03.4 - Applied Aerodynamics
INVESTIGATION ON THE HIGH-EFFICIENCY PROPULSION MECHANISMS OF DUCK-WEBBED PADDLING FOR BIOINSPIRED AIRCRAFT APPLICATIONS
S.S. Cao¹, W.Q. Yang¹, Y.G. Zhang¹, X.L. Xu¹; ¹Northwestern Polytechnical University, China
Amphibious aerial-aquatic unmanned aerial vehicles (UAVs) possess promising prospects in crossmedium missions, and bionic duck webbing offers an effective route to high-efficiency underwater thruster design. A high-fidelity 3D bionic model of mallard webbed foot is built via CATIA with inherent asymmetry, interdigital concaves and curved membrane edges, avoiding the oversimplified flat-plate assumption widely adopted in previous numerical studies. Systematic CFD simulations using the SST k-ω turbulence model are performed to quantify the effects of flapping frequency, swing amplitude, bilateral phase difference and concave structure on hydrodynamic performance.Results reveal that thrust rises in a super-quadratic manner dominated by flapping frequency, while swing amplitude improves thrust mildly with a lower power exponent. Synchronous dual-foot oscillation generates the maximum average thrust and lift yet induces violent force fluctuation; a phase difference near 0.3T optimizes propulsion efficiency, raises force duty cycle and restrains lateral disturbance. Compared with the original concave model, the flat-plate counterpart improves average thrust by 11.6% and reduces lateral force by 84.4% with negligible lift drop, verifying that geometric simplification enhances propulsive capacity. Despite superior hydrodynamic efficiency of flat plates, moderately thick skeleton structures should be reserved in practical thruster design for structural integrity and multi-functionality. This study clarifies the biomechanical propulsion mechanism of natural duck paddling and provides theoretical guidance for parametric optimization of bionic webbed thrusters for amphibious UAVs.