Aerodynamics of a Modified High-Lift Low Reynolds Number Airfoil: Preliminary Analysis

Abstract

Airfoil selection is a crucial phase in the design of a small unmanned fixed-wing aircraft to allow a minimum size and weight of the lifting surfaces. The present study analyzesairfoils to be used in low operating Reynolds number unmanned aerial vehicles (UAV) using XFLR5 software, which was validated against wind tunnel data. Three baseline airfoils were investigated, namely NACA4412, Miley M06-13- 128 and Selig S1223. The best performing airfoils are then modified using the inverse airfoil design method to improve their performance in cruising flight. The modified airfoil resulted in larger leading edge radius and slightly thicker chord of the airfoil compared to the baseline airfoil. In general, the modified airfoil showed an improvement in stall characteristic, lift and drag coefficients in the post-stall regime, and a lower magnitude of moment coefficient for almost all investigated angles of attack compared to the baseline airfoil.