Reply To: How to improve the convergence of the EWF model?

[Rob]

The model uses the wall shear to calculate film motion. But it's also a thin film model. This can mean trying to get a y+ =1 mesh means the cell is thinner than the film. That then causes problems with phase change as the source terms are added to the near wall cell. 

In regions where the film is thin-nonexistant there's no liquid to absorb heat which may explain the temperature issues. If you tighten the limits too much any excess heat (or cold) is thrown away, that tends to give unrealistic results and may prevent the solver reaching a stable solution. 

There is some of the maths for EWF in the LWF section of the manual - that has been raised before to the DOC team. 

The wall function won't alter the wall film mass transfer. However, it may effect the rate a species reaches the wall which may then effect how the film forms.