It has been used for describing bubbling and circulating fluidized beds and spouted beds. MFiX calculations give transient data on the three-dimensional distribution of pressure, velocity, temperature, and species mass fractions. MFiX code is based on a generally accepted set of multiphase flow equations. The code is used as a "test-stand" for testing and developing multiphase flow constitutive equations.

2013 Non-Newtonian Multiphase Flow Slurry Workshop

NETL hosted the meeting at its Morgantown campus from August 19-20, 2013. The objective of this special two-day meeting was to develop a roadmap to address technical issues associated with the handling of non-Newtonian multiphase slurries across various applications managed by Department of Energy's Office of Environmental Management (EM). These include the Tank Farm Project and Waste Treatment & immobilization Plant (WTP) Project, which store, mobilize, and transport slurries at the Hanford Office of River Protection (ORP) in Richland, WA. Please visit the workshop page for additional details.

Challenge Problem Update



The Department of Energy's, National Energy Technology Laboratory (NETL) is pleased to announce the release of a multiphase flow simulation Small Scale Challenge Problem (SSCP-I) based on experimental measurements in a 3"x9"x48" fluidized bed. The purpose of SSCP-I is to improve the reliability of computational modeling of multiphase flows by validating with accurate and well defined experimental data. State-of-the-art experimental techniques will be utilized including high speed particle image velocimetry (HsPIV) for velocity measurements and high speed pressure transducers for pressure data acquisition. Data submissions will be accepted until September 30, 2013 when the experimental results will be released. Please visit the Challenge problem page for additional details.

News and Announcements...




February 11th, 2015
(FE) NETL Researcher to Join Editorial Board of Advanced Powder Technology (APT)


Dear MFIX user,

Dr. Sofiane Benyahia was invited to join the editorial board of APT . This Elsevier journal started as the International Journal of the Society of Powder Technology of Japan and now is expanding world-wide. The journal publishes articles not only on various aspects of powder and particles, but also on all kinds of materials produced from powders. (Sofiane Benyahia , +1 304-285-1373, 670, Computational Science & Engineering Division).

Regards,
MFIX Development Team


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February 3rd, 2015
Workshops on Multiphase Flow Science and NETL Advanced Gasification


Please "SAVE THE DATE" for the U.S. Department of Energy, National Energy Technology Laboratory's (NETL) 2015 Workshop on Multiphase Flow Science. Pending approval, this conference will be held Wednesday, August 12 through Thursday, August 13, 2015, at Lakeview Golf Resort & Spa, 150 Lakeview Drive, Morgantown, WV, 26508.

This event will brings together international leaders from industry, academia and government laboratories in the area of multiphase flow science to discuss current research projects and discuss future research and development needs in the area of Multiphase Flow Science including gas-solid, liquid-solid, gas-liquid, and gas-solid-liquid multiphase flow. Industrial presenters are encouraged to attend and to share their experiences and specific applications in this area.

You are invited to submit an abstract (around 300 words) for a 15 minute presentation, by April 17, 2015 to MFiX Workshop. Final agenda and notification to presenters will follow by May 30, 2015 assuming conference approval. Due to limited time slots available for presentation, the organizing committee will ask the author(s) to either make a presentation or provide a poster presentation.

The conference will cover topics in:

  • Fundamental research in multiphase flows
  • Advancements in CFD model development for multiphase flows
  • Application of multiphase CFD to industrial systems such as gasification, combustion, fossil fuel extraction and utilization, chemical processes, etc.
  • Novel measurement techniques in multiphase flows
  • Uncertainty quantification techniques in multiphase flow simulation

We are also pleased to announce that this year's conference will be held in conjunction with the NETL Advanced Gasification Workshop which is pending approval for Monday, August 10 and Tuesday, August 11, 2015 at Lakeview Golf Resort & Spa, 150 Lakeview Drive, Morgantown, WV, 26508. Therefore, presentations dealing with multiphase flow aspects of gasification and related processes are greatly encouraged for the Multiphase Science Workshop.

The workshop attendance is by invitation only and seating will be limited. Your official invitation and registration link will be forthcoming. Please set this date aside and register promptly. If you have any questions or require more information feel free to contact me at 304-285-4272 or william.rogers@netl.doe.gov

Sincerely,

William Rogers, Ph.D., P.E.
Leader, Multiphase Flow Team
Office of Research & Development
U.S. Department of Energy
National Energy Technology Laboratory
Phone: 304-285-4272
Email: william.rogers@netl.doe.gov



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January 30th, 2015
Modeling and Simulation Tools Complement CLC Lab Work


Dear MFIX user,

An article describing how simulation tools (here OpenFOAM) are used to complement Chemical Looping experiments is featured in the January 2015 issue of Research News, a monthly publication from NETL's Office of Research and Development.



Regards,
MFIX Development Team


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January 9th, 2015
Significant speedup and enhanced modeling capabilities achieved in MFIX


Dear MFIX user,

A significant upgrade has been made to the MFIX-Discrete Element Method (MFIX-DEM) version of the software where a huge speedup has been achieved along with enhanced modeling capabilities to increase accuracy. MFIX-DEM has the ability to track the motion, reactions, and temperatures of individual particles which provides detailed insight into equipment behavior. This modeling technique, aided by the NETL Supercomputer high performance computing platform, can now be used to track tens-of-millions of particles in multiphase equipment used in power generation and industrial processes. A factor of 10 increase in speed has been obtained over the baseline test case (2013-2 release version) resulting from novel algorithms to minimize the frequency of expensive calculations. Furthermore, advanced numerical techniques have been implemented to greatly increase the accuracy of the model predictions. Faster, more accurate simulations make it possible for researchers and designers to increase the pace of transformational energy and environmental R&D with no loss of confidence in the predicted results. This improved version (speedup of 10) will be released in Spring 2015.

DEM Speedup history over 2014. The 2014-1 Release version shows a speedup of 4 and the current develop version shows a speedup of 10.

Regards,
MFIX Development Team


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November 21st, 2014
Presentation at the AIChE Annual Meeting, November 2014 - CFD Model Validation of a Small Scale Carbon Capture Unit


Dear MFIX user,

A presentation was made at the AIChE Special Session: Festschrift for Professor Dimitri Gidaspow's 80th Birthday and Career Long Accomplishments. The presentation describes the use of the MFIX CFD code to support NETL's Carbon Capture Simulation Initiative and detailed validation experiments using NETL's multiphase flow experimental facilities. MFIX predictions are compared to very detailed experiments studying carbon capture using solid amine-based sorbents. Fixed and bubbling bed tests are compared to non-reacting and reacting simulations to validate hydrodynamic predictions and adsorption kinetics. To-date, results compare very well qualitatively, however more accurate values of sorbent properties will be needed for better quantitative comparison. Additional tests are underway to reduce the uncertainty of sorbent property values. A PDF version of the presentation can be found here.

Regards,
MFIX Development Team


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November 5th, 2014
Gasification modeling presented at the 2014 Gasification Technologies Conference


Dear MFIX user,

An NETL researcher presented recent findings from ongoing gasification modeling work at the 2014 Gasification Technologies Conference. The presentation entitled "Computational Fluid Dynamic Simulations of a Pilot-Scale Transport Gasifier Using Mississippi Lignite Feedstock" was co-authored by ORD researchers Tingwen Li and William Rogers; Douglas McCarty of Southern Company Services; and Jenny Tennant of NETL's Strategic Center for Coal. The presentation describes a comprehensive set of detailed multiphase computational fluid dynamic simulations using NETL's MFIX code. These simulations are based on testing performed at the Power Systems Development Facility (PSDF) for the TRIGTM gasifier operating over a broad range of conditions with Mississippi Lignite feedstock. NETL has previously modeled PSDF TRIGTM gasifier performance for both bituminous and Powder River Basin coals and comparison with SCS data has been very good. This work builds on these efforts and uses enhanced MFIX capabilities and the new NETL-based supercomputing facility to create more detailed models to more accurately model TRIGTM performance. With the enhanced meshing capability for dealing with complex flow geometry, detailed feed distributions in the gasification process are fully accounted for in the model to allow investigation of their impact on gasifier performance. The new coal chemistry enhancement to MFIX, called Carbonaceous Chemistry for Computational Modeling (C3M) leverages the kinetic models from leading coal kinetic packages to provide the detailed reaction kinetics in the gasification process for the MFIX gasifier model. Gasifier performance over a range of operating conditions has been modeled to verify the ability of the model to predict parametric behavior. Excellent agreement between model predictions and experimental measurements has been seen over a broad range of operating conditions. These results reinforce the ability of the MFIX code to serve as a tool to help the industrial designers and operators improve the process efficiency and reduce risks in design and operation. The presentation can be found here and an animation of the gasifier simulation can be found here.

Regards,
MFIX Development Team


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October 31st, 2014
MFIXGUI Beta 0.1 Release Annoucement


Dear MFIX user,

We are pleased to announce the first release of the mfixgui (0.1 beta). The mfixgui has been designed to act as a front end tool that allows users to quickly set-up MFiX computational fluid dynamic models, run the developed models, and provide post-processing tools with the goal of making MFiX easy to use. The mfixgui is not required to run MFiX and does not need a valid MFiX source code to function. However, having a valid MFiX source code allows the gui to extract keyword documentation for error checking and documentation.

The GUI is written in pure Python, leveraging the strengths of Python for quick code development, extensive existing libraries, and flexibility. The GUI will run on any operating system that Python can be installed on including Linux, Windows, and Mac. Please see the documentation for further details and dependencies.

The source can be downloaded here.

Note: This is a beta release. As such, bugs are guaranteed. The intent is for the MFiX user community to explore the use of the gui and provide feedback about the design, layout, methodology, features, and bugs. Please send any gui related questions and suggestions to the mfix-gui@mfix.netl.doe.gov mailing list.

Regards,
MFIX Development Team

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October 1st, 2014
MFIX2014-1 Release Announcement


Dear MFIX user,

We are pleased to announce the release of the new version of MFIX (MFIX2014-1). Please visit http://mfix.netl.doe.gov/members/download.php 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 mfix-help@mfix.netl.doe.gov or administrative questions to admin@mfix.netl.doe.gov.

Regards,
MFIX Development Team


Changes from MFIX2013-2 (Date: 09/18/2013) to MFIX2014-1 (Date: 10/01/2014)


Some feature improvements are fairly aggressive and required major changes to the code. As a result, backward compatibility is not guaranteed for either input or restart files. Please contact the development team through the mailing list (See User Guide [1]) if you have difficulties running a previous model with the new release.



New features added:
  • Variable solids density
    • The material density of a solids phase changes as a result of chemical reactions (changing species composition) with the assumption that the solids volume fraction remains constant.
  • DEM Complex boundaries
    • The DEM/Cartesian cut-cell implementation was updated such that boundaries (walls) can be defined through STL files. This change allows for greater geometry complexity with better particle-wall collision detection.

Changes in existing features:
  • DEM code refactoring for better performance gave a 4x speedup compared to the Release 2013-2 (for tutorials/FluidBed_DES with 38,400 particles running in serial.)
  • DEM particle configuration is based on initial condition settings (e.g., IC_EP_s).
  • Cartesian grid cut-cell re-indexing method was implemented to re-order cells when a large number of inactive cells are generated. This provides a more efficient way of looping through computational cells which can substantially speedup the code execution for complex geometries.
  • The make_mfix build script was completely overhauled.
    • Build script was split into several files/scripts.
    • Build settings can be passed as build arguments.
    • Parallel-make build support.
    • Automatic Makefile generation at build time for dependency detection.
    • Each supported system and compiler has its own settings file allowing for easier modification and maintenance.
  • Improved checks for user input
    • Checks on solids model specifications are restricted to the solids model type so that unnecessary data is no longer needed. This improvement applies mainly to DEM and PIC solids models.
    • Error messages are consistently managed based on user input settings. If FULL_LOG is specified, error messages are written the LOG file and sent to std-out. Otherwise, error messages are only written to the LOG file.

Documentation:
  • Updated documents
    • Readme file renamed to MFIX User Guide [1]

Community Involvement:
  • Improved center-line treatment for cylindrical coordinate systems. Bakshi, A., Altantzis, C., Ghoniem, A.F. (2014). "Towards accurate three-dimensional simulation of dense multi-phase flows using cylindrical coordinates," Powder Technology, 264:242-255.
  • A shape dependent particle-fluid drag coefficient was used to create a tutorial for the new user defined drag functions (see mfix/tutorials/usr_drag).
  • Dioguardi, F., Dellino, P., Mele, D. (2014). "Integration of a new shape-dependent particle-fluid drag coefficient law in the multiphase Eulerian-Lagrangian code MFIX-DEM," Powder Technology, 260:68-77.


Project Metrics:
  • Change from 2013-2 Release:
    • 46 files and about 6,000 lines of code were added (net count)
  • 2014-1 Total count:
    • Files: 572
    • Lines: 211,825
    • Blank Lines: 32,272
    • Code Lines: 120,990
    • Comment Lines: 62,139
    • Statements: 87,625

References:
  1. https://mfix.netl.doe.gov/documentation/mfix_user_guide.pdf

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August 13, 2014
2014 NETL's Multiphase Flow Workshop


Dear MFIX user,

On August 5-6, 2014, the U.S. Department of Energy - National Energy Technology Laboratory's (NETL) 2014 Workshop on Multiphase Flow Science was held at Lakeview Golf Resort &Spa, 150 Lakeview Drive, Morgantown, WV. Approximately 60 people attended the meeting, representing industry, academia and federal laboratories- both domestic and international. There were 25 presentations and 5 posters dealing with a broad range of multiphase flow topics pertinent to FE programs and showcasing the use of FE/NETL computational techniques. This regular, annual event brings together international research leaders working in the area of multiphase flow science to discuss current research projects and discuss future research and development needs in the area of multiphase flow science. This year's topics ranged from four-phase dusty plasma flow such as that encountered in the Martian atmosphere to the application of NETL computational models to analyze behavior of Hawaiian volcanoes. Day 1 of the conference highlighted the fundamental aspects of multiphase model development and model validation. Day 2 of the conference included model application and novel experimental techniques. A special emphasis session was provided to showcase the NETL MFIX code and report on additional MFIX capabilities and speed that have resulted from recent increased development efforts. There were two presentations that reported on the use of NETL Multiphase Flow Challenge Problem data. This data was of great benefit to help better understand model performance and diagnose performance problems as reported by participants. One industry presentation provided their feedback on the requirements for multiphase flow models for application to their energy technologies. This information will be of great value to the multiphase research community. Please visit the workshop page for additional details.

Regards,
MFIX Development Team


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September 25, 2013
MFIX2013-2 Release Announcement


Dear MFIX user,

We are pleased to announce the release of the new version of MFIX (MFIX2013-2). Please visit http://mfix.netl.doe.gov/members/download.php 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 mfix-help@mfix.netl.doe.gov or administrative questions to admin@mfix.netl.doe.gov.

Regards,
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.

Documentation
  • 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

References:
  1. https://mfix.netl.doe.gov/documentation/Readme.pdf

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