无人机机翼鸟撞下的气动特性变化数值分析  

Numerical Analysis of Aerodynamic Characteristics of UAV Wing under Bird Impact

作　　者：杨轶民 许晓宁 王永虎 YANG Yi-min;XU Xiao-ning;WANGYong-hu(School of Civil Engineering;School of Aeronautics,Chongqing Jiaotong University,Chongqing 400000,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400000 [2]重庆交通大学航空学院,重庆400000

出　　处：《湖北工业职业技术学院学报》2022年第4期79-84,共6页Journal of Hubei Industrial Polytechnic

摘　　要：为研究大型固定翼无人机机翼在发生鸟撞事故后的冲击变形以及机翼变形后的气动特性,运用有限元方法,在Ls-dyna软件中,基于SPH法模拟了不同速度下鸟体正面碰撞机翼的全过程,然后应用Ansys-Fluent软件对变形前后的机翼气动性能进行了数值模拟分析。仿真结果表明:随着鸟体速度的增加,机翼蒙皮的变形不断加大,当鸟体冲击速度达到120 m/s时,机翼蒙皮达到极限塑性应变发生破坏。对于3 mm和4 mm不同厚度的机翼蒙皮,鸟体撞击速度相同时,随着蒙皮厚度的增加,蒙皮节点位移和蒙皮能量在减小,而撞击应力增加。鸟撞会对机翼气动外形造成影响,压力分布和表面流线发生变化,进而影响机翼的气动力特性,造成升力系数下降阻力系数升高。鸟体的冲击速度越大,对机翼造成的“减升增阻”效应就越明显。in order to study the impact deformation and aerodynamic characteristics of a large fixed wing UAV after bird impact accident,the frontal impact of a bird body on the wing at different speeds is simulated by using the finite element method in LS DYNA software based on SPH method,and then the aerodynamic performance of the wing before and after deformation is numerically simulated and analyzed by using Ansys Fluent software.The simulation results show that the deformation of the wing skin increases with the increase of the bird speed.When the bird impact speed reaches 120 m/s,the wing skin reaches the limit plastic strain and fails.For different wing skin thicknesses of 3 mm and 4 mm,when the bird impact velocity is the same,it can be concluded that with the increase of skin thickness,the skin node displacement and skin energy decrease,while the impact stress increases.Moreover,bird impact will affect the aerodynamic shape of the wing,change the pressure distribution and surface streamline,and then affect the aerodynamic characteristics of the wing,resulting in the decrease of the lift coefficient and the increase of the drag coefficient.It can be found that the greater the impact velocity of the bird is,the more obvious the effect of “reducing lift and increasing drag” on the wing is.

关 键 词：鸟撞 无人机 SPH 气动力系数 数值模拟 

分 类 号：V211[航空宇航科学与技术—航空宇航推进理论与工程]