Ansys Employee

You may need to switch to a 3d sector and have a look at the wall film models. Otherwise you're relying on the DPM out files to see how much mass hit where to see what film/build up is formed. I'm not quite sure what you mean by which part it should be applied to: surely the wetted surface that's where you want to measure the number of hits? 

I suggest going through a few tutorials, and post a few images. Not least we we can see what you're looking at and why there's a nonconformal interface in the domain.