Effects of belly flap on take-off and landing characteristics of a flying-wing vehicle

Taking a flying wing configuration model as the initial shape of flying wing configuration aircraft, the location and the deflection angle of belly-flaps in the take-off and landing process are studied by the method of numerical simulation, and the influence law of belly-flap deflection on elevator rudder effect and ground effect is obtained.The results show that when the belly-flap is located at 40% mean aerodynamic chord behind the center of gravity, a high lift enhancement efficiency can be maintained at high angles of attack, and there is a small change in the pitching moment.As the deflection angle of the belly-flap increases, the lift and the drag show a quasi linear growth, while the change of the pitching moment is small and can be trimmed by about 1° deflection of the elevator.When the belly-flap is deflected, the rudder efficiency of the elevator decreases by about 6%, and the increment of lift caused by ground effect increases, while the longitudinal static stability is decreased. © 2022, Beihang University Aerospace Knowledge Press. All right reserved.