共查询到19条相似文献,搜索用时 187 毫秒
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根据船舶运动方程,采用线性系统理论分析船舶在波浪中的摇荡运动规律.通过使用水平移动台、垂直升降台、旋转台和摆动台组成的运动平台来模拟船舶在波浪中运动时通讯机的运动,并以横摇运动为例给出它的一个运动实现,为在实验室条件下研究船舶大气激光通信提供实验平台. 相似文献
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海洋结构物的水动力性能研究对于安全、经济的工程设计至关重要.近年来,由海浪巨大波浪引起的事故越来越多地见诸报道,因此,有必要深入研究波浪尤其是畸形波对结构物产生的载荷及运动响应.海上浮式平台的运动响应与系泊载荷密切相关,而文中的出发点正是研究在何种波浪条件下会引起平台的最大运动响应.通过对一座设计作业水深为500 m的半潜式平台进行频域计算,获得了平台在自由漂浮状态下的响应函数(RAO),并与实验数据进行了比较.通过时域模拟,获得了新年波和"三姐妹"波作用下的平台运动响应,研究了畸形波的存在对于平台运动的影响.此外,还研究了畸形波中最大波峰值及连续大波的出现间隔对平台垂荡和纵摇运动的影响,可为后续研究和工程设计提供参考. 相似文献
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与采用理论公式生成的波浪谱不同,实际浅水中的波浪谱密度在0~0.2 rad/s频率范围内会出现明显的低频能量成分,这会对海洋核动力平台的低频响应产生极大的影响。因此,基于数值模拟和水池试验2种方法得到的波浪谱,采用频域数值计算,分析平台在浅水中2种不同波浪谱下的纵荡、垂荡和纵摇低频响应。结果表明,与数值模拟波浪谱相比,在水池试验得到的实际浅水波浪谱中,平台的纵荡1阶低频运动响应和2阶低频波浪慢漂力,以及垂荡1阶低频波浪力和1阶低频运动响应都存在明显的增大,这说明在进行平台浅水水动力预报时需要重点考虑波浪谱中低频能量成分对平台低频响应的影响。本文可为其他同类型船体在浅水中的低频响应预报提供参考。 相似文献
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减摇水舱性能试验摇摆模拟台是根据相似准则建立的一种模拟在波浪作用下船舶横摇运动的试验装置。为使摇摆模拟台能够模拟各种类型船舶的运动,要求模拟台的转动惯量、阻尼力矩和波浪干扰力矩都是可调节的。利用硬件方法模拟阻尼力矩具有许多不确定因素,很难保证模拟的阻尼力矩值与要求的阻尼力矩一致,这给减摇水舱性能预报带来诸多困难。本文提出了一种利用软件模拟船舶横摇阻尼力矩的方法,仿真分析和试验结果表明该方法能够模拟各种船舶的阻尼力矩,满足模拟台阻尼力矩模拟要求。 相似文献
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为了研究船舶运动响应可视化的问题,将虚拟现实技术运用到船舶运动中.根据船舶在迎浪状态下纵向运动方程求解纵摇和升沉时的历解,为运动仿真提供原始数据.以MAXSCRIPT语言和VC++为工具,3DSMAX为平台,初步开发了船舶运动仿真系统,并通过了系统测试.结果表明文中建立了一个具有良好交互性、效果逼真的仿真系统,比一般数值模拟更具有说服力,船舶在波浪中的运动仿真已经能够较好地实现. 相似文献
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《船舶与海洋工程学报》2020,(1)
The launching and recovery process of a human-occupied vehicle(HOV) faces more complex wave effects than other types of submersible operations. However, due to the nonlinearity between the HOV and its mother ship, difficulties occur in theoretically simulating their coupled motion and hydrodynamics. The coupled motion responses and the load under different regular wave conditions are investigated experimentally in this study. The optimized design of the experimental scheme simulated the launching and recovery process of the mother ship and HOV in regular waves. The attitude sensor performed synchronous real-time measurement of the coupled motion between the mother ship and HOV as well as obtained the load data on the coupled motion under different cable lengths. The results show that models in heading waves mainly lead to the vertical motion of the hoisting point. In beam waves, the transverse and vertical motions of the hoisting point occur in a certain frequency of waves.Under the heading and beam wave conditions, the longer the hoisting cable is, the greater the movement amplitude of the submersible is. Moreover, compared with the condition of the beam waves, the hoisting submersible has less influence on the mother ship under the condition of the heading waves. The findings provide theoretical support for the design optimization of the launching and recovery operation. 相似文献
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《船舶与海洋工程学报》2018,(3)
Ship maneuvering in waves includes the performance of ship resistance, seakeeping, propulsion, and maneuverability. It is a complex hydrodynamic problem with the interaction of many factors. With the purpose of directly predicting the behavior of ship maneuvering in waves, a CFD solver named naoe-FOAM-SJTU is developed by the Computational Marine Hydrodynamics Lab(CMHL) in Shanghai Jiao Tong University. The solver is based on open source platform OpenFOAM and has introduced dynamic overset grid technology to handle complex ship hull-propeller-rudder motion system. Maneuvering control module based on feedback control mechanism is also developed to accurately simulate corresponding motion behavior of free running ship maneuver. Inlet boundary wavemaker and relaxation zone technique is used to generate desired waves. Based on the developed modules, unsteady Reynolds-averaged Navier-Stokes(RANS) computations are carried out for several validation cases of free running ship maneuver in waves including zigzag, turning circle, and course keeping maneuvers. The simulation results are compared with available benchmark data. Ship motions, trajectories, and other maneuvering parameters are consistent with available experimental data, which indicate that the present solver can be suitable and reliable in predicting the performance of ship maneuvering in waves. Flow visualizations, such as free surface elevation, wake flow, vortical structures, are presented to explain the hydrodynamic performance of ship maneuvering in waves. Large flow separation can be observed around propellers and rudders. It is concluded that RANS approach is not accurate enough for predicting ship maneuvering in waves with large flow separations and detached eddy simulation(DES) or large eddy simulation(LES) computations are required to improve the prediction accuracy. 相似文献
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介绍了船舶在海浪中运动的可视化技术。给出了可视化设计过程的流程图,并讨论了建立船舶模型的可行方法和三维波浪模型的数学模型,以及如何应用OpenGL函数库来生成船舶在海浪中运动的动画。在讨论可视化技术时,使用了具有平台独立性的OpenGL图形库。 相似文献
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准确预报船体运动响应对于砰击等波浪载荷的计算以及合理结构设计具有重要意义。船舶在大幅波浪中的运动呈明显的非线性,而现阶段耐波性预报多采用线性切片方法。三维水动力分析软件 WASIM基于时域势流理论,采用 Rankine面元法预报船舶在波浪中的运动响应,并考虑了多种非线性因素。本文以标模 DTMB5512为对象,采用 WASIM预报其在不同航速下的耐波性,并与基于线性切片理论的计算结果和模型试验结果进行对比。结果表明:利用 WASIM计算得到的船体运动响应比其他方法更接近试验值,合理体现了船舶在风浪中的实际耐波性能。因此,利用 WASIM能够较好地评估船舶在波浪中的非线性耐波特性。 相似文献
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基于iSIGHT的船型耐波性优化研究 总被引:1,自引:0,他引:1
将船型变换程序接入到iSIGHT系统中,进行系列船型的变换,生成船型库;应用三维时域面元法(Wasim软件)对船型库中的系列船型进行耐波性的计算,将计算结果绘制成图谱,对耐波性与主要船型参数之间的关系总结归纳,并编写插值程序。将船型变换程序与插值程序相连,再接入到整个优化系统中,寻找到耐波性能更优良的船型。以某远洋渔船船型为例,验证了基于iSIGHT的耐波性优化系统的可行性。 相似文献
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目前,国内外的船模水动力性能测试装置均为平面运动机构,使得船舶水动力导数的测量范围有限,而一种新型船模水动力性能测试装置,即六自由度船模水动力性能测试装置可以扩大这一测量范围.从六自由度平台的工作原理,六分力天平量程的确定和测试装置总体设计3个方面来具体研究和设计六自由度船模水动力性能测试装置.首先具体介绍六自由度平台的工作原理,即平台6根运动杆的运动与船舶六自由度运动的对应关系;然后建立船舶六自由度运动所受力和力矩的初步计算公式,以国内外平面运动机构的具体技术性能指标为依据,确定试验装置中的六分力天平的量程;最后确定测验装置的整体设计,设计出现有船池拖车平台的具体形状与尺寸.以此为依据,综合考虑拖车平台的受力情况及拖车架和六自由度平台的安装方式,确定拖车架的具体结构形式与尺寸大小,得到三维示意图、二维安装图与尺寸图,进行结构强度分析. 相似文献
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Evaluation of added resistance in regular incident waves by computational fluid dynamics motion simulation using an overlapping grid system 总被引:2,自引:0,他引:2
A computational fluid dynamics simulation method called WISDAM-X was developed to evaluate the added resistance of ships in waves. The Reynolds-averaged Navier–Stokes (RANS) equation was solved by the finite-volume method and a MAC-type solution algorithm. An overlapping grid system was employed to implement rigorous wave generation, the interactions of ships with incident waves, and the resultant ship motions. The motion of the ship is simultaneously solved by combining the solution of the motion of the ship with the solution of the flow about the ship. The free surface is captured by treatment by the density-function method. The accuracy of WISDAM-X is examined by a comparison with experimental data from a container carrier hull form, and shows a fairly good agreement with respect to ship motion and added resistance. Simulations were also conducted for a bow-form series of a medium-speed tanker to examine the effectiveness of the WISDAM-X method as a design tool for a hull form with a smaller resistance in waves. It was confirmed that the WISDAM-X method can evaluate the added resistance with sufficient relative accuracy and can be used as a design tool for ships. 相似文献
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根据深海石油平台支援船(OSV)的特点,研究了风、浪、流、推进器和舵的数学模型,并用MATLAB里的M文件对船舶的回转运动以及在风浪流作用下的运动进行了仿真,结果与实验一致,验证了数学模型的合理性. 相似文献