A Computational and Experimental Study of Flexible Insect-based Flapping Wing Aerodynamics and Structural Deformation

Abstract

Combined flowfield and structural deformation experiments, in conjunction with a coupled computational aeroelastic analysis, were performed for well characterized, low-aspect ratio, insect-based flexible flapping wings at micro air vehicle (MAV) scale. Two-component time-resolved particle image velocimetry (PIV) measurements were performed to determine the evolution of the vortical flowfield about the wing. Additionally, a VICON motion capture system was used to track the passive wing deformations throughout the course of a flap cycle. The experimental flowfield and deflection measurements were compared against the results of the coupled computational fluid dynamics - computational structural dynamics (CFD-CSD) model. The CFD analysis was conducted using an unsteady Reynolds-averaged Navier–Stokes (URANS) solver and the CSD analysis consists of a general purpose multibody dynamics solver capable of modeling geometrically nonlinear beam and shell elements. Overall, the CFD-CSD results showed good agreement with the measured experimental flowfield and wing deformation data. Additionally, the coupled CFD-CSD solver was used to determine the effect of varied chordwise flexibility on the aerodynamic forces and flowfield. For the cases analyzed, decreasing chordwise flexibility was seen to significantly increase aerodynamic lift with minimal impact on aerodynamic drag. Aeroelastic tailoring of the wing may be used to improve wing performance and efficiency.