Prediction of Stabilization of Ship in Random Wave

In this paper we show thc method of energy in part with which we can get the model of random wave,and predict theroll motion of unstabilized ship and stabilized ship using the wave model.The control parameters of fin stabilizer are determinedaccording to the performance index. The simulation of the system is also made in this paper. The comparison of the simulationwith real ship indicates that the method can be used in the prediction of roll motion of a stabilized ship in random wave.     

Locomotion by mechanical pectoral fins

The objectives of this study were the development of a new device for maneuvering an underwater vehicle using the mechanism of a fish swimming, an experimental and theoretical analysis of the hydrodynamic characteristics of the device, and its application to maneuvering a fish robot. Observations and experimental analysis of the pectoral fins of a black bass (Micropterus salmoides) revealed that the locomotion of the fish, such as swimming forward at low speed, swimming backward, and turning in a horizontal plane is generated by using a combination of a feathering motion and a lead-lag motion of the pectoral fins. A mechanical pectoral fin making a feathering motion and a lead-lag motion generates a thrust force in a range of phase differences between both motions. The unsteady vortex lattice method, including the effect of viscosity, can express fairly well the unsteady forces acting on the mechanical pectoral fin in the range of phase differences where it exerts the thrust force. The fish robot, consisting of a model fish body and a pair of mechanical pectoral fins, can not only swim forward and turn in almost the same position, but can also swim in a lateral direction without changing the yaw angle. Translation of an article that appeared in the Journal of The Society of Naval Architects of Japan, vol. 182 (1997): The original article won the SNAJ prize, which is awarded annually to the best papers selected from the SNAJ Journal, JMST, or other quality journals in the field of naval architecture and ocean engineering.     

静水中扭波推进水动力的数值模拟

尼罗河魔鬼鱼（GNF)采用长背鳍扭波推进,具有较高的推进效率和机动性,而鱼体主体可以保持直线不变形。为适应扭波推进过程中鳍面的大摆角变形,文中采用动网格技术求解了静水中扭波推进非定常流场,鳍面最大计算摆角达到85°,并通过与水动力实验结果比较验证了数值计算方法的可靠性。文中还分析了鳍面压力分布随相位的变化及其与推力产生的关系,以及水动力随扭波频率的脉动规律。研究表明,推力系数不随扭波频率而变化,轴向、垂向力波动频率是扭波频率的2倍,而侧向力脉动频率与扭波频率一致。     

计及热辐射及翼翅效应的VLGC温度场计算

运用热力学理论,对设有A型独立液货舱的大型全冷式液化气船（VLGC）的液货、船体结构及海水和空气之间的热传递过程作了研究并对船体结构温度分布作了计算。计算中,除考虑传统的对流和传导之外,还考虑了热辐射以及船体结构加筋板架翼翅效应（fin effect）的影响,提高了计算精度。建立了热传递能量平衡方程,并通过迭代法进行求解,最终得出了船体结构温度场分布。     

不同计算方法所得扁管直翅换热器翅片肋效率的比较

采用数值计算方法对翅片管管片式换热器的肋效率进行了计算和分析,研究扁管肋片厚度、导热系数等因素对肋效率的影响,得出翅片管管片在局部换热系数和平均换热系数下,肋效率的对比分析.     

具有不同尾翼形式潜艇的阻力数值模拟与分析

现代潜艇尾翼的形式普遍采用十字形和X形两种基本形式,文中通过采用求解RANS方程的数值计算方法,结合RNG-kε、S-kω、SST-kω3种湍流模型,对带有30°、45°,60°3种X形尾翼以及十字形尾翼的潜艇阻力进行数值模拟,通过计算结果发现:对各种方案采用RNG-kε和SST-kω湍流模型进行计算时,阻力比较接近,而采用S-kω湍流模型时,阻力比前两种要大;在所有方案中,45°尾翼具有最小的阻力。     

加装减摇鳍船舶横摇运动的计算研究

船舶加装减摇鳍目的是减小船舶的横摇运动.鳍的运动通过由PID控制的液压装置驱动.文章考虑了船舶的粘性阻尼系数,结合减摇鳍运动特性,通过PID控制法对加装减摇鳍船舶横摇进行预报并通过实船验证.     

现代有轨电车的意象与情感化设计

当前,我国现代有轨电车进入了蓬勃发展阶段,但我国现代有轨电车外观及客室设计方法与理论体系相对滞后。意象结合情感认知的设计是国外现代有轨电车设计的发展趋势。结合法国马赛海港城市特点,对其Flexity Outlook现代有轨电车"取象仿生"的外观设计和客室中的情感化设计进行了分析,以期为体现我国各地地域文化和城市形象的现代有轨电车外观及客室设计提供有益的参考。     

Icepak在计算机联锁系统热设计中的应用

计算机联锁系统在工作时会耗散大量热量,为保证元器件和设备的热可靠性,热分析和热控制必不可少.Icepak是目前较流行的、专业的、面向工程师的电子产品热分析软件之一.利用它,可以大大减少计算量,缩短研制周期,降低成本.较详细地介绍Icepak进行某款计算机联锁系统热设计仿真的过程,并对计算结果进行分析、比较,得到最有效的设计方案.     

柔性尾鳍仿金枪鱼水下机器人自主游动研究

文章数值模拟了柔性尾鳍的仿金枪鱼水下机器人从静止加速到稳定巡游的自主游动过程,分析了其运动过程中的运动和水动力性能特点及变化,并与刚性尾鳍模型进行了比较.同时详细分析了尾鳍的运动参数如频率,摆动幅度,横移振幅对仿金枪鱼自主游动过程的影响.结果表明,仿金枪鱼在启动加速时效率较低,柔性变形可以较大地提高仿金枪鱼的推进效率;尾鳍的运动参数对自主游动过程有很大的影响:在一定的范围内,增大尾鳍的运动频率、摆动幅度和横移振幅可以提高运动速度、推力和推进效率,但过大的摆幅会降低推进效率.