In order to achieve accurate and undamaged landing with low speed of airdropped cargo under limited area, the high angle of attack aerodynamic and operational characteristics of tandem wing cargo UAV was researched. Focus on the problem of aerody-namic nonlinearity at high angle of attack and the strong coupling of front and rear wings of tandem wing UAV, the detached eddy simulation (DES) method was used to analyze the nonlinear aerodynamic characteristics at high angle of attack, and the lift coefficient, drag coefficient and pitch moment of each component and aerodynamic center were calculated with the variation of the angle of attack. The influence of different fuselage cross sections on the longitudinal stability of the UAV was further studied. The coupling mechanism of tandem wing was analyzed according to the distribution characteristics of wing surface pressure and the structure of surrounding flow field. A manipulation scheme for the fully-moving rear wing at high angle of attack in tandem wing UAV was proposed. The results show that the static stability of the square fuselage cross section is more stable than the round cross section under high attack angle. In the wide range of attack angle from 0° to 50°, there is aerodynamic coupling between the front wing and the rear wing. The pressure distribution of the rear wing is affected by the aerodynamic coupling between the front wing and the rear wing, and the lift loss of the rear wing is up to 32%. The fully-moving rear wing increases the controllable angle of attack to 50°, which can provide sufficient control torque for deep stall landing at high angle of attack.
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