Study on aerodynamics of annular wing for unmanned aerial vehicles

Wind-tunnel measurements were conducted on a reference planar Clark-Y wing and on a circular wing that utilizes the same airfoil in its upper and lower halves. The results were used to validate previous numerical simulations of these wing configurations. At the same time measurements were conducted to explore the aerodynamic characteristics of ellipse annular wings which are thought to have properties intermediate between those of the planar and of the circular wing. Models of the wings were 3D printed and tested in a subsonic, closed-loop wind tunnel at different freestream velocities and angles of attack. Numerical simulations were performed of these wings inside a wind-tunnel test section to verify the ability to predict the aerodynamic characteristics observed in the experiments.