Numerical and Experimental Investigation of the Role of Flexibility in Flapping Wing Flight

Abstract

†The role of flexibility in flapping wing flight is explored using dynamically-scaled experiments and numerical simulations. To limit the dimension of the parameter space, the target of study is a two-dimensional two-component wing connected by a hinge with a torsional spring. The motion of the lead body is prescribed with flapping kinematics, while the trailing body motion is passive. Experiments are conducted in a water tank, enabling flow visualization with suspended particles. Numerical simulations rely on the viscous vortex particle method (VVPM) for coupled fluid-body dynamics. In both the experiments and the computations, the behavior of the wing is characterized by monitoring the evolution of the hinge angle, with favorable agreement between them. Flow structures are identified and compared for representative cases. Analysis of lift force and energy consumption from numerical simulations indicates that wing flexibility can improve wing performance when measured in terms of energy spent per unit lift.