AUV自航对接的类物理数值模拟

为了预报dock对自主水下机器人（AUV）水动力性能的影响，提高AUV水下对接成功率，提出一种多块混合网格结合动态层方法和用户自定义函数（UDF）的方法，应用于基于离散螺旋桨的AUV自航对接的类物理数值模拟。所提方法采用移动子区域代替传统的移动边界，可提高数值计算效率。在验证了AUV自航试验速度的基础上，对AUV自航对接的水动力和流场进行分析。结果表明，AUV在螺旋桨定转速300 r/min推进作用下，自航对接时间约16 s，终端速度为0.75 m/s。对接速度满足对接碰撞需求。dock对AUV运动影响:在对接井口B点之前起阻碍作用，在B点之后起吸附作用。AUV对接阻力增加2.4%，增幅小，可实现与dock对接。 

Physics-based numerical simulation of AUV docking by self-propulsion

To predict the effect of dock on hydrodynamic performance of autonomous underwater vehicle (AUV) and to improve AUV underwater docking success rate, a method of multi-block hybrid grids combined with dynamic layer method and user defined function (UDF) was presented, which was applied to the physics-based numerical simulation of AUV underwater docking by self-propulsion with a discretized propeller. In this method, subdomain-moving substitutes for boundary-moving used in traditional dynamic mesh, which could improve the calculation efficiency. After the numerical validation of the velocity history of AUV self-propulsion against the experimental results, the hydrodynamic performance and flow field of AUV underwater docking were investigated. The results demonstrate that the time of AUV underwater docking from rest by a constant rotating propeller of 300 r/min is about 16 s. The end velocity reaches 0.75 m/s, which meets the demand for collision. The effect of the dock on AUV locates on the neck point B. There is a drag on AUV before B, followed by a suction after B. The increment of resistance is small with a value of 2.4%. Therefore, it is achievable for AUV docking with the dock.