Unmanned air vehicles have various flow structures in different flight phases, such as take-off, landing, and cruise, and their aerodynamic performances also vary. In this study, the aerodynamic performance of a non-slender delta wing with a National Advisory Committee for Aeronautics 0012 geometry having a sweep angle of \(50^\circ \) under ground effect is investigated. The measurement of aerodynamic forces is measured from \(0^\circ \) to \(42^\circ \) with an increase of \(3^\circ \) steps. In these experimental studies, the aerodynamical performance changes in a flight phases, such as takeoff, landing and cruise, the distance ratio between height from ground to chord length (h/C) values are set to 0.1, 0.2, 0.5 and 1, respectively. For the purpose of deep understanding the changes in aerodynamic performance and examining the changes in flow topologies inducted on the wing, titanium-dioxide (TiO \(_2\) ) surface oil experiments are observed examining the angle of attack (AoA) from \(0^\circ \) to \(40^\circ \) with \(5^\circ \) steps. The aerodynamic forces that are the lift coefficient \((C_L)\) , the drag coefficient \((C_D)\) , and the lift/drag coefficient (L/D) are demonstrated by performing these experiments. Through TiO \(_2\) surface oil visualization experiments, important flow phenomena, such as vortex breakdown, reattachment region, inner primary vortex, secondary reattachment line, secondary separation line and flow trace, at different angles of attack have been revealed. In addition to all these, the results of flight tests of this unmanned aerial vehicle starting with real-time ground take-off and continuing with out of ground effect are presented.
