【作者】 高霓；

【导师】 万磊；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋结构物设计制造， 2013， 博士

【摘要】 微小型水下潜器具有航行体积小、阻力低、隐身性能好、机动灵活等特点，在海洋开发中占有重要的地位。当其从水面搭载平台布放和回收、航行一段时间后上浮进行导航定位时，将处于近自由液面航行状态。此时扰流环境远比无界绕流要复杂，而微小型水下潜器本身艇体较小，推进能力有限，极易受到自由液面的扰动。操纵性是水下潜器的重要性能，研究微小型水下潜器近自由液面的操纵性有着重要的意义。本文基于CFD技术分别研究了微小型水下潜器在无界绕流和近自由液面的水动力性能，计算不同潜深下的水动力系数，并进行了近自由液面的操纵性水动力实验。通过运动预报观察其运动特性，论文主要完成了以下工作：1.采用分区域网格划分方法，利用混合网格计算了椭球体和微小型水下潜器在无界绕流中的水动力性能，模拟其直航、斜航和六个自由度的运动，求得其部分水动力系数，并和面元法及实验结果进行对比。2.分别计算了在1.5倍、2.5倍、3.5倍潜体最大直径三种潜深下特征长度相同的椭球体、微小型水下潜器和流线型潜体直航的水动力。讨论了随潜深减小阻力、垂向力和纵倾力距的改变，观察流场发生的变化，分析阻力增加的原因，并模拟了自由液面的兴波，计算兴波范围和波高随潜深及航速的变化。讨论了附体对微小型水下潜器近自由液面航行的水动力和兴波产生的影响。计算微小型水下潜器在不同潜深垂直面斜航和水平面斜航的水动力特性，观察潜深对垂直面斜航带来的影响。3.模拟了微小型水下潜器在近自由液面时升沉、俯仰、横荡、横摇运动，计算其运动产生的力和力矩随潜深的改变，观察不同潜深的水动力系数变化，并同无界绕流的结果相对比，寻找其变化规律。分析了流场中动压力、速度和兴波随运动频率、航速、潜深的变化。4.利用平面运动机构进行了微小型水下潜器的近水面操纵性相关实验。利用六分力天平测量了其不同深度不同航速下直航的阻力、升力和纵倾力距。测量了不同潜深下水平面斜航的侧向力和偏航力矩。同时使微小型水下潜器在不同潜深下做升沉、俯仰运动，测得其垂直面运动的水动力系数，发现变化规律，并和计算结果进行对比分析。5.进行近自由液面运动预报，观察近自由液面水动力系数的改变对垂直面运动产生的影响，讨论了其直航速度的改变、操舵后产生的纵倾角和垂向速度的变化；微小型水下潜器在近自由液面出现埋艏下潜的现象，并且操舵响应变慢，恢复力矩变小。更多还原

【Abstract】 The Mini Underwater Vehicle is very important in ocean exploitation on account of itscharacteristics such as small volume, low resistance, high stealth performance and goodmaneuverability. It needs to rise for navigation and localization after sailing some time. TheMini Underwater Vehicle is deployed and reclaimed from carrying platform. In theseconditions the Mini Underwater Vehicle sails near free surface. The flow environment is morecomplicated than limitless drainage area. The Mini Underwater Vehicle is easy to be disturbedby free surface because its small size and finite propulsion capability. Maneuverability is veryimportant to the Mini Underwater Vehicle, and the research of maneuverability is especiallymeaningful. In this paper, study about hydrodynamic performance of the Mini UnderwaterVehicle near free surface has been done, while the hydrodynamic coefficients in differentdepth are solved with computational fluid dynamics（CFD） method. Also the experiment ofmaneuverability near free surface is accomplished, and the motion characteristics can beobserved. The following work has been completed in this paper:1. The structural and unstructured mesh is gendered in different area to compute thehydrodynamic capability of the ellipsoid model and the Mini Underwater Vehicle whilesailing straight and with drift angle in limitless area. The hydrodynamic coefficients can bework out via simulation of movement in six degrees of freedom. The hydrodynamiccoefficients are also solved by experiment and Hess-Smith method. The results by CFD turnto be with good precision.2. The hydrodynamic performance is calculated in different depth of1.5times,2.5times,3.5times the maximum diameter of modules. The calculated modules contain the ellipsoidmodel, the streamlined model and the Mini Underwater Vehicle. The change of resistance,vertical force and trim moment versus depth and velocity is discussed. The reason of increaseof resistance is discussed. Free surface is simulated with CFD software. The range of wavemaking and wave height changes with depth and velocity. The appendages also cause wave.Wave and resistance caused by different appendages are computed. The hydrodynamicperformance of the Mini Underwater Vehicle sailing with attack angle and drift angle isdiscussed.3. Simulation of the Mini Underwater Vehicle conducted heaving, pitching, swaying and yawing is to calculate forces and moments caused by the motion in different depth.Hydrodynamics are computed by calculated results. Different hydrodynamic coefficient hasrespective changing rules versus depth. Dynamic pressure, velocity and wave making of theflow field are shown in this paper. Velocity, depth and motion frequency all make the flowfield different.4. Maneuverability experiment of the Mini Underwater Vehicle in different depth has beendone with planar motion mechanism. The resistance, vertical force and trim moment versusvelocity are measured by six-component balance in different depth. The lateral force and yawmoment of the Mini Underwater Vehicle sailing in drift angle is scaled in different depth.Also the Mini Underwater Vehicle is conducted heaving and pitching to calculatehydrodynamic coefficients of vertical plane in different depth.5. Motion features of the Mini Underwater Vehicle change near free surface because ofdifferent hydrodynamic coefficients. The maximum velocity diminishes near free surface.Trim angle and vertical velocity are different by dropping rudder and elevating rudder. TheMini Underwater Vehicle will submerge when sailing near free surface. Response to ruddertakes more time and the restoration moment shrinks.更多还原