Aerodynamic Characteristic of Deflected Slipstream Aimed at Vertical Takeoff and Landing

Abstract

The deflected slipstream is one kind of vertical takeoff and landing technology with lightweight lift machinery. Thus, the influence of different parameters on the aerodynamic characteristics of a multi-element wing under propeller slipstream is experimentally studied. The parameters concerned here include horizontal distance between propeller and wing, flap deflection angles, and inclination angle between propeller shaft and wing main chord direction. In addition, Gurney flaps are also used to further improve the aerodynamic performance. It is indicated that the horizontal distance between propeller and wing has little influence. The efficiency of first flap deflection in redirecting propeller slipstream is greater than that of the second flap deflection. The maximum turning angle can reach 44 deg, and the magnitude of resultant force can reach 78% of propeller thrust when the first flap deflects 50 deg and the second flap 40 deg for the cases when the inclination angle is equal to 0 deg. The turning angle can increase to 56 deg when the inclination angle is equal to 18 deg, which is beneficial to vertical takeoff and landing. With the addition of Gurney flaps, the turning angle can be further enhanced, though the resultant force is reduced. These findings can provide valuable reference for the implementation of vertical takeoff and landing based on deflected slipstream.