[kagoc8]

I want to convert the grid that is available on NASA TMR for the periodic hill geometry to .cgns format using the tecplot_to_cgns utility available in the cgns toolset.

The grid is stored in a simple point format, with each cell identified using an x,y, and z coordinate. The first few lines of that file are shown below:

TITLE = "hill"
VARIABLES = "x", "y", "z"
ZONE I=197, J=129, K=1, F=POINT
-4.157690192E-09 1.000000000E+00 0.0
3.214285523E-02 1.000000000E+00 0.0
6.428571045E-02 1.000000000E+00 0.0
9.642857313E-02 1.000000000E+00 0.0
1.285714060E-01 9.995964170E-01 0.0

tecplot_to_cgns identifies this file as a valid tecplot ascii file, but fails to write a .cgns.
It does not throw an error, but instead fails to identify any nodes.

The output of the tecplot_to_cgns command is as follows:

./tecplot_to_cgns hill_grid_point.dat hill.cgns
reading Tecplot file from hill_grid_point.dat
writing CGNS data to hill.cgns
zone Zone1:25413 nodes... 0 elements... done

Can anyone with experience with the cgns toolset provide guidance regarding this issue?

[Svetlana]

Does it work for a tiny mesh like below?

TITLE = "test"
VARIABLES = "x", "y", "z"
ZONE I=2, J=2, K=1, F=POINT
0.0 0.0 0.0
0.0 1.0 0.0
1.0 1.0 0.0
1.0 0.0 0.0

[kagoc8]

No luck for the simple test file you suggested that I try.

[kagoc8]

It does work however, when going back and forth between .cgns and Tecplot ascii when using the "bump.dat" sample .cgns file available here: https://cgns.github.io/CGNSFiles.html

[Svetlana]

Can you paste the bump.dat headers (first 4-5 lines of the bump.dat file)? I will be able to test this in my Tecplot in the next few days, but not today.

[kagoc8]

The header looks like this:

TITLE = "bump"
VARIABLES = "X", "Y", "Z"
ZONE T="Zone 1", N=36562, E=18000, F=FEBLOCK, ET=BRICK
-3.19885 -3.19885 -2.99627 -2.99627 -2.80402
-2.80402 -2.62157 -2.62157 -2.44842 -2.44842
-2.28410 -2.28410 -2.12816 -2.12816 -1.98017
-1.98017 -1.83972 -1.83972 -1.70644 -1.70644
-1.57995 -1.57995 -1.45991 -1.45991 -1.34599
-1.34599 -1.23787 -1.23787 -1.13527 -1.13527
-1.03791 -1.03791 -0.945502 -0.945502 -0.857809
-0.857809 -0.774587 -0.774587 -0.695608 -0.695608
-0.620656 -0.620656 -0.549525 -0.549525 -0.482022
-0.482022 -0.417960 -0.417960 -0.357164 -0.357164
-0.299467 -0.299467 -0.244713 -0.244713 -0.192750
-0.192750 -0.143437 -0.143437 -0.0966375 -0.0966375
-0.0522244 -0.0522244 -0.0100757 -0.0100757 0.0299240
0.0299240 0.0678843 0.0678843 0.103909 0.103909


the full file is on the cgns site mentioned above. Thanks for your help!

[Svetlana]

Here I've modified the small file above to include the zone title:

TITLE = "test"
VARIABLES = "x", "y", "z"
ZONE T="myzone", I=2, J=2, K=1, F=POINT
0.0 0.0 0.0
0.0 1.0 0.0
1.0 1.0 0.0
1.0 0.0 0.0

Could you possibly check whether this works? The other difference is BLOCK datapacking, here is an example for it:

TITLE = "myDataSet"
VARIABLES = "X", "Y", "Z", "U"
ZONE I=5, DATAPACKING=BLOCK
2 3 5 6 7
4 9 25 36 49
0 0 0 0 0
0 1 4 1 0

Please check whether any of this works.

Thanks and regards,
Svetlana

[kagoc8]

No luck with either of these approaches.