A numerical research on aerodynamic interference of diamond-wing sensor-craft

Aerodynamic configuration design is conducted on a new diamond-wing sensor-craft. The diamond-wing, the front wing and the aft wing are investigated respectively by numerical simulation, which is applied to studying the longitudinal aerodynamic performance and the three-dimensional flow field characteristics of the diamondwing. The internal mechanism of aerodynamic interference is analyzed through the difference of flow-field between diamond-wing and independent front/aft wing. Finally, sweep angles of both wings are altered, and three models called close-coupled, medium-coupled and distant-coupled are obtained in order to compare the aerodynamic interference effect of longitudinal distance between the front and aft wing. The numerical results show that the lift-to-drag ratio can be as large as 27.7, however, the pitching moment changes non-linearly with the angle of attack increasing between 0° to 2°. The flow characteristics analyses reveal that the aft wing rises the front wing up by suppressing wing-tip vortices and reducing flow separation. Nevertheless, the downwash flow generated by the front wing changes the pressure distribution of the aft wing in some degree, which leads to the loss of lift for aft wing. The aerodynamic interference, which affects the lift-drag and pitching moment characteristic badly, weakens as the longitudinal distance increases.