The TFM-DEM hybrid is not supported and is in no way guaranteed to work. There is code in the solver to run hybrid simulations, and there is also code present in the GUI, which is disabled. We do not encourage creation of new TFM-DEM hybrid models but the GUI will automatically enable the Hybrid mode if it finds a Hybrid model.
To access this “hidden” feature - create a new case from the “blank” template. In the “Model Setup” pane, Set “Solver” to “TFM”. In “Solids”, create 2 solids phases. Then save the file and exit.
Now, in an editor, open the .mfx file and change the solids_model for the second solid from TFM to DEM. Save the file and restart MFiX. You will now have the Hybrid mode enabled.
This is not guaranteed to work and we can only offer limited support for the hybrid model at this time - it is not under active development.