breakup model for cleaning processes

Tim

I would like to simulate a cleaning process with CFX. The idea is to define particles at the walls of the fluid region and to show, how they are effected by the fluid and transported to the outlet. The next step would be to realise breakup conditions. I read about all the primary and secondary breakup models in CFX, but I have problems to realise it. The particles should keep their position at the wall. If the (drag) forces are big enough the fluid should effect them. Has anyone a idea, which breakup model is adequate for this?