Thanks for sharing your results. This appears to be the same topic as Error in MFiX results - #11 by mohsenclick
A few comments/suggestions:
- It is misleading to say mfix-2013.1 and mfix-2021.4 don’t give the same results because you are not actually using mfix-2013.1, it is a modified version. If you are still in touch with M. R. Haghgoo, please inquire if the code was modified to fix a bug or to improve the model.
- The first step would be to run the unmodified mfix-2013.1 version and compare with the unmodified 2021.4. I believe you will do this next.
- The asymmetry you see with 2021.4 could very well be a bug. It could also be that it takes longer to reach pseudo-steady state with the original code than with the modified code.
- Have you tried to run a 2D simulation? This may be faster to troubleshoot.