Wake Flow Characteristics of Rotating Beetle Wings

In our efforts to advance bio-inspired flight systems, understanding the wake dynamics and aerodynamic performance is crucial. We focused on the long-horn beetle (Batocera rufomaculata), known for its enduring flight capabilities at low Reynolds number (Re~10⁴). Our study examines fluid-structure interactions pivotal to their performance in a rotating setting akin to current quadcopter UAVs. Using Particle Image Velocimetry (PIV), we conducted flow field measurements on rotating beetle wings to explore the intricate aerodynamics of this motion. We analyzed various Angles of Attack (α) combined with rotational motion to discern their impact on flow dynamics. The near wake flow field was characterized by mean velocity field, vorticity field, Reynolds stress and Turbulent Kinetic energy. Our investigation highlights changes in momentum and energy relative to Angles of Attack (α) within a rotational frame of reference, revealing higher turbulence activity at lower angles of Attack (α). Additionally, employing numerical eduction techniques like Proper Orthogonal Decomposition (POD) and swirl ratio elucidate the formation of flow structures and their correlation with wing aerodynamics. This study offers essential insights into the intricate interplay among wing morphology, kinematics, and fluid dynamics. It aims to advance the design and optimization of rotating-wing UAV systems for enhanced performance and maneuverability across diverse environments.