Hi Everybody,

I am doing dye injection simulation in water channel with CFX 10. I am using additional variable approach with defining dye as scalar has unit kg/m^3. I am injecting it at a certain point for 1 sec at 0.01 kg/s rate. After this injection I am running it again 20 sec to see how dye moves and to see concentration changes. In CFX post I am creating a point and then a chart of dye vs time at that point. What I am getting is, kg/m^3 vs sec graph. My question is, does this chart show dye concentration at that point with that much of kg in 1 m^3 water? Or to get concentration value, do I have to define anything in CFX pre? Could you please make this point clear?

Thanks alot,

Mike

Dear Mike,

What kind of Additional Variable are you using? Specific, or Volumetric..

For an Specific AV, the ANSYS CFX solver will write 2 fields to the results file:

- dye <-- Should be dimensionless - dye.Volumetric <-- Units of concentration

For an Volumetric AV, it will write

- dye <-- Should be in concentration units kg/m^3 - dye.Specific <-- Should be dimensionless

Then, in CFX-Post, you will plot the concentration based on your setup..

Good luck, Opaque

Dear Opaque

Thank you very much for your help. I used volumetric, thus dye is in kg/m^3 and shows concentration. And this is kg dye concentration per m^3 water (or water + dye) at that point. Am I right?

Thanks again,

Mike