Mechanism analysis and durability evaluation of anti-icing property of superhydrophobic surface

Abstract

In this study, numerical and experimental investigations were performed to analyse the anti-icing mechanism of superhydrophobic surface (SHS) and to evaluate the durability of anti-icing property of artificial SHS respectively. Firstly, by coupling the Level set-Volume of Fluid (CLSVOF) and solidification-melting model, a three-dimensional Computational Fluid Dynamics (CFD) model was proposed to track the morphological changes of droplets, as well to simulate the phase transition process. Then, the freezing process of single droplet on different wettability surfaces was simulated and compared. Results showed that the nucleation position inside the droplet was located at the center of the contact region between the droplet and cold surface. Meanwhile, the temperature change, thermal equilibrium state and solid–liquid interface in droplet during freezing were studied systematically. Furthermore, the freezing delay function of SHS was measured qualitatively and quantitatively by using the solidification/melting cloud and the variations in solid volume fraction, respectively, and the action mechanism on anti-icing properties of contact angle (CA) was revealed by the stable shape of droplet. On the basis of simulation, inspired by the clover leaf bionic concept, we obtained SHSs with anti-icing properties by double-discharge machining of high speed wire electrical discharge machining (HS-WEDM) and evaluated its durability through experiments. Results showed that the anti-icing properties of such surface had mechanical durability and long-term durability.