or to monitor the efficiency and effectiveness of transport services. Subsequent sections examine issues related to data collection and management, and the more general issue of institutional arrangements. Policy and research agendas needed to support further consideration of the subject are then identified. 相似文献
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介绍青藏高原多年冻土的冻融特性,并结合我局在青藏铁路十二标段的具体施工,分析了冻土的冻融特性及具体防止措施. 相似文献
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Geoffrey Wood 《Maritime Policy and Management》2004,31(2):157-171
This paper explores the current state of coastal and inland shipping in Tanzania. It provides an overview of the state of ports and shipping in Tanzania, and the reasons underlying the present crisis of competitiveness in terms of both global pressures and national and regional dynamics. Problems of competitiveness are at least partially due to under-investment, management failures, skills shortfalls and difficulties in interfacing with the railway network. Less easy to resolve structural problems include the great imbalance between imports and exports, heightened regional competition and ongoing political instability in the Great Lakes region. 相似文献
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风量与风压的简易测量及应用 总被引:2,自引:0,他引:2
锅炉正常燃烧必须有充足的风量,当锅炉鼓风或引风不足将导致锅炉效果恶化,锅炉出力、热效应率明显下降。结合工程实例,介绍结托管简揭测试鼓、引风系统各部分风压、风量,帮助判断分析工程实际问题的简便方法。 相似文献
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Elizabeth A. Wilman 《Coastal management》2013,41(3):211-230
As the controversy over Outer Continental Shelf (OCS) oil and gas leasing continues, with environmentalists and fishermen seeking to block or delay leasing decisions that they think will adversely affect their interests, the need for better estimates of the environmental costs associated with OCS development becomes increasingly apparent. Although high degrees of precision in such estimates may never be economic, let alone feasible, better knowledge would reduce the uncertainty surrounding the magnitude of such costs, and would make it easier to come to grips with the problem and reduce, if not resolve, the controversy. 相似文献