This study investigates the unsteady aerodynamic mechanisms underlying the efficient flight of birds and proposes a biomimetic flapping-wing aircraft design utilizing a double-crank double-rocker mechanism. Building upon a detailed analysis of avian flight dynamics, a two-stage foldable flapping mechanism was developed, integrating an optimized double-crank double-rocker structure with a secondary linkage system. This design enables synchronized wing flapping and spanwise folding, significantly enhancing aerodynamic efficiency and dynamic performance. The system’s planar symmetric layout and high-ratio reduction gear configuration ensure movement synchronicity and stability while reducing mechanical wear and energy consumption. Through precise modeling, the motion trajectories of the inner and outer wing segments were derived, providing a robust mathematical foundation for motion control and optimization. Computational simulations based on trajectory equations successfully demonstrated the characteristic figure-eight wingtip motion. Using 3D simulations and CFD analysis, key parameters—including initial angle of attack, aspect ratio, flapping frequency, and flapping speed—were optimized. The results indicate that optimal aerodynamic performance is achieved at an initial angle of attack of 9°, an aspect ratio of 5.1, and a flapping frequency and speed of 4–5 Hz and 4–5 m/s, respectively. These findings underscore the potential of biomimetic flapping-wing aircraft in applications such as UAVs and military technology, providing a solid theoretical foundation for future advancements in this field.

In order to better understand the flight performance and kinematics performance of flapping wing aircraft designed and developed based on the principle of bionics, a space crank rocker mechanism was tried to carry out the virtual prototype design of the bionic aircraft in space motion, and on this basis, its movement characteristics were analyzed. Analyzing the flight mechanisms and scale laws of common flying organisms yields various physical estimation parameters that affect flight characteristics. Flight patterns and motion patterns are analyzed based on the design principles of seabirds, and structural designs and mathematical models are established. Secondly, carry out the design of its flapping and transmission structures, and based on this, carry out the overall structural design and establish a three-dimensional model. Here, the kinematics analysis of its flapping amplitude and angular velocity value is carried out by combining its mechanism motion diagram, and the kinematics simulation results are compared with the theoretical results, which proves the correctness of the theoretical analysis and the feasibility of the design structure.