CFX

CFX is a general purpose computational fluid dynamics package. CFX uses a conservative finite element based control volume method with unstructured meshes. HPC licenses CFX, including the parallel solver, for use on the HPC Linux Cluster. The current default version is 19.1.

External Links:
ANSYS CFD website



Users using tcsh as their default shell can set up their environment to run CFX by entering the command

module load ansys

to set up ANSYS environment.

To run CFX solver, create a job script file such as the following.

#!/bin/tcsh

#BSUB -W 120
#BSUB -o cfx.out.%J
#BSUB -e cfx.err.%J
#BSUB -n 1

module load ansys
cfx5solve -def UserProblem.def -batch

This script file, say that is named runcfx.csh, would be submitted to LSF with the bsub command.

bsub < runcfx.csh

The '#BSUB' lines in the script pass parameters to bsub and could also appear as command line arguments. The current working directory when bsub is issued should be where the problem definition file is located.

Running CFX Solver using multiple processors

A limited number of licenses are available for running CFX in parallel. Users should not ask for more than 4 licenses. To run the parallel version, the following script "psjp" can be used. It assumes that the file gethosts.pl exists in the same directory as psjp.

cp /home/gwhowell/apps/samples/cfx/sample/gethosts.pl .
cp /home/gwhowell/apps/samples/cfx/sample/psjp .

will copy both psjp and gethosts.pl to your current working directory. Then you can formulate a job script similar to the following:

#!/bin/tcsh                                                        

#BSUB -W 12
#BSUB -o cfx.out.%J
#BSUB -e cfx.err.%J
#BSUB -n 4 

module load ansys
./gethosts.pl > hosts.%J
sleep 2
cfx5solve  -ccl itpn2 -def JetA4.def -ini JetA4_004.res -batch -par-dist `grep blade hosts.%J`


You need to change the run time limit "#BSUB -W 12" to actual time you want for your real job.

The "-ccl itpn2 -def JetA4.def -ini JetA4_004.res" refer to input files in /home/gwhowell/apps/samples/cfx/sample so that the job can be run from that directory. These are for a particular problem (unchanged from the serial version) but presumably this is not a problem you are interested in. The ./gethosts.pl file is the lines


 
#! /usr/bin/perl
#  Takes a host list with space separators 
#    (from the environmental variable LSF_HOSTS)
#  Returns a comma separated host list 
$_ = $ENV{"LSB_HOSTS"};
@blades = split(/ /,$_);  # splits on spaces 
$last = $#blades;         # this should be the number of processors
for ($i = 0; $i < $last ; $i++) {
   print "$blades[$i],";         # inserting commas between host names
}
print "$blades[$last]";


If you choose to type it in instead of copying it, make it executable by


chmod +x gethosts.pl


ANSYS CFD also provides a GUI version of CFX solver. If you want to use the GUI version you need to use it in the HPC environment on VCL nodes. Please visit HPC-VCL node to learn generally how to run jobs under VCL.
On VCL node, after you have used the command

module load ansys

to set up ANSYS environment. The GUI version of CFX solver can be launched with the command

cfx5

In case you need, CFX documentation is available in the GUI under the Help menu.

Last modified: March 23 2022 13:18:10.