Effect of the Change of Micro Spike that a Wing has of Dragonfly gives to Aerodynamic at the Gliding Flight

Abstract

In recent years, attention has been paid to the activity of Unmanned Aerial vehicles such as disaster site surveys and home delivery using drones. However, the current UAV cannot fly for a long time because of the influence of viscosity. The application of biomimetics is being considered to improve the performance of UAVs. Dragonflies are known to have high flight performance among flying organisms, and the fine structure existing in the wings of dragonflies is considered to be important. There are some types that can fly over 7100 km by using gliding flight. In this paper, we focused on the micro spike of about 100 μm on the wing surface of the dragonfly and performed computational fluid dynamics on changes in spike height using ANSYS FLUENT. As a result, It was confirmed that increasing the spike reduces the drag coefficient. It is thought that this is because the flow velocity is reduced by the micro spikes, which suppresses the growth of the vortex and reduces the pressure difference. From the above, it was considered that the pressure drag was reduced by the micro spikes. This consideration could be confirmed from the analysis results.