Research on Aerodynamic Characteristics of Unmanned Aerial Vehicle Rotating Wing Opening Process

A rotating variant wing aircraft has wings that rotate around a fixed axis. Compared with traditional symmetrical variant aircraft, rotating wing aircraft has many advantages, such as compact mechanism, low-weight structure, and suitability for stealth launch. During the rotating wing opening, the pressure center of the rotating wing aircraft changes continuously, and the coupling interference exists between the rotating wing and the fuselage flow, adversely affecting the lift resistance characteristics and vertical and horizontal stability. Therefore, the aircraft’s aerodynamic characteristics during the rotating wing’s opening are analyzed utilizing a high-speed wind tunnel test. First, the test model and environmental conditions are defined. Then, according to the typical state, repeated tests were carried out to verify. Then, the aerodynamic characteristics and essential flow field characteristics are analyzed according to the different rotation angles of the wings under transonic velocity. Finally, the aircraft’s lateral aerodynamic characteristics at various flight speeds are investigated. The results show that with the increase of the angle of the rotating wing opening process, the slope of the lift line and the drag coefficient increase, and the change of the pressure center causes the longitudinal static stability to increase gradually (the static stability is about 5% when the transonic speed is fully opened), the force asymmetry on the left and right side of the wing, and the lateral aerodynamic stability changes significantly.