Hi I'm solving a case but the UDS concentration always becomes negative. How can I set solution limit (min. 0) for it? thx.

Can anyone here help me?

[c_023]

Reviving this thread because I am wondering about that, too.
Is there a way of Setting solution Limits to a UDS equation? Maybe through a TUI command (using Fluent 19.3). I am sure that is a common problem and there exists an easy solution..

Thanks in advance.

[c_023]

Nobody ever came across this Problem?

[vinerm]

Actually, it is fairly easy to implement. The way is already given in solidification-melting model; the source term.

Define a source for the UDS based on upper and lower limits that you want. Check if the value is beyond the limits and then multiply the difference between actual value and the bound by a large number, that's what constant in S-M model does, and apply it as a source.