共查询到19条相似文献，搜索用时 78 毫秒
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《海洋技术学报》2014,(2)
文中针对一款配置4个螺旋桨且五自由度运动可控的微型缆控水下观测机器人进行了推进动力性能分析,采用流体力学方法计算了螺旋桨推力和扭矩,以及机器人的总体运动阻力和运动效率等关键动力参数。该水下机器人利用水平配置的螺旋桨推进器可实现前后移动和横向转弯,利用两个V型配置螺旋桨推进器可完成垂向、横向和横滚运动。文章首先对单个螺旋桨转速分别为3 000 rpm,4 000 rpm,5 000 rpm时进行了水动力学分析,计算了不同转速下对应的前向推力和阻力扭矩,拟合了转速-推力和转速-扭矩曲线;其次,对水下机器人整体模型在前向、横向和垂向三个方向上进行了水动力学计算,分析了机器人的整体运动阻力,拟合了机器人的速度-阻力曲线;然后,对应比较螺旋桨的转速-推力曲线和机器人的速度-阻力曲线,大致得出不同螺旋桨转速下机器人的推进速度,明确螺旋桨转速与机器人运动速度的对应关系,为螺旋桨水动力分析确定入口速度;最终,根据螺旋桨入口速度,重新计算螺旋桨水动力,绘制了转速-推力和转速-扭矩曲线,并确定机器人的推进效率,得出了螺旋桨转动和水下机器人整体运动的关键动力参数。 相似文献
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水下滑翔机尾部增加推进器实现其快速前进,螺旋桨是推进器的核心部件,要求其具有较高的推进效率、振动小、噪声低。首先通过分析螺旋桨的推进效率随直径、转速的变化关系,引入低速高效螺旋桨的设计理念,提出基于数学计算软件及三维建模软件的螺旋桨三维建模方法;然后,运用数学计算软件及螺旋桨曲线算法快速绘制螺旋桨的三维曲线,并对螺旋桨的直径、叶数、叶片厚度及倾角进行优化,大幅提高螺旋桨的推进效率;最后,在数学计算软件中计算出螺旋桨的特征点在空间笛卡尔的坐标,将桨叶的特征点导入三维建模软件,生成三维实体。文中所述方法提高了设计螺旋桨的推进效率及模型构造的准确性。 相似文献
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潜艇指挥台围壳对阻力和伴流场影响数值研究 总被引：2，自引：0，他引：2
采用Reynolds平均Navier-Stokes(RANS)方法计算潜艇三维粘性流场,分析潜艇指挥台围壳对潜艇水动力性能的影响.采用全附体SUBOFF模型验证了CFD方法,通过将螺旋桨盘面处的实效伴流场、艇体表面压力分布以及模型总阻力的模拟结果与Taylor船池的实验结果进行对比.比较结果显示CFD计算结果与实验数据具有很好的一致性,表明CFD方法可以用于潜艇指挥台围壳设计的水动力计算.通过数值计算研究指挥台围壳的高度和在艇上的分布位置对其后方的流场、螺旋桨盘面处的伴流场和阻力的影响. 相似文献
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基于磁力耦合器的载人潜水器电力推进装置研究 总被引：1，自引：0，他引：1
基于磁力耦合传动技术,对载人潜水器电力推进装置进行了系统设计与传动特性研究。采用电磁场有限元方法研究了永磁式磁力耦合器的运行机理和矩角特性,分析了其稳定传动区域和失步条件;分析了螺旋桨的负载特性,采用切比雪夫多项式研究了螺旋桨的四象限全工况动态模型;建立了水下无刷直流推进电机的数学模型和传递函数,设计了推进电机的转速闭环控制系统以抑制转速波动,提高输出推力的平稳度。完成了样机的设计与制造,通过水池试验验证了该推进装置在载人潜水器上的可行性与适用性。 相似文献
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吊舱推进装置在极地船舶中被广泛应用，其转舵模块可以带动螺旋桨摆动从而产生任意方向的推进力，使船舶操纵更为灵活。提出了一种吊舱推进船舶冰区操纵的离散元方法，对具有吊舱推进装置的冰区船舶破冰过程进行了数值模拟。以“雪龙2”号破冰船为研究对象，计算分析了船舶定速直航时的冰阻力，并通过与Lindqvist经验公式的对比验证了冰阻力计算的合理性。在此基础上进一步对船舶在不同冰厚、不同吊舱转向角下的回转破冰运动进行了离散元模拟，分析了回转半径与船长比值随冰厚的变化规律。计算结果表明：船舶的回转性能随冰厚的增大而降低，并随吊舱转向角的增大而显著提高。 相似文献
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为提高母型船阻力性能,以船体阻力性能为优化对象,基于改造母型船法,研究船舶球鼻艏以及船尾线型的改变对船舶阻力性能的影响.采用高度集成化的Tribon系统、可视化绘图软件Auto CAD及CFD(Computational Fluid Dynamics)通用前处理软件ICEM联合建模的方法来建立船体模型.通过模拟计算结果与实验值的对比分析,验证CFD技术在船舶阻力性能预报中的合理性和有效性.通过对比3种不同球鼻艏时的船体阻力得知:从阻力性能方面考虑,对于低速丰满型船舶选用普通型球鼻艏以及中高速船舶采用上翘型球鼻艏均可以获取较好地减阻效果.同时比较不同航速下尾部线型对船体总阻力的影响表明,选优后的方形尾在相同的航速下阻力低、消耗的功率小、形状效应小、黏压阻力和摩擦阻力也相对较小. 相似文献
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摆动尾鳍水动力性能的试验和数值研究 总被引：1，自引：0，他引：1
鱼类能够在水下高速度、低噪音、高效率地游动。鱼类出色的推进性能通过其摆动尾鳍实现。这种摆动尾鳍推进方式已经用在了水下无人航行器上。因此研究摆动尾鳍的水动力性能是非常有意义的。对摆动尾鳍的推进水动力性能进行了详尽的研究。设计、装配了一套仿尾鳍推进系统,并对其进行了相应的水动力试验。在试验中研究了运动参数对摆动尾鳍水动力性能的影响。与此同时,采用基于雷诺平均N-S方程的数值方法对摆动尾鳍的水动力性能进行了研究。在数值计算中采用了k-ωSST湍流模型和有限体积法。数值计算结果和水动力试验结果进行了比较。对尾鳍表面的压力分布和流场中的尾涡结构进行了分析。水动力试验和数值计算都表明摆动尾鳍可以产生推进力和较高的推进效率。 相似文献
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The hydrodynamic performance of a hybrid CRP pod propulsion system was studied by RANS method with SST turbulence model and sliding mesh. The effect of axial spacing on the hydrodynamic performance of the hybrid CRP pod propulsion system was investigated numerically and experimentally. It shows that RANS with the sliding mesh method and SST turbulence model predicts accurately the hydrodynamic performance of the hybrid CRP pod propulsion system. The axial spacing has little influence on the hydrodynamic performance of the forward propeller, but great influence on that of the pod unit. Thrust coefficient of the pod unit declines with the increase of the axial spacing, but the trend becomes weaker, and the decreasing amplitude at the lower advance coefficient is larger than that at the higher advance coefficient. The thrust coefficient and open water efficiency of the hybrid CRP pod propulsion system decrease with the increase of the axial spacing, while the torque coefficient keeps almost constant. On this basis, the design principle of axial spacing of the hybrid CRP pod propulsion system was proposed. 相似文献
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This paper presents dynamical modeling and robust control of a Mini Unmanned Underwater Vehicle (MUUV) equipped with a new arrangement of water jet propulsion. The water jet propulsion includes some advantages comparing with a propeller one, such as, reducing the number of required motors, desired number and arrangement of the propulsions, removing adverse torque and cavitation due to propeller rotation and etc. In order to model the proposed MUUV, the gray box method is used in such a way that the dynamical equation of motion is derived analytically by Euler-Lagrangian method, and then the hydrodynamic coefficients (such as added mass and drag coefficients) are derived by performing some tests in a Computational Fluid Dynamic (CFD) software. The dynamical model is used to simulate the MUUV system and also to design the proposed controllers, which are Feedback Linearization Controller (FLC) and Sliding Mode Controller (SMC). In order to investigate and compare the performance of the MUUV and the applied controllers, three types of tests including a desired signal tracking case and two desired path tracking cases are designed. To do so, a method is presented to obtain the desired signals from a desired path under predetermined conditions. Then, an MUUV prototype is designed and constructed in order to investigate the performance of the proposed water jet propulsions and controllers for regulation and tracking desired signal purpose, experimentally. As it is expected, the simulation and experimental results show better performance of the SMC compared to FLC. Furthermore, the experimental results reveal that the water jet propulsion is implementable to practical prototypes and also can be produced in an industrial level. 相似文献
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A dynamic marine propeller simulation system was developed, which is utilized for meeting the experimental requirement of theory research and engineering design of marine electric propulsion system. By applying an actual ship parameter and its accurate propeller J’~ KT’ and J’~KP’ curve data, functional experiments based on the simulation system were carried out. The experiment results showed that the system can correctly emulate the propeller characteristics, produce the dynamic and steady performances of the propeller under different navigation modes, and present actual load torque for electric propulsion motor. 相似文献
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A Variable Buoyancy Control System for a Large AUV 总被引：1，自引：0，他引：1
A large autonomous undersea vehicle (AUV), the Seahorse, has been designed, constructed, and tested by the Applied Research Laboratory at Pennsylvania State University (ARL/PSU, University Park, PA) for the U.S. Naval Oceanographic Office (NAVOCEANO, Stennis Space Center, MS). The vehicle is required to launch in shallow water (<10 m) and to hover without propulsion. Additionally, due to the very large size of the vehicle, low operating speeds and very long missions, small changes in vehicle trim resulting from battery replacement, sensor exchanges, and water temperature variations can result in significant drag-induced energy penalties over the duration of a mission. It is, therefore, important to continually maintain the AUV in fore-aft trim over the course of the mission. The vehicle is equipped with a two tank variable buoyancy system (VBS) to meet these requirements. The resulting control problem is one where the control variable, pump rate, is proportional to the third derivative of the sensed variable, depth; there are significant delays, and forces are nonlinear (including discontinuous) and highly uncertain. This paper describes the design of the VBS and the control software operating in two modes: depth control mode and trim control mode. In-water test data and simulation results are presented to illustrate the performance of the VBS controller. The benefits of the presented approach lie in the intuitiveness and simplicity of the design and the robustness as evidenced by the performance in both fresh and salt water. This paper provides practical insight into the operation of a VBS with an AUV and discusses actual operational experience. To our knowledge, no previous work considers the significance of an observed surface capture phenomenon to the design of a VBS control system, especially in very shallow water. 相似文献
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In terms of the nonlinear characteristics of hydraulic propulsion system used in 3500 m rated work-class ROV (remotely operated underwater vehicle), the paper improved the responsiveness of the hydraulic propulsion system by adding an impulse signal to the input end of the system. Because the maximum static damping moment provided from water is much larger than the dynamic damping moment, it results in large dead zone of thrust during the startup process of the hydraulic propulsion system. The dead zone of thrust caused by static damping moment can be effectively reduced by adding a specific impulse signal to the input end of the propulsion system. The results of numerical simulations and underwater experiments show that using this method, the nonlinear characteristics of the hydraulic propulsion system have been significantly improved. 相似文献
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水下柔性鱼形机构原理及单尾鳍板水动力试验研究 总被引：4，自引：0，他引：4
柔性鱼形机构是模拟鱼类运动的一种仿生机械系统。对鱼类运动的观察与研究 ,实质上是寻求水域中最优推进形式的过程 ,是工程优化设计的途径之一。在研究及优化柔性鱼形机构时涉及到水动力学及控制模型的问题 ,因此取出鱼形机构的尾鳍部分进行敞水试验 ,既能为有关模型的建立提供依据 ,更重要的是对鱼形机构的可行性进行论证 相似文献
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Propulsion system with flexible/rigid oscillating fin 总被引：1，自引：0，他引：1
Yamamoto I. Terada Y. Nagamatu T. Imaizumi Y. 《Oceanic Engineering, IEEE Journal of》1995,20(1):23-30
The purpose of this paper is to describe the feasibility research on an oscillating fin propulsion control system as a vehicle actuator. The system is designed and constructed in order to be combined with ship models. Tank cruising tests are conducted to confirm the system's feasibility. As a result, several advantages of the oscillating fin system are found. A neural network is successfully applied for an identification of the ship model with the oscillating fin, and its effectiveness is confirmed 相似文献
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Flapping wings located beneath or to the side of the hull of the ship are investigated as unsteady thrusters, augmenting ship propulsion in waves. The main arrangement consists of horizontal wing(s) in vertical oscillatory motion which is induced by ship heave and pitch, while rotation about the wing pivot axis is actively controlled. In this work we investigate the energy extraction by the system operating in irregular wave conditions and its performance concerning direct conversion to propulsive thrust. More specifically, we consider operation of the flapping foil in waves characterised by a spectrum, corresponding to specific sea state, taking into account the coupling between the hull and the flapping foil dynamics. The effect of the wavy free surface is accounted for through the satisfaction of the corresponding boundary conditions and the consideration of the wave velocity on the formation of the incident flow. Numerical results concerning thrust and power coefficients are presented, indicating that significant thrust can be produced under general operating conditions. The present work can be exploited for the design and optimum control of such systems extracting energy from sea waves for augmenting marine propulsion in rough seas, with simultaneous reduction of ship responses offering also dynamic stabilisation. 相似文献