[cp703]

Hi. In an attempt to determine how well ANSYS/CFX deals with scenarios were surface tension effects play a significant role in fluid flow, my adviser has suggested that I first try to model a large droplet of water on a surface and vary the contact angle. To do this, I have scoured the ANSYS tutorials and the internet (to be honest, most of the useful information has come from the cfd-online.com forums...). I created an air/water fluid domain (in the shape of a rectangular prism) with the walls all having a no slip wall boundary condition. I defined an initialized water volume fraction in the shape of a sphere near the "bottom" (in terms of the direction of gravity g in the -y direction) of the domain. After including all the surface tension effects (including specifying the wall contact angle in the wall BC), there doesn't seem to be any difference in the shape of the droplet when I change the wall contact angle.

After investigating problems that people have had with free surface models and taking into account surface tension, etc. I feel like I've covered my bases: I have the multiphase free surface model turned on and the free surface model turned "on", the surface tension coefficient specified for water in air, the surface tension model set to "continuum surface force", turned on and then off the volume fraction smoothing, changed the curvature under relaxation factor, etc.

I really feel like I am missing something. Is this a silly thing to try in CFX? Am I going about it totally wrong?