Study on Aerodynamic Characteristics and Flight Dynamics of Multi-body Aircraft

The wingtip-hinged multi-body combined unmanned aerial vehicle (UAV) is a novel conceptual aircraft that consists of multiple individual unmanned aircraft connected through wingtip hinges, enabling relative roll motion. It presents notable differences in layout parameters and flight dynamics characteristics compared to traditional aircraft, primarily due to the presence of aerodynamic coupling between individual UAVs. Initially, a state-space vortex lattice method (VLM) is utilized to derive specific aerodynamic derivatives for this aircraft type. Subsequently, the Newton-Euler equations are used to establish a flight dynamics model for trim calculation and stability analysis, which reveals its unstable compound motion flight modes predominantly governed by relative roll motion. Lastly, an investigation is conducted to explore the effects of layout parameters on flight dynamics stability. Through analysis, it is determined that reducing the trim roll angle of individual UAVs and increasing the sweep angle can enhance flight stability, whereas an optimal distance between the wing and tail contributes to improved stability. These research findings offer valuable guidance and references for the design of wingtip-hinged multi-body combined unmanned aerial vehicles.