Failure to read CGNS files generated by Fluent
 

I have always found that using a CGNS file is the more convenient way to export Fluent results to Tecplot. Anyway it looks like I am not able to use this option anymore. I have tried to export my results in CGNS format with both Fluent 15.0 and Fluent 17, but when I try to open them in Tecplot 360 EX 2016 R1 I am geting the same error message for both files, i.e.:

File Error: File not found or Invalid CGNS format. array size exceeds that for a 32-bit integer

I have always been able to import CGNS files generated with previous Fluent versions. Is anybody else experiencing the same issue?
Thanks
Andrea

Hi Andrea. 64-bit values are probably being used in some nodes in your CGNS file. The Tecplot CGNS loader currently only supports 32-bit integer data types.

We are aware of this issue and are currently working on fixing this.

Have you tried using the Tecplot Fluent loader with your CAS and DAT Fluent files? (We support Fluent version 14.0 or earlier.)

Thank you, Straton, Tecplot Support

Hi Straton,

thanks for your message. I have tried to switch from double to single precision when exporting the CGNS from Fluent but I am still having the same problem.

I have also tried to use the Fluent Data Loader in Tecplot, but this is not working very well for me. Although the main field variables (i.e. velocities, pressure) are imported correctly, Tecplot messes up with some variables that are important to me (I am running a reactive case with quite a lot of "secondary" variables like species concentration, source terms etc...). CGNS was very handy for this reason (and also because it allows you to chose which variables you want to include in the file, helping to reduce its size).

Btw exporting the data from Fluent using the EnSight format and read it in Tecplot seems to be working fine, but I have to analyse the outcome more in depth to be positive about this.

Regards
Andrea

Thank you Andrea for the further useful details.

It is very important to us that we have a better understanding of your exact datasets. We would like to work with you on this issue in the context of a formal Tecplot support incident. And hopefully you will be able to share some sample Fluent, CGNS, and Ensight files with us.

To start the process, please do me the favor of contacting me at this email: support at tecplot dot com

Thank you, Straton

Hello Andrea. I forgot to ask which exact version of 360 you are using?

Is it our latest version 360ex 2016 R2? If not, I highly recommend you use our latest version 2016 R2. Thank you, Straton

Hello, Andrea and Straton,

Have you solved the problem? I have the same problem, i.e. Tecplot 360 EX 2016 R2 cannot load CGNS exported from FLuent 16 with the error: File not found or Invalid CGNS format. array size exceeds that for a 32-bit integer.

Thanks
HG

Hi,

I dont think that the problem is issued with Tecplot.

Fluent v15 and v17 cgns export format is different than other versions. Please try to export your data from surface mesh with a lower face size (approx. 60.000 faces)

V17 should fix this problem.

Is there any idea?