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  1. Which pre- and post-processor should I use?


    Gambit is the default pre-processor of FLUENT solver. With the upgrading to Fluent 12, Workbench is recommended by the software developer as the pre-processor.

    For post-processing, you can either use the build-in post-processor of Fluent or CFD-Post. You can also export the result to a neutral file and visualise it with EnSight, a powerful 3D visualisation software that is also available to use.

  2. Where can I run the interactive pre- and post-processor?


    You can run the interactive Gambit, Workbench, Fluent and CFD-Post  at MobileVisLab or an Xterm window of Cluster_AtlasX from HPC Portal --> Run Jobs/Apps.

  3. How to run the pre-processor Gambit and Workbench?


    Gambit and Workbench are graphics intensive modeling tool. You are recommended to run the two software interface on MobileVisLab.

    To start Gambit interface, just enter "gambit  &" at the command prompt. This will start Gambit session using default database name default.dbs.

    To start Gambit with an existing dbs file, you can enter command as "gambit -id xxx", where xxx is the session/database file name.

    To start Workbench, enter command “workbench &” at the command prompt.

  4. I cannot open gambit session, the message I get is similar as ".... the gambit session default_id is currently open...". What should I do?


    This is because the previous gambit session was not exited properly, thus a lock file was generated. Please go to the gambit working directory (normally, is the directory where you enter gambit command) and remove the lock file via the following command and then try again:

    >  rm  -f  *.lok

  5. Where can I find Fluent and GAMBIT tutorial files to practice the tutorials?


    To access the tutorial files, you need logon to any HPC host. The Fluent tutorial files are saved in folder /app1/common/Fluent.Inc/fluent6.3.26/help/tutfiles/. Please copy the needed files to your own space for practice. To unzip the files, use command "unzip  filename.zip".

    GAMBIT tutorial files are saved in folder /app1/common/Fluent.Inc/gambit2.3.16/help/tutfiles/. Please copy the needed files to your own directory for practice.

  6. Where can I run the solver and How?


    You can run the FLUENT solver interactively at MobileVisLab or Cluster_AtlasX (from HPC Portal --> Run Jobs/Apps) for small jobs.

  7. Where can I run batch Fluent solver and How?


    For large and long hours FLUENT simulation jobs, you should submit the jobs to batch queues for batch computing. Check the FLUENT Parallel Computing part for more details and instructions.

  8. Where can I run parallel Fluent solver and How?


    When your FLUENT model is too huge and needs hours, days or even a couple of weeks to complete, you should submit the jobs to batch queues and run batch parallel computing FLUENT solver to speed up the simulation. Check the FLUENT Parallel Computing part for more details and instructions.

  9. How to run the post-processor?


    FLUENT interface includes the post-process tool. You can visualize the results from the pull down menu of "Display" and "Plot".

    You can also use CFD-Post to visualise the Fluent result. CFD-Post comes with a better animation functions and is easy to use. To start CFD-Post, enter command "cfdpost  &" at the command line prompt.

  10. How to couple my UDF with FLUENT?


    FLUENT User Define Functions (UDF) shall be written in C language. A good way to start trying of UDF is to check FLUENT documentation at UDF Manual --> Examples. You can copy and modify the example UDFs if they are relevant.

  11. Why my Fluent batch job fail though I am sure the script and model are correct?


    The Fluent script created on Windows/DOS may not work properly when you use the script file for the batch Fluent jobs. For example, you may notice the following Error message in the LSF job std output:

    Error: eval: unbound variable
    Error Object: 20
    Invalid integer.

    Under this situation, you need to check and convert the script file from a Windows/DOS text file into a Unix/Linux text file. For example, you can do the following on a Linux command line prompt:

    > file run1.txt
    run1.txt: ASCII text, with CRLF line terminators

    > dos2unix -o run1.txt
    dos2unix: converting file run1.txt to UNIX format ...

    > file run1.txt
    run1.txt: ASCII text

    Once you convert the file into a purely "ASCII text" file without the “CRLF line terminators”, you can submit the job again and it should work fine.

  12. Why I cannot compile my UDF code though I am sure the syntax is correct?


    When you encounter the following Error during the compilation of your UDF in Fluent:

    Error: velocity.c: line 2: syntax error.

    it may indicate that the UDF file format is not properly set. You can correct it with the method mentioned in the previous question.

  13. How to check the license usage of FLUENT and GAMBIT?


    You can use the following command to check the FLUENT/GAMBIT license usage.

    >      fluent -use

Last Modified on 26th August 2010. Copyright - All Rights Reserved.

 

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