Learning Forum

[pv00170]

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]

Hello, 

what is the command you are using to run Fluent?

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

[pv00170]

Please find the reply attached.

[pv00170]

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]

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]

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]

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

[pv00170]

Yes, the X11 forwarding is enabled.

[pv00170]

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]

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]

.

[pv00170]

Thank you, now it is solved!