Computational biomechanics in bio-inspired flights: Aerodynamics, flight dynamics and maneuvering stability

Hao Liu
Chiba University

Insect flight is now an active and well-integrated research area, attracting participation from a wide range of talents. Aiming at developing an effective tool to unveil key mechanisms in bio-flight as well as to provide guidelines for bio-inspired Micro Air Vehicles (MAVs) design, we propose a comprehensive computational framework, which integrates aerodynamics, flight dynamics, vehicle stability and maneuverability. This framework consists of 1) a Navier-Stokes unsteady aerodynamic model, 2) a linear finite element model for structural dynamics, 3) a fluid-structure interaction (FSI) model for coupled flexible wing aerodynamics aeroelasticity, 3) a free-flying rigid body dynamic (RBD) model utilizing the Newtonian-Euler equations of 6 degree- of-freedom (DoF) motion, and 4) flight simulator accounting for realistic wing-body morphology, flapping-wing and body kinematics, and a coupling model accounting for the nonlinear 6DoF flight dynamics and stability of insect flapping flight. The present approach can support systematic analyses of bio-and bio-inspired flight.

Here we highlight computational results of rigid- and flexible-wing aerodynamics of hovering hawkmoth, aerodynamics and flight dynamics of butterfly undergoing take-off, and maneuvering stability of hovering fruitfly. Based on these results and knowledges, we have developed a bio-inspired, flapping wing MAV with a weight of 2.6 g and a wingspan of 10 cm ~ 12 cm. An integrated study of the exile wing aerodynamics is carried out to provide a quantitative prediction of unsteady aerodynamics of the four-winged MAV, which confirms the effectiveness of the clap and flying mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs.