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MFIX2013-2 Release Announcement

Dear MFIX user,

We are pleased to announce the release of the new version of MFIX (MFIX2013-2). Please visit to download the latest version. Please see the release notes below that highlight the changes from the previous version.

Please send any software related questions to or administrative questions

MFIX Development Team

Changes from MFIX2013-1 (Date: 03/06/2013) to MFIX2013-2 (Date: 09/25/2013)

New features added:

  • Stiff chemistry model
    • The stiff chemistry solver was completely overhauled to eliminate any user coding. This capability can now be activated with a single keyword.
  • Point Source
    • The ability to specify mass inlet point source anywhere in the domain was added. This can be useful when modeling a small side inlet, without having to resolve the actual geometry.
  • Subgrid models
    • The two-fluid Igci and Milioli filtered models were implemented and can be activated by new keywords.
  • DEM cluster detection
    • An algorithm to detect clusters and collect information was implemented.

Changes in existing features:

  • Parallel execution
    • The SMP directives have been updated in key-subroutines. The SMP compilation options (including hybrid SMP+DMP) have been turned back on. Please note that the reported CPU time may be inaccurate in SMP mode.
  • Bug fixes and enhancements
    • Cyclic boundaries with pressure drop: flags CYCLIC_AT_E/N/T were corrected.


  • Updated documents
    • Readme file [1]

Under Development:

    • Variable solids density
      • Ability to have solids density vary as a function of species composition (Eulerian/Eulerian solver)


Project Metrics:

  • Change from 2013-1 Release:
    • 13 files were removed due to stiff-solver overhaul (net count)
  • 2013-2 Total count:
    • Files: 526
    • Lines: 195,755
    • Blank Lines: 26,750
    • Code Lines: 116,321
    • Comment Lines: 56,292
    • Statements: 85,702