中尺度涡是普遍存在于世界各个海域的一种海洋现象，具有长期、封闭环流 的特点，通常典型的空间尺度可以达到几十至几百千米,生命周期为几天到上百 天,是海洋环境的重要组成部分，对海洋物理、化学、生物等有着多方面的影响， 因此具有重要的研究意义，也一直是海洋研究的热点问题。 利用潜标系统、卫星高度计、浮标等观测平台对中尺度涡的观测存在一定的 局限性，且对于中尺度涡的观测也不够完善。水下滑翔机是 20 世纪末投入应用 的一种自主式水下无人观测平台，具有工作时间长、航行距离远、低噪声、小巧、 易于布放回收等优点，可携带不同的传感器进行海洋水文参数观测。因此，本文 提出了利用水下滑翔机对中尺度涡进行观测，研究成果对于完善中尺度涡观测提 供了新思路，同时，对于拓展水下滑翔机在中尺度涡观测中的应用提供理论指导。 本文根据现有的中尺度涡观测、研究成果，分析了中尺度涡的时空特征、温 盐特征以及流场特征，以此为基础设计了滑翔机对中尺度涡的周向观测与径向观 测两种观测策略。 通过 CFD 数值模拟，利用动网格方法和 6-DOF 模型，分别计算水下滑翔机 在周向观测与径向观测过程中海流的影响下的六自由度空间运动，分析了水下滑 翔机的运动特性。沿着中尺度涡周向进行观测时，水下滑翔机处于垂直面内的顺 向流场中，水平位移会增大，垂向位移会减小，俯仰角也会减小，而侧向位移、 横滚角、偏航角没有明显变化。沿着中尺度涡径向进行观测时，水下滑翔机处于 侧向来流的流场中，与静水中的航行过程相比，侧向位移逐渐增大并趋向于线性 增长，偏航角增大，而水平位移、垂向位移、俯仰角和横滚角没有明显变化。水 下滑翔机从涡旋边界向涡旋中心航行的过程中，会产生明显的侧向偏移，在涡旋 边界处海流速度最快，侧向偏移也最大；随着与涡旋中心的距离减小，侧向偏移 也会减小。 根据水下滑翔机 6-DOF 运动仿真结果，以半径 100 km 的中尺度涡为例，测 算了不同观测策略情况下滑翔机航线调整策略。对于周向观测策略，水下滑翔机 从目标区域外边界经过内边界并再次航行至外边界，经过 24 个剖面后超出目标 区域，需要改变航向，重新回到目标区域。对于径向观测策略，从边界区开始连 续航行 5 个剖面后，滑翔机的侧向偏移就会超出设定航行区域，需要进行航线校 正。 为验证仿真分析结果，开展了水下滑翔机对中尺度涡观测的海域试验，通过 分析水下滑翔机的下潜速度与俯仰姿态变化，验证了仿真计算结果的准确性，证 明了观测策略分析是可信的。I 关键词，水下滑翔机，中尺度涡，观测策略，6-DOF 运动仿真，可行性分 析II ABSTRACT Mesoscale eddy is a kind of ocean phenomenon which can be found in each sea area in the world. It can be characterized by long-term closed circulation, which has the typical spatial scale of tens or hundreds kilometers and time scale of tens or hundred days. Mesoscale eddy is an important component of marine physical environment. Because it has significant effect on marine physics, chemistry and creature, etc. mesoscale eddy is of important research significance and also hot issue in marine research. There are some limitations to the observation platforms currently in use, such as submersible mooring, satellite altimeter and buoy. The observations to the mesoscale eddy are still not perfect. The underwater glider is a kind of autonomous underwater mobile observation platform, which was applied to the marine observation at the end of the 20th century. It has the advantages of strong endurance, long distance, low noise, lightweight and convenience of launch and recovery, and plays an important role in the field of oceanographic measurement. The underwater glider developed by our country has also entered the application stage. The underwater glider can conducts observations of the ocean hydrological parameters with the mounted various sensors. Therefore, the idea of observing the mesoscale eddy by the underwater glider was proposed in the current work. Achievements in the thesis provide a new way to perfect mesoscale eddy observation. At the same time, they also provide a theoretical guidance for the application of underwater glider in mesoscale eddy observation. Based on the existing data and research achievements of mesoscale eddy observations, the space-time characteristics, temperature and salinity characteristics, velocity characteristics of mesoscale eddy were qualitatively analyzed. Based on the analysis, two observation strategies including observation along the circumferential direction and along the radius direction were proposed. Through the computational fluid dynamics (CFD) numerical simulation with the moving grid method and the six degrees of freedom (6-DOF) model, the 6-DOF space motion of the glider was simulated and the motion characteristics of the glider were analyzed in the two observation strategies. In the circumferential observation, the moving direction of the glider is in line with the direction of the mesoscale eddy in the vertical plane, and the glider is in the vertical flow field. The horizontal moving distance of the glider is longer than that in the condition of static water. The vertical moving distance and pitch angle of the glider are less than those in static water. The lateral displacement, roll angle, yaw angle have no significant change. In the radial observation, the glider is in the lateral flow field. Compared with the navigation in the static water, the lateral displacement increases almost linearly, the yaw angle increases, while the horizontal displacement, vertical displacement, pitch angle andII roll angle have little change. The glider will have a significant lateral displacement during flight from the eddy boundary to eddy center. At the eddy boundary, the current with greater speed makes the larger lateral displacement. with the glider moving toward the eddy center, the lateral deviation also decreases. Based on the results of the 6-DOF simulation for the glider, take example of a mesoscale eddy with radius of 100km, the route adjustment schemes of the glider were developed for different observation strategies. In the circumferential observation, trajectory of the glider will be out of the preset ideal circular area after 24 profiles and have to be adjusted during the glider flights from outer boundary to inner boundary, and then to outer boundary of the ideal circular area. In the radial observation from the outer boundary to the center of mesoscale eddy, the glider will exceed the preset ideal band area after 5 profiles and have to do an adjustment for its trajectory. To demonstrate the validity of simulation, the trial of mesoscale eddy observation is implemented. By analyzing the dive velocity and pitch attitude of underwater glider，the accuracy of simulation is verified，and it is proved that the analysis of observation Strategy is correct. KEYWORDS，Underwater glider; Mesoscale eddies; Observation stragegy; 6-DOF numerical simulation; Feasibility analysisIII 目 录 摘要........................................................................................................................I ABSTRACT.........................................................................................................II 目 录.................................................................................................................III 图清单................................................................................................................. VI 表清单..............................................................................................................VIII 字母注释表 ........................................................................................................ IX 第一章 绪 论 .....................................................................................................1 1.1引言...........................................................................................................1 1.2传统中尺度涡观测平台研究现状...........................................................1 1.2.1海洋调查船......................................................................................1 1.2.2潜标系统..........................................................................................2 1.2.3卫星高度计......................................................................................3 1.2.4浮标..................................................................................................5 1.3水下滑翔机观测中尺度涡的现状...........................................................6 1.4研究目的与意义.......................................................................................9 1.5主要研究内容.........................................................................................10 第二章 中尺度涡特征及观测策略 ...................................................................11 2.1引言.........................................................................................................11 2.2传统中尺度涡观测方法.........................................................................11 2.3中尺度涡的特征.....................................................................................12 2.3.1中尺度涡时空特征........................................................................12 2.3.2中尺度涡温盐特征........................................................................15 2.3.3中尺度涡流场特征........................................................................16 2.4水下滑翔机的观测策略.........................................................................18 2.4.1中尺度涡周向观测........................................................................18 2.4.2中尺度涡径向观测........................................................................18 2.5观测区域的确定.....................................................................................19 2.6观测策略对水下滑翔机的要求.............................................................19 IV 2.7本章小结.................................................................................................21 第三章 周向观测策略可行性分析 ...................................................................22 3.1引言.........................................................................................................22 3.26-DOF 运动仿真基本原理 .....................................................................22 3.2.16-DOF 仿真用动力学模型 ............................................................22 3.2.2动网格技术....................................................................................23 3.2.3UDF 函数........................................................................................24 3.3水下滑翔机 6-DOF 动力学模型 ...........................................................25 3.3.1坐标系的建立与参数定义............................................................25 3.3.2水下滑翔机受力分析....................................................................28 3.4水下滑翔机 6-DOF 运动仿真 ...............................................................29 3.4.1水下滑翔机几何模型....................................................................29 3.4.2计算区域的选取............................................................................30 3.4.3划分网格与参数设置....................................................................31 3.4.4边界条件设置................................................................................32 3.4.5控制方程及湍流模型....................................................................32 3.4.6加载 UDF 函数..............................................................................33 3.4.7动网格设置....................................................................................34 3.4.8求解方法与参数设置....................................................................34 3.5计算结果分析.........................................................................................35 3.6周向观测策略分析.................................................................................37 3.7本章小结.................................................................................................39 第四章 径向观测策略可行性分析 ...................................................................41 4.1引言.........................................................................................................41 4.2水下滑翔机运动仿真.............................................................................41 4.3计算结果分析.........................................................................................41 4.4滑翔机径向观测策略分析.....................................................................44 4.5海试数据验证.........................................................................................47 4.6本章小结.................................................................................................49 第五章 总结与展望 ...........................................................................................50 5.1全文总结.................................................................................................50 V 5.2工作展望.................................................................................................50