A Comparative Study on Aerodynamic Characteristics and Stability of Twin-Boom UAVs with Typical Tail Configurations Under Propeller Slipstream Interference

The present study concentrates on aerodynamic behavior and static stability characteristics, and propeller slipstream interference of twin- boom unmanned aerial vehicles (UAVs) with three typical tail configurations. This study adopts a coupled VSPAERO approach, which incorporates a VLM-based solving technique and the Actuator Disk Model. Simulation results under the no-slipstream baseline condition reveal that the inverted V-tail layout delivers the highest aerodynamic efficiency. Its lift/drag ratio is considerably superior to those of the U-tail and inverted U-tail designs. While all configurations maintain good stability in longitudinal and directional axes, only the U- tail exhibits lateral static stability. When propeller slipstream is introduced, the lift-to-drag ratio of all layouts decreases noticeably, mainly due to strong local low-pressure regions that substantially increase pressure drag. In addition, the slipstream has little influence on longitudinal static stability, leaving pitching moment characteristics nearly unchanged. Nevertheless, the swirling flow generated by the propeller effectively improves lateral stability. It enhances the stabilizing effect of the U-tail, turns the lateral instability of the inverted U-tail into stable behavior, and reduces the lateral unstable characteristics of the inverted V-tail. In addition, the findings show that the sideslip angle β’s impact on the yawing moment is affected by the angle of attack α. Coupling between α and β, as well as propeller slipstream, should be considered in directional stability analysis. Increasing propeller diameter appropriately improves aerodynamic efficiency and directional static stability, while placing the propeller at or slightly forward of the baseline position minimizes adverse tail interference.