solidification
 

I am modeling a solidification problem. That is to say a water film falling along a cooled plate from a length L and a width W, maintained at a constant temperature and on which a layer of ice is formed gradually.
The objective of my work is to determine the thickness of the layer of ice formed in a given time
I do not know how resolver this problem with CFD

There is no built in model for this in CFX. This is a difficult simulation to do. What are you trying to get out of a CFD analysis of it?

I agree with Glenn. CFD may not be the most time effective way to solve this problem. Perhaps you can work out some chiller and storage tank and pump chilled liquid into a think channel to serve as the constant temperature plate.