Learning Forum

[carson]

Hi, I'm attempting to run a fluent simulation on an hpc system with 250 individual batch simulations. When I run the code with one-four iterations at a time, everything works fine, but when I try to run 250, the simulation breaks when it tries to compile my UDF files. Is there a way to fix this?

Here is the first error to show up:
error: unknown type name cxboolean

Here is the line of code I use to open fluent in the hpc :
fluent 2ddp -gu -i PackedBed_journal_1.jou -driver null

Thanks for any help you can provide.

[Ahmed Hussien]

The error "unknown type name 'cxboolean'" might be related to multiple jobs trying to compile the same UDF at the same time. One possible cause is a conflict during concurrent UDF compilation, which can lead to corrupted or incomplete builds. As a potential workaround, you could try compiling the UDF once in a separate Fluent session and then have each simulation load the precompiled libudf instead of compiling it again. To minimize the chance of file-access issues, make sure each job runs in its own directory with a separate copy of the libudf. It’s also worth checking that all necessary Fluent modules and environment settings are correctly applied in your batch jobs.

[carson]

Thank you for your suggestions!

I fixed the issue late last night with the help of my university's HPC system staff. I'll share just in case others come up with the same issue:

I created a couple common environmental variables TMPDIR,TMP, and TEMP and assigned them a path to a new folder (outside of the original file system) where I saved the compiled libudf folder and all my source UDF code. I then changed the UDF directory to that folder from the UDF ribbion in Fluent. Once I did all that, everything worked perfectly. 

Theoretically, only one of these variables is needed, but I wasn't sure what environmental variable ANSYS uses for temporary folders. Heres the code:

TMPDIR=//tmp
TMP=$TMPDIR
TEMP=$TMPDIR
export TMPDIR TMP TEMP