MFiX 20.3 Release Announcement

We are pleased to announce the MFiX 20.3 release. Please visit the download page to 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:

  • DEM Polydispersity [1]: Ability to specify a particle size distribution (PSD) within an initial condition region or along a mass inlet boundary condition. Current PSDs include:
    • Normal distribution
    • Log-normal distribution
    • Custom (user-defined through a text file)
  • New DEM particle initialization options: Provides more flexibility when initializing particles.
    • Lattice style: Users can choose between a hexagonal packing (default setting) and a simple cubic lattice packing (this was the only option in MFiX 20.2 and prior versions). The hexagonal lattice can achieve a denser packing than a cubic lattice.
    • Lattice spacing: Scaling factors are now available for particle spacing, either globally in all three directions, or specifically along x, y, or z axis.
    • Spatial randomness: Users can now specify random positional shifts in the lattice structure.
    • Amount of particles: Users can now specify either the solids volume fraction, number of particles, or mass of particles per phase in a given initial condition region.
  • Histogram view: Output data (any variable in vtu and vtp files) can be viewed as a histogram. Useful when looking at particle size distribution.
  • New particle_input.dat format. The new format allows to specify which variables are read from the file. The old format is still supported for backward compatibility.
  • Added option to update the DEM solids time step at regular intervals.
  • Added option to specify starting and ending time of DEM mass inlets.
  • Added two hopper tutorials to illustrate the DEM polydispersity capability.


[1] Chen, S., Adepu, M., Emady, H., Jiao, Y. and Gel, A., 2017. Enhancing the physical modeling capability of open-source MFIX-DEM software for handling particle size polydispersity: Implementation and validation. Powder Technology, 317, pp.117-125.