Dear MFIX user,
We are pleased to announce the release of the new stable version of MFIX (MFIX2007-4). Please visit https://mfix.netl.doe.gov/members/download.php to download the latest version. Please see the attached release notes that highlight the changes from the previous version.
Please send any software related questions to mfix-help@mfix.netl.doe.gov or administrative questions to admin@mfix.netl.doe.gov.
Regards,
MFIX Development Team
Changes from MFIX2006-4 to MFIX2007-4 (Date: 12/31/2007)
Changes in existing features:
- Significant bug fixes were made to the DEM model implemented in MFIX (see log listing at [1]). Most of the modifications were made by Rahul Garg at Iowa State during his summer internship at NETL. Here is a brief summary of the changes:
- Number of bug fixes and enhancements were made to handle general multiparticle mixtures with varying density as well as particle size
- The code has tested 2D and 3D capability
- Added/modified some test cases and tutorial cases. The test and tutorial cases are benchmarked and the summary tables are located in respective directories.
- Several bug fixes and please have a look at the log history for a more detailed list of changes at [2]. Some notable ones are:
- Fixed an error in the calculation of the enthalpy transfer because of mass transfer
- The divergence terms are called consistently when solids viscosity is a constant
- Bug fixed for wall cells that may be tagged as fluid in cyclic cases
- Changed old-time velocity V_s0 to current velocity U_s, V_s and W_s in calc_s_ddot_s. This will accelerate convergence.
- Moved read_database call from check_data_01 to check_data_06
- Updated equations document [3]
- Updated Readme - part of the distribution and readily available from [4]
New features added:
- The following additions were made to the DEM code [5]:
- A new and efficient cell linked list based search algorithm has been implemented and tested in 3-D DEM simulations
- Added an interpolation suite that can be turned on to calculate the individual drag forces on the particles based on particle locations rather than cell averages
- Added a small tool to generate input deck for DEM cases for multiparticle mixtures in mfix/tools/DES_Particle_Generator/
- Make file has following additions
- Option to compile using g95 under Cygwin
- Modified the selection table under 32 bit compilers, instead of multiple questions for versions of Intel compiler etc., everything is under single list similar to 64 bit compiler options
- Have an option to link dgtsv if machine optimized libraries are available
- The make_file has additional options for CRAY XT3/XT4 systems
- Modifications to make an optimized scalable version of MFIX for large parallel machines
- The residual calculations are collected into 4 calls for every iteration
- The dot-products in BiCGStab are reduced by almost 50%
- Additional preconditioning (alternating sweep directions) and solver options (CG, SOR) have been added
- Additional tools to collect statistics about scalability and load-balance
References
- https://mfix.netl.doe.gov/cgi-bin/cvsweb.cgi/mfix/model/des/#dirlist
- https://mfix.netl.doe.gov/cgi-bin/cvsweb.cgi/mfix/model/#dirlist
- S. Benyahia, M. Syamlal, T.J. O’Brien, “Summary of MFIX Equations 2005-4”, From URLhttps://mfix.netl.doe.gov/documentation/MfixEquations2005-4-3.pdf, July 2007.
- https://mfix.netl.doe.gov/documentation/Readme.pdf
- The MFIX-DEM document is currently being updated and the DEM mailing list will be informed as soon as the document is available.
