Learning Forum

[lucasissa94]

Hi everyone,

I am experiencing one issue during intermediate data saving procedure in batch mode; basically even if I ask at the beginning of the calculation (without having error messages):

file/auto-save/case-frequency    if-mesh-is-modified
file/auto-save/data-frequency    250
file/auto-save/retain-most-recent-files    yes
file/auto-save/max-files    1
file/auto-save/root-name    "....path...."

Fluent does not keep in memory only the most recent file, but it retains all the *.dat.h5. In particular, each time the solver saves it prints:

Warning: Need to save case file at least once before saving data
Forcing a save

I am not able to understand the reason to this problem, it seems it happens sometimes when I replace the mesh with another one.

Thanks.

[Rob]

What are you appending to the file name to get a unique ID, ie time step, flow time etc? If your journal is file/ and not /file/ you also run the risk of incomplete steps breaking the journal. The first / forces the root menu level to be used. 

[lucasissa94]

If I understood well your answer, Fluent automatically insert the number of the iteration (I am working in steady state) related to the data saved. My journal is file/, but it does not change if compared with other runs where I had no problems of this type. Usually, the first thing the journal does is reading the case file and then it sets the auto-save options. 

[Rob]

OK, it wasn't clear what you'd already set in autosave. Check the iteration is appended and try retaining 4-5 files. I never assume a file will write OK so always have at least one previous save: you never know when the network will hiccup when saving the only data file you have. What happens if you run though the commands one at a time? 

[lucasissa94]

First of all, thanks for the advice, I will modify the journal to retain more than one file. In any case, each command runs well; the console does not print warnings or errors of any kind, even running one command at time.

[Rob]

Not even the case file warning? 

[lucasissa94]

Fluent somehow refers to this case file, but it does not save case files at all.

[Rob]

Try saving case & data before you iterate. By setting those commands you're telling Fluent to only save on changes to the mesh, but in doing so you're changing the case file: that's not recommended and may be triggering the warning as you've created a trap in the checks.