• Why do you expect the water to be 80-90C if the wafer is 65C? Are there other sources?
  • Are there multiple phase or fluids where we need to keep track of the interface between them?  That is what the VOF model is good for. If not, and we have just liquid water, then we do not need VOF.
  • If you want the temperature distribution in the glass, then you will need to include it in the model. The solid will not have to have such a fine mesh as the fluid domain as it is only solving conduction here.
  • In your first post you mentioned that you were not seeing convection. My question was related to how you were judging that. To me, the first place I would look would be the temperature field.

EDIT: I would really recommend that you work through the exhaust manifold tutorial. Don't focus on the meshing part (unless you plan on using Fluent meshing), but understand the basics of setting up the model and the theory behind why we chose what we chose.