MFiX 21.2 Release Announcement

MFiX 21.2 Release

Dear MFiX user,

We are pleased to announce the MFiX 21.2 release. Please download the latest version. See the release note below that highlights the changes from the previous version.

Please visit the MFS forum for any software related questions, or send administrative questions to

The MFiX Development Team

New features:

  • Ability to specify a constant Coarse Grain particle size for each solids phase in Coarse Grain DEM simulations.
  • Reaction rates can now be saved directly in vtu (cell data) and vtp (particle/parcel data) files, without the need to write any code.
  • The particle_input.dat file (used as initial conditions for DEM) and the particle_output.dat file (written at the end of a DEM simulation) can both be filtered based on particle coordinates and variable values (diameter, density, velocity, temperature, species and user-defined variables).
  • Ability to save force chain data in vtp files.


  • Improved data check for species thermochemical properties (specific heat coefficients and molecular weight) to avoid setting simulations with zero values.
  • More robust initial particle temperature and species settings in DEM simulations.

Notable bug fixes:

  • Fixed Restart_2 simulation after copying files to a new directory.
  • Added consistent update of ROP_G in PIC simulations.
  • Various segfaults occurring when arrays where not properly allocated or accessed were fixed. This includes a segfault in SRIVASTAVA friction model, SCALAR_NODE_ATWALL not allocated when reading mesh during a restart, and an invalid memory reference to AREA_CUT.