Unsteady and Flux UDFs for UDSs

tom

I'm completing a simulation in which I incorporate a UDS transport equation. I want to alter the unsteady and flux terms using UDFs. However, to ensure they are correct, I first used the exact UDFs for mass flux and unsteady term as given in the pdf help file for UDFs. However, these "default" UDFs do not give the same results that the default unsteady and mass flow flux setting do when not using UDFs?!?!

In other words, when using the default settings for unsteady and flux in the UDS panel, the scalar will be transported with only the mass flow. But, when I use the UDFs that are supposed to be the same thing, the scalar will move without the mass flow moving.

Has anyone run into the problem or have ideas to what the problem might be?

Thanks, Tom