Abstract: Reasonable use of wake surfing technology during formation flight will lead to significant lift enhancement performance for the rear aircraft. Based on this principle, a formation consisting of two fixed wing unmanned aerial vehicles was designed according to the "V" shape formed by migratory birds during flight. CFD was used to draw overset grids between the unmanned aerial vehicles and the fluid domain, numerical simulation was conducted on flight formation, and the aerodynamic parameters of the flight formation were analyzed. Research results show that under aerodynamic action, the wake surfing effect has a minimal impact on the front aircraft and a significant impact on the rear aircraft. The longitudinal and vertical spacing of the twin aircrafts affect the lift coefficient, drag coefficient, lift drag ratio, pitch torque and other parameters of the rear aircraft. At the appropriate position and angle of attack, the lift coefficient of the rear aircraft can be increased by 11.7%.

Key words: aeronautical engineering; formation flight; wake surfing; numerical simulation; overset grid; lift coefficient

摘要： 在编队飞行中合理利用尾流冲浪技术，可使得后机获取明显的增升性能。基于该原理，按照候鸟迁徙飞行时所排成“V”字形设计了两架固定翼无人机组成的编队；利用CFD绘制无人机与流体域的重叠网格，对该飞行编队进行了数值模拟；并对飞行编队的气动参数进行了分析。研究结果表明：在气动作用下，尾流冲浪效应对前机的影响很小，对后机的影响明显；双机纵向间隔和垂直间隔对后机的升力系数、阻力系数、升阻比、俯仰力矩等参数均有影响；后机在合适的位置和迎角下，升力系数可提升11.7%。

关键词: 航空工程；编队飞行；尾流冲浪；数值模拟；重叠网格；升力系数