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在IACS统一解释文件UI SC246 Rev.1提出根据非满载试航船舶操舵试验结果对满载航行状态船舶舵机能力进行验证的换算方法之后,相当一部分采用半悬挂舵的船舶出现了无法按该方法通过舵机能力验证的状况。为解决上述问题,本文基于常规船型半悬挂舵的3种典型布置方案,通过设计相同的舵面积和不同的几何外形,得到3个计算模型,利用计算流体力学(CFD)方法对各方案的全浸没和部分浸没状态分别进行计算分析。计算结果表明,舵叶平衡比对舵杆水动力扭矩存在直接影响,适当大的舵叶平衡比设计可以显著降低舵叶全浸没状态和部分浸没状态的舵杆水动力扭矩。基于此结论,对某型未能通过换算验证的船舶舵系进行优化设计,适当增大了舵叶平衡比。后续船试航结果表明,舵机能力验证满足UI SC246 Rev.1的要求,确认了CFD计算结论的正确性,为以降低舵杆水动力扭矩为目标的舵系优化设计提供了理论和实践依据。 相似文献
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采用结构和非结构网格结合的方法,运用滑移网格技术对单桨双舵系统周围的流动进行了数值模拟。着重考察了桨一舵系统的水动力性能计算,得到了用以评价桨推进、舵操纵的水动力性能的数据。同时,文中还对单桨双舵系统周围的流场进行了分析。数值计算的结果与试验结果吻合良好,验证了文中方法对于桨舵干扰水动力性能模拟的叮谨性。 相似文献
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对复合材料舵和传统钢质舵的振动特性进行试验研究和对比分析.通过设计相关试验模型,对复合材料舵和钢质舵的前三阶固有振动模态及10 Hz~1 kHz频段内结构的动态响应进行测试,并对试验结果进行对比分析.研究结果表明:复合材料舵与钢质舵的模态振型基本相同,但复合材料舵所对应的固有频率高于钢质舵;同时,在白噪声激励载荷作用下,10 Hz~1 kHz频段内,复合材料舵整体加速度总级较钢质舵降低可达15 dB,且复合材料舵在局部壳板振动抑制方面明显优于钢质舵.本文研究将为复合材料舵的优化设计和工程应用提供参考和指导. 相似文献
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在船舶舵装置结构系统的强度分析中,以往采用解析法进行计算分析,在计算中必须引入大量的简化假设,导致其结果精度较低。现针对某船舵装置系统结构采用三维有限元进行离散,通过选取适当单元,使用内部多点约束和接触算法、建立包括舵杆、舵板、半悬挂舵臂和船体舵机舱结构的完整有限元模型;使模型与结构的相似度较传统方法有很大的提高。最后通过施加流体软件计算的水动力载荷分析舵装置系统各部分的应力和变形,从而对结构的强度作出评价。 相似文献
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针对半悬挂舵和全悬挂舵回转性能差异问题,建立用于模拟螺旋桨推力的体积力模型,评估两种不同形式舵的回转性。对标模KCS船型回转运动进行计算流体动力学(Computational Fluid Dynamics,CFD)模拟,船后螺旋桨作用使用体积力模型替代。开展半悬挂舵回转性CFD模拟,并与试验结果对比验证。设计全悬挂舵并模拟其回转性,与半悬挂舵回转性进行比较。结果显示,半悬挂舵除战术直径与试验结果相差9.48%外,其他回转特性参数与试验结果相差均在3%以内,说明基于体积力法模拟回转性具有较高的可信度。全悬挂舵的回转特性参数均优于半悬挂舵,说明全悬挂舵的回转性能更佳。 相似文献
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《Marine Structures》2000,13(1):53-72
A computational method is presented that models fluid structural interaction problems for three-dimensional marine structures. Flow can be modelled with either potential or viscous incompressible flow. The structure deformation is modelled by a shell finite element formulation. The two fields are coupled by a domain decomposition approach that uses virtual surfaces to transfer information. A typical spade rudder has been modelled for steady-state three-dimensional problems in a free stream and in way of a propeller race. These computational models have been tested for mesh dependancy in both the fluid and structural domains as well as the virtual surface definition. The results show increased correlation to experimental data from uncoupled hydrodynamic modelling as well as detailed structural deformation. Of note is the variation in rudder stock bending moment from that utilised by classification society scantling rules. 相似文献
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在分析潜艇X型舵水动力特性的基础上,建立X型舵与十字型舵操纵力的等效关系,用于指导潜艇X型舵的初步设计;分析X型潜艇的操控与潜艇运动的关系,用于潜艇X型舵的自动控制装置设计,部分解决了X型舵自动控制装置相关理论问题。 相似文献
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A study on improving the course-keeping ability of a pure car carrier in windy conditions 总被引:1,自引:1,他引:0
Kazuhiko Hasegawa Donghoon Kang Masaaki Sano Vishwanath Nagarajan Makoto Yamaguchi 《Journal of Marine Science and Technology》2006,11(2):76-87
The course-keeping ability of a pure car carrier (PCC) in windy conditions is discussed in this article. Numerical simulations
of two PCCs were carried out to compare their course-keeping abilities in wind. The two PCCs had the same hull form but different
types of rudder. One PCC was fitted with a semispade rudder (hereinafter, the normal rudder), whereas the other was fitted
with a spade-type Schilling rudder (hereinafter, the Schilling rudder). Both PCCs were designed to a new concept for the accommodation
structure and hull form above the load water line. In this new design concept, there are no sharp corners in the superstructure
so as to reduce wind resistance and improve steering performance. The limits of course keeping for the two PCCs were investigated
through simulations. The course-keeping abilities of the two PCCs, each with two different types of autopilot system, were
also investigated in wind. To develop the numerical simulation, the hydrodynamic coefficients of the two PCCs were predicted
based on the data published for a third PCC having similar principal particulars. The numerical model of the two PCCs was
validated by comparing its behavior with the respective full-scale trial results. Wind resistance coefficients were predicted
by combining the results of wind tunnel experiments of the object PCCs and a regression model. Numerical simulations under
steady wind conditions were also carried out and the results compared with some full-scale experiments to validate the mathematical
model of the PCC. 相似文献
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现代潜艇尾操纵面建筑形式主要选择十字舵与X舵,这2种形式的舵各有其优缺点.在以往关于这2种舵形潜艇操纵性水动力的研究中,有研究者通过编制潜艇六自由度运动仿真程序,对十字舵与X舵在水平面和垂直面的水动力性能进行了综合比较,得出X舵的水动力性能优于十字舵.本文以十字舵和X舵Suboff为研究对象,通过CFD数值方法模拟了潜艇直航运动和垂直面变攻角运动这2种具有典型代表意义的运动情况,分别计算了2种舵形潜艇的操纵性水动力,通过分析计算结果,定量地比较了在舵面积相等的情况下十字舵与X舵潜艇的水动力性能,得出与编程仿真相同的结论:X舵的水动力性能优于十字舵. 相似文献
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为了有效解决悬挂舵舵叶在整体制作加工过程中遇到的加工车间吊装能力不足、需要大型加工机床等问题,对比在分体制作和整体制作过程中不同的工艺过程,综合分析了悬挂舵舵叶的舵杆承座部分在机加工时可能遇到的问题及解决方法,阐述了悬挂舵舵叶分体制作相对于整体制作的优点及其研配加工的工艺过程。 相似文献
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Vishwanath Nagarajan Dong Hoon Kang Kazuhiko Hasegawa Kenjiro Nabeshima 《Journal of Marine Science and Technology》2008,13(1):24-39
A simulation model of a very large crude carrier (VLCC) with either a mariner type Schilling rudder or a mariner rudder was
developed from captive and free-running model tests. Kijima’s regression formula was used to predict the hydrodynamic hull
forces on the VLCC. To simulate full-scale maneuvering at cruising speed, the constant torque operation of the main engine
was assumed. Considering the higher normal lift force and maneuverability of the mariner type Schilling rudder as compared
to the mariner rudder, the size of mariner type Schilling rudder is kept smaller as compared to mariner rudder. To compare
the efficiency of the two types of rudder system, maneuvering simulations at constant engine torque and course-keeping simulations
at various gusting wind speeds and encounter angles were carried out. Based on the simulation results, the two rudder types
were compared from the viewpoint of maneuvering and fuel efficiency in windy conditions. 相似文献
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建立了桨后舵水动力的CFD数值计算方法,对两种舵的压力分布和舵力进行了比较,结果显示扭曲舵可以明显减小0°舵角时舵上的横向力和舵轴扭矩。在拖曳水池中进行了自航约束模舵力测量试验,对扭曲舵和普通舵的舵力进行了测量,试验结果也表明,在0°舵角时,扭曲舵上的受力状态得到明显改善。将舵力的数值计算结果与试验结果进行比较,两者有较好的一致性,说明建立的数值计算方法可以对桨后舵舵力进行较好的模拟计算。 相似文献
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反应舵在螺旋桨尾流中的水动力性能 总被引:1,自引:0,他引:1
本文对反应舵在螺旋桨尾流中的水动力性能及桨舵干扰进行了研究。舵的水动力及周围流场用面元法计算,螺旋桨性能用无限叶数的简易螺旋桨理论预估。桨舵干扰作用以迭代方法求得。采用面元法计算反应舵的性能,可以更精确地反映较复杂的反应舵表面形状对水动力性能的影响。通过计算得到的舵表面压力分布可看出反应舵节能的原因。本文还对反应舵的操纵性能进行了计算和研讨。 相似文献