Research on drag reduction characteristics of the surface of springtail cuticle

Abstract

The technology of underwater drag reduction is one of critical paths to break through the problem of ocean-going, and the bionic drag reduction is a very promising method. The bionic drag reduction uses sliding effect on the liquid-gas interface to reduce the drag, while the gas film is very unstable and the drag reduction function is easy to fail. The concave corner microstructure of springtail cuticle can make the air retention, which has very important significance to solve the problem of instability of gas film. In the paper, a model is established by referring to the concave corner microstructures of springtail cuticle. The k-ε turbulence model and volume of fluid multiphase flow model were used. The results show: the simulation model can be used to calculate the flow characteristics of the concave corner microstructure of springtail cuticle; as the area ratio of free shear increases, so does the drag reduction rate, which is beneficial for drag reduction; the drag reduction rate of different microstructure is slightly different, but it is mainly related to the area ratio of free shear of microstructure.