Rob
Ansys Employee

You also need to factor in the force from the surface contact at that scale. The surface tension normally has a local effect on a bulk flow. At this scale the surface tension dominates everything, and that will lead to a stiff solution needing a small time step. You may also find that parallel is less efficient as the free surface may only be present in very few of the partitions: load balancing will help. 

The time step is going to need to be small to get an accurate result.