A UAV Lift Augmentation via Gurney Flap

This paper investigates the effect of using a Gurney flap on aerodynamic characteristics of a UAV, named Persian Gulf. It is very likely to happen for the UAVs to carry payloads slightly more than what they have been designed for. In these cases, lift augmentation methods would be the most economical and effective solution to broaden their payload range. A 2D numerical study was performed to find the effective flap size for the Persian Gulf wing section, NACA 4415. The results obtained using the one-equation Spalart-allmaras (SA) turbulence model. Numerical simulations showed that, if the flap length is selected about 0.9 boundary layer height, the maximum L/D ratio would be achievable. The results, suggested that by adding this flap to the wing planform, a 6kg additional lift would be obtained. Finally 3D numerical investigations verified the design process and guarantied this increase