Design and aerodynamic characteristics analysis of ultra-small bionic butterfly flapping-wing aircraft

Addressing the challenges of aircraft stealth and power efficiency, this paper presents the design of an ultra-small bionic butterfly flapping-wing aircraft. By referencing the wing morphology of Hypolimnas bolina (black-striped mimic butterfly), a dual-motor drive mechanism was developed. Through SolidWorks modeling and Ansys Fluent simulations incorporating dynamic mesh technology with User-Defined Functions (UDF) for wing-flapping motion, the influence patterns of critical parameters, including wing attack angle and flapping frequency, on aerodynamic performance, were systematically investigated. A lightweight design approach combined with 3D printing technology enabled the fabrication of a prototype weighing 8.2 g with a maximum wingspan of 280 mm. A test platform is constructed to conduct flapping experiments. Flight tests demonstrated stable indoor operation with 2-minute endurance, though resistance to airflow disturbances requires further improvement. This study provides technical references for the miniaturization of bionic butterfly flapping-wing aircraft.