3D SIMULATION OF DROPLET IMPACT ON STATIC AND MOVING WALLS

In the present study, the contact angle model and the origin of the parasitic current, precisely, the relation of the parasitic current with grid distribution, have been studied to accurately predict droplet impact on static and moving walls in the volume of fluid (VOF) framework. The authors have quantitatively shown that the number of neighboring cells of the central cell influences the gradient calculations regarding the generation and spatial distribution of parasitic current. Accordingly, the polyhedral cell structure provides smoother interface gradient distribution than the Cartesian grid structure. After implementing a modified Kistler contact angle model in OpenFOAM and using the polyhedral grid for the simulations, we could accurately validate transient droplet shapes formed upon impact with those obtained from experiments. Droplet outcomes obtained, such as deposition, partial rebound, and split deposition on stationary and moving smooth surfaces, are consistent with experimental results.