Aerodynamic Characteristics of Unmanned Aerial Vehicle with Z-Shaped Folding Wings

To accurately capture the flowfield distribution of Z-shaped folding wings under different configurations, especially the airflow separation caused by the dihedral angles between wing segments, the impact of the folding angle on the aerodynamic performance of the wings is investigated under both quasi-steady and transient conditions. Initially, when the wing folding rate is low, a quasi-steady computational algorithm is used to obtain the steady aerodynamic characteristics of the Z-shaped folding wings at various angles of attack and flow velocities. Subsequently, a dynamic mesh method capable of instant reconstruction is developed to account for the inertial force effects caused by the folding rate, which can quickly and accurately capture the gradient changes of parameters such as lift, drag, and pitching moment. The results indicate that the folding effect can enhance the maneuverability of the wings at high angles of attack and effectively reduce the bending moment and pitching moment at the wing root. Additionally, step changes in the folding angle introduce hysteresis effects on the aerodynamic performance of the folding wings, and the lift coefficient at the same angle of attack decreases as the folding rate increases.