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In this paper, the hydrodynamic characteristic of a synthetic jet steered underwater vehicle is studied. The steering motion studied is the lateral motion and the yaw motion. The lateral motion is induced through the in-phase work of this two actuators and the yaw motion is realized through the out-of-phase work. The vehicle studied is REMUS AUV with synthetic jet actuator mounted inside. The hydrodynamic characteristic of the vehicle under different cruising speed is studied. The driving parameters of the SJ actuator keep invariant in different cases. When the two actuators work in phase, the average steering force is smaller than the thrust of the isolated actuator and keeps nearly invariant under different cruising speed. When the two actuators work out of phase, the average steering moment also keeps invariant with cruising speed. The mathematical model of the additional drag of the vehicle, the thrust of the actuator, the steering force as well as the steering moment is given. The velocity distribution is also given to assistant the analysis in this paper. From the analysis given it can be known the steering method based on SJ is realized through position control other than velocity control. 相似文献
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Significant progress has been made in understanding some of the basic mechanisms of force production and flow manipulation in oscillating foils for underwater use. Biomimetic observations, however, show that there is a lot more to be learned, since many of the functions and details of fish fins remain unexplored. This review focuses primarily on experimental studies on some of the, at least partially understood, mechanisms, which include 1) the formation of streets of vortices around and behind two- and three-dimensional propulsive oscillating foils; 2) the formation of vortical structures around and behind two- and three-dimensional foils used for maneuvering, hovering, or fast-starting; 3) the formation of leading-edge vortices in flapping foils, under steady flapping or transient conditions; 4) the interaction of foils with oncoming, externally generated vorticity; multiple foils, or foils operating near a body or wall. 相似文献
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混合驱动自主潜航器融合了自主潜航器机动灵活和水下滑翔机续航能力强的优点,针对自身携带能源有限的问题,对在两种工作模式下如何实现最大航行距离进行了研究.从航行过程中的能源消耗入手,得出航行距离与速度、电子设备功率等的关系,通过理论分析和仿真手段得出最大续航能力的实现方法.在螺旋桨驱动模式下,当以经济航速航行时,可以达到最大航行距离;在浮力驱动模式下,当以最大滑翔效率航行时,水平方向上的滑翔距离最大,并且水平方向上的滑翔距离随着剖面深度的增大而增大,当剖面深度大到一定程度之后,最大滑翔距离趋于恒定.该研究方法可为类似水下航行器电源管理系统的能源分配提供参考,也可为航行器外形的设计和传感器的选型提供理论指导. 相似文献
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以载人深潜器的各种水动力参数和实际尺寸为基础,根据几何空间坐标方程建立了其运动学模型,采用MultiGen公司的Creator建模工具和Vega视景环境完成了在深海虚拟环境下的系统仿真。该系统可以实现深海机器人的可视化,更加直观、生动和实时的反映其位姿状态和水面、水下巡航过程。该系统实际应用在中国科学技术馆深海机器人展馆项目上,一方面展示载人深潜器的水下工作过程,同时也使得观众有机会亲身体验潜水器的操纵与驾驶。实际运行结果表明,该系统逼真地演示了载人深潜器水面备航、无动力下潜以及近海底巡航等仿真过程,能够满足系统仿真的实时性要求。该系统还可以应用到深海环境模拟研究、水下机器人运动仿真、控制系统调试以及操纵驾驶训练等中。 相似文献
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《Oceanic Engineering, IEEE Journal of》2008,33(2):59-68
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The hybrid Cartesian/immersed boundary method is applied to simulate effects of flexibility on propulsive force acting on a heaving foil in a viscous flow. Immersed boundary nodes are distributed inside an instantaneous fluid domain. Velocity vector is reconstructed at the immersed boundary node based on an interpolation along a local normal line. Using the staggered/non-staggered grid method, the demand for pressure at boundary nodes is removed. Elastic deformation of the flexible foil is modelled based on the dynamic thin-plate mechanics. The developed code is validated through comparisons with other computations on flow fields around a flapping foil. The generation of the reverse Karman vortex street is investigated. Forces acting on heaving foils are compared for flexible and rigid cases and the increased thrust of the flexible foil is attributed to the deformed configuration near the tip. The flexibility of the heaving foil decreases vertical force and improves propulsion efficiency. The variations of force and deformation are investigated according to bending stiffness of the foil. 相似文献
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Numerical simulation for hydrodynamic characteristics of a bionic flapping hydrofoil 总被引：2，自引：1，他引：1
In order to study the propulsion mechanism of the bionic flapping hydrofoil (BFH), a 2-DoF (heave and pitch) motion model is formulated. The hydrodynamic performance of BFH with a series of kinematical parameters is explored via numerical simulation based on FLUENT. The calculated result is compared with the experimental value of MIT and that by the panel method. Moreover, the effect of inlet velocity, the angle of attack, the heave amplitude, the pitch amplitude , the phase difference, the heave biased angle, the pitch biased angle and the oscillating frequency are investigated. The study is useful for guiding the design of bionic underwater vehicle based on flapping propulsion. It is indicated that the optimal parameters combination is v=0.5m/s, θ0=40°.θ0=30°,Ψ=90°,Фbias=0°,θbias=0°and f=0.5Hz . 相似文献
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Madden J.D.W. Schmid B. Hechinger M. Lafontaine S.R. Madden P.G.A. Hover F.S. Kimball R. Hunter I.W. 《Oceanic Engineering, IEEE Journal of》2004,29(3):738-749
A decade of research into electroactive polymer actuators is leading to the exploration of applications. These technologies are not ready to compete with the internal combustion engine and electric motors in high power propulsion systems but are suitable for intermittent or aperiodic applications with moderate cycle life requirements, providing an alternative to solenoids and direct drive electric motors. Polypyrrole, an emerging actuator material, is applied to drive hydrodynamic control surfaces and in particular to change the camber of a foil. The foil is intended for use in the propeller blade of an autonomous underwater vehicle. A scaled prototype is constructed which employs polypyrrole actuators imbedded within the blade itself to vary camber. The kinematics required to generate camber change are demonstrated, with >30/spl deg/ deflections of the trailing edge being observed from both bending bilayer and linear actuator designs. Forces developed in still conditions are five times lower than the 3.5 N estimated to be required to implement variable camber. The observed 70 kJ/m/sup 3/ polypyrrole work density however is more than sufficient to produce the desired actuation from within the limited blade volume, enabling an application that is not feasible using direct drive electric motors. A key challenge with the polypyrrole actuators is to increase force without sacrificing speed of actuation. 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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设计了一种拉线机构驱动的仿鱼型自主巡游机器人,阐述了其机械结构、电路系统及控制算法的设计方案,同时开展开敞水域试验对其游动性能进行研究。研究表明,在直行及转弯试验中,当摆尾频率相同时,随着尾鳍摆动幅度的增加,机器鱼的游动速度上升;当尾鳍摆动幅度相同时,随着摆尾频率的增加,机器鱼游动速度先升后降,且在0.60 Hz附近时达到峰值;在目标角度转向试验中,当摆尾频率及目标角度相同时,随着尾鳍摆动幅度的增加,机器鱼的角度响应时间逐渐减小;当尾鳍摆动幅度及目标角度相同时,随着摆尾频率的增加,角度响应时间先降后升;当摆尾频率及摆动幅度相同时,目标角度的增加会使得角度响应时间呈上升趋势。研究成果验证了该机器鱼平台的可靠性,为将来进一步理论研究及实际应用提供了一定的参考。 相似文献
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Westneat M.W. Thorsen D.H. Walker J.A. Hale M.E. 《Oceanic Engineering, IEEE Journal of》2004,29(3):674-683
Fin-based propulsion systems perform well for both high-speed cruising and high maneuverability in fishes, making them good models for propulsors of autonomous underwater vehicles. Labriform locomotion in fishes is actuated by oscillation of the paired pectoral fins. Here, we present recent research on fin structure, fin motion, and neural control in fishes to outline important future directions for this field and to assist engineers in attempting biomimicry of maneuverable fin-based locomotion in shallow surge zones. Three areas of structure and function are discussed in this review: 1) the anatomical structure of the fin blade, skeleton, and muscles that drive fin motion; 2) the rowing and flapping motions that fins undergo for propulsion in fishes; and 3) the neuroanatomy, neural circuitry, and electrical muscle activity that are characteristic of pectoral fins. Research on fin biomechanics, muscle physiology and neural control is important to the comparative biology of locomotion in fishes and application of fin function for aid in aquatic vehicle design. Recommendations are made regarding fin propulsor designs based on the fin shape, activation pattern, and motion. Research on neural control of fins is a key piece in the puzzle for a complete understanding of comparative fin function and may provide important principles for engineers designing control systems for fin-like propulsors. 相似文献
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Design and implementation of time efficient trajectories for autonomous underwater vehicles 总被引：1，自引：0，他引：1
This paper discusses control strategies adapted for practical implementation and efficient motion of autonomous underwater vehicles (AUVs). For AUVs we would like efficiency in both the measured time and the energy consumption, the mission dictating the weight to put on each of these cost. As a first approach to this problem, we focus in this paper on time minimization. Based on the structure of the time optimal trajectories and of the pure motions, we develop an algorithm to design time efficient trajectories corresponding to piecewise constant thrust arcs with few actuator switchings. We do that by solving a new optimization problem where the unknowns are the time period between two actuator switchings as well as the values of the constant thrust arcs. We apply a direct method to compute the solutions numerically. With our algorithm, we gain considerable computational time. Moreover, with as few as three actuator switchings, the duration of our trajectories is within 10% of the optimal trajectories. Since our control strategies have a simple structure they can be implemented on a test-bed vehicle. For the experiments displayed in this paper we use a spherical underwater vehicle which exhibits with almost no preference of direction or orientation for movement; this gives us a very controllable and versatile vehicle. 相似文献
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To predict the cycle and propulsive performance, and further instruct the integral engine design, an ideal power cycle model for a two-phase underwater ramjet is established. Four performance parameters are defined to evaluate overall performance of the two-phase underwater ramjet systems: transmission efficiency, propulsive efficiency, overall efficiency and specific impulse. Then, a scaled-down experimental ramjet engine was tested in a direct-connect ground testing system to validate the present model, and the predictions with present model compare favorably with experimental results. Subsequently, the influences of cruise velocity, air/water mass ratio and cruising depth on the theoretical performance of the two-phase underwater ramjet are discussed. The results indicate that one of the most outstanding advantages of two-phase underwater ramjet is its high propulsive efficiency with the order of 50–95%. As a result, the overall efficiency magnitude are as high as 30% at cruise speed of 100 m/s. Furthermore, regarding rules of specific impulse vs cruise velocity under a certain air/water mass ratio, the occurrence of peak specific impulse of order 400 s is observed. 相似文献
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Compact zero-mass pulsatile jet actuators are proposed for low-speed maneuvering and station keeping of small underwater vehicles.1 The flow field of such jets are initially dominated by vortex ring formation. Pinched-off vortices characterize the extremum impulse accumulated by the leading vortex ring in a vortex ring formation process. Relevant parameters in this process are identified in order to design simple and low cost zero-mass pulsatile jet actuators. Thrust optimization of synthetic jets for maximal thrust generation is achieved by enforcing the jet formation number to be around 4. Prototypes of such actuators are built and tested for underwater maneuvering and propulsion. The actuators could be used in two ways: (i) to improve the low-speed maneuvering and station keeping capabilities of traditional propeller driven underwater vehicles, and (ii) as a synthetic jet for flow control and drag reduction at higher cruising speeds. A model for calculating the rotation rate of the underwater vehicle is also proposed and verified. 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