摘要
舰载系留无人机工作在海洋上,必定会受到海洋上风的作用.海洋风场中存在着垂直切变现象.为探究垂直切变对舰载系留无人机系统动力学响应的影响,本文忽略大气层结状态以及边界层厚度等因素,采用指数律模型来描述海洋风场的垂直切变,同时由于无人机与缆绳相互耦合,因此将无人机平台看作系留缆绳上端点的边界条件;将舰船的垂荡运动看作缆绳下端点的垂向激励,建立了垂直切变风场下舰载系留无人机系统的动力学模型,计算了不同切变指数下缆绳各位置处的最大张力以及无人机运动速度与位移,分析了切变指数对缆绳最大张力和无人机运动的影响.结果表明:最大张力沿缆绳的分布呈现非线性上升趋势;与不考虑切变的情况相比,切变指数为0.30时上端点的最大风速增大为1.37倍,缆绳最大张力减小了11.4%,说明风切变的影响不可忽略;3种风速下缆绳最大张力均呈现先减小后增大的趋势,即缆绳最大张力都存在极小值,并且风速越大,缆绳张力曲线极小值处的切变指数越小;切变指数增加不会改变无人机的运动性质,无人机始终为倍周期运动,但会改变无人机的偏移量,在计算参数范围内,水平最大偏移增大了9.4 m,竖直最大偏移减小了3.1 m,以水平偏移为主.研究结果明确了风切变对舰载系留无人机系统的影响规律,为舰载系留无人机系统的工程设计与安全工作提供了参考.
The shipborne tethered unmanned aerial vehicle(UAV)system operating on the ocean is inevitably affected by ocean winds,which exhibit vertical shear.To investigate the impact of vertical shear on the dynamic response of the shipborne tethered UAV system,this paper employed an exponential law model to describe the vertical shear in the ocean wind field while excluding factors such as atmospheric junction state and boundary layer thickness.Additionally,owing to the coupling between the UAV system and the tethered cables,the UAV platform was treated as the boundary condition at the tether endpoints.Considering the ship’s heave motion as the vertical excitation at the cable lower end,a dynamics model of the shipborne tethered UAV system under vertical shear wind conditions was developed.The maximum tension at each position along the cable,as well as the speed and displacement of the UAV system under different shear indices,were calculated.The effects of shear indices on the maximum tension in the cable and the drone motion of the UAV system were analyzed.The results show that the distribution of maximum tension along the cable exhibits a nonlinear upward trend.Compared with the case where shear is not considered when the shear index is 0.30,the maximum wind speed at the upper endpoint increases by 1.37 times,while the maximum tension in the cable decreases by 11.4%.This indicates that the influence of wind shear is significant and cannot be ignored.Under the three wind speeds,the maximum tension in the cable firstly decreases and then increases,meaning that the maximum tension has a minimum value.As the wind speed increases,the shear index at which the minimum tension occurs decreases.The increase in the shear index does not alter the motion characteristics of the UAV,which always exhibits period-doubling motion.However,it does affect the UAV offset:within the range of the calculated parameters,the maximum horizontal offset increases by 9.4 m,while the maximum vertical offset decreases by 3.1 m,with the horizontal offset being the primary change.The research results highlight the effect of wind shear on the shipborne tethered UAV system and provide a reference for the engineering design and safety of such systems.
作者
张素侠
朱清荣
吴思琛
Zhang Suxia;Zhu Qingrong;Wu Sichen(School of Mechanical Engineering,Tianjin University,Tianjin 300350,China;Tianjin Key Laboratory of Nonlinear Dynamics and Control,Tianjin University,Tianjin 300350,China;National Key Laboratory of Vehicle Power System,Tianjin 300350,China)
出处
《天津大学学报(自然科学与工程技术版)》
北大核心
2025年第10期1069-1075,共7页
Journal of Tianjin University:Science and Technology
基金
国家自然科学基金资助项目(51479136)
天津市自然科学基金资助项目(17JCYBJC18700)
装备预研基金重点资助项目(61403110101).
关键词
垂直切变
舰载系留无人机系统
动力学响应
缆绳张力
无人机运动
vertical shear
shipborne tethered unmanned aerial vehicle(UAV)system
dynamics response
cable tension
drone motion
