Learning Forum

[Monta]

I am trying to run a simulation (transient flow) on a HPC-System. Fluent is supposed to read a case and data then run a calculation, for which I define time step, number of time steps & number of iter/time-step. The input Journal looks like:

-------------------------------------

rc SYS-3.1-1-00923.cas.gz

rd SYS-3.1-1-00923.dat.gz

solve/time-step 0.01

solve/dual-time-iterate 1000 100

wc Ergebnis.cas.gz

wd Ergebnis.dat.gz

exit

yes

--------------------------------------

In the output file the only problem is with the 2 command lines:

solve/time-step 0.01

solve/dual-time-iterate 1000 100

since I get for both the error:

Error: = (equal): invalid argument [1]: wrong type [not a number]

Error Object: #f

Reading & writing case & data files are totally fine! There is no problem.

I searched in Internet & in many documentations are the two command lines used. So here is my question are the command lines to run transient simulation correct?

Thanks for the help!

Monta.

[DrAmine]

If you open Fluent interactive mode you might test the commands and check if they are working

[DrAmine]

https://forum.ansys.com/discussion/13/change-the-time-step-size-using-tui-commands-and-journal-files

[DrAmine]

Always record journal files first by trying different commands interactively

[Monta]

So trying the command line solve/dual-time-iterate interactively worked. That's why I am asking why did this one command line cause a problem in batch mode while starting the simulation on HPC-System.

[Monta]

An update to what I tried to figure out the problem. I opened the case & then the data file in Fluent interactively on the cluster. I tried to run the simulation through the GUI and through TUI to see if the problem only occrus when Fluent reads the journal in batch mode. I get the same problem ( see the Foto)

Maybe there is someone here who already had experience with such erros and can guess what can cause it.
Remark: The case and data files were generated by Fluent 2021R2 & here I am trying to continue the simulation in HPC system with Fluent 2020R2 ( only available).

thanks!

[DrAmine]

So step back: When are you starting getting that error message? After reading the case?
Please use the full command as follows /solve/dual-time-iterate 1 100

[Monta]

Problem solved! It is apparently so: I prepared my case locally with fluent 2021R2 and generated initial data for the hpc simulation. On the HPC-System is only fluent 2020R2 so far available. So running the simulation on a earlier version causes this error! This leads me now to the next question:
why I cannot carry on a simulation with 2020R2, which already been created and run in 2021R2?
Is there a way to adapt the simulation to the earlier version or solve this issue?

[DrAmine]

1/You should be able to do that. But you cannot run a case built up in newer version in an older version: that will generally result in issues ( that is what you wrote you prepare in 2021r2 and want to run in 2020r2).
2/I always recommend to create a journal which reads the mesh, setup the case and then run it. This should be release agnostic as much as possible: it will also contain a line telling Fluent which TUI version to be used.