ANSYS FLUENT (called FLUENT hereafter) is a state-of-the-art computer program for modeling fluid flow and heat transfer in complex geometries.
FLUENT is available on the Oakley Cluster. The versions currently available at OSC are:
You can use
module avail fluent to view available modules for a given machine. Feel free to contact OSC Help if you need other versions for your work.
Use of ANSYS products for academic purposes requires validation. In order to obtain validation, please contact OSC Help for further instruction.
Currently, there are in total 25 ANSYS CFD base license tokens and 68 HPC tokens for academic users. These base tokens are shared by available ANSYS CFD related projusts (see "Academic Research -> ANSYS Academic Research CFD" in this table for details). These HPC tokens are shared with all ANSYS products we have at OSC. A base license token will allow FLUENT to use up to 4 cores without any additional tokens. If you want to use more than 4 cores, you will need an additional "HPC" token per core. For instance, a serial FLUENT job with 1 core will need 1 base license token while a parallel FLUENT job with 12 cores will need 1 base license token and 8 HPC tokens.
Contact OSC Help for getting access to FLUENT if you are a commerical user.
module load fluent. To select a particular software version, use
module load fluent/version. For example, use
module load fluent/16.0to load FLUENT version 16.0 on Oakley.
When you log into oakley.osc.edu you are actually logged into a linux box referred to as the login node. To gain access to the mutiple processors in the computing environment, you must submit your FLUENT analysis to the batch system for execution. Batch jobs can request mutiple nodes/cores and compute time up to the limits of the OSC systems. Refer to Queues and Reservations and Batch Limit Rules for more info. Batch jobs run on the compute nodes of the system and not on the login node. It is desirable for big problems since more resources can be used.
Interactive mode is similar to running FLUENT on a desktop machine in that the graphical user interface will be sent from OSC and displayed on the local machine. Interactive jobs are run on compute nodes of the cluster, by turning on X11 forwarding. The intention is that users can run FLUENT interactively for the purpose of building their model and preparing their input file. Once developed this input file can then be run in no-interactive batch mode.
To run interactive FLUENT GUI, a batch job need to be submitted from the login node, to request necessary compute resources, with X11 forwarding. Please follwoing the steps below to use FLUENT GUI interactivly:
-l nodes=1:ppn=12), for a walltime of one hour (
-l walltime=1:00:00), with one FLUENT license (modify as per your own needs):
qsub -I -X -l nodes=1:ppn=12 -l walltime=1:00:00 -l software=fluent+1
Once the interactive job has started, run the following commands to setup and start the FLUENT GUI:
module load fluent fluent
A batch script can be created and submitted for a serial or parallel run. You can create the batch script using any text editor you like in a working directory on the system of your choice.
Below is the example batch script (
job.txt ) for a serial run with an input file
run.input ) on Oakley:
#PBS -N serial_fluent #PBS -l walltime=5:00:00 #PBS -l nodes=1:ppn=1 #PBS -l software=fluent+1 #PBS -j oe # # The following lines set up the FLUENT environment # module load fluent # # Move to the directory where the job was submitted from # You could also 'cd' directly to your working directory cd $PBS_O_WORKDIR # # Copy files to $TMPDIR and move there to execute the program # cp test_input_file.cas test_input_file.dat run.input $TMPDIR cd $TMPDIR # # Run fluent fluent 3d -g < run.input # # Where the file 'run.input' contains the commands you would normally # type in at the Fluent command prompt. # Finally, copy files back to your home directory cp * $PBS_O_WORKDIR
As an example, your run.input file might contain:
file/read-case-date test_input_file.cas solve/iterate 100 file/write-case-data test_result.cas file/confirm-overwrite yes exit yes
In order to run it via the batch system, submit the
job.txt file with the command:
FLUENT can be run in parallel, but it is very important that you read the documentation in the FLUENT Manual on the details of how this works.
In addition to requesting the FLUENT base license token (
-l software=fluent+1 ), you need to request copies of the ansyspar license, i.e., HPC tokens. However the scheduler cannot handle two "software" flags simultaneously, so the syntax changes. The new option is
-W x=GRES:fluent+1%ansyspar+[n] , where [n] is equal to the number of cores you requested minus 4.
Parallel jobs have to be submitted on Oakley via the batch system. An example of the batch script follows:
#PBS -N parallel_fluent #PBS -l walltime=1:00:00 #PBS -l nodes=2:ppn=12 #PBS -j oe #PBS -W x=GRES:fluent+1%ansyspar+20 #PBS -S /bin/bash set echo on hostname # # The following lines set up the FLUENT environment # module load fluent # # Move to the directory where the job was submitted from and # create the config file for socket communication library # cd $PBS_O_WORKDIR # # Create list of nodes to launch job on rm -f pnodes cat $PBS_NODEFILE | sort > pnodes export ncpus=`cat pnodes | wc -l` # # Run fluent fluent 3d -t$ncpus -pinfiniband.ofed -cnf=pnodes -g < run.input