ANSYS

ANSYS is a comprehensive coupled physics tool combining structural, thermal, CFD, acoustic and electromagnetic simulation capabilities. HPC upgrades the campus ANSYS license managed by the College of Engineering from the university version to the research version.

ANSYS version 11.0 is the currently installed on the university Linux cluster (henry2). Users using tcsh as their default shell can set up their environment to run ANSYS by entering the command 'add ansys'. The ANSYS launcher then be started by the command 'launcher110'. The ANSYS launcher and other GUI components use X-Windows to display onto users' desktop systems. [See X-Windows Setup if you are having problems getting the GUI to display on your system.] ANSYS documentation is available from the launcher under the help menu.

To access ANSYS users must accept the license terms. Select the "request access" button from the HPC software web page to accept the license terms. Access should be enabled within a day of accepting the terms.

For non-trivial problems the ANSYS solver must not be run on the login nodes. As with all processes that require more than a few minutes to run, non-trivial ANSYS solutions must be submitted to the cluster queuing system LSF. For ANSYS solver this can be done by selecting 'LSF' from the launcher or by creating a script file such as the following. If you want to run ANSYS interactively for more than a few minutes and access the HPC file system, you can access your own HPC node via VCL. Point your web browser to http://vcl.ncsu.edu, login and select an HPC Linux image. You can reserve a blade for up to 4 hours. A typical way to run ANSYS on the HPC is to use an LSF batch job for analyses of more than 4 hours, but to do post and pre processing interactively via VCL.

Currently (Oct. 2007), ANSYS is a 64 bit code so it is better to run the launcher on the 64 bit VCL HPC image as opposed to the 32 bit image. Onece you've logged into a 64 bit VCL HPC image, you can do "add ansys" and "launcher110" to get an interactive session.

The following job submission script has been modified (Sept. 2007) to request use of 64 bit compute nodes (this is the #BSUB -R em64t line in the script).

#! /bin/tcsh
#
#BSUB -n 1
#BSUB -W 10
#BSUB -R em64t
#BSUB -e vm2.err.%J
#BSUB -o vm2.out.%J
#BSUB -J vm2
#
ansys110 -j VM  -b -p aa_r < vm2.dat >& vm2.out

 This script file, say it is named runansys.csh, would be submitted to LSF with the bsub command:

 bsub < runansys.csh

 The #BSUB lines in the script pass parameters to bsub and could also appear as command line arguments. The example above requests 10 minutes of run time (-W 10) and one processor (-n 1). NC State ANSYS license does not support the parallel solver, so requesting more than one processor will only result in potentially longer wait time in the queue without any faster execution.

The flag (-p aa_r ) requests the research license. If you have a small job, you may find you can use the flag (-p aa_t_a ) which requests the teaching license. Another option is to use ABAQUS, a commercial finite element package for which our licensing is less restricted.

Prior to issuing the bsub command the user needs to have issued an add ansys command.

The bsub command should be issued from the directory that contains the ANSYS input file. The standard output and standard error output from the job will be placed in the directory where the bsub command was issued.