Reply To: Strange Divergence in natural circulation simulation simulation using VOF

[Rob]

Read the background for wall boiling models: you don't want to overrefine the near wall region. The other problem you've got now is the cell aspect ratio. Inflation is great for aero type models with no change in the streamwise gradients, they're a liability in multiphase as they're just a very high aspect ratio cell in precisely the wrong place. 

Now, if your domain is initially full of water, and you boil that. Where does the volume go/come from in the model? In reality you may compress something or deform the casing, in CFD if you've not set material properties it's not going to do what you expect.