Application of Gurney flap on certain target drone

Experiments of Gurney flap on aerodynamics of a certain target drone were conducted in wind tunnel, the height of Gurney flap is in the range of 0.83%c~4.2%c (c-root chord length of target drone wing in the experiment). For the target drone without sideslip, Gurney flap could enhance lift at medium and small angles of attack, and decrease the angle of attack where lift to drag ratio reaches maximum value. Meanwhile, besides of the 4.2%c Gurney flap, the others could increase the lift to drag ratio and the maximum lift to drag ratio. For the model with sideslip, the corresponding aerodynamic performance is similar to that without sideslip in longitudinal direction. However, in yaw and rolling directions, rolling moment increases with Gurney flap height, and yaw moment increases too when the Gurney flap height is in the range of 0.83%c~3.3%c, but the yaw moment decreases abruptly when Gurney flap height is 4.2%c. There exists the optimum Gurney flap height for improving the target drone aerodynamics, Experimental results show that it could increase the lift and the maximum lift to drag ratio with little variation of the moments in three directions when the Gurney flap height is 1.7%c.