Influence of the Pappus Shape of Bionic dandelion aircraft on Drag Characteristics

摘要

This paper mainly reveals the inherent mechanism how dandelion pappus shape affects the formation of stable separated vortex ring (SVR) and the flight drag characteristics of bionic dandelion aircraft. Firstly, based on the morphometric results of super dandelion seeds and dandelion seeds, the geometric model of bionic dandelion aircraft was established. Secondly, the computational fluid dynamics (CFD) simulation of a single cylindrical pappus, a cuboid pappus and bionic aircraft models with cylindrical or cuboid pappi is carried out. Finally, the simulation results are analyzed and compared with the relevant experimental results. The results proves that the porosity of bionic dandelion aircraft is not the absolute factor to determine the drag coefficient, and the pappus shape is also an important factor which should be considered in the design of bionic dandelion aircraft. The results of this paper can explain how the pappus shape affects the formation of stable SVR and the drag coefficient, which is of great significance for the design of bionic dandelion aircraft.