摘要
针对自主水下机器人极近海底航行的可行性和安全性问题,本文采用坐标转换法和移动网格法对不同极近海底距离、不同航速的自主水下机器人直航运动进行水动力预报。数值结果表明:自主水下机器人在极近海底壁面附近航行时,海底会对自主水下机器人产生复杂的“坐底”效应。移动网格法相对坐标转换法,自主水下机器人的阻力偏小。随着间隙变小,移动网格法能预报垂向力由吸力变为斥力,艉倾变为埋艏的动态过程,而坐标转换法则不能。这种差异源于2种方法采用了不同的坐标系、产生的不同边界层厚度,以及流体的惯性量大小。当间隙小到边界层影响范围内,移动网格法更适合模拟极近海底操纵运动,为这种工况下的安全航行提供技术保障。
To address the feasibility and safety of autonomous underwater vehicles(AUVs)cruising in very close proximity to the seafloor,the coordinate transformation method(CTM)and moving mesh method(MMM)are used to forecast the hydrodynamic motion of AUVs at different speeds and distances away from the seafloor.Numerical results show that the seafloor produces a complex“squat effect”on AUVs when they navigate very close to the sea-floor.The results by MMM have less drag on AUVs compared with that by CTM.As the distance of an AUV to the seabed gets smaller,MMM can predict the processes where the vertical force changes from suction to repulsion and where stern pitch turns to bow pitch,whereas CTM cannot predict these changes.This difference stems from the different coordinates and different boundary layer thicknesses produced by these two methods,as well as the magni-tude of fluid inertia.When the gap reduces to the influence range of the boundary layer,MMM is more suitable for simulating the maneuvering motion of AUVs very close to the seabed and can provide a technical guarantee for safe navigation under this working condition.
作者
吴利红
李超
刘社文
封锡盛
李硕
阎述学
曾俊宝
WU Lihong;LI Chao;LIU Shewen;FENG Xisheng;LI Shuo;YAN Suxue;ZENG Junbao(College of Naval Architecture and Ocean Engineering,Dalian Maritime University,Dalian 116026,China;State Key Laboratory of Robotics,Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang 110016,China)
出处
《哈尔滨工程大学学报》
北大核心
2025年第6期1047-1053,共7页
Journal of Harbin Engineering University
基金
国家重点研发计划(2021YFC2801102)
广东省重点领域研发计划(2020B1111010004)
辽宁省自然科学基金项目(2020-KF-12-05)
机器人重点实验室项目(2024-O13,2023-O15)。
关键词
自主水下机器人
海底
坐标转换法
移动网格法
直航
坐底效应
水动力
计算流体力学
autonomous underwater vehicle(AUV)
seabed
coordinate transformation method
moving mesh method
straight motion
squat effect
hydrodynamics
computational fluid dynamics(CFD)
