框架四叉树的自主水下航行器追踪动态目标研究(英文)

An autonomous underwater vehicle (AUV) must use an algorithm to plan its path to distant, mobile offshore objects. Because of the uneven distribution of obstacles in the real world, the efficiency of the algorithm decreases if the global environment is represented by regular grids with all of them at the highest resolution. The framed quadtree data structure is able to more efficiently represent the environment. When planning the path, the dynamic object is expressed instead as several static objects which are used by the path planner to update the path. By taking account of the characteristics of the framed quadtree, objects can be projected on the frame nodes to increase the precision of the path. Analysis and simulations showed the proposed planner could increase efficiency while improving the ability of the AUV to follow an object.     

三峡库区架空墩式散货码头结构模态分析

架空墩式码头结构是适用于三峡库区大型散货码头的新结构型式。本研究以重钢环保搬迁大型散货出口码头为例,采用有限元法对其码头结构建立三维有限元模型,并进行模态分析,在得到结构的各阶模态后,提取关键模态分析结构的振形特点。最后,结合码头的基本工况,评价码头结构的安全性。     

溃坝问题的数值仿真和实验(英文)

In this paper, two novel numerical computation methods are introduced which have been recently developed at Research Institute for Applied Mechanics ( RIAM ), Kyushu University, for strongly nonlinear wave-body interaction problems, such as ship motions in rough seas and resulting green-water impact on deck. The first method is the CIP-based Cartesian grid method, in which the free surface flow is treated as a multi-phase flow which is solved using a Cartesian grid. The second method is the MPS method, which is a so-called particle method and hence no grid is used. The features and calculation procedures of these numerical methods are described. One validation computation against a newly conducted experiment on a dam break problem, which is also described in this paper, is presented.     

中速三体船型PCC的可行性研究(英文)

In the present paper, a new trimaran Pure Car Carrier (PCC) is proposed and a feasibility study on the ship is carried out. In this study, first, the effective horse power (EHP)/car of the PCC running in still water is predicted. By comparing the predicted EHP/car with that of a conventional mono-hull PCC, it is found that the trimaran PCC is superior to the conventional mono-hull PCC at rather higher speed. As ship speed increases, the reduction of the resistance of the trimaran is bigger. It is also found that at common service speed of PCCs, the EHP/car of a small PCC is lower than that of a conventional PCC. Secondly, the optimal L/B of a main-hull of the trimaran PCC in still water is determined. The optimal L/B of the main-hull varies with ship speed and size because the wave resistance decreases but the frictional resistance increases as L/B of the hull increases. As ship size increases, the optimal L/B of the main-hull of the trimaran PCC decreases.     

基于Pspice仿真的某型装备电路故障诊断方法

利用Pspice仿真软件,研究了某型装备电路故障诊断的方法,设计了虚拟测试设备以实现对电子线路的测试与诊断。并结合该装备的电源板控制电路,详细说明了故障诊断的具体方法和步骤,为电路测试与诊断提供了一种新的思路。     

基于PERT的弹道导弹装填作业流程优化研究

通过对多枚弹道导弹装填网络作业流程进行分析,建立了三组数学模型。基于该模型将多枚导弹装填的问题转化为一种寻求最优方案的问题,并以三枚导弹装填网络作业流程的优化为例,阐述多枚导弹装填优化模型的过程,最后给出了多枚弹装填的时间公式。     

边界控制方法在DVR样机研制中的应用

动态电压恢复器（DVR）可在供电电压发生电压下陷时维持负载电压稳定,以保护敏感负载。由于在正常电力系统中,电压下陷故障出现的频率相对不高,使得DVR的利用率较低。将一种基于二阶开关平面理论的边界控制器应用于DVR系统,使其既可用于电压下陷补偿又能用于稳态下电压电能质量控制,大大提高了设备利用率。通过预测DVR逆变器的某次开关动作后,其系统状态矢量的运动轨迹可得到上述二阶开关平面。将该平面作为状态轨迹沿理想开关平面运动的上界,可约束轨迹使其趋向理想工作点。为考察其动态特性,应用上述控制器的DVR样机针对源端谐波畸变和伴有畸变的下陷电压波形进行了补偿试验。结果证实上述边界控制方案可获得优于其它一些控制策略的谐波补偿效果。     

浅谈港口文化建设

港口是国民经济和社会发展的重要基础设施和基础产业,是经济运行的命脉。港口文化建设特别重要。阐述了港口文化建设的意义。介绍了港口文化建设的方法和注意事项。     

流场中任意厚度阻尼复合圆柱壳的声辐射(英文)

The insertion loss of acoustic radiation of damped cylindrical shell described by 3-D elasticity Navier equations under radial harmonic applied load in fluid is presented. The classical integral transform technique, potential theory and Lamè resolution are used to derive the solutions of Navier equations. The higher precision inversion computation is introduced to solve the linear equations. Comparing with acoustic radiation of one-layer cylindrical shell, the influence of thickness, mass density, dilatational wave loss factor and Young's modulus of damping material and circumferential mode number of the cylindrical shell on the insertion loss is concluded. The theoretical model in the paper can be used to deal with the arbitrary thickness and any frequency of the coated layer in dynamic problem. The conclusions may be of theoretical reference to the application of damping material to noise and vibration control of submarines and underwater pipes.     

循环水槽弯管导流形式三维数值模拟研究

为探讨弯管与导流片形式对流场品质的影响,基于RANS方程结合RNG湍流模型对水平循环水槽的弯管导流形式进行三维数值模拟,对出口处速度均匀性及弯管处压强分布进行比较分析。依据数值模拟结果,将非均匀布置导流片形式应用于实际水槽建造中,结果显示流场品质得到了明显的改进。