Fluent

Ansys Fluent is a computational fluid dynamics (CFD) software package used to model fluid flow, heat transfer, and other related phenomena. It provides a comprehensive suite of tools for fluid simulation across various industries and research applications.

Fluent on Euler¶

On Euler the following versions are available via modules:

Version	Module load command (students)	Module load command (non-students)
25.1	`module load stack/2024-06 fluent/25.1_teaching`	`module load stack/2024-06 fluent/25.1_research`
24.2	`module load stack/2024-06 fluent/24.2_teaching`	`module load stack/2024-06 fluent/24.2_research`
23.1	`module load stack/2024-06 fluent/23.1_teaching`	`module load stack/2024-06 FLUENT/23.1_research`

The Ansys teaching licenses are restricted to students. Everyone else must use the research licenses.

Multinode jobs with fluent on Euler¶

For single node jobs, no special settings for MPI are necessary and therefore jobs that request up to 192 cores on a single Euler node are running fine.

When running a multi-node job on Euler, fluent cannot get the hostfile for MPI from Slurm. It needs to be created on the fly with srun and then specified through the -cnf option of fluent

Example script:

#!/usr/bin/bash
#SBATCH --nodes=2
#SBATCH --ntasks=8
#SBATCH --job-name="test"
#SBATCH --time=01:00:00
#SBATCH --mem-per-cpu=2g
#SBATCH --constraint=ib

module load fluent/24.2_research

HOSTS_FILE=hostlist-job${SLURM_JOB_ID}
srun hostname | sort | uniq > ${HOSTS_FILE}

fluent 3ddp -t${SLURM_NTASKS} -pib -mpi=openmpi -cnf=${HOSTS_FILE} -scheduler_custom_script -g -i journal.jou > output.out