共查询到19条相似文献,搜索用时 796 毫秒
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以KCS船、KP505桨及NACA0018舵为研究对象,基于FINE/Marine软件,运用滑移网格技术,根据提出的翼型舵球尺寸,对粘性流场中的桨-舵、桨-舵-舵球组合系统进行水动力性能计算。计算得出该翼型舵球在低进速下,最佳节能效果可达1.66%。在此基础上,对船-桨-舵、及船-桨-舵-舵球系统进行计及自由液面的非定常干扰数值模拟,计算结果表明船-桨-舵-舵球系统的计算结果与桨-舵-舵球系统计算值趋势一致,且该舵球在航速V=2.1968m/s时,其节能效果达2.06%,是相同进速系数下,桨-舵-舵球组合系统的两倍左右,验证了该翼型舵球在两种组合系统下的节能效果,为舵球的实际工程应用提供了重要的理论依据。 相似文献
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《船舶力学》2016,(9)
文章对桨后普通舵和扭曲舵的水动力性能进行了试验研究,并采用计算流体力学方法对桨舵系统的水动力性能进行计算,得到了不同进速系数下的推力系数、扭矩系数以及敞水效率,并绘制了敞水性能曲线。通过桨舵模型试验值与计算值的对比,验证了计算方法的可靠性。为了进一步提高扭曲舵的节能效果,在扭曲舵前安装了舵球,优化舵球的半径后在舵球两端安装推力鳍,通过优选推力鳍的各个参数(安装位置、展弦比和安装角),使桨舵系统的敞水效率逐步提高。确定了舵球鳍的最优参数后,桨—扭曲舵系统的效率进一步提高1.2%。最后通过观察舵表面压力分布、舵附近轴向速度和迹线分布,分析了舵球鳍对桨舵干扰的影响。 相似文献
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为研究整流导管(Flow Straightening Duct,FSD)对船舶水动力性能的影响,分析其节能机理,采用计算流体力学(Computational Fluid Dynamics,CFD)技术,对某散货船加装整流导管前后的水动力性能变化进行数值分析。在计算时考虑螺旋桨的真实几何形状,采用滑移网格方法对船、桨、舵和节能附体相互干扰问题进行数值求解,评估整流导管的节能效果,将计算结果与模型试验结果相对比进行对标验证,研究整流导管对船舶阻力、流场和自航因数的影响,结合微观流场分析导管的节能原理。研究结果表明:采用的整流导管能效分析方法能有效预测导管的节能效果,基于流场分析总结整流导管的节能原理,对船舶节能附体设计有一定的指导作用,可应用于整流导管能效评估和优化设计中。 相似文献
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文章对桨后普通舵和扭曲舵的水动力性能进行了试验研究,并采用计算流体力学方法对桨舵系统的水动力性能进行计算,得到了不同进速系数下的推力系数、扭矩系数以及敞水效率,并绘制了敞水性能曲线。通过桨舵模型试验值与计算值的对比,验证了计算方法的可靠性。为了进一步提高扭曲舵的节能效果,在扭曲舵前安装了舵球,优化舵球的半径后在舵球两端安装推力鳍,通过优选推力鳍的各个参数(安装位置、展弦比和安装角),使桨舵系统的敞水效率逐步提高。确定了舵球鳍的最优参数后,桨—扭曲舵系统的效率进一步提高1.2%。最后通过观察舵表面压力分布、舵附近轴向速度和迹线分布,分析了舵球鳍对桨舵干扰的影响。 相似文献
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七0八所开发的桨前扇形整流鳍(FPHFS)是一种新型船舶水动力节能装置,由2至3片呈扇形分布的鳍翼组成,安装于桨前适当位置,改善螺旋桨的进流,提高推进效率。本文介绍长江1942kw双桨内河推船两型船采用本装置的模型试验和实船试航对比结果,实船试航结果证实模型试验预报的节能效果。加装本节能装置后I型船(带减速齿轮箱)推13000dwt驳船航速14km/h和12km/h时节能效果分别为3.4%和6.4 相似文献
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本文基于面元法理论对桨后贝克舵的水动力性能进行了研究。首先结合空泡水筒试验的试验结果检验了面元法程序的计算精度及可靠性,并将面元法计算所得水动力系数绘制成敞水性能曲线,对两种桨舵系统的水动力性能进行比较分析得出贝克舵的节能效果。然后改变桨与贝克舵之间的距离考察其对节能效果的影响,并与实验结果对了对比,结果显示,桨舵间距越大,桨舵系统的效率也就越高。 相似文献
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通过计算流体动力学(CFD)方法对敞水桨、桨-舵组合和优化间距的桨-舵组合装置进行数值仿真研究,分析桨-舵间距对其组合系统水动力性能的影响。螺旋桨敞水工况的计算值与物理模型试验值的吻合度良好,验证了数值计算方法的可行性。通过对比桨-舵间距大于推荐值的3个工况发现:在较低的进速系数下,系统的节能效率稍有增加,随着桨-舵间距的增大,节能效率呈现下降的趋势;在较高的进速系数下,随着桨-舵间距的增大,节能效率逐步下降。在较低的和中等的进速系数下,节能效率随着桨-舵间距的减小呈现逐步升高的趋势,在桨-舵间距减少10 mm时,组合体的节能效率最大可增加1.937%;在较高的进速系数下,节能效率随着桨-舵间距的减小有下降的趋势。 相似文献
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基于滑移网格与RNG k-ε湍流模型的桨舵干扰性能研究 总被引:2,自引:0,他引:2
结合RNG k-ε湍流模型,运用滑移网格技术对粘性流场中桨舵相互干扰引起的三维非定常湍流进行了计算,得到了随进速系数的变化,桨舵之间相互干扰性能的变化规律;同时获得了桨舵干扰性能随桨舵之间的距离的改变而相应的变化规律。文中给出了桨舵干扰水动力性能的计算结果,并与试验测量值作了比较。从对计算结果的分析可知,利用滑移网格技术及RNG k-ε湍流模型,可以较好地模拟桨舵干扰的水动力性能问题。同时文中分析了桨舵表面压强分布规律以及舵的存在对螺旋桨尾流场的影响。 相似文献
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船舶推进节能技术研究与进展 总被引:7,自引:2,他引:7
随着船舶燃油价格的上涨,船舶节能技术得到了广泛的关注,本文旨在介绍国内外船舶推进与节能方面的研究与进展。其中包括优秀船型的研究、开发附加流体水动力节能装置、新型高效推进器以及一些特殊船舶节能技术的研究。重点介绍了非对称尾船型、双尾鳍船型、可调距螺旋桨、对转螺旋桨、桨后自由旋转助推叶轮、舵附推力鳍以及一些特殊船舶推进节能装置的研究与应用等。 相似文献
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基于CFD技术,分别预报了单个螺旋桨、桨舵组合的水动力性能,并将计算结果与试验值比较,结果显示预报结果与试验值吻合良好.在此基础上,对螺旋桨-舵-舵球组合进行了计算,并比较了舵球设计参数对节能效果的影响.计算结果表明,舵球可以有效地提高螺旋桨的效率,在舵球直径与螺旋桨直径之比为0.292时,其节能效果最好,达7.66%. 相似文献
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基于MMG分离式建模思想,考虑作用在船体、螺旋桨、舵、鳍的水动力作用,建立双桨双舵船舶四自由度非线性数学运动模型,对某船模在静水中的回转性能进行仿真分析,将单独舵控制的仿真结果与船模试验结果进行了验证和分析,并对比了单独舵控制和舵、鳍联合控制下的回转性能,结果表明鳍参与控制回转时能明显缓解回转过程中的横倾。 相似文献
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This paper introduces a new method for the prediction of ship maneuvering capabilities. The new method is added to a nonlinear
six-degrees-of-freedom ship motion model named the digital, self-consistent ship experimental laboratory (DiSSEL). Based on
the first principles of physics, when the ship is steered, the additional surge and sway forces and the yaw moment from the
deflected rudder are computed. The rudder forces and moments are computed using rudder parameters such as the rudder area
and the local flow velocity at the rudder, which includes contributions from the ship velocity and the propeller slipstream.
The rudder forces and moments are added to the forces and moments on the hull, which are used to predict the motion of the
ship in DiSSEL. The resulting motions of the ship influence the inflow into the rudder and thereby influence the force and
moment on the rudder at each time step. The roll moment and resulting heel angle on the ship as it maneuvers are also predicted.
Calm water turning circle predictions are presented and correlated with model test data for NSWCCD model 5514, a pre-contract
DDG-51 hull form. Good correlations are shown for both the turning circle track and the heel angle of the model during the
turn. The prediction for a ship maneuvering in incident waves will be presented in Part 2. DiSSEL can be applied for any arbitrary
hull geometry. No empirical parameterization is used, except for the influence of the propeller slipstream on the rudder,
which is included using a flow acceleration factor. 相似文献
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Michio Ueno Yasuo Yoshimura Yoshiaki Tsukada Hideki Miyazaki 《Journal of Marine Science and Technology》2009,14(4):469-484
Circular motion test data and uncertainty analysis results of investigations of the hydrodynamic characteristics of ship maneuvering
are presented. The model ships used were a container ship and two tankers, and the measured items were the surge and sway
forces, yaw moment, propeller thrust, rudder normal and tangential forces, pitch and roll angles, and heave. The test parameters
were the oblique angle and yaw rate for the conditions of a hull with a rudder and propeller in which the rudder angle was
set to zero and the propeller speed was set to the model self-propulsion conditions. Carriage data showing the accuracy of
the towing conditions in the circular motion test are also presented. It was confirmed that the uncertainties in the hydrodynamic
forces such as the surge and sway forces, yaw moment, rudder tangential and normal forces, and propeller thrust were fairly
small. The reported uncertainty analysis results of the circular motion test data may be beneficial in validating data quality
and in discussing reliability for simulation of ship maneuvering performance. 相似文献
18.
《船舶与海洋工程学报》2019,(4)
Reducing the fuel consumption of ships presents both economic and environmental gains. Although in the past decades,extensive studies were carried out on the flow around ship hull, it is still difficult to calculate the flow around the hull while considering propeller interaction. In this paper, the viscous flow around modern ship hulls is computed considering propeller action. In this analysis, the numerical investigation of flow around the ship is combined with propeller theory to simulate the hull-propeller interaction. Various longitudinal positions of the rudder are also analyzed to determine the effect of rudder position on propeller efficiency. First, a numerical study was performed around a bare hull using Shipflow computational fluid dynamics(CFD) code to determine free-surface wave elevation and resistance components.A zonal approach was applied to successively incorporate Bpotential flow solver^ in the region outside the boundary layer and wake, Bboundary layer solver^ in the thin boundary layer region near the ship hull, and BNavier-Stokes solver^in the wake region. Propeller open water characteristics were determined using an open-source MATLAB code Open Prop, which is based on the lifting line theory, for the moderately loaded propeller. The obtained open water test results were specified in the flow module of Shipflow for self-propulsion tests. The velocity field behind the ship was recalculated into an effective wake and given to the propeller code that calculates the propeller load. Once the load was known, it was transferred to the Reynolds-averaged Navier-Stokes(RANS) solver to simulate the propeller action. The interaction between the hull and propeller with different rudder positions was then predicted to improve the propulsive efficiency. 相似文献