Research on the influence of ducted fan position on the performance of powered high-lift system

Abstract The ducted fan-powered high-lift system realizes the lift increase effect in the form of blowing flaps. The position of a ducted fan is the most critical parameter in the design of a ducted fan-powered high-lift system. An analysis model of ducted fan blowout flap of a vertical/short take-off and landing (V/STOL) Unmanned Aerial Vehicle (UAV) with three ducts is established in this paper. T-Rex unstructured grid technique and Reynolds mean method (RANS) were used for simulation calculation. The influence of the position of the ducted fan on the performance of the ducted fan high-lift system is studied on this basis. The results show that the horizontal forward movement of the ducted fan can increase the lift coefficient and lift drag ratio. When the ducted fan moves up, the lift-drag ratio increases, but the lift coefficient decreases. In the vertical direction, the proper position is chosen by the wing as far as possible. The negative installation angle of the ducted fan will obtain a larger lift coefficient. Changing the position of the ducted fan for greater lift usually also results in greater bow torque, which puts a greater burden on the tail trim.