Visualization of Vortex Structures Around a Flapping Wing Considering Ground Effect

Abstract

During recent decades, the understanding of the aerodynamic of flapping flight has been paid much attention by studying two flight modes, namely hovering and forward flight. However, there has not been much attention on investigation of the aerodynamic characteristics during the take-off of an insect. In the previous study, we found that Rhinoceros beetle, Trypoxylusdichotomus , takes off without jumping, which is uncommon for the other insect. In this study, we built a scale-up electromechanical model of the flapping wing and investigated fludi flow around the beetle's wing model. It noted that the effect of ground surface could be significant during the take-off. In particular, the present dynamically-scaled mechanical model has the wing kinematics pattern achieved from the real beetle's wing kinematics during the take-off. In addition, we systematically could change the three-dimensional inclined motion of the flapping model through each stroke. We used a digital particle image velocimetry (DPIV) with a high spatial resolution and could qualitatively and quantitatively study the flow field around the wing at Reynolds number of around 10,000. The present results provide an insight the understanding of aerodynamics and the evolution of vortical structures as well as the ground effect for beetle's wing during take-off. This is useful for researcher in developing a micro air vehicle that have a beetle-like flapping wing motion.