ANSYS FLUENT

This document provides basic information for using ANSYS FLUENT on the 5th system. Therefore, it does not include instructions on using ANSYS FLUENT software or the 5th system/Linux. For information on using the 5th system/Linux, please refer to the Nurion user guide available in the resources section of the KISTI website (https://www.ksc.re.kr). (updated: 2023. 11)

A. Usage Policy

• A single user ID can run programs with up to 40 CPU cores. (mpiprocs : based on the number of processes per node to be used)

• Since a limited license is shared among supercomputing users, if usage exceeds the policy limit, the job may be forcibly terminated by the administrator.

• To prevent overload on the login nodes (login01~04), pre/post-processing tasks are not permitted on the login nodes. However, some pre/post-processing tasks are allowed through VDI. (Refer to the Nurion VDI guide for details - https://docs-ksc.gitbook.io/nurion-user-guide/undefined-2/appendix-9 -how-to-use-vdi)

• After March PM (March 14) in 2019, the job submission script must include the “#PBS -A ansys” option.

B. Software Installation Information

1. Installation version

• v145, v170, v181, v191, v192, v195, v201, v212, v221, v222, v231, v232, v241

2. Installation location

• /apps/commercial/ANSYS/(version)/fluent

3. Path to the executable file

• /apps/commercial/ANSYS/(version)/fluent/bin

※ Replace the version in the above path with the desired Fluent version, such as v145, v170, v181, v191, v192, v195, v201, v202, v221, v222, v231, or v232.

C. How to run the software

• Run the environment setup script before executing the command.

• (Example) To use Fluent v181, execute as follows:

$ module load fluent/v222

※ A module environment setup file exists. Refer to the above example to configure the appropriate environment.

• Enter the command to run the job in batch mode as follows:

Format	fluent [version] [-help] [option]
version	2d (2D, single precision) 3d (3D, single precision) 2ddp (2D, double precision) 3ddp (3D, double precision)
option	-g (run without GUI) -i journal (read the specified journal file) -g -i journal (run the job in background mode) -tx (specify the number of processors as x)

• Interactive execution on the login node is limited to 10 minutes of CPU time.

• Long-running calculations must be submitted using the scheduler.

1. Example of a FLUENT input (journal) file

Refer to and appropriately modify the /apps/commercial/test_samples/ANSYS/wst.in file.

(set! *cx-exit-on-error* #t)
 rc wst.cas                                     # read case file
 /solve/init/init                               # initialize the solution
 it 100                                         # calculate 100 iterations
 wd wst.dat                                     # write data file
 exit                                           # exit FLUENT
 yes

2. Writing a scheduler job script file

On the 5th system, jobs must be submitted using the PBS Professional scheduler from the login node. Example files for using PBS Professional on the 5th system are available at the following path, so please refer to them when creating your job files.

• Example files

  • /apps/commercial/test_samples/ANSYS/fluent_v181.sh (Performed on a single node)

  • /apps/commercial/test_samples/ANSYS/fluent_v181_multinode.sh (Performed on multiple nodes)

※ Below is an example of job submission on the Nurion system. (Performed on a single node)

#!/bin/sh
#PBS -V
#PBS -N fluent_job                                        # Specify job name
#PBS -q commercial                                      # Specify queue
#PBS -l select=1:ncpus=40:mpiprocs=40:ompthreads=1     # Specify the number of MPI tasks and threads
#PBS -l walltime=04:00:00                 # Specify the estimated job duration
#PBS -A ansys

cd $PBS_O_WORKDIR

###### Do not edit #####
TOTAL_CPUS=$(wc -l $PBS_NODEFILE | awk '{print $1}')
#######################

module purge
module load fluent/v181

fluent 3d -pethernet -t${TOTAL_CPUS} -g -i wst.in > wst.output

• The user should appropriately modify the content above as needed.

• After March PM (March 14) in 2019, the job submission script must include the #PBS -A ansys option.

• Job submission is only allowed in the scratch directory.

• Each user's scratch directory is located at /scratch/$USER.

• Since scratch disks are deleted after a certain period following job completion, it is recommended to back up your data as soon as the job is finished.

• For additional commands and usage instructions related to the scheduler, please refer to the Nurion user guide.

D. Job monitoring

1. Queue inquiry

$ showq

2. Node status inquiry

$ pbs_status

3. Checking the job status

- View currently running/queued jobs
$ qstat -u $USER

- View including the completed jobs
$ qstat -xu $USER

$ qstat <-a, -n, -s, -H, -x, …>
ex> qstat
Job id Name User Time Use S Queue
-------------------------------------------------------------------
0001.pbcm test_01 user01 8245:43: R commercial
0002.pbcm test_03 user03 7078:45: R commercial
0003.pbcm test_04 user04 1983:11: Q commercial

4. How to submit a job

• Example: If the script file name is fluent.sh

$ qsub fluent.sh

5. Forcefully terminate a submitted job

• Usage : qdel {job ID}

• The job ID is the information displayed on the far left when the qsub command is executed. (ex. 0001.pbcm test_01 user01 8245:43: R norm_cache)

• Example : If the job ID is 0001.pbs

$ qdel 0001.pbs

E. Additional information

Start Guide documents for each version of ANSYS Fluent

Last updated on November 06, 2024.