考虑不确定性因素的路径优化(英文)

A route optimization methodology in the frame of an onboard decision support/guidance system for the ship’s master has been developed and is presented in this paper.The method aims at the minimization of the fuel voyage cost and the risks related to the ship’s seakeeping performance expected to be within acceptable limits of voyage duration.Parts of this methodology were implemented by interfacing alternative probability assessment methods,such as Monte Carlo,first order reliability method(FORM) and second order reliability method(SORM),and a 3-D seakeeping code,including a software tool for the calculation of the added resistance in waves of NTUA-SDL.The entire system was integrated within the probabilistic analysis software PROBAN.Two of the main modules for the calculation of added resistance and the probabilistic assessment for the considered seakeeping hazards with respect to exceedance levels of predefined threshold values are herein elaborated and validation studies proved their efficiency in view of their implementation into an on-board optimization system.     

船模在简谐激励存在时的运行模态分析(英文)

A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm (NExT-ERA) is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.     

船舶虚拟装配集成化建模方法研究(英文)

A new method of virtual ship assembly modeling which integrates ship three-dimensional design and ship construction planning was described in this paper. A workflow model of simulation modeling based on the virtual ship assembly process was also established; furthermore, a method of information transformation between the ship three-dimensional design and ship construction plan was formulated. To meet the requirements of information sharing between different systems in the ship virtual assembly, a simulation database was created by using the software engineering design method and the relational data model. With the application of this database, the information of ship three-dimensional design, construction planning, and virtual assembly can be integrated into one system. Subsequently, this new method was applied as a tool to simulate the virtual assembly of a ship, and the results guarantee its rationality and reliability.     

军船雷达目标有效截面预报和缩减研究(英文)

Radar cross section(RCS) is the measurement of the reflective strength of a target.Reducing the RCS of a naval ship enables its late detection,which is useful for capitalizing on elements of surprise and initiative.Thus,the RCS of a naval ship has become a very important design factor for achieving surprise,initiative,and survivability.Consequently,accurate RCS determination and RCS reduction are of extreme importance for a naval ship.The purpose of this paper is to provide an understanding of the theoretical background and engineering approach to deal with RCS prediction and reduction for naval ships.The importance of RCS,radar fundamentals,RCS basics,RCS prediction methods,and RCS reduction methods for naval ships is also discussed.     

开源环境下的高精确度船舶水动力学仿真(英文)

The numerical simulation of wake and free-surface flow around ships is a complex topic that involves multiple tasks: the generation of an optimal computational grid and the development of numerical algorithms capable to predict the flow field around a hull. In this paper, a numerical framework is developed aimed at high-resolution CFD simulations of turbulent, free-surface flows around ship hulls. The framework consists in the concatenation of tools, partly available in the open-source finite volume library Open FOAM. A novel, flexible mesh-generation algorithm is presented, capable of producing high-quality computational grids for free-surface ship hydrodynamics. The numerical frame work is used to solve some benchmark problems, providing results that are in excellent agreement with the experimental measures.     

舰船气泡尾流数值模拟(英文)

Based on a volume of fluid two-phase model imbedded in the general computational fluid dynamics code FLUENT6.3.26, the viscous flow with free surface around a model-scaled KRISO container ship (KCS) was first numerically simulated. Then with a rigid-lid-free-surface method, the underwater flow field was computed based on the mixture multiphase model to simulate the bubbly wake around the KCS hull. The realizable k-ε two-equation turbulence model and Reynolds stress model were used to analyze the effects of turbulence model on the ship bubbly wake. The air entrainment model, which is relative to the normal velocity gradient of the free surface, and the solving method were verified by the qualitatively reasonable computed results.     

海洋中晕船问题的案例研究(英文)

Motion sickness is one of the main reasons why travelling by sea becomes a bad memory for a number of people, mainly due to a nauseating symptom. The aim of this paper is to characterize a condition called seasickness that has affected many people from a mathematical and psychological point of view. Based on the mathematical characterization, an existing model will be reviewed and described. In the psychological aspects, a statistical study of two hundred and thirteen people was performed in order to provide a comprehensive view of the different psychological factors affecting the passengers. Motion sickness also impacts onboard safety, as it reduces the effectiveness and the operating capability of the crew when responding to hazardous situations.     

水动力效率最高的鳗鱼推进器(英文)

It is hypothesized that steady anguilliform swimming motion of aquatic animals is purely reactive such that no net vortex wake is left downstream. This is versus carangiform and tunniform swimming of fish, where vortex streams are shed from tail, fins, and body. But there the animal movements are such to produce partial vortex cancellation downstream in maximizing propulsive efficiency. In anguilliform swimming characteristic of the eel family, it is argued that the swimming motions are configured by the animal such that vortex shedding does not occur at all. However, the propulsive thrust in this case is higher order in the motion amplitude, so that relatively large coils are needed to produce relatively small thrust; the speeds of anguilliform swimmers are less than the carangiform and tunniform, which develop first order thrusts via lifting processes. Results of experimentation on live lamprey are compared to theoretical prediction which assumes the no-wake hypothesis. Two-dimensional analysis is first performed to set the concept. This is followed by three-dimensional analysis using slender-body theory. Slender-body theory has been applied by others in studying anguilliform swimming, as it is ideally suited to the geometry of the lamprey and other eel-like animals. The agreement between this new approach based on the hypothesis of wakeless swimming and the experiments is remarkably good in spite of the physical complexities.     

三维测量数据的钢结构虚拟装配过程仿真系统(英文)

The virtual erection simulation system was explained for a steel structure including ship and ocean plant blocks.The simulation system predicted the erection state to optimize any gap or overlap of blocks based on 3-D measurement data.The blocks were modified(cut) on the basis of the simulation result on the ground before erecting them by crane.The re-cutting process was not required and the blocks were erected into a mother ship speedily.Therefore,the erection time is reduced,increasing the dock turnover.     

纵倾优化下的船舶能效数值模型

通过Fluent数值计算和Simulink建模仿真的方法,建立船舶的CFD计算模型及能确定转速(n)-航速(V_s)-船舶能效营运指数(EEOI)间对应关系的船舶能效准稳态仿真模型,进而分析不同工况下纵倾变化对船舶营运能效的影响。以定转速航行模式的46000t油轮为目标船,经模型的计算和船模试验的验证,发现适当纵倾可提高目标船的营运能效。结合相关海事公约法规,计算目标船的最佳纵倾在艉倾2.61m处,可降低EEOI达0.8%。     

发展绿色舰船,抢占未来舰船发展制高点

针对舰船装备发展面临的低碳、环保等热点问题,阐述了“绿色舰船”和“绿色舰队”的内涵,介绍了美、欧等世界先进海军国家绿色舰船的发展现状。从节能、减排、防污和能源安全等角度,分析了我国海军发展绿色舰船的必要性。提出了发展绿色舰船应采取的系统性举措,包括:加强战略规划论证、更新舰船设计理念、注重绿色能源探索、强化配套装备研发、提升绿色建造能力、重视绿色管理研究、关注国际绿色舰船装备与技术新动向、积极开展国内外交流和合作等。     

Overview of intelligent ship route optimization methods北大核心CSCD

智能船舶航线优化在学术界和工业界均受到越来越多的关注。针对智能船舶航线优化问题,从航线设计方法和航线优化算法这2个层面,分别阐述各种设计方法和优化算法的特点。结合近5年来的最新研究成果,在分析国内外智能船舶航线优化技术发展现状的基础上,将航线设计方法归纳为3种,即基于气象数据的航线优化、基于油耗模型的航线优化以及基于航线库或航路点库的航线优化,剖析其技术内涵及应用情况;深入分析改进的等时线法、动态规划法、图形搜索算法、智能算法、人工智能和机器学习算法的特性及不足,总结归纳将各类算法应用于智能船舶航线优化时存在的主要问题。最后,简要展望智能船舶航线优化的发展趋势,为未来在该领域的研究提供一定的思路。     

船舶多清洁能源混合动力系统优化设计方法

多清洁能源混合动力系统可通过采用多种清洁能源有效提高船舶的绿色化水平,但多清洁能源的不同特点会增加混合动力系统配置优化设计的复杂性,目前缺少对多清洁能源混合动力系统优化配置方法的研究。对此,基于燃料电池、锂离子电池、超级电容和柴油发电机的混合动力系统形式,提出一种基于小波变换和遗传算法的多清洁能源混合动力系统优化配置方法。分析结果表明:提出的混合动力系统优化配置方法能在满足船舶最大功率需求的同时,提高船舶的经济性,降低二氧化碳排放,进而提高船舶的整体能效水平。     

集装箱船纵倾优化数值模拟

随着全球能源和环境问题越来越严峻,航运市场低迷和竞争的日益激烈,节能减排已成为航运业的迫切需求。船舶纵倾优化具有成本低、易实现和效果佳等优点,是一种更好的节能减排方法。以KCS集装箱船在设计吃水时平吃水状态为基础,对船舶分别进行不同纵倾状态调节,利用RANS方法和切割体自动划分网格技术,计算船舶在不同首倾和尾倾状态下的阻力数值。结果表明,在不考虑水深影响的情况下,KCS集装箱船在不改变船舶航速、载重量的前提下,可以通过纵倾优化调节减少船舶阻力。     

智能货运船舶研究现状与发展思考

针对内河复杂航道特点,提出一种基于绿色智能散货船多能源并联混合动力系统的直流组网系统设计方案。

首先,分析混合动力系统采用直流组网的优势,采用功率链计算法得出各典型工况下的混合动力直流组网推进效率。然后,研究针对绿色智能船舶附加标志具体要求的直流组网系统应用设计特点。最后,对实船直流配电系统保护及安全设计进行综合分析。

结果表明,实船采用包含储能系统的并联柴电/气电混合动力直流组网推进系统,整体性能优于常规主机推进和全电力推进方式。采用多种装置相结合的保护措施及失电恢复解决方案,确保了直流组网系统实船应用的安全可靠性。

直流组网可为实现内河船舶最高绿色等级水平提供柔性能源平台,并为智能机舱、智能能效管理及智能集成平台技术应用提供全方位支撑。研究成果可为绿色智能混合动力船舶直流组网的设计提供参考。

     

基于BP神经网络的客滚船营运风险评估

随着客滚船运输行业的兴起,客滚船的营运安全日益受到各方面的关注。文中利用BP神经网络评价方法,由人、船、环境、管理四要素所构成的客滚船营运风险进行评估,最终确定某客滚船具体航次的营运风险。经过验证,基于BP神经网络客滚船营运风险评估方法与实际相符,为客滚船风险评估提供一条新的途径。     

等离子体技术处理舰船固体废弃物的进展

随着国际海洋保护法律法规的日益严格以及我国海军远洋航行任务的逐渐增加,军用舰船需要增强固体废弃物的现场无害化处理能力,使其能在世界任何水域自由航行。简要介绍73/78防污公约对固体废弃物排放的要求,以及美国海军为适应该公约而采取的处理策略。通过对现有固体废弃物处理技术的综合分析,指出等离子体焚烧技术最适合处理舰船固体废弃物,其固体残渣和尾气排放完全符合73/78防污公约。最后,介绍了等离子体焚烧技术在舰船上的应用情况。     

风翼-柴油机混合动力船主机降速模式

为了探索风翼-柴油机混合动力船主机降速航行模式,分析了风翼船机桨的能量传递,以及风翼助航对船舶阻力和主机的影响.分别研究了定速航行和定功率航行两种主机降速航行模式的特点.通过对比得出定速航行更适合于风翼-柴油机混合动力船舶,为风翼-柴油机混合动力船舶的推广应用提供了理论依据.     

作战软件模型检验方法研究

作战模型是作战软件的基础。采用合适的检验方法对作战模型进行检验,对于提高作战软件辅助决策的正确性、实用性,实现预定的功能需求,减少工程研制风险具有重要的意义。在分析作战模型研制过程的基础上,提出了作战模型检验方法的组合应用策略,为正确有效的开展模型检验活动提供了技术支持。