It is a material property according to the developers. But I have never found one.
So it must be done experimentally. Equations are in the help to guide the experiments or simulations. Including the relationship to heat transfer coefficient.
Strong considerations must be made for changing flow conditions and relationship to the value based on the experiments.
We have never successfully found a way to come up with a generic value for all cards for a specific pours medium, even having worked with the developers.
Do you have a link to the guide?
hi, its just the helpfile
open a file
help > simulation > flow help