Aerodynamic optimization for short range UAV using vortex lattice method and wind tunnel verification

According to the aerodynamic geometry of the UAV that operates at low Reynolds number, winglet was designed to improve the efficiency of the UAV by using vortex lattice method(VLM). Optimized designs were validated by wind tunnel tests. First, several key parameters were analyzed for winglet design. Second, the optimized winglet was obtained by the VLM for UAV at cruising state. Last, a wind tunnel test for the UAV with and without winglet was carried out. Based on comparison of VLM results to full scale measured wind tunnel test data, it can be seen that they match well during linear segment. It means that the winglet was designed properly using VLM thus the lift to drag ratio of the UAV was increased by 12%, and the roll damping was increased but the yaw damping was not changed, on the other hand, these results should provide valuable guidance in designing winglet for UAV by using VLM.