Can't find out the cause of non-convergence

MFiX
#1

My case is a very simple fluidized bed reactor, the particle size is about 0.13mm. So I want to use MFIX-PIC to simulate the particle fluidization without chemical reaction. But MFIX always report “DT < DT_MIN” error after a very short simulation time (between 0.007-0.18 s).

1
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I have tried the method suggested in the User Guide or other topics, but the problem still remains.
So, I don’t konw which part in my case should be modifed.
Any help would be greatly appreciated!
cold_stage_2024-09-22T133021.287323.zip (4.9 MB)

#2

Please try to turn Explicit coupling (Solids>PIC>Advanced tab) to see if it helps.

1 Like
#3

Thank you so much jeff !!! :laughing: :laughing:
I tried to enable Explicit coupling, and yes !!! the case did not report “DT < DT_MIN” again.
but I’m very curious about this option, can you tell me why my case should to turn this option on? or what kind of situation does this option apply to? if I couple with some chemical reactions in this case, can this option still be turned on?