【作者】 何漫丽；

【导师】 王树新；

【作者基本信息】 天津大学 ， 机械制造及其自动化， 2005， 博士

【摘要】 小型AUV(Autonomous Underwater Vehicles)是一种无人无缆水下自主航行器,可以进行海洋水下多种参数的测量。基于一定的测量任务需要,天津大学和国家海洋技术中心联合研制了一种坐底式、主体可分离的小型AUV,称为水下自航行器。本文通过适当选取坐标系,建立了水下自航行器的运动学和动力学模型,对航行器所受水动力进行了分析与计算,为航行器稳定性、操纵性分析与控制系统设计提供了依据。使用计算流体动力学(CFD)的方法,基于一种典型外形,研究了AUV外形、阻力(系数)与航速的关系,指出:对于小型AUV,由于其航行速度一般都比较低(对应流场雷诺数较低),在AUV的速度范围内,水动力系数是随速度变化的。而鱼雷等高速航行体在其速度范围内可以认为水动力系数是常数。因而AUV设计中,即使可以查到外形鱼雷等航行体的资料,但由于很难满足动力学相似的条件而不能使用。基于流线型航行体常采用的假设:将航行器阻力处理为各部件阻力之和,运用CFD方法对两轮设计的航行器进行水动力计算,对航行器外形参数进行了研究与设计改进,指出后续可以进一步改进外形设计以减小阻力的空间;通过分析计算结果,获得航行器主要水动力特征。针对两轮设计外形,对航行器进行了两次水动力试验。基于第一次试验结果及阻力特征分析,对水动力试验安装、测量方法,没入水下深度等进行了分析与调整;通过对试验结果与数值计算结果的比较,调整了数值计算模型参数。在第一轮外形阻力特征基础上,对航行器总体结构与外形进行了改进设计,对第二轮设计样机进行了水动力试验,得到航行器主要水动力参数;并将试验结果与修正后的数值计算模型结果进行了比较,结果证明调整后的数值计算模型是可行的且具有合理的精度。更多还原

【Abstract】 Small AUV (Autonomous Underwater Vehicle) is one kind of unmanned anduntethered underwater vehicles which can fulfill many kinds of oceanicenvironmental survey. To fulfill some certain measurement, one kind of smallAUV is developed by Tianjin University and the National Oceanic TechnologyCenter. This paper describes a dynamics model of the AUV. External forces acting onthe vehicle are analyzed, such as gravity, buoyancy, hull and control planehydrodynamic forces etc. This model allows the analysis of the stability,maneuverability and controllability. Applying Computational Fluid Dynamics (CFD) method, one kind of typicalhull form is chosen to study the drag characteristic of small AUV with low speed.The results emphasize that the drag coefficient of the AUV is varied with its speed.This is very different from torpedo etc. with high speed, so the drag coefficient oftorpedo is not suitable for the AUV even if the two have the same hull form. Based on the usual assumption that the drag of the streamlined vehicle can bebroken down into individual drag components, CFD method is employed to studythe hydrodynamics of all components of the AUV. Through computational resultsanalysis, the hull form of the AUV is modified to reduce drag and thehydrodynamic characteristics are achieved.Two hydrodynamic tank tests are carried out to study the hydrodynamiccharacteristics of the AUV. Based on the first test, the measurement andconnection method and the underwater depth are adjusted. The first experimentaldata are compared with the numerical results and the computational model isrectified according to the test results. The modified CFD model is applied to carryout new computations to study the hydrodynamic characteristics of the AUV. Thesecond test results are also compared with the numerical results and it proves thatthe numerical model is computationally efficient and has reasonable accuracy.更多还原