Openfoam

Installed versions

Resource	Version
Dardel/cpe23.12	2406, 2312, 2012, 11, 10, 9, 7, 6

General information

How to use OpenFOAM on PDC machines

OpenFOAM is a free, open source CFD software package.

To see which versions of OpenFOAM are installed on any of the machines at PDC log into the machine and type module avail openfoam As the current versions of OpenFOAM are very easily to generate massive small files, you mast consider questions before running OpenFOAM such as:

How often do you save your solution?
What trace/history of your iterations do you write to file(s)?

To control this behavior you need to modify the corresponding parameters in system/controlDict

writeControl    timeStep;
writeInterval   10000;

i.e. specify the number of timeStep for writeInterval as large as possible.

Moreover, setting writeCompression to compressed would really do a damper on the /cfs/klemming file system. We already know that if someone set runTimeModifiable to yes that will have an adverse effect on performance since OpenFOAM then will check a lot of files at every single iteration. As a result, you should adapt the simulations to the system by tweaking the following parameters:

writeCompression                    uncompressed;
runTimeModifiable                   no;

It is highly recommended that you run OpenFoam on your project directory to avoid any disk quota problems

See https://www.pdc.kth.se/support/documents/data_management/lustre.html for more information about the project directory

How to use

Running on the Batch system

sample job script

#!/bin/bash -l

#The name of the script is mytest
#SBATCH -J mytest

#SBATCH -A <allocation>

# 12 hour wall-clock time will be given to this job
#SBATCH -t 12:00:00

# Set the partition for your job. 
#SBATCH -p <partition>

# Number of nodes
#SBATCH --nodes=2

# Number of MPI processes per node (default 128)
#SBATCH --ntasks-per-node=128

# Load the openfoam module
module load PDC
module load openfoam/v2312

# Set the openfoam environment variables
. $FOAM_BASHRC

# Change OpenFoam user directory to the project directory
# Comment the three lines below if not running on the project directory

WM_PROJECT_DIRECTORY2=$(pwd)
export WM_PROJECT_USER_DIR=$WM_PROJECT_DIRECTORY2/$WM_PROJECT/$USER-$WM_PROJECT_VERSION
export FOAM_RUN=WM_PROJECT_USER_DIR/run

# Start the OpenFOAM job with 256 MPI-tasks on 2 nodes

srun -n 256 -N 2 <openfoam binary> -case <path to case directory> -parallel > my_output_file 2>&1