[Quinos]

I am trying to write a UDF to describe mass transfer between phases. One website (http://aerojet.engr.ucdavis.edu/flue...udf/node57.htm) says that DEFINE_MASS_TRANSFER returns units in kg/m^3. However, when describing the example code, it also says that, "The following UDF, named liq_gas_source, specifies a simple mass transfer coefficient based on saturation temperature."

I thought that mass transfer coefficients were in the units of m/s, not kg/m^3. What exactly is DEFINE_MASS_TRANSFER supposed to return?

Thank you for any help.

[pakk]

To add a third option: my version of the help says:

Your UDF will need to return the real value of the mass transfer to the solver in the units of kg/m^3/s.

I never used it, so I don't know what is true.