太阳能无人机机翼颤振动力学建模与分析

Dynamic Modeling and Analysis of Solar UAV Wing Flutter

太阳能无人机作为一种大展弦比轻质飞行器,其机翼的气动弹性效应显著,其中颤振问题尤为关键;此类飞机具有大尺寸和低刚度特点,通过风洞试验研究机翼颤振问题,成本高而且难度大,难以实现,因此仿真计算是分析此类飞机颤振问题的主要手段;针对国内某翼展为40米的太阳能无人机大展弦比机翼,首先对机翼有限元模型进行工程化处理,在此基础上开展结构动力学分析和颤振计算,重点计算了机翼上不同吊舱布置下的颤振速度;经过仿真计算,得到该太阳能无人机机翼颤振速度为26 m/s,满足设计要求,进一步分析表明,可以通过增加发动机连杆的长度、在发动机上增加配重以及改变吊舱在机翼上的展向站位等手段来提高此无人机的颤振速度。

Solar-powered UAV is a lightweight aircraft with high aspect ratio,and its wing has a significant aeroelastic effect,especially flutter.This kind of aircraft has the characteristics of large size and low stiffness.It is costly and difficult to realize that wing flutter is studied through wind tunnel test.Therefore,simulation calculation is the main means to analyze the flutter problem of this kind of aircraft.Aiming at the high aspect ratio wing of a solar UAV with the wingspan of 40 meters,the finite element model of the wing was firstly treated by engineering.On this basis,the structural dynamics analysis and flutter calculation were carried out,and the flutter velocity under different arrangements of the pod on the wing was mainly calculated.The simulation results show that the flutter speed of the solar UAV wing is 26m/s,which meets the design requirements.The further analysis shows that the flutter speed of the UAV can be improved by increasing the length of the engine connecting rod,increasing the counterweight on the engine and changing the spanwise position of the pod on the wing.