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Fluids

Fluids

Topics related to Fluent, CFX, Turbogrid and more.

HPC – Fluent error

    • pv00170
      Subscriber

      I am usisng and HPC to run Ansys fluent. I use a batch which opens the fluent journal.

      Inside the journal is written:

      ;Set the TUI version for Fluent
      /file/set-tui-version "22.2"
      ;Read the case. The default folder
      /file read-case URANS.cas.h5
      ;Set Number of Iterations
      /solve/dual-time-iterate 10 30
      ;Outputting solver performance data upon completion of the simulation
      ;/parallel timer usage
      ;Write out the simulation results.
      /file write-case-data result.cas.h5
      ;After computation, exit Fluent
      /exit

      Everything looks fine, but an error takes place/ I can read inside the error file

      /opt/software/pkgs/ansys/2022r2-fluids_structs/ansys_inc/v222/fluent/fluent22.2.0/bin/fluent: line 2886: 1931186 Segmentation fault      (core dumped) $NO_RUN $CORTEX_PRE $EXE -f $FLUENT_PROD $CX_FLAGS "$CX_FUNCTION"

      and in the output file, at the end

      outlet
      inlet
      geom_surface
      interior-geom_surface
      atm
      fluid-geom_surface
           parallel,
      Done.
      Illegitimate input at /Report; PPTRootTemplateGuid
      Illegitimate input at /Report/ReportItem; PPTSlide
      Illegitimate input at /Report/ReportItem; PPTSlide
      Illegitimate input at /Report/ReportItem; PPTSlide
      adjoint/                parallel/               server/
      define/                 parametric-study/       solve/
      display/                plot/                   surface/
      exit                    preferences/            views/
      file/                   print-license-usage
      mesh/                   report/


      I dont know which PPTSlide is mentioning....
       
      What can I do?
    • Federico
      Ansys Employee

      Hello, 

      what is the command you are using to run Fluent?

      Do you have any report definitions set up in your case file?

      • pv00170
        Subscriber

        Please find the reply attached.

    • pv00170
      Subscriber

      Hi Federico,

      So the following Batch opens the Fluent journal

      #!/bin/bash Before it was #!/bin/sh hope nothing changed
       
      #SBATCH --partition=shared
      #SBATCH --job-name="cubeRANS"
      #SBATCH --nodes=1
      #SBATCH --ntasks-per-node=20
      #SBATCH --time=01:00:00
      #SBATCH --mem=60G
      #SBATCH --output=fltest.out
      #SBATCH -e fltest.err
      # # SBATCH --constraint=avx512 I have removed this since I think it does not exist anymore
       
      ml ansys/2022r2-fluids_structs  
       
      # # MPI_EXEC=/opt/proprietary-apps/Intel_Parallel_Suite/xe_2019_5/compilers_and_libraries_2019.5.281/linux/mpi/intel64/bin/mpirun
      # # MPI_EXEC=/opt/software/pkgs/intel-compilers/2022.1.0/mpi/2021.6.0/bin/mpirun
      # # export MPI_EXEC=$(which mpirun) I have remove this since it is also old
       
      # # FLUENT_ARCH=lnamd64 
      # # export FLUENT_ARCH I dont know if this is necesary
       
      /opt/software/pkgs/ansys/2022r2-fluids_structs/ansys_inc/v222/fluent/bin/fluent -g 2ddp -t 20 -i AnsysJournal.jou
      # # fluent -g 2ddp -t 20 -i AnsysJournal.jou If I use this line is the same as the previous one, isn't it?
       

      Which launches Fluent Journal with:

      /file/set-tui-version 22.2 I have deleted this line, since nothing changes
      /file read-case URANS.cas.h5
      /file read-data URANS.cas.h5
      /file/confirm-overwrite? no
      /solve/dual-time-iterate 10 30 This is the point where it collapses
      /file/write-case Results.cas.h5
      /file/write-data Results.dat.h5
      exit
      yes

      I don’t think the problem is related with the PPTSlide as I could run it using Fluent Wo
      rkbench.


      Yes, I am using Named Expressions and Report Definitions which are used for OUTPUT files.

      Seems like the program loads everything but then just stops. The error is still:

      /opt/software/pkgs/ansys/2022r2-fluids_structs/ansys_inc/v222/fluent/fluent22.2.0/bin/fluent: line 2886: 387716 Segmentation fault      (core dumped) $NO_RUN $CORTEX_PRE $EXE -f $FLUENT_PROD $CX_FLAGS “$CX_FUNCTION”

       

      • Federico
        Ansys Employee

        I believe this error is related to a graphical issue. Are you connecting remotely to a machine?

        Also, not related to the error but in this line: /opt/software/pkgs/ansys/2022r2-fluids_structs/ansys_inc/v222/fluent/bin/fluent -g 2ddp -t 20 -i AnsysJournal.jou

        try removing the space after -t to make use of the 20 nodes. It should read -t20.

         

        • pv00170
          Subscriber

          Yes, I am accessing remotely using MobaXterm (that works with Putty)

          Do you think the problem could be related with any of these two of the Batch?

          Since I am not using the constraint nor the mpirun

          # # SBATCH –constraint=avx512

          ps: I have changed the -t20

           

        • Federico
          Ansys Employee

          Ensure that X11 forwarding is enabled. If accessing through Putty, under the menu 'Connection'->'SSH'->'X11' and tick to enable.

        • pv00170
          Subscriber

          Yes, the X11 forwarding is enabled.

    • pv00170
      Subscriber

      When I try to run it using PyFluent (script) instead of the HPC (Sbatch + script) it works well. 

      The pyFluent script is similar:

      import ansys.fluent.core as pyfluent
      solver = pyfluent.launch_fluent(precision=”double”, version=”2d”, processor_count=6, mode=”solver”)
      solver.tui.file.read_case(‘URANS.cas.h5’)
      solver.tui.file.read_data(‘URANS.dat.h5’)
      solver.tui.define.models.unsteady_2nd_order(“yes”)
      solver.tui.solve.dual_time_iterate(1, 2)
      solver.tui.file.write_case(‘Results.cas.h5’, overwrite=True)
      solver.tui.file.write_data(‘Results.dat.h5’, overwrite=True)
      print(“Done!”)

      The only difference is that HPC fails to compile whereas pyFluent works.

    • Federico
      Ansys Employee

      Can you try this?

      You will need to have a graphics node with a certified, professional graphics card with the latest driver installed on the remote machine.

      https://www.ansys.com/-/media/ansys/corporate/files/pdf/solutions/it-professionals/platform-support/graphical-display-graphics-cards-tested-19.pdf?la=en

      On the graphics node, you will then be able to launch Fluent or any Ansys application interactively.  You will also need to use one of the Remote Display tools that Ansys supports. Please see below for more information about Remote Display and Graphics

      Requirements.

      Remote Display Requirements

      https://www.ansys.com/-/media/ansys/corporate/files/pdf/solutions/it-professionals/platform-support/remote-display-and-virtual-desktop-support-19.pdf?la=en

      • pv00170
        Subscriber

        .

      • pv00170
        Subscriber

        Thank you, now it is solved!

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