Feed concentration
 

Hi CFD users, I am among the 'few' who are still using CFX4. I want to introduce some liquid solution into the bulk fluid, in a main pipe (single phase). I know that I can either use a USER3D patch... USERSCALARS or or a routine like USRSRC. I have chosen the USER3D option. However there are a few things I am not sure of:

1.Does it matter whether I introduce it as inlet (set under boundary conditions) or source (set under sources)? 2.How do I specify the concentration?

Many thanks for reading this. Diu