Super hydrophobic surfaces find uses in many applications; therefore proper design of super hydrophobic surfaces is very crucial. A lot of work has already been done for static droplets and super hydrophobic surface interactions. There have also been some significant experiments carried out for dynamic droplet impact on super hydrophobic surfaces. The present work focuses on the super hydrophobic surface under dynamic conditions, with the study predominantly carried out through numerical simulation. Various parameters during impact and time variance after impact (typically up to 10 μs) were considered. The transition from water hammer pressure (order of ρCV) to flow pressure (order of 1/2 ρV2) is taken as the main parameter of analysis. During water hammer pressure domain, a strong tendency to cause wetting (Wenzel state) is seen. During flow pressure domain, wetting tendency is significantly reduced (Cassie-Baxter state). These states and the transition from one to the other are very crucial to the design of super hydrophobic surfaces. Hence analyses of pressure regimes are important in designing super hydrophobic surfaces for dynamic conditions. Furthermore, the transition from water hammer pressure regime to normal flow regime is studied. A parametric study is done on this transition of regime.
Simulation of droplet impact on super hydrophobic surface
D. JohnsonRelated information
1 Department of Mechanical Engineering, Indian Institute of Technology, Madras, Chennai 600036, India
, Sarit DasRelated information1 Department of Mechanical Engineering, Indian Institute of Technology, Madras, Chennai 600036, India
Published Online: November 28, 2013
Abstract