Simulation and Experimental Study on Droplet Impact Rebound Behavior on Stainless Steel Surface

Abstract

The droplet impact rebound behavior is one of the most direct ways to study the hydrophobicity of materials. Different from the previous study, a series of groove structures with the same groove to the column ratio and the column height but various width sizes were constructed on the 316L stainless steel surface. The volume of fluid (VOF) method and experiments were used to observe the morphological evolution process of droplets impacting on the surface of this series of 316L stainless steel grooves at the same speed. The simulation and experimental data reveal that the grooved structure on 316L stainless steel surfaces markedly enhances the rebound coefficient of droplets and diminishes the spreading coefficient as compared to the smooth surface. The maximum rebound coefficient of the groove structure surface with the width of 100 μm increased the most by 2.093, the maximum spreading coefficient of the groove structure surface with a width of 200 μm decreased the best by 0.805, indicating that the establishment of groove structures significantly improves hydrophobicity. At the same time, as the groove width increases from 50 to 300 μm, the wetting state of droplets on the stainless steel groove surface gradually changes from the Cassie Baxter state to the Wenzel state, and the rebound coefficient decreases with transformation of the wetting state, but the spreading coefficient is not affected transformation of the wetting state.