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41.
Sang-Joon?LeeEmail author Min-Seok?Koh Choung-Mook?Lee 《Journal of Marine Science and Technology》2003,8(2):76-87
The main purpose of this investigation was to demonstrate a useful application of the particle image velocimetry (PIV) method to analyze the complex flow characteristics around a ship. For a sample illustration, the KRISO 3600TEU container ship model was chosen. The flow structure in the stern and near-wake region of the model has been investigated experimentally in a circulating water channel. Instantaneous velocity fields measured by the PIV velocity field measurement technique have been ensemble-averaged to give details of flow structures such as the spatial distributions of the local mean velocity, vorticity, and turbulent kinetic energy. The free-stream velocity was fixed at U
o = 0.6m/s, and the corresponding Reynolds number based on the length between perpendiculars was about 9.0 × 105. The container ship model shows a complicated three-dimensional flow structure in the stern and near-wake regions. The PIV results clearly revealed the formation of large-scale bilge vortices in the stern region and their effect on the flow in the near-wake. The results shown here provide valuable information for hull form design and the validation of viscous ship flow codes and of turbulence models. 相似文献
42.
H.T. LIN 《西南交通大学学报(英文版)》2012,20(2):70-75
Vortex motion in superconductors of higb-Tc superconducting maglev system is studied by a computational simulation.The vortex system is treated in a similar fashion,as a system where defects arc arrang... 相似文献
43.
Jungyong Wang Ayhan Akinturk Neil Bose Stephen J. Jones Yun Young Song Ho Hwan Chun Moon Chan Kim 《Journal of Marine Science and Technology》2008,13(3):244-255
The objective of this study was to investigate the performance of a model azimuthing podded propulsor in ice-covered water.
Model tests were carried out with two different depths of cut into the ice (15 and 35 mm), two different ice conditions (presawn
and pack ice conditions), and four different azimuthing angles. The depth of cut is the maximum penetration depth of the propeller
blade into the ice block. The 0.3-m-diameter model propeller was operated in a continuous ice milling condition. Ice loads
were measured by several sensors which were installed in various positions on the model. Six one-axis pancake-style load cells
on the top of the model measured the global loads and two six-component dynamometers were installed on the shaft to measure
the shaft loads. One six-component dynamometer was attached to the one of the propeller blades inside the hub to measure the
blade loads. The pod unit and propeller performance in ice are presented. Ice-related loads, which were obtained when the
blade was inside the ice block, are introduced and discussed. During the propeller–ice interaction, a blade can experience
the path generated by the previous blade, which is called the shadowing effect. The effects of shadowing, depth of cut, azimuthing
angle, and advance coefficient on propulsor performance are presented and discussed. 相似文献
44.
地下水池通常存在于大型的地下污水厂、城市雨污水泵站、调蓄池等工程中。然而地下水池结构的抗震分析存在一系列难题,如设计理论的选取、流体作用力分析、构造措施的设计、设缝形式的影响等。介绍了常用的地下结构抗震设计理论,对地下水池结构存在的问题和抗震设计特点进行了分析和总结,并通过一系列案例提出了设计中的注意点,可供相似工程参考。 相似文献
45.
铁路罐式集装箱空箱调配优化模型及遗传模拟退火算法 总被引:1,自引:0,他引:1
针对罐式集装箱运输的特殊性,考虑重箱流和空箱流调配的综合优化,以罐箱运输费用最小为目标,建立铁路罐式集装箱空箱调配优化多商品网络流模型,并构造了1种嵌入模拟退火操作的遗传算法对之进行求解。为了使模型与算法可得到更符合实际、操作性更强的结果,给出了3种空罐箱调配的策略,作为隐含条件加入到算法求解过程中。利用自适应遗传模拟退火算法对随机生成的实际规模问题算例进行求解,并与用通用代数建模系统软件GAMS的计算结果进行对比。结果表明,前者得出的结果与最优解差距不大,而且运算速度更快,更能满足解决实际问题的需要,为铁路罐箱调配优化提供了良好的决策支持模型和算法。 相似文献
46.
以武汉三金潭污水处理厂项目中2座13900m^3卵形消化池工程为实例,概要介绍了消化池施工特点及整体方案,以及伞形模架系统设计及安装、大体积混凝土、无粘结预应力施工等关键技术。伞形模架系统的成功实践,是对卵形消化池传统模板施工工艺的一次技术革新,同时对其他类似曲面体构筑物的施工也具有很大参考价值。 相似文献
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水舱阻尼是影响减摇水舱减摇性能的重要因素,在减摇水舱的工程应用中,如何获得最佳的水舱阻尼成为水舱设计最关键的环节之一。一般情况下,可以通过调节水舱挡板来改变水舱底部通道截面积的大小,以达到改善水舱阻尼的目的。本文利用FLUENT软件,计算了二维水舱模型中不同挡板开度条件下水舱稳定矩的变化,得到该仿真模型最佳阻尼所对应的挡板开度的参考数值,并与减摇水舱台架试验的结果进行比较,表明了利用数值仿真的方法来研究水舱阻尼是可行的,该数值仿真的结果是合理的。 相似文献