Learning Forum

[valparadiso12]

Hey community,

I am working on a mixing simulation in a stirred tank. First, I set up a transient, single-phase flow simulation and let it run for 10s. Then I run a mixing time simulation (species transport with a tracer with same properties as water) on it. As a result, I get unlogical long mixing times. When my colleague is doing it on her computer setting up the exact same flow (we checked that several times), she gets better results. When she gives me her simulated flow case and data files and I run the mixing time simulation on them, then I also get good results. So, there must be something wrong with my flow simulation (not the mixing time simulation), again, its the same setting as my colleagues.

So my question is, are there any background settings of Fluent which might be different on her computer compared to mine? Do you have any ideas on what we could check? It seems very weird to me that the same model gives different results. Maybe someone here had experienced something similar before?

Thanks for your help!

[RK]

Hello,
May I know which version you are using? Are you both using Windows or Linux? How many solver processes? Make sure you both are using double precision.

[valparadiso12]

Hey,
thanks for the answer. We are both using Fluent 2021 R1 on Linux. Both are using Double precision and 2 solver processes.
Any other idea what it could be?

[RK]

Since you are getting good results from the case setup from your colleague, I am assuming there is some setup you missed. As a test, you can ask your colleague to write out the case settings (you can use the TUI command), open the case file settings using a text editor to make sure what setting you missed or if it is the same.

[Rob]

Classic mistakes are having air instead of water and mm instead of m. Check materials (try and delete air) and scale.