Ansys Fluent Guide

This how-to article explains and demonstrates how to launch the Ansys fluent suite on HPC.

Instructions

Module File

First check the available fluent modules

module avail fluent

To load fluent version 2023R2:

module load fluent/2023R2

Parallel Job

To run several tasks in parallel on one or more nodes, here is an example fluentP.sh batch script for older versions of Fluent:

#!/bin/bash
#SBATCH -N 2 # allocate 2 nodes for the job
#SBATCH --ntasks-per-node=20
##SBATCH --exclusive # no other jobs on the nodes while job is running
#SBATCH -o fluentP_%J.out # the file to write stdout for fluent job
#SBATCH -e fluentP_%J.err # the file to write stderr for fluent job

source /etc/profile.d/modules.sh
module load fluent/$VERSION

if [ -z "$SLURM_NPROCS" ]; then
  N=$(( $(echo $SLURM_TASKS_PER_NODE | sed -r 's/([0-9]+)\(x([0-9]+)\)/\1 * \2/') ))
else
  N=$SLURM_NPROCS
fi

echo -e "N: $N\n";

# run fluent in batch on the allocated node(s)
fluent 2ddp -g -slurm -t$N -pdefault (or -pinfiniband) -ssh -i foo.txt

Make sure to replace foo.txt in the last line with the name of your job file. Then, submit your job with:

Parallel Job for new fluent versions

Here is an example fluentP.sh batch script for newer versions of Fluent:

Make sure to replace foo.txt in the last line with the name of your job input file. Then, submit your job with:

Interactive Job

Start the interactive session on 1 node with 12 CPUs with fisbatch:

Fluent

The first parameter to fluent is the version (namely, 2ddp below). The version can be either 2d, 3d, 2ddp, or 3ddp; change it to whatever you need. The "dp" stands for "double precision".

Run fluent with:

Type "exit" to end the session.

Ansys Electromagnetics Suite

Run the graphical launcher for Ansys Electromagnetics Suite with:

OSX users should not use XQuartz 2.7.9 because of an OpenGL bug and should instead downgrade to version 2.7.8

User Guide

The command-line help usage actually provides very limited information:

The only place Ansys supplies to read more documentation is from the "Help" inside the Fluent GUI. Open a terminal in X2Go, load the fluent module, and then run `fluent` from the command-line to launch the GUI. Click on the Help button > Help on Starting and Executing Fluent.