Reply To: Volume Fraction too Low. How to Improve?

[Rob]

You've got it - the reference values are nearly always a problem. The other issue is the "other" temperature used in literature/correlations as opposed to the Fluent model. There's even the lack of the solid conduction effects in some cases: you're reporting a h value but possibly comparing with U. 

CFF's can be used, the issue can be how to get the various temperatures into the equation as they're done on a cell basis. Expressions may work as you can return area average values and use (some) local values. The "best" approach is often to extract raw data from Fluent (flux, temperature etc) and use a spreadsheet or similar: that way you control the refrence values.