Learning Forum

[conor_oboyle]

Hello,

I'm looking to use the FMU import function to run analysis with changing boundary conditions determined by an FMU. The setup works perfectly on my Windows system but when the case is sent to a Linux cluster it returns an error when the FMU is initialized saying :

"0 is an invalid FMU instance ID", "FMU Library TEST-xxxxx/binaries/linux64/TEST.so failed to load"

I'm using an FMU that has been generated in Dymola using the WSL Linux cross-compiler, and I've tested the FMU file using FMPy on an Ubuntu installation and everything works fine. The case was setup through the fluent GUI on the Linux machine using the Linux compiled FMU and the exact same steps as the Windows version that runs without errors, and the FMU generates input parameters that can be used as boundary conditions and accepts output parameters from the solution.

The error then occurs when the simulation is initialized.

I'd be very grateful if anyone has any insight into what this error could be or ways to solve it!

Many thanks, Conor

[conor_oboyle]

I should add I am using Fluent 2020 R2 on both systems

[RK]

Hi Conor,
Sorry for the delay in response. During initialization, Fluent creates an instance of FMU and then initializes it. Looks like there is an issue in this step. Can you please go over this link and check if any of this information would help you : https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v212/en/flu_ug/flu_ug_file_import_FMU.html?q=FMU%20fluent

[conor_oboyle]

Hi RK, thanks for the reply!
Fortunately I solved the issue already but just forgot to update my post. Our cluster runs a different Linux OS from the one which I initially setup my WSL install with, so 2 of the packages (glibc and libstdc+) were running older versions on the cluster side and the model failed to create an instance. There was no real error/debugging message from Fluent other than the 'invalid ID' one which is why I didn't catch this error initially. The fix was fairly simple, just had to install CentOS 7 on my Windows machine so it matched the cluster OS and recompile the FMU.
Hope this helps if anyone else runs into a similar issue in future!
Cheers, Conor

[RK]

Hi Conor,
Thank you for updating this post with the solution.