Aerodynamic Numerical Analysis of the Low Reynolds Number Diamond Joined-Wing Configuration Unmanned Aerial Vehicle

Aerodynamic numerical simulation of low Reynolds number long-endurance Diamond Joined-Wing configuration unmanned aerial vehicle was performed. First, low Reynolds number aerodynamic characteristics of a typical wing are numerically simulated by solving the Reynolds averaged Navier–Stokes (RANS) equations based on the structural grid technology and the k–k_L–ω transition model. To prove the accuracy of this method, experimental data and numerical simulation results were compared. Second, the performance of low Reynolds number Diamond Joined-Wing configuration UAV (unmanned aerial vehicle) aerodynamic characteristics and control surfaces was studied by numerical simulation and theoretical analysis. The analysis of the interference between the Frt-wing (front wing) and the Aft-wing (after wing) of the Diamond Joined-Wing configuration UAV and the reason for the change in the pitching moment in the lateral-directional motion is carried out. The results show that the Diamond Joined-Wing configuration UAV has a typical low Reynolds number surface flow characteristics, Frt-wing and Aft-wing flow interference are relatively minor at a small angle of attack, which has a high basic aerodynamic performance in addition to good stall characteristics, with longitudinal and lateral-directional static stability. The performance of control surfaces and flaps is higher to meet the design requirements. Finally, the accuracy of the numerical simulation results was verified by vehicle aerodynamic testing.