Study on the maneuverability of a large vessel installed with a mariner type Super VecTwin rudder

The suitability of the Mariner type Super VecTwin rudder (hereinafter, the MSV rudder) for a large vessel is assessed in this article. Several experiments in a maneuvering pond were carried out and their results analyzed and summarized. Free-running tests such as turning, zigzag, and stopping tests were carried out with a 4-m free-running model of a very large crude carrier (VLCC) ship with the MSV rudder and the Mariner rudder. The results were compared to validate the maneuverability of a VLCC-sized a ship installed with the MSV rudder. A mathematical model of an MSV rudder is proposed for maneuvering simulation of a large vessel. To develop a maneuvering simulation for the model ship that was used in the free-running tests, hydrodynamic coefficients were estimated based on Kijima's regression formula. The coefficients of interaction between the hull and rudder (t_R, a_H, x_H) were obtained from a self-propulsion test in a towing tank. The complicated flow around the rudders is simplified to model the flow speed around the rudders. This simplified flow speed is utilized to compare the time histories of the free-running tests with the simulations. The mathematical model of the MSV rudder was further improved using the results of this comparison.     

A study on improving the course-keeping ability of a pure car carrier in windy conditions

The course-keeping ability of a pure car carrier (PCC) in windy conditions is discussed in this article. Numerical simulations of two PCCs were carried out to compare their course-keeping abilities in wind. The two PCCs had the same hull form but different types of rudder. One PCC was fitted with a semispade rudder (hereinafter, the normal rudder), whereas the other was fitted with a spade-type Schilling rudder (hereinafter, the Schilling rudder). Both PCCs were designed to a new concept for the accommodation structure and hull form above the load water line. In this new design concept, there are no sharp corners in the superstructure so as to reduce wind resistance and improve steering performance. The limits of course keeping for the two PCCs were investigated through simulations. The course-keeping abilities of the two PCCs, each with two different types of autopilot system, were also investigated in wind. To develop the numerical simulation, the hydrodynamic coefficients of the two PCCs were predicted based on the data published for a third PCC having similar principal particulars. The numerical model of the two PCCs was validated by comparing its behavior with the respective full-scale trial results. Wind resistance coefficients were predicted by combining the results of wind tunnel experiments of the object PCCs and a regression model. Numerical simulations under steady wind conditions were also carried out and the results compared with some full-scale experiments to validate the mathematical model of the PCC.     

直尾舵的水动力性能分析研究

船舶操纵性主要通过性能优良的舵保证.研究开发性能优良的舵型,改善舵的水动力性能,对提高船舶操纵性十分重要.通过研究,本文提出一种新型实用的直尾舵,它是在普通流线型舵的后缘加装一块平直的尾板而成,称之为直尾板.基于CFD软件Fluent计算了舵球舵、制流板舵、鱼尾舵和直尾舵的水动力性能系数,并对比分析了直尾舵的水动力性能优缺点.相比舵球舵和制流板舵,直尾舵的正车水动力性能有较大幅度的提高,比鱼尾舵的水动力性能略差.但是,直尾舵的倒车性能优于鱼尾舵和制流板舵.因此,直尾舵属于正车、倒车水动力综合性能最好的组合舵.     

船用电动伺服舵机性能仿真研究

为降低船舶传统液压操舵噪声及提高舵机的可维护性,提出一种船用电动伺服舵机方案,该方案主要由直流力矩电机和谐波齿轮组成。建立该舵机的模型,采用 Matlab软件进行性能仿真,并分析影响该舵机性能的主要因素。结果表明,电动伺服舵机的稳定性、精度、响应等性能可满足船舶的操纵要求,研究结果可为电动伺服舵机在船舶上的应用提供支撑。     

扭曲舵水动力数值计算和自航约束模试验测量研究

建立了桨后舵水动力的CFD数值计算方法,对两种舵的压力分布和舵力进行了比较,结果显示扭曲舵可以明显减小0°舵角时舵上的横向力和舵轴扭矩。在拖曳水池中进行了自航约束模舵力测量试验,对扭曲舵和普通舵的舵力进行了测量,试验结果也表明,在0°舵角时,扭曲舵上的受力状态得到明显改善。将舵力的数值计算结果与试验结果进行比较,两者有较好的一致性,说明建立的数值计算方法可以对桨后舵舵力进行较好的模拟计算。     

复合材料舵水动力载荷等效施加方法及试验研究

针对复合材料舵水动力载荷的等效施加方法及可行性进行了理论和试验研究。以复合材料双支承舵、悬挂舵为研究对象,以舵叶载荷特性及变形特征为依据,提出了两型舵叶的水动力载荷试验等效施加方法,即双支承舵采用单面多块、悬挂舵采用单面单块加载;并通过有限元仿真分析,分别对两型舵叶在等效载荷与实际载荷作用下的位移、应力分布规律进行对比,验证了载荷等效方法的合理性;进而,制作复合材料悬挂舵模型,并开展了等效载荷下舵叶静强度、刚度特性试验研究,对等效载荷施加方法的可行性进行了验证。     

基于自航流场数值模拟的舵球节能流场分析

本文采用快速性数值模拟方法对加装舵球的36000吨散货船进行了节能评估。结果显示,加装舵球能起到一定的节能效果。之后本文对有、无舵球的两种方案的自航数值模拟流场进行了对比,分析获得了舵球节能的原理。本文模拟结果不仅可作为模型试验的有力补充,也可为舵球的优化设计提供重要参考。     

十字舵与X舵潜艇的水动力性能数值比较

现代潜艇尾操纵面建筑形式主要选择十字舵与X舵,这2种形式的舵各有其优缺点.在以往关于这2种舵形潜艇操纵性水动力的研究中,有研究者通过编制潜艇六自由度运动仿真程序,对十字舵与X舵在水平面和垂直面的水动力性能进行了综合比较,得出X舵的水动力性能优于十字舵.本文以十字舵和X舵Suboff为研究对象,通过CFD数值方法模拟了潜艇直航运动和垂直面变攻角运动这2种具有典型代表意义的运动情况,分别计算了2种舵形潜艇的操纵性水动力,通过分析计算结果,定量地比较了在舵面积相等的情况下十字舵与X舵潜艇的水动力性能,得出与编程仿真相同的结论:X舵的水动力性能优于十字舵.     

基于减摇鳍辅助回转的船舶操纵性能研究

基于MMG分离式建模思想，考虑作用在船体、螺旋桨、舵、鳍的水动力作用，建立双桨双舵船舶四自由度非线性数学运动模型，对某船模在静水中的回转性能进行仿真分析，将单独舵控制的仿真结果与船模试验结果进行了验证和分析，并对比了单独舵控制和舵、鳍联合控制下的回转性能，结果表明鳍参与控制回转时能明显缓解回转过程中的横倾。     

舵装置的优化设计

为使"渤船"第五代苏伊士船型具有良好的操纵性能,提高市场竞争力,对船体设备舵装置设计方案和实际选型计算进行研究和讨论。对多个舵选型公式进行对比,在完成船型研发任务的同时形成一套合理的舵系设计流程:参考同类型先进船型信息,结合规范要求和水池方意见,确定舵装置设计参数。该设计流程可在较大程度上提高工作效率和质量,为快速研发新船型提供支持。     

大型船舶挂舵臂设计研究

对挂舵臂的作用和结构形式进行介绍;对挂舵臂的受力情况进行分析,给出各力的分量计算公式。以某32万吨级超大型油船(VLCC)为例,对挂舵臂的弯曲、剪切、扭转和等效强度进行演算。对铸钢件挂舵臂的材料和热处理的相关要求进行阐述,并对铸钢件无损探伤方法进行分析,绘制挂舵臂无损探伤位置图。此外,对挂舵臂的结构连续性、焊接及加工圆角进行研究。研究得出:挂舵臂设计前,首先要弄清挂舵臂与舵的连接形式,建立合适的力学模型计算挂舵臂受到的弯矩、剪力和扭矩,再按规范校核强度;如果挂舵臂是由铸钢材料制成的,还须特别关注铸钢材料的质量控制和焊接的特殊要求。     

Prediction of the maneuverability of a large container ship with twin propellers and twin rudders

The maneuvering characteristics of a large container ship with twin propellers and twin rudders were investigated using the horizontal planar motion mechanism (HPMM) test and computer simulation. A mathematical model for maneuvering motion with four degrees of freedom (DOF) for twin-propeller and twin-rudder systems was developed and included the effects of roll motion. To obtain the roll-coupling hydrodynamic coefficients of a container ship, a four-DOF HPMM system having a roll motion mechanism and a roll moment measurement system was used. At the full load condition, HPMM tests were carried out for two different 12 000-TEU container ship models, one with twin propellers and the other with a single propeller. Using the hydrodynamic coefficients obtained from the tests, computer simulations were carried out. Simulation results for the container ship with twin propellers and twin rudders were compared with the results for the container ship with a single propeller and single rudder.     

基于统一模型的船舶迎浪参数横摇数值预报及其舵减摇研究

国际海事组织（IMO）正致力于第二代完整稳性规范的制定,而参数横摇一直是船舶动态完整稳性研究的热点。文章采用考虑船舶操纵性和耐波性运动耦合的统一模型对迎浪规则波下的船舶参数横摇运动进行了时域数值模拟。在时域模型中,六自由度耐波性运动辐射绕射力采用切片理论计算,并由脉冲响应函数法转化到时域。非线性回复力和入射波力采用瞬时湿表面压力积分方法计算。操纵性运动基于MMG模型,依据统一理论将操纵性与耐波性运动进行耦合计算。文中先应用简化三自由度模型对三艘集装箱船进行了参数横摇样船计算,并进行了初步的模型实验验证,依据结果对比分析了横摇惯性矩、初稳性高和方形系数对参数横摇的影响。基于统一模型分析了操纵性运动对参数横摇的影响,并进行了参数横摇舵减摇研究。     

Parametric roll mitigation using rudder control

Severe roll angles can be developed by parametric excitation in relatively moderate weather without any apparent pre-warning for the crew onboard. In this study the prospect of using rudder control to mitigate parametric roll was investigated using multi-degree of freedom simulations. A typical modern Pure Car and Truck Carrier was considered and modelled by coupling a roll model with a planar motion manoeuvring model. The combined model was calibrated using in-service, full-scale trials and model tests. Irregular variations of the metacentric height were applied to simulate recorded, full-scale events of parametric roll that have occurred with the considered design. These simulations with rudder roll control showed promising results and demonstrate that the approach could be very efficient for mitigation of parametric roll.     

基于有限元及试验对舵系无键连接的可靠性分析

以舵系的实际工况和参数为依据,采用无键连接的方式来优化舵系的连接,并利用有限元分析舵系新型无键连接的可靠性,通过有限元计算在不同工况下无键连接方式的应变及应力的分布初步验证了该连接方式的可靠性;同时以舵系实际工况的弯矩、扭矩和过载为依据建立了舵系无键连接的实验平台来验证有限元分析的结果。实验数据和分析结果表明:通过液压螺母在舵系上形成的预加载荷使舵柄和舵杆之间产生适当的静摩擦力,该静摩擦力可以提供舵系所需要的弯矩、扭矩并能够保证超载条件下舵系工作状态的稳定性及可靠性。     

导缘带凹凸结节船用舵的模型试验研究

系统研究了导缘带凹凸结节的船用舵水动力性能,通过循环水槽模型试验的方法模拟船用舵在一定来流的水中工作情况。制作导缘光滑和导缘带凹凸结节的船用舵的试验模型;针对同一个模型在循环水槽中进行三次来流速度相同的试验;记录并处理试验数据。模型试验结果表明：当其他条件相同时,在船用舵的导缘布置正弦的凹凸结节,可以提高船用舵的水动力性能,并延缓失速现象的发生。     

船舶操纵模拟器操纵仿真数学模型

系统地论述了船舶操纵仿真数学模型。包括船舶操纵基本模型、水动力、螺旋桨推力及扭距、主机扭距、舵力及其力矩、风、浪、流、锚、缆、拖轮的作用力、浅水影响及侧壁效应,最后给出了主要仿真结果和主要结论     

悬挂式扭曲舵设计及计算

以某支线集装箱船为研究对象，逐步论述、权衡并确定其舵的几何参数，根据该几何校算所需的舵杆直径和舵机功率，应用CAESES和STAR-CCM+软件分别进行舵的参数化建模和舵周流场的数值仿真，基于流场信息完成舵的扭曲设计，最终得到与该集装箱船相匹配的扭曲舵方案。数值试验结果表明，该设计扭曲舵在节能和抗空化性能上的表现较普通舵获得了可观的提升。     

CFD simulation of propeller and rudder performance when using additional thrust fins

To analyse a possible way to improve the propulsion performance of ships,the unstructured grid and the Reynolds Average Navier-Stokes equations were used to calculate the performance of a propeller and rudder fitted with additional thrust fins in the viscous flow field.The computational fluid dynamics software FLUENT was used to simulate the thrust and torque coefficient as a function of the advance coefficient of propeller and the thrust efficiency of additional thrust fins. The pressure and velocity flow behind the propeller was calculated. The geometrical nodes of the propeller were constituted by FORTRAN program and the NUMBS method was used to create a configuration of the propeller,which was then used by GAMMBIT to generate the calculation model. The thrust efficiency of fins was calculated as a function of the number of additional fins and the attack angles. The results of the calculations agree fairly well with experimental data,which shows that the viscous flow solution we present is useful in simulating the performance of propellers and rudders with additional fins.     

船舶在波浪中操纵运动仿真

本文研究了双浆双舵船在规则波中的回转运动，首先进行了约束模型试验，得到了操纵运动数学模型中的水动力系数，然后，进行了静水操纵运动数值仿真，并与自航模型试验结果进行了比较。最后，预报船舶在规则波中的回转运动，对一些影响回转运动的因素进行了讨论。