[CFDReiziger]

Hi,
I am new to the CGNS library and currently working with an in-house CFD solver where CGNS is utilized for writing the solution. My objective is to rewrite the solution file (solution.cgns) to include one or more additional arrays. Specifically, I aim to map fields A/B/C/D to A/B/E/G. In OpenFOAM, achieving this is possible using mapFields. The optimal approach seems to be utilizing the CGNS library.
Could you please provide some guidance on where to start?
Thank you very much for your help.

[NotOverUnderated]

Originally Posted by CFDReiziger

Dear,
I am very new to the CGNS library. I work with an in-house CFD solver where CGNS is used to write the solution. What I want to do is to rewrite the solution (solution.cgns) so that it contains one or more additional arrays. For instance, in a reactive case, I want to be able to restart from a converged solution with 2 species to a new case with 3 species and set the third species' concentration to desired values. Alternatively, I may want to map fields A/B/C/D to A/B/E/G. In OpenFoam, using mapFields would make that possible. However, with the in-house software, there is no such utility, and the best approach would be to modify the CGNS file.
In the CGNS library, there are many useful examples. In CGNS examples (I use the one for Fortran), you can see that there are mainly two files: cgread.F90 and cgwrite.F90. However, these files involve reading and writing items. This confuses me, as I wonder whether for instance I need to go through all the flow equation set attributes (Gas Model Type, Viscosity Model Type, Turbulence Closure Type, etc.) to achieve what I have in mind. I highly doubt it, given that I want the files to remain the same except for adding or swapping the data for given scalar fields.
Thank you very much for your help.

Hi,
I believe that your question is not clear. Please take a look at this link: Guide: How to ask a question on the forums

Kind regards

[JBeilke]

You might have a look at
https://github.com/CGNS/CGNS/discussions

[CFDReiziger]

Thank you, Joern, for your suggestion. I will definitely have a look at the website your provided.