共查询到20条相似文献，搜索用时 15 毫秒
1.
为配合我国南海重要岛礁陆域拓展及海洋资源开发,提出了一种基于新型单桩缓冲系泊与波浪能装置(WEC)集成的具有潮汐自适应特性的模块化浮体结构系统。基于三维势流理论,综合考虑浮体模块与单桩缓冲结构的相对运动及相关波浪能装置的机械耦合机理,重点研究了新型单模块浮式结构系统在典型海况下的动力响应特征,获得了单桩缓冲系泊系统的初步优化设计参数,并对极端海况进行安全校核,提出了优化自存策略。数值结果表明,此带有波浪能装置的新型单桩缓冲系泊系统,不仅可以有效地降低浮体模块的运动响应幅值并改善平台舒适度,还可以获得可观的发电量,而且在极端海况下,可以通过调整阻尼装置系统来稳定浮体模块的运动。 相似文献
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In this study, we develop a numerical method for a 3D linear hydroelastic analysis of floating structures with liquid tanks subjected to surface regular water waves and compare the numerical results with experimental tests. Considering direct couplings among structural motion, sloshing, and water waves, a mathematical formulation and a numerical method extended from a recent work [1] are developed. The finite element method is employed for the floating structure and internal fluid in tanks, and the boundary element method is used for the external fluid. The resulting formulation completely incorporates all the interaction terms including hydrostatic stiffness and the irregular frequency effect is removed by introducing the extended boundary integral equations. Through various numerical tests, we verify the proposed numerical method. We also performed 3D hydroelastic experimental tests of a floating production unit (FPU) model in an ocean basin. The measured dynamic motions are compared with the numerical results obtained using the proposed method. 相似文献
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针对深海采矿实际需求,提出将集矿车上的液压站与集矿车分离,设计成相对独立、悬浮于集矿车前部上方的浮游体。设计了多金属结核概念车浮游体(以下简称浮游体)外形,并利用三维设计软件SolidWorks建立了其三维几何模型。在此基础上,对几何模型进行简化处理,建立了浮游体流体动力学计算模型。利用流体动力学仿真分析软件ANSYS CFX,采用雷诺时均算法(RANS算法)和两方程的k-ε湍流模型,得到了不同工况的阻力数据。采用Matlab曲线拟合功能,研究了浮游体阻力特性,验证了外形设计方案的可行性。 相似文献
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The floating oil storage system has been proposed as a new facility for Strategic Petroleum Reserve (SPR) in China. Mooring is one of the key technologies to ensure the safety, reliability, and performance of the oil storage system. This paper describes the concept, analysis, design and reliability of the mooring system. For mooring system design of these oil vessels, analysis is essential of the behavior of the vessel in connection with mooring facilities of nonlinear resilience. A nonlinear mathematical model for analyzing a moored vessel is established and solved. Some results of numerical simulations are presented. Assessment of the safety regarding the mooring system in terms of failure probability is carried out. Another simulation model for calculating the failure probability of the mooring system is proposed. The design parameters that have an influence on the characteristics of the failure probability have been identified. The simulation results show that the mooring system has an annual reliab 相似文献
6.
Ma Peisun Ma Lie Lu Shunshou Associate Professor Shanghai Jiaotong University Shanghai Graduate Shanghai Jiaotong University Shanghai Engineer Shanghai Jiaotong University Shanghai 《中国海洋工程》1991,(4)
To fulfil the need of development of offshore oil floating production system, the performance of turret assembly in an inboard turret mooring system has been investigated in the paper. By means of systematic evaluation, the optimal structure of the turret for single-point mooring systems has been determined. Through model tests of a turret mooring system, several groups of data such as forces, moments and displacements under different environmental conditions have been obtained. Stresses and strains of the turret structure have been calculated by means of the finite element method corresponding to the situation in the model experiment. The study shows that the selected turret structure and the designed turret assembly are technically feasible. 相似文献
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《中国海洋工程》2020,(4)
A conceptual design of using novel telescopic piles to position a multi-modular very large floating structure(VLFS),which is supposed to be severed as a movable floating airport, is proposed. The telescopic piles can automatically plug in the soil to resist the environmental loads and pull out from the soil to evacuate or move on to the next operational sea. The feasibility demonstration of the conceptual design includes two parts: function verification and structure design. In the latter part of the conceptual design, a time-domain structural analysis is firstly conducted by using Abaqus software. The simulation results suggest that the preliminary structure scheme is not optimum due to the insufficient structure utilization, although both structure safety of the piles and positioning accuracy are guaranteed. To realize a cost reduction of construction and installation, a Genetic Algorithm-Finite Element Analysis(GA-FEA) method is employed to perform structural optimization. After optimization, 31 percent of the weight of each pile is reduced and higher structure utilization is maintained. The difference of the self-weight and allowable buoyancy of a single module(SMOD) of a semisubmersible-type VLFS is much larger than the weight of the piles.Combined with the function verification in our previous work, the conceptual design of using the novel telescopic pile to position VLFS is demonstrated to be feasible. 相似文献
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针对半潜式超大型浮式结构中典型的移动式海上基地(Mobile Offshore Base,MOB)在高等级海况下的动力响应问题展开研究。在MOB结构"刚性模块-柔性连接构件(Rigid Modules and Flexible Connectors,RMFC)"模型的前提下,根据动力学基本原理,经理论推导并计算得到MOB分别在6、7、8级海况的随机波激励下,其上各模块的动力响应位移结果。详细分析了MOB结构同一模块在不同海况条件下的动力响应位移随浪向角及连接构件刚度的变化规律。研究成果可为半潜式超大型浮式结构动力响应研究及结构优化设计提供一定的技术支撑。 相似文献
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为研究顺应式海洋平台慢漂运动的影响因素,以截断圆柱和漂浮方箱为例进行了不规则波作用下的慢漂运动模型试验。测量了不同系泊刚度条件下的漂浮方箱以及相同系泊刚度条件下的截断圆柱和漂浮方箱在静水中自由衰减运动和在不规则波中的运动响应,并将运动响应分解成一阶波频运动响应和二阶低频运动响应,分析了系泊刚度和浮体形状对浮体运动的影响。通过物理模型试验发现了系泊刚度及浮体形状对顺应式系泊浮体一阶运动标准差和二阶低频运动平均漂移值和标准差的关系。结果表明由于顺应式浮体的固有周期远离波浪谱峰周期时,系泊刚度以及浮体形状对慢漂运动的一阶运动响应影响不大;二阶低频运动相对偏离平衡位置的平均值和标准差均随系泊刚度增大而减小,浮体形状同样对慢漂运动的二阶低频纵荡运动响应影响较大。试验结果为实际海洋工程的外形选择和系泊刚度选择提供数据支持。 相似文献
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缓波型立管由于设计参数较多且优化目标之间相互影响,设计结果具有很大的不确定性。随着代理模型和智能优化算法的发展,针对缓波型立管的优化可以提出更好的解决方案。以提高力学性能和经济效益为优化目标,采用基于Kriging插值模型和NSGA-II算法的多目标优化策略,对考虑顶部浮体影响的深水缓波型立管进行动力响应分析,并开展线型—截面双目标优化集成设计和线型—浮筒三目标优化集成设计。将处于不同几何尺度的设计变量进行集成,旨在各目标存在相互竞争的情况下,与截面、浮筒设计形成有效互动以提高线型设计的总体性能。结果表明,Pareto最优解集可提供多个选择方案,以满足工程实际需要。将所选最优方案与初始设计进行对比,并以疲劳性能和成本估算作为优化的校核指标,取得了理想的优化效果。 相似文献
11.
Dike resilience against wave overtopping has gained more and more attention in recent years due to the effect of expected future climate changes. The overtopping flow velocities and flow depths on dikes have recently been studied in 2D small-scale experiments. This has led to semi-empirical formulae for the estimation of flow depths and flow velocities across a dike. The results have been coupled to the actual erosion of the landward dike slope determined by full-scale 2D tests using the so-called “Overtopping Simulator”. This paper describes the results from 96 small-scale tests carried out in a shallow water basin at Aalborg University to cover the so far unknown 3D effects from oblique long-crested and short-crested waves. Based on results from the laboratory tests, expansions are proposed to the existing 2D formulae so as to cover oblique and short-crested waves. The wave obliquity is seen to significantly reduce the overtopping flow velocities and flow depths on especially the landward slope of a sea dike. Moreover, the tests showed that the average flow directions on the dike crest from oblique long-crested and short-crested waves correspond approximately to the incident wave direction. Flow depths and the squared flow velocities on the dike are concluded to be Rayleigh-distributed in case of both long-crested and short-crested waves for all considered incident wave obliquities. Findings in the present paper are needed to obtain more realistic estimates of dike erosion caused by wave overtopping. 相似文献
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The most common method of reducing roll motion of ship-shaped floating systems is the use of bilge keel which act as damping elements. The estimation of the damping introduced by bilge keel is still largely based on empirical methods. The present work adopts the CFD approach to the estimation of roll damping, both without and with bilge keel and validates the results with experiments conducted in a wave flume. Specifically, free oscillation tests are conducted at model scale to obtain roll damping, both by experiments and CFD simulation and reasonably good comparisons are obtained. The experiments also include PIV study of the flow field and attempt has been made to correlate the measured flow field with that obtained by CFD. The CFD methodology has the potential to determine rationally the size and orientation of bilge keels in design with reasonably accurate estimate of the additional roll damping that it provides to ship's roll motion. 相似文献
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Three-dimensional hydroelasticity theory is used to predict the hydroelastic response of flexible floating interconnected structures. The theory is extended to take into account hinge rigid modes, which are calculated from a numerical analysis of the structure based on the finite element method. The modules and connectors are all considered to be flexible, with variable translational and rotational connector stiffness. As a special case, the response of a two-module interconnected structure with very high connector stiffness is found to compare well to experimental results for an otherwise equivalent continuous structure. This model is used to study the general characteristics of hydroelastic response in flexible floating interconnected structures, including their displacement and bending moments under various conditions. The effects of connector and module stiffness on the hydroelastic response are also studied, to provide information regarding the optimal design of such structures. 相似文献
14.
随着智能化研究成为当今科技发展的热点,结合智能优化算法的浮体系泊系统自动化设计成为一个将现代方法应用于传统工程领域并提高设计效率的研究对象。针对浮体的系泊系统,以悬链线式系泊方式为研究对象,分析得出了系泊缆与不同选材参数之间的规律,建立系泊系统自动化设计方法,选用遗传算法作为算法基础,实现方案的智能优选,进行了有效的探索研究;开发了系泊系统自动化设计的自主程序,完成了典型的单根系泊缆的单点系泊系统以及多段组成风分布式系泊系统的研究,验证了方法的可行性,为系泊系统的自动化设计这一技术问题提供了解决方法与工程的应用手段。 相似文献
15.
开发并验证了一种基于CFD-FEM耦合的弹性浮体水弹性响应计算模拟方法。采用CFD方法建立黏性数值水池模拟非线性波浪,弹性浮板进行有限元离散,并在交界面进行数据交互实现耦合计算;通过与水池试验数据和三维板理论在各种波浪环境下的浮体垂向位移结果对比,证实CFD-FEM耦合方法的有效性。并进一步研究了浮板的厚度、入射波波幅和浮板的三维效应对浮板水弹性响应的影响。结论表明,波幅的增加会加剧弹性浮板的水弹性响应,浮板各点处的垂向位移随波幅的增加而增大;当浮板厚度改变时,不同厚度浮板自由端处的垂向位移差异较小,而在中部等位置处,厚度对浮板的水弹性响应有较大的影响。 相似文献
16.
《Coastal Engineering》2005,52(10-11):867-885
New unique laboratory experiments on low-crested structures (LCSs) have been performed within the DELOS project. The experiments were carried out in three European laboratories aiming at extending and completing existing available information with respect to a wide range of engineering design properties such as structural stability, wave and current flows and wave transmission. 3D wave basin tests were performed to provide information especially about the wave obliquity, where almost no research has been done before. Flow velocities inside and close to the surface of structures were studied in a wave channel at small scale, and scale effects regarding wave transmission and reflection were studied in a wave channel at a large scale facility. The paper describes the experiments and associated databank with respect to objectives, test program, set-ups and measurements. Results, guidelines and recommendations elaborated from the tests are included in the other companion papers of the Coastal Engineering Special Issue on DELOS. 相似文献
17.
Tidal current power is one of the promising and reliable renewable energies with the advantage of continuous and predictable resource. It can make stable electricity regardless of weather conditions or seasons all year around. The required technologies for tidal current power in the ocean have been developed for years and now recognized that it could be commercialized after intensive field tests and successful demonstrations. There are several tidal farm development projects in the world, such as the MeyGen project in UK with its commercialization at hand. However, various research subjects in the tidal current energy field are seeking improvements and industrialization of tidal current power in terms of economy and technical reliability. This paper introduces the resource assessment procedure of tidal energy that has been applied in Korea coastal regions. The key research subjects for tidal current power together with the interaction effect of multi-arrangement is described. Also, this paper is to introduce the research output of each subject such as turbine design, experimental validation, turbine interaction and wake, multi-array module, FSI (fluid-structure interaction), and duct application. 相似文献
18.
非通航孔桥墩自适应拦截网防撞装置实船拦截试验与水动力计算 总被引：1，自引：0，他引：1
针对非通航孔桥墩,研发了一种自适应拦截网防船舶撞击装置,主要由系泊大浮体、系泊锚链和固定锚、自适应小浮筒、拦截网、恒阻力缆绳以及触发钢索所组成。阐述了该防撞装置设计原理,即偏航船舶撞击该防撞装置,小浮筒会带动拦截网自适应地从水平状态竖起展开,包裹住来撞船首,再通过相连浮体的运动阻力和恒阻力缆绳来吸收船舶动能,拦截住船舶,保护非通航孔桥墩安全。随后介绍在福建平潭海峡大桥引桥附近海域实施的实船撞击自适应拦截网防撞装置的大型试验,试验结果显示:自适应拦截网成功升起,船舶被安全拦截,从而实验证实了设计原理与设计方案的可行性和可靠性。最后,采用大型水动力分析软件AQWA对防撞装置拦截船舶过程进行数值模拟,模拟结果与实验结果基本一致,说明了数值仿真具有较好的计算精度和可靠性,能够为该防撞装置的结构设计与优化提供重要的参考。 相似文献
19.
Design and projected performance of a flapping foil AUV 总被引：1，自引：0，他引：1
Licht S. Polidoro V. Flores M. Hover F.S. Triantafyllou M.S. 《Oceanic Engineering, IEEE Journal of》2004,29(3):786-794
The design and construction of a biomimetic flapping foil autonomous underwater vehicle is detailed. The vehicle was designed as a proof of concept for the use of oscillating foils as the sole source of motive power for a cruising and hovering underwater vehicle. Primary vehicle design requirements included scalability and flexibility in terms of the number and placement of foils, so as to maximize experimental functionality. This goal was met by designing an independent self-contained module to house each foil, requiring only direct current power and a connection to the vehicle's Ethernet local area network for operation. The results of tests on the foil modules in the Massachusetts Institute of Technology (MIT) Marine Hydrodynamics Water Tunnel and the MIT Ship Model Testing Tank are both used to demonstrate fundamental properties of flapping foils and to predict the performance of the specific vehicle design based on the limits of the actuators. The maximum speed of the vehicle is estimated based on the limitations of the specific actuator and is shown to be a strong function of the vehicle drag coefficient. When using four foils, the maximum speed increases from 1 m/s with a vehicle C/sub D/ of 1.4 to 2 m/s when C/sub D/=0.1, where C/sub D/ is based on vehicle frontal area. Finally, issues of vehicle control are considered, including the decoupling of speed and pitch control using pitch-biased maneuvering and the tradeoff between actuator bandwidth and authority during both the cruising and hovering operation. 相似文献
20.
Numerical Analysis on the Effects of Submerged Depth of the Grid and Direction of Incident Wave on Gravity Cage 总被引：1，自引：0，他引：1
In this paper,the numerical model of the net cage with the grid mooring system in waves is set up by the lumped mass method and rigid kinematics theory,and then the motion equations of floating system,net system,mooring system,and floaters are solved by the Runge-Kutta fifth-order method.For the verification of the numerical model,a series of physical model tests have been carried out.According to the comparisons between the simulated and experimental results,it can be found that the simulated and experimental results agree well in each condition.Then,the effects of submerged depth of grid and direction of incident wave propagation on hydrodynamic behaviors of the net cage are analyzed.According to the simulated results,it can be found that with the increase of submerged depth of grid,the forces acting on mooring lines and bridle lines increase,while the forces on grid lines decrease;the horizontal motion amplitudes of floating collar decrease obviously,while the vertical motion amplitudes of floating collar change little.When the direction of incident wave propagation changes,forces on mooting lines and motion of net cage also change accordingly.When the propagation direction of incident wave changes from 0° to 45°,forces on the main ropes and bridle ropes increase,while the forces on the grid ropes decrease.With the increasing propagation direction of incident wave,the horizontal amplitude of the forces collar decreases,while the vertical amplitude of the floating collar has little variation. 相似文献