基于CFD不同AUV艇体阻力性能研究

为了研究不同类型AUV艇体阻力性能特点以及十字舵和整流罩附体对总阻力的影响,在充分研究4种艇型型线的基础上,建立几何模型,选取标准k-ε,RNG k-ε,SST k-ω湍流模式,通过CFD对艇体进行阻力数值模拟。结果表明,十字舵引起的艇体阻力增加比例大约在10%~20%,且随着展弦比的增加而呈减小趋势,直径与艇体最大直径相当的整流罩引起的艇体阻力增加比例大约在40%~50%;流线型BLUEFIN阻力增加值随航速变化较大,而钝性BLUEFIN阻力增加值几乎不受航速的影响,AUTOSUB型AUV阻力性能最优,AUTOSUB和HUGIN适合中高速航行,REMUS和BLUEFIN适合低速航行。     

多航态新概念艇型阻力性能分析

针对海上特殊任务的要求,结合水面船和潜艇的优势,提出一种新概念艇——多航态艇.基于计算流体力学(CFD)方法对目标艇在水面航行和水下航行状态下的阻力性能进行数值模拟,并对初始方案进行改进,获得更好的阻力性能.通过对采用改进方案的模型进行阻力性能试验,验证数值方法在预测新概念艇阻力性能方面的可靠性.     

艉部斜升角对滑行艇阻力性能影响数值模拟

关于滑行艇在静水中阻力性能以及航行姿态的预报问题,运用商用软件STAR-CCM+进行数值模拟,将所得结果与试验值以及SIT法计算结果对比,验证流体计算软件STAR-CCM+预报滑行艇阻力性能的可行性。以直棱柱型滑行艇为模拟船型,探讨艉部斜升角的变化对滑行艇阻力及其航行姿态影响规律,找出使得该滑行艇阻力性能最优的艉部斜升角。     

带阻流板和水平翼的高速深V复合艇新构型研究

高性能复合艇通常比常规高性能艇具有更好的航行性能,本文以某高速深V型快艇为研究对象,采用阻流板和水平翼组合附体的方式对该深V复合艇进行CFD水动力性能数值模拟,对过渡状态及滑行状态下该复合快艇的阻力性能以及航行姿态进行评估,结合自由面兴波以及艇体表面压力分布情况,最终获得了一型深V复合艇构型设计方案,该复合艇运动姿态得到大幅改善,过渡状态下模型总阻力值较原型减少18.97%。     

水面水下两用艇艇型设计及其水面阻力性能CFD预报分析

水面水下两用艇集水面高速航行与水下运载功能于一体,1个平台兼具2种运行功能,可以完整执行海上特殊任务。本文首先对国外水面水下两用艇发展现状及艇型特点进行简要叙述,而后采用重叠网格技术,基于RANS方程,对水面水下两用艇及双折角双防溅条滑行艇的水面高速自由模拖曳运动(计及升沉和纵倾)进行预报,对比分析了两用艇独特的艇体外形设计对其水面高速航行时阻力特性的影响,最后讨论阻流板对两用艇水面航行性能的影响规律,为两用艇的艇型设计以及水动力性能研究提供参考。     

槽道参数对倒V型槽道滑行艇阻力性能的影响

依据双体滑行艇的外形特征和三体滑行艇的工作原理衍生出全新的倒V型槽道滑行艇,具有特殊的槽道结构及内倾式滑行面。基于槽道形状的3个参数,利用CFD技术探究出适合倒V型槽道艇的设计方案,模拟结果表明:槽道参数对倒V型槽道滑行艇阻力性能有一定的影响。     

自主水下航行器固定舵对尾舵水动力的影响

自主水下航行器(AUV)为保证尾舵受到撞击等不可控因素而不损坏,通常在全动舵前面安装起保护作用的固定舵。利用三维计算流体力学(CFD)软件对自主水下航行器的全动舵以及安装在全动舵之前起保护作用的固定舵,进行水动力特性分析。分析了固定舵安装之前和安装之后的升阻比,铰链力矩等水动力参数;通过改变固定舵与全动舵之间的缝隙大小,分析各个变量对整体水动力参数的影响,找到了固定舵的最佳安装位置,得出固定舵片对铰链力矩的影响。研究结果为自主水下航行器尾舵部位的保护舵设计提供了理论依据和参考。     

倒V型槽道滑行艇船型的水动力性能研究

考虑到高速航行时常规双体滑行艇阻力较大且艇体兴波严重,以及三体滑行艇独特船型所带来的优异快速性和兴波小等优良水动力性能,文章借鉴三体滑行艇的工作原理并应用于双体滑行艇,创新性提出倒V型槽道滑行艇的概念,并进行艇型结构设计和CFD水动力分析。模拟计算结果表明该艇型具有高航速时阻力增加缓慢和纵倾角变化平缓等优点。     

基于STAR-CCM+的滑行艇阻力研究

为研究滑行艇的航行阻力问题,首先建立滑行艇的几何模型,然后基于STAR-CCM+软件对其运动进行数值模拟。获得滑行艇航行时阻力随航速的变化规律,并将数值计算结果与试验值进行比较,得到的计算结果与试验值数据基本吻合。证明了在STAR-CCM+中能够有效模拟滑行艇运动的阻力性能,该方法对于文中的实例具有较高的准确性,可为滑行艇阻力的预报提供参考。     

回转体艇型阻力近似计算方法与试验研究

研究了试验设计和近似模型技术,确定了回转体艇型曲线的6个控制参数,根据系列回转体阻力数值计算结果,建立了水下航行器阻力近似计算的响应面模型及径向基神经网络模型。通过系列模型试验验证了多种近似模型的拟合精度,与工程估算方法以及CFD方法进行了比较。结果表明,4阶响应面模型及径向基神经网络模型精度远高于工程经验公式,能够正确反映艇型参数对阻力结果的影响,为后续艇型优化设计带来一定的参考价值。     

Estimation of the hydrodynamic coefficients of the complex-shaped autonomous underwater vehicle TUNA-SAND

Hydrodynamic coefficients strongly affect the dynamic performance of autonomous underwater vehicles (AUVs). Thus it is important to have the true values of the coefficients in order to simulate the AUV’s dynamic performance accurately. Although these coefficients can be predicted by many methods, most are only applicable for AUVs with streamlined shapes. Computational fluid dynamics (CFD) can be applied to estimate the hydrodynamic coefficients of AUVs with complex shapes. In this study, CFD was applied to estimate the hydrodynamic coefficients of the AUV TUNA-SAND (which stands for terrain-based underwater navigable AUV for seafloor and natural resources development), which has a complex block-like structure. First, the validity of the CFD simulation was verified by comparison with experimental results. Second, the relationships between hydrodynamic loads and motions for all six degrees of freedom were analyzed using the simulated results. Third, the importance of each hydrodynamic coefficient was investigated based on these relationships. There are 16 key damping coefficients that relate to viscosity and 12 key inertial coefficients that relate to the potential flow around TUNA-SAND. Finally, the values of all the key coefficients were obtained and verified by comparing the solutions of the simulated dynamics with the experimental results.     

探查水下矿物资源的AUV动力控制系统开发

Valuable mineral resources are widely distributed throughout the seabed. autonomous underwater vehicles (AUVs) are preferable to remotely-operated vehicles (ROVs) when probing for such mineral resources as the extensive exploration area makes it difficult to maintain contact with operators. AUVs depend on batteries, so their power consumption should be reduced to extend exploration time. Power for conventional marine instrument systems is incorporated in their waterproof sealing. External intermittent control of this power source until termination of exploration is challenging due to limitations imposed by the underwater environment. Thus, the AUV must have a power control system that can improve performance and maximize use of battery capacity. The authors developed such a power control system with a three-step algorithm. It automatically detects underwater operational states and can limit power, effectively decreasing power consumption by about 15%.     

自主式水下航行器水下回收融合引导技术方案及算法

[目的]为解决母艇携载的自主式水下航行器(AUV)在水下自主回收和对接的问题,基于惯导(INS)、声学超短基线定位(USBL)、光学等信号引导的多源数据融合,提出一种面向移动平台的AUV水下回收对接引导方法.[方法]为此,设计融合多传感器信息的扩展联邦卡尔曼滤波器,采用分散滤波并再经信息融合方法以提高滤波精度.分别以I...     

水下无人航行器外挂吊舱水动力试验及操纵性分析

在循环水槽开展了某带吊舱水下无人航行器的水动力试验,绘制出了航行器阻力曲线,得到了与操纵性相关的主要水动力系数,在此基础上对水下无人航行器的运动稳定性进行了分析,并与不带吊舱情况下的水下无人航行器操纵性进行了比较。试验结果可为水下无人航行器推进系统设计及运动控制与仿真提供依据。     

AUV hull shape design based on desired pressure distribution

The role of autonomous underwater vehicles (AUVs) is more important in the quest to reach the deep seas today than ever before. The hull shape of the AUV can differ depending on the special mission considered for the vehicle. Therefore, different types of algorithms for the body shape design of these kinds of vehicles are being developed every day. In the current work, a new procedure has been proposed for designing the body shape of an AUV. Using this method which is based on a desired pressure distribution, it is possible to obtain the desired hull shape design. Artificial neural network algorithm has been used for this purpose. Preliminary data for training and testing of the network have been obtained from CFD simulation of the flow around the body of Hydrolab500 AUV. In this regard, pressure distribution has been evaluated around each body by changing the nose and tail profile of AUV. The results obtained from this research indicate that a body correlated to the desired pressure can be designed properly.     

Power efficient formation configuration for centralized leader–follower AUVs control

Autonomous underwater vehicles (AUVs) have rapidly developed in the last few decades due to their autonomous properties in the investigation of an underwater environment. The goal of this paper is to develop a power efficient formation control for the cooperative motion of AUVs with a support vessel as a leader. In this paper, a kinematic algorithm for the joint motion of an AUV with a support vessel was developed and that algorithm was expanded for the formation of AUVs. The AUV yaw, surge and sway control loops were designed for that purpose. The complexing navigation system structure for the AUV was also developed. Simulation results demonstrated efficiency of the proposed kinematic algorithm for the joint motion of AUVs. Also, influence of lateral ocean current was considered. After development of the centralized leader?Cfollower formation control for the group of AUVs with a support vessel as a leader, we optimized a formation configuration in terms of power efficiency. Drag forces caused by AUV motion in the water can significantly influence power consumption. We investigated the relationship between the AUV's formation configuration, underwater coverage efficiency, communication quality and power consumption. As a result of research, we proposed a power efficient formation configuration for typical underwater operations. As a result, the effect of the AUV formation configuration on the power consumption was investigated and a trade-off solution for the optimal AUV positions in formation with minimal energy consumption, high coverage efficiency and small communication power consumption was derived.     

Biogeography-based combinatorial strategy for efficient autonomous underwater vehicle motion planning and task-time management

Autonomous Underwater Vehicles (AUVs) are capable of spending long periods of time for carrying out various underwater missions and marine tasks. In this paper, a novel conflict-free motion planning framework is introduced to enhance underwater vehicle’s mission performance by completing maximum number of highest priority tasks in a limited time through a large scale waypoint cluttered operating field, and ensuring safe deployment during the mission. The proposed combinatorial route-path planner model takes the advantages of the Biogeography-Based Optimization (BBO) algorithm toward satisfying objectives of both higher-lower level motion planners and guarantees maximization of the mission productivity for a single vehicle operation. The performance of the model is investigated under different scenarios including the particular cost constraints in time-varying operating fields. To show the reliability of the proposed model, performance of each motion planner assessed separately and then statistical analysis is undertaken to evaluate the total performance of the entire model. The simulation results indicate the stability of the contributed model and its feasible application for real experiments.     

Development trend and key technologies of autonomous underwater vehicles北大核心CSCD

为推进和引导我国自主水下航行器(AUV)的发展,总结国内外AUV的研究现状,提出其系列化、集群化、体系化、大型化的发展趋势。重点探讨AUV总体多学科优化设计、结构与材料设计、动力与推进、导航与控制、探测与通信等关键技术,为更好地利用AUV经略海洋,从而实现“进入海洋、探测海洋、利用海洋”的战略目标提出发展意见。     

基于粒子群优化算法的水下航行器深度控制研究

提出了一种基于粒子群优化算法的水下航行器深度控制器参数优化设计方法。针对水下航行器运动参数变化的特性,采用粒子群优化算法收敛速度快、寻优特性好等特点,将其应用到控制器参数的优化设计中。仿真结果表明,利用粒子群优化算法进行优化设计的水下航行器深度控制器具有良好的控制性能。