Learning Forum

[krndv]

Hello,

I am simulating a species transfer in a tank with 8 species. I have attached (image) the source term for 1st species. Please confirm whether I'm doing it right or not? What's the purpose of ds in equation? Is it really required to include it in UDF?

[Rob]

dS is the derivative, and it's use is covered somewhere in the manual. Strictly you can set it as zero but doing it properly can assist in solver stability.
As to whether it's right, work through what you're doing and decide. One think to note, in the above you'll be converting one species to another so you may want a mass source too. If you add a mass source you may want an energy source to make sure it's the right temperature: older versions of the code added mass at 298.15K but I'm less sure on the more recent builds.

[krndv]

Than you. Could you please elaborate on adding mass source? I am explicitly defining source term for all species and initializing the mass fraction of some species which are present in the beginning of reaction. Do I need mass source also?

[Amine Ben Hadj Ali]

If you want to add a mass into system (or extract) you require a source term for the bulk continuity.